JP6847446B2 - Electrolyte and power generator - Google Patents

Electrolyte and power generator Download PDF

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JP6847446B2
JP6847446B2 JP2017028444A JP2017028444A JP6847446B2 JP 6847446 B2 JP6847446 B2 JP 6847446B2 JP 2017028444 A JP2017028444 A JP 2017028444A JP 2017028444 A JP2017028444 A JP 2017028444A JP 6847446 B2 JP6847446 B2 JP 6847446B2
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友 星野
友 星野
本帥 郭
本帥 郭
鉄兵 山田
鉄兵 山田
帆 高
帆 高
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Description

本発明は、電解液、およびその電解液を用いた発電装置に関する。 The present invention relates to an electrolytic solution and a power generation device using the electrolytic solution.

温度勾配を電気エネルギーへと変換する技術として熱電変換素子があり、テルル化ビスマスなどの熱電変換素子が一般に用いられる。しかしこれらは高価で毒性の高い元素を用いるため、実用可能な範囲に限界があった。また温度差1℃あたりに発生する電圧(ゼーベック係数)が0.2mV/K程度と小さいため、実用化が困難であった。 There is a thermoelectric conversion element as a technique for converting a temperature gradient into electric energy, and a thermoelectric conversion element such as tellurized bismuth is generally used. However, since these use expensive and highly toxic elements, there is a limit to the practical range. Further, since the voltage (Seebeck coefficient) generated per 1 ° C. of the temperature difference is as small as about 0.2 mV / K, it is difficult to put it into practical use.

また温度勾配をイオン濃度勾配に変換して、再利用可能なエネルギーへの変換や酸性ガスの回収に利用するシステムが知られている。特許文献1のシステムでは、温度に応じてpKaが大きく変化する物質である温度応答性電解質が用いられる。そしてこの温度応答性電解質により、イオン濃度勾配を生じさせ、発電等が行われる。 Further, there is known a system that converts a temperature gradient into an ion concentration gradient and uses it for conversion into reusable energy and recovery of acid gas. In the system of Patent Document 1, a temperature-responsive electrolyte, which is a substance whose pKa changes greatly depending on the temperature, is used. Then, this temperature-responsive electrolyte creates an ion concentration gradient, and power generation or the like is performed.

国際公開第2013/027668号International Publication No. 2013/027668

特許文献1のシステムでは、温度差電池や燃料電池への応用の可能性については言及されている。また、水素と酸素を燃料として用いた燃料電池の高効率化の為のイオン濃度勾配の生成方法について言及されている。しかし、温度差電池については、具体的な実現方法についての記述が存在しない。 In the system of Patent Document 1, the possibility of application to a temperature difference battery or a fuel cell is mentioned. In addition, a method for generating an ion concentration gradient for improving the efficiency of a fuel cell using hydrogen and oxygen as fuels is mentioned. However, there is no description about a concrete implementation method for the temperature difference battery.

本発明は上述の課題に鑑みてなされたものであり、その目的は、実用上可能な高い起電力およびゼーベック係数を発生させることのできる電解質を提供し、それにより得られる発電装置を提供するものである。 The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide an electrolyte capable of generating a practically high electromotive force and a Seebeck coefficient, and to provide a power generation device obtained thereby. Is.

上記目的を達成するための電解液の特徴構成は、温度に応じてpKaが変化する電解質である温度応答性電解質と、酸化還元活性種(ヒドロキノン誘導体を除く)とを含有する点にある。酸化還元活性種としては、pHに応答して酸化還元電位が変化するものが望ましい。N,N,N’,N’−テトラメチル−p−フェニレンジアミン、ニコチンアミド、N置換型ニコチンアミド、プロフラビンヘミ硫酸塩水和物、リボフラビン、アントラキノン、硫酸化アントラキノン、メチレンブルー、ジチオトレイトール、フェロシアン化合物、N1-ferrocenylmethyl-N1,N1,N2,N2,N2-pentamethylpropane-1,2-diaminium dibromide、メチルビオロゲン、ナフトキノン、メナジオンが例示される。或いは、これらの化合物の誘導体あるいはこれらの化合物と類似した構造を有する化合物でもよい。また、redox flow電池等の酸化還元活性種として用いられる化合物でも良い。またプロトン共役電子移動反応であることが好ましい。またこれらの酸化還元活性種の酸化体もしくは還元体が共存することが望ましい。ここでアントラキノン、硫酸化アントラキノン、ナフトキノンおよびこれらの誘導体は、ヒドロキノン誘導体に該当せず、本発明に係る酸化還元活性種として好適に用い得るものである。なお本明細書におけるヒドロキノン誘導体とは、ヒドロキノン骨格を含む単環芳香族化合物を意味するものとする。 The characteristic composition of the electrolytic solution for achieving the above object is that it contains a temperature-responsive electrolyte, which is an electrolyte whose pKa changes with temperature, and redox active species (excluding hydroquinone derivatives). As the redox active species, those whose redox potential changes in response to pH are desirable. N, N, N', N'-tetramethyl-p-phenylenediamine, nicotinamide, N-substituted nicotinamide, proflavin hemisulfate hydrate, riboflavin, anthraquinone, sulfated anthraquinone, methylene blue, dithiotreitol, fe. Examples include Russian compounds, N1-ferrocenylmethyl-N1, N1, N2, N2, N2-pentamethylpropane-1,2-diaminium dibromide, methylviologen, naphthoquinone, and menadione. Alternatively, it may be a derivative of these compounds or a compound having a structure similar to these compounds. Further, a compound used as a redox active species such as a redox flow battery may be used. Further, it is preferably a proton-coupled electron transfer reaction. Further, it is desirable that oxides or reduced forms of these redox active species coexist. Here, anthraquinone, sulfated anthraquinone, naphthoquinone and derivatives thereof do not correspond to hydroquinone derivatives and can be suitably used as redox active species according to the present invention. The hydroquinone derivative in the present specification means a monocyclic aromatic compound containing a hydroquinone skeleton.

発明者らは鋭意検討の末、温度応答性電解質と酸化還元活性種とを併用することで、温度差1℃あたりに発生する電圧を向上させることを想到した。そして上に例示した酸化還元活性種と温度応答性電解質とを用いて、電位差を発生させ、電極表面で酸化還元反応を起こすことで発電が可能なことを実験で確認し、発明を完成したのである。 After diligent studies, the inventors have come up with the idea of improving the voltage generated per 1 ° C. temperature difference by using a temperature-responsive electrolyte and a redox active species in combination. Then, using the redox active species and the temperature-responsive electrolyte exemplified above, it was confirmed by experiments that power generation is possible by generating a potential difference and causing a redox reaction on the electrode surface, and the invention was completed. is there.

すなわち上記の特徴構成によれば、酸化還元種の酸化還元平衡反応に於いてプロトンの生成あるいは消費が伴うため、温度に応じてpKaが変化する電解質である温度応答性電解質を含有することにより、温度応答性電解質により生成されたプロトンは、ルシャトリエの原理により酸化還元活性種の酸化還元平衡をプロトンが消費される方向にずらすことが可能となる。また上に例示した酸化還元活性種が、酸化還元反応の前後で温度応答性電解質に均一分散可能である点も、不要な沈殿の生成を抑制して反応速度および反応の継続性を高める点で有利である。なお、酸化還元活性種の酸化体もしくは還元体の一方を用いて電解液を製造した場合であっても、液中で酸化体もしくは還元体の他方が生成され、酸化還元反応の平衡状態が生じるから、本発明の実施品となる。 That is, according to the above-mentioned characteristic composition, since the redox equilibrium reaction of the redox species involves the generation or consumption of protons, by containing a temperature-responsive electrolyte which is an electrolyte whose pKa changes according to the temperature, The redox equilibrium of the redox active species can be shifted in the direction in which the protons are consumed by the protons generated by the temperature-responsive electrolyte according to Le Chatelier's principle. In addition, the redox active species exemplified above can be uniformly dispersed in the temperature-responsive electrolyte before and after the redox reaction in that the formation of unnecessary precipitates is suppressed and the reaction rate and the continuity of the reaction are enhanced. It is advantageous. Even when the electrolytic solution is produced using one of the redox active species oxidant or the reduced isomer, the oxidant or the other of the reduced isomer is produced in the solution, and an equilibrium state of the redox reaction occurs. Therefore, it becomes an embodiment of the present invention.

温度応答性電解質として、極性基と、疎水性基と、イオン化可能な官能基とを有する分子を用いることが可能である。また相転移を示す物質を含有することが可能である。 As the temperature-responsive electrolyte, a molecule having a polar group, a hydrophobic group, and an ionizable functional group can be used. It is also possible to contain a substance that exhibits a phase transition.

上記目的を達成するための発電装置の特徴構成は、
上述の電解液を用いて発電を行う発電装置であって、正極と負極と加熱機構と冷却機構とを有し、前記正極および前記負極は前記電解液に浸漬され、
前記加熱機構は、前記正極と前記負極のうち一方の近傍の前記電解液を加熱し、
前記冷却機構は、前記正極と前記負極のうち他方の近傍の前記電解液を冷却する点にある。
The characteristic configuration of the power generation device to achieve the above objectives is
A power generation device that generates electricity using the above-mentioned electrolytic solution, which has a positive electrode, a negative electrode, a heating mechanism, and a cooling mechanism, and the positive electrode and the negative electrode are immersed in the electrolytic solution.
The heating mechanism heats the electrolytic solution in the vicinity of one of the positive electrode and the negative electrode.
The cooling mechanism is at a point of cooling the electrolytic solution in the vicinity of the other of the positive electrode and the negative electrode.

上記の特徴構成によれば、加熱機構は、正極と負極のうち一方の近傍の電解液を加熱し、冷却機構は、正極と負極のうち他方の近傍の電解液を冷却するため、正極の近傍と負極の近傍との間でプロトン濃度勾配を生じさせ、酸化還元種の酸化還元平衡をずらすことにより電位差を生成し、この際生じる酸化還元反応の結果、発電を行うことができる。 According to the above characteristic configuration, the heating mechanism heats the electrolytic solution in the vicinity of one of the positive electrode and the negative electrode, and the cooling mechanism cools the electrolytic solution in the vicinity of the other of the positive electrode and the negative electrode. A potential difference is generated by creating a proton concentration gradient between the electrode and the vicinity of the negative electrode and shifting the redox equilibrium of the redox species, and as a result of the redox reaction generated at this time, power generation can be performed.

加熱機構が、温度応答性電解質に含まれる相転移を示す物質の相転移温度より高い温度に電解液を加熱し、冷却機構が、温度応答性電解質に含まれる相転移を示す物質の相転移温度より低い温度に電解液を冷却すると、更に大きなプロトン濃度勾配が発生し、発電装置の発電性能を向上でき好適である。 The heating mechanism heats the electrolyte to a temperature higher than the phase transition temperature of the substance showing the phase transition contained in the temperature-responsive electrolyte, and the cooling mechanism heats the phase transition temperature of the substance showing the phase transition contained in the temperature-responsive electrolyte. When the electrolytic solution is cooled to a lower temperature, a larger proton concentration gradient is generated, which is preferable because the power generation performance of the power generation device can be improved.

発電装置を次の様に構成することも可能である。すなわち、正極槽と負極槽と循環機構とを有し、前記電解液が前記正極槽および前記負極槽に収容され、前記正極が前記正極槽の前記電解液に接触し、前記負極が前記負極槽の前記電解液に接触し、前記加熱機構が前記正極槽と前記負極槽のうち一方の前記電解液を加熱し、前記冷却機構が前記正極槽と前記負極槽のうち他方の前記電解液を冷却し、前記循環機構が前記正極槽と前記負極槽との間で前記電解液を循環させる。それにより、加熱機構および冷却機構により、正極槽と負極槽との間にプロトン濃度勾配が生成し、酸化還元種の酸化還元平衡をずらすことにより正極と負極から電気を取り出すことができる。そして循環機構により電解液が循環して、新たに供給された電解液内の酸化還元種の酸化還元平衡が常にずれることにより酸化還元反応が継続し、発電を継続的に行うことができる。 It is also possible to configure the power generation device as follows. That is, it has a positive electrode tank, a negative electrode tank, and a circulation mechanism, the electrolytic solution is housed in the positive electrode tank and the negative electrode tank, the positive electrode comes into contact with the electrolytic solution in the positive electrode tank, and the negative electrode is the negative electrode tank. The heating mechanism heats the electrolytic solution of one of the positive electrode tank and the negative electrode tank, and the cooling mechanism cools the electrolytic solution of the other of the positive electrode tank and the negative electrode tank. Then, the circulation mechanism circulates the electrolytic solution between the positive electrode tank and the negative electrode tank. As a result, a proton concentration gradient is generated between the positive electrode tank and the negative electrode tank by the heating mechanism and the cooling mechanism, and electricity can be extracted from the positive electrode and the negative electrode by shifting the redox equilibrium of the redox species. Then, the electrolytic solution is circulated by the circulation mechanism, and the redox equilibrium of the redox species in the newly supplied electrolytic solution is constantly deviated, so that the redox reaction is continued and power generation can be continuously performed.

本発明に係る発電装置の別の特徴構成は、熱交換機構を有し、前記熱交換機構は、前記循環機構が前記正極槽に送る前記電解液と、前記循環機構が前記負極槽に送る前記電解液との間で熱交換を行う点にある。 Another characteristic configuration of the power generation device according to the present invention is the heat exchange mechanism, wherein the heat exchange mechanism sends the electrolytic solution to the positive electrode tank and the circulation mechanism to the negative electrode tank. The point is to exchange heat with the electrolytic solution.

上記の特徴構成によれば、加熱機構からの熱を有効利用して、発電装置のエネルギー効率を高めることができ好適である。 According to the above-mentioned characteristic configuration, it is possible to effectively utilize the heat from the heating mechanism to improve the energy efficiency of the power generation device, which is preferable.

発電装置の概要を示す図Diagram showing the outline of the power generation device 発電原理確認試験の試験装置の概要を示す図The figure which shows the outline of the test apparatus of the power generation principle confirmation test 2槽電位差測定試験の試験装置の概要を示す図The figure which shows the outline of the test apparatus of the two-tank potentiometric test. 2槽電位差測定試験の結果を示すグラフGraph showing the result of the two-tank potentiometric test 2槽電位差測定試験の結果を示すグラフGraph showing the result of the two-tank potentiometric test 2槽電位差測定試験の結果を示すグラフGraph showing the result of the two-tank potentiometric test

以下、電解液および発電装置について詳しく説明する。本実施形態に係る電解液は、温度応答性電解質と酸化還元活性種とを含有する。 Hereinafter, the electrolytic solution and the power generation device will be described in detail. The electrolytic solution according to the present embodiment contains a temperature-responsive electrolyte and a redox active species.

温度応答性電解質としては、温度の変化により電解質中のイオンや酸化還元活性種との親和性が変化するもの、例えば温度に応じてpKaや疎水性が変化する電解質であれば特に限定されないが、例えば、高分子体のものであることが好ましい。
より詳細に説明すると、温度応答性電解質としては、界面活性剤や、ポリNイソプロピルアクリルアミド、ポリペプチド(タンパク質やペプチド)の様な、分子内に極性基と疎水性基を両方有し、さらに、水溶液中でイオンを放出することができる(イオン化可能な)官能基を有するものが挙げられる。
The temperature-responsive electrolyte is not particularly limited as long as it is an electrolyte whose affinity with ions and redox active species in the electrolyte changes with a change in temperature, for example, an electrolyte whose pKa and hydrophobicity change with temperature. For example, it is preferably a polymer.
More specifically, the temperature-responsive electrolyte has both polar and hydrophobic groups in the molecule, such as surfactants, polyNisopropylacrylamide, and polypeptides (proteins and peptides), and further. Examples thereof include those having a functional group capable of releasing ions (ionizable) in an aqueous solution.

イオン化可能な官能基としては、Hを放出する酸性基でも、正電荷となり得る塩基性基でもよく、本発明の適用目的に応じて、適宜、選択し得るものである。酸性基としては、例えば、硫酸基、カルボン酸基、リン酸基、フェノール性水酸基等が挙げられる。塩基性基としては、例えば、アミノ基、イミダゾール基、ピリジル基等が挙げられる。 The functional group that can be ionized may be an acidic group that releases H + or a basic group that can be positively charged, and can be appropriately selected depending on the application purpose of the present invention. Examples of the acidic group include a sulfuric acid group, a carboxylic acid group, a phosphoric acid group, a phenolic hydroxyl group and the like. Examples of the basic group include an amino group, an imidazole group, a pyridyl group and the like.

このような温度応答性電解質は、分子内に極性基と疎水性基を両方有する分子に、イオン化可能な官能基を共有結合で結合させて作製してもよい。また、イオン化可能な電離基を有するモノマー成分と極性基を有するモノマー成分と疎水性基を有するモノマー成分、あるいは、イオン化可能な電離基を有するモノマー成分と極性基及び疎水性基を有するモノマー成分を共重合することによって作製してもよい。 Such a temperature-responsive electrolyte may be prepared by covalently bonding an ionizable functional group to a molecule having both a polar group and a hydrophobic group in the molecule. Further, a monomer component having an ionizable ionizing group, a monomer component having a polar group and a hydrophobic group, or a monomer component having an ionizable ionizing group and a polar group and a monomer component having a hydrophobic group may be used. It may be produced by copolymerization.

界面活性剤や、ポリNイソプロピルアクリルアミド、ポリペプチド(タンパク質やペプチド)の様な、分子内に極性基と疎水性基を両方有する分子は、低温においては水に良く溶解・分散するが、ある温度以上に加温すると疎水性相互作用により集合・収縮・凝集・ゲル化・沈殿する温度応答性を有する。 Molecules that have both polar and hydrophobic groups in the molecule, such as surfactants, polyNisopropylacrylamide, and polypeptides (proteins and peptides), dissolve and disperse well in water at low temperatures, but at a certain temperature. When heated above, it has a temperature responsiveness that aggregates, shrinks, aggregates, gels, and precipitates due to hydrophobic interactions.

一方で、電解質の電離度(pKa)は、電解質が存在する環境(極性)や電解質間の距離に応じて可逆的に変化する。例えば、硫酸は、極性の高い水溶液中においては殆ど電離し、極性の高い硫酸アニオン(HSO やSO 2-等の陰イオン)の構造をとるが、有機溶媒を加えて媒体の極性を下げると電離度が低下し多くが極性の低い硫酸(HSO)の構造となる。また、多くのカルボン酸を一つの分子や高分子、材料上に密集させると近接するカルボキシラートアニオン間で静電反発が働きイオン(RCOO-等の陰イオン)がエネルギー的に不安定化されるため、電離度が下がり電荷を持たないカルボン酸(RCOOH)の割合が増える。また、カルボン酸をプロトン化した状態で極性の低い高分子内部に導入するとカルボン酸がイオン化されにくくなり電離度が下がり電荷を持たないカルボン酸(RCOOH)の割合が増える。 On the other hand, the degree of ionization (pKa) of the electrolyte changes reversibly depending on the environment (polarity) in which the electrolyte is present and the distance between the electrolytes. For example, sulfuric acid, little ionization during highly polar aqueous, highly polar sulfate anion - take the structure (HSO 4 and SO 4 2-like anions), the polarity of the medium by adding an organic solvent When it is lowered, the degree of ionization decreases, and most of them have a structure of low-polarity sulfuric acid (H 2 SO 4). In addition, when many carboxylic acids are concentrated on one molecule, polymer, or material, electrostatic repulsion acts between adjacent carboxylate anions, and ions (anions such as RCOO-) are energetically destabilized. Therefore, the degree of ionization decreases and the proportion of uncharged carboxylic acid (RCOOH) increases. Further, when the carboxylic acid is introduced into a polymer having a low polarity in a protonated state, the carboxylic acid is less likely to be ionized, the degree of ionization is lowered, and the proportion of uncharged carboxylic acid (RCOOH) is increased.

本実施形態に係る温度応答性電解質は、極性基と疎水性基の2つの性質を組み合わせ、さらにイオン化可能な官能基(電解質)を組み合わせることで、温度差を用いてイオン濃度勾配を発生させる。 The temperature-responsive electrolyte according to the present embodiment combines two properties of a polar group and a hydrophobic group, and further combines an ionizable functional group (electrolyte) to generate an ion concentration gradient using a temperature difference.

このような温度応答性電解質は、高温域においては、分子が集合・収縮・凝集・ゲル化・沈殿し、これによりイオン周囲の環境が疎水性(低極性)になり、または、イオン間の距離が近づくことにより電解質がイオン化し難くなる。一方、低温域においては分子が分散・膨潤・溶解するために、周囲の極性が高くなり、又は、イオン間の距離が遠くなることにより電解質がイオン化しやすくなる。すなわち、硫酸やカルボン酸等の酸(負電荷となり得る官能基)を有する温度応答性電解質は低温においては低いpKa値を示すが、高温域においてはpKaの値が高くなる。一方、アミンの様な塩基(正電荷となり得る官能基)を有する温度応答性電解質は低温においては共役酸であるアンモニウム基が高いpKaを有するが高温域においてはpKaの値が低くなる。 In such a temperature-responsive electrolyte, molecules aggregate, shrink, aggregate, gel, and precipitate in a high temperature range, which makes the environment around the ions hydrophobic (low polarity), or the distance between the ions. The closer the electrolyte is, the more difficult it is for the electrolyte to ionize. On the other hand, in the low temperature region, the molecules are dispersed, swollen, and dissolved, so that the polarity of the surroundings becomes high, or the distance between the ions becomes long, so that the electrolyte is easily ionized. That is, a temperature-responsive electrolyte having an acid (functional group that can be negatively charged) such as sulfuric acid or carboxylic acid shows a low pKa value at a low temperature, but a high pKa value in a high temperature range. On the other hand, a temperature-responsive electrolyte having a base (functional group that can be positively charged) such as amine has a high pKa of an ammonium group as a conjugate acid at a low temperature, but a low pKa value in a high temperature range.

実際に、カルボン酸を有するアクリル酸とNイソプロピルアクリルアミドを共重合体した温度応答性ナノ微粒子電解質を合成し、温度を変化させながら、pHを測定したところ温度を上昇させるとある温度を境に急激にpHが上昇する。この時、観察されたpH勾配は最大0.1K-1に達した。これはネルンストの式によると数十mVK-1に相当する。また、動的光散乱法によりこのナノ微粒子の粒径の温度依存を測定すると、pHが上昇し始める温度を境にナノ微粒子が相転移を起こし、急激に収縮し始めることがわかった。すなわち、この温度応答性電解質(カルボン酸を有するポリNイソプロピルアクリルアミド共重合体ナノ微粒子)は低温においては膨潤しているため多くのカルボン酸がイオン化しているが、温度上昇とともに収縮しカルボン酸のイオン化度が低下することが示された。この現象は、カルボン酸の様な酸性の温度応答性電解質だけでなく、アミン基やイミダゾール基の様な塩基性の温度応答性電解質を用いても観察される。 Actually, a temperature-responsive nanoparticles electrolyte obtained by copolymerizing acrylic acid having a carboxylic acid and N-isopropylacrylamide was synthesized, and when the pH was measured while changing the temperature, when the temperature was raised, it suddenly reached a certain temperature. The pH rises. At this time, the observed pH gradient reached a maximum of 0.1K -1. This corresponds to several tens of mVK -1 according to the Nernst equation. Further, when the temperature dependence of the particle size of the nanoparticles was measured by the dynamic light scattering method, it was found that the nanoparticles undergo a phase transition at the temperature at which the pH starts to rise and begin to contract rapidly. That is, since this temperature-responsive electrolyte (polyNisopropylacrylamide copolymer nanoparticles having a carboxylic acid) swells at a low temperature, many carboxylic acids are ionized, but shrinks as the temperature rises, and the carboxylic acid It was shown that the degree of ionization decreased. This phenomenon is observed not only with acidic temperature-responsive electrolytes such as carboxylic acids, but also with basic temperature-responsive electrolytes such as amine and imidazole groups.

アクリル酸の替わりにイミダゾール基(1-H-Imidazole-4-N-acryloylethanamine)やアミン基(N-[3-(Dimethylamino)propyl]methacrylamide)(DMAPM)を有する塩基性モノマーをNイソプロピルアクリルアミドと共に共重合した温度応答性ナノ微粒子電解質を合成し、温度応答的なpH変化を観察すると、相転移点より低温においては比較的高いpHを示したが、温度を上昇させていくと相転移点付近で急激にpHが下がり始める。この時のpH勾配も最大約0.1K-1でありネルンストの式によると数十mV K-1に相当する。イミダゾールの代わりにアミン基を有するN-[3-(Dimethylamino)propyl]methacrylamideを共重合した温度応答性電解質においても高温域においてpkaが低下する。さらにN-[3-(Dimethylamino)propyl]methacrylamideを共重合した温度応答性ナノ微粒子電解質を各温度において塩酸を用いてpH滴定を行うと、相転移点前後で見かけの中和点が大きくシフトする。すなわち、ジメチルアミノ基の一部は相転移温度以下では塩基として作用するが、相転移温度以上にすると収縮した高分子鎖の内部に埋もれて塩基として作用しない。
これまで電解質のpHは一般的に温度を変化させると変化することが知られていたが、通常の電解質のpH変化は1℃あたり0.01K-1前後であった。本実施形態に係る温度応答性電解質を用いることにより既存の電解質では見られなかった顕著なpH変化を達成できる。
A basic monomer having an imidazole group (1-H-Imidazole-4-N-acryloylethanamine) or an amine group (N- [3- (Dimethylamino) propyl] methacrylamide) (DMAPM) instead of acrylic acid is copolymerized with Nisopropylacrylamide. When the polymerized temperature-responsive nanoparticles electrolyte was synthesized and the temperature-responsive pH change was observed, the pH was relatively high at a temperature lower than the phase transition point, but when the temperature was raised, it was near the phase transition point. The pH begins to drop sharply. PH gradient at this time is also equivalent to several tens of mV K -1 According to is the Nernst equation up to about 0.1 K -1. Even in a temperature-responsive electrolyte copolymerized with N- [3- (Dimethylamino) propyl] methacrylamide having an amine group instead of imidazole, pka decreases in a high temperature range. Furthermore, when pH titration of a temperature-responsive nanoparticulate electrolyte copolymerized with N- [3- (Dimethylamino) propyl] methacrylamide using hydrochloric acid at each temperature is performed, the apparent neutralization point shifts significantly before and after the phase transition point. .. That is, a part of the dimethylamino group acts as a base below the phase transition temperature, but when it is above the phase transition temperature, it is buried inside the contracted polymer chain and does not act as a base.
Until now, it has been known that the pH of an electrolyte generally changes when the temperature is changed, but the pH change of a normal electrolyte is around 0.01 K-1 per 1 ° C. By using the temperature-responsive electrolyte according to the present embodiment, a remarkable pH change not found in the existing electrolyte can be achieved.

温度応答性電解質の多くは相転移点を有し、相転移温度前後で急激に集合・収縮・凝集・ゲル化・沈殿状態が変化する。そのため、該温度応答性電解質を含む水溶液等は、僅かな温度変化で急激にpHを変化させることが出来る。また、相転移温度は、該温度応答性電解質を含む溶液の極性・イオン強度や温度応答性電解質の濃度だけでなく、温度応答性電解質の親疎水性バランス、電解質密度により制御可能である。 Most temperature-responsive electrolytes have a phase transition point, and the state of aggregation, shrinkage, aggregation, gelation, and precipitation changes rapidly before and after the phase transition temperature. Therefore, the pH of an aqueous solution or the like containing the temperature-responsive electrolyte can be rapidly changed with a slight temperature change. Further, the phase transition temperature can be controlled not only by the polarity / ionic strength of the solution containing the temperature-responsive electrolyte and the concentration of the temperature-responsive electrolyte, but also by the hydrophobic balance of the temperature-responsive electrolyte and the electrolyte density.

さらに、変化させるpH領域や温度領域は、電解質の種類(強酸、弱酸、弱塩基、強塩基等)や密度、さらには集合・収縮・凝集・ゲル化・沈殿の度合いをコントロールすることで制御可能である。すなわち、分子設計や媒体の設計に応じて非常に低いpHから高いpHまで、目的の温度応答性をもって制御可能である。例えば、温度応答性電解質高分子(ナノ微粒子)の合成の際に、N,N‘−メチレンビスアクリルアミドのような架橋性モノマー量(架橋性モノマーの共重合率)を調整することにより、温度変化による膨潤割合を調整することができる。また、温度応答性電解質高分子(ナノ微粒子)の合成の際に、N−t−ブチルアクリルアミドのような疎水性モノマー含有量(疎水性モノマーの共重合率)を調整することにより、相転移温度を調整することができる。 Furthermore, the pH range and temperature range to be changed can be controlled by controlling the type and density of the electrolyte (strong acid, weak acid, weak base, strong base, etc.), and the degree of aggregation, shrinkage, aggregation, gelation, and precipitation. Is. That is, it is possible to control from a very low pH to a high pH with a desired temperature responsiveness according to the molecular design and the design of the medium. For example, when synthesizing a temperature-responsive electrolyte polymer (nanoparticles), the temperature is changed by adjusting the amount of crosslinkable monomer such as N, N'-methylenebisacrylamide (copolymerization rate of the crosslinkable monomer). The swelling rate can be adjusted. Further, when synthesizing a temperature-responsive electrolyte polymer (nanoparticles), the phase transition temperature is adjusted by adjusting the content of a hydrophobic monomer such as Nt-butylacrylamide (copolymerization rate of the hydrophobic monomer). Can be adjusted.

実際にアミン含有ゲル粒子のpKa域およびpKa変化については論文「Design rationale of thermally responsive microgel particle films that reversibly absorb large amounts of CO2: fine tuning the pKa of ammonium ions in the particles」(Chemical Science, 2015, 6, 6112-6123)に報告されているとおり、アミンの種類、重合時のpH、架橋密度、粒子径、疎水性官能基の設計により自在にチューニング可能であることが報告されている。 Regarding the pKa region and pKa change of amine-containing gel particles, the paper "Design rationale of similarly responsive microgel particle films that reversibly absorb large amounts of CO2: fine tuning the pKa of ammonium ions in the particles" (Chemical Science, 2015, 6) , 6112-6123), it has been reported that it can be freely tuned by designing the type of amine, pH at the time of polymerization, cross-linking density, particle size, and hydrophobic functional group.

また、カルボン酸含有ゲル粒子のpKa域およびpKa変化については論文「Rational Design of Synthetic Nanoparticles with a Large Reversible Shift of Acid Dissociation Constants: Proton Imprinting in Stimuli Responsive Nanogel Particles」(ADVANCED MATERIALS, 2014, 26, 3718-3723)に報告されているとおり、カルボン酸の種類、重合時のpH、架橋密度、粒子径、疎水性官能基の設計により自在にチューニング可能である。 Regarding the pKa region and pKa change of carboxylic acid-containing gel particles, the paper "Rational Design of Synthetic Nanoparticles with a Large Reversible Shift of Acid Dissociation Constants: Proton Imprinting in Stimuli Responsive Nanogel Particles" (ADVANCED MATERIALS, 2014, 26, 3718- As reported in 3723), it can be freely tuned by designing the type of carboxylic acid, pH at the time of polymerization, cross-linking density, particle size, and hydrophobic functional group.

<酸化還元活性種>
本実施形態で用いられる酸化還元活性種は、電子授受による酸化還元の過程で酸化体および還元体がともに水溶液に可溶であり、かつ酸化還元反応の系の中に水素イオン(プロトン)が含まれる。そして本実施形態に係る酸化還元活性種は、電解液において平衡状態(酸化還元平衡)を形成する。
<Redox active species>
In the redox active species used in the present embodiment, both the oxidant and the reduced product are soluble in an aqueous solution in the process of redox by electron transfer, and hydrogen ions (protons) are contained in the redox reaction system. Is done. The redox active species according to the present embodiment form an equilibrium state (oxidation-reduction equilibrium) in the electrolytic solution.

また本実施形態の酸化還元活性種としては、pHに応じて酸化還元電位が変化するものが用いられる。また、温度に応じて温度応答性電解質との相互作用が変化するものも用いられる。相互作用としては疎水性相互作用、静電相互作用、水素結合のいずれかあるいはそれらの組合せであってもよい。 Further, as the redox active species of the present embodiment, those whose redox potential changes according to pH are used. In addition, those in which the interaction with the temperature-responsive electrolyte changes according to the temperature are also used. The interaction may be any of hydrophobic interactions, electrostatic interactions, hydrogen bonds, or a combination thereof.

なお本実施形態では、酸化体とは、酸化還元活性種が酸化還元反応において酸化された状態を指し、いわゆる酸化剤として機能する状態を指す。還元体とは、酸化還元活性種が酸化還元反応において還元された状態を指し、いわゆる還元剤として機能する状態を指す。後述する図1では、酸化体を「Ox」として表し、還元体を「Re」として表している。 In the present embodiment, the oxidant refers to a state in which the redox active species is oxidized in the redox reaction, and refers to a state in which it functions as a so-called oxidizing agent. The reduced form refers to a state in which a redox-active species is reduced in a redox reaction, and refers to a state in which it functions as a so-called reducing agent. In FIG. 1, which will be described later, the oxidized product is represented as “Ox” and the reduced product is represented as “Re”.

本実施形態では酸化還元活性種として、アントラキノン誘導体、ニコチンアミド誘導体、N置換ニコチンアミド、リボフラビン誘導体、プロフラビン誘導体が用いられる。また、メチレンブルー、N,N,N’,N’−テトラメチル−p−フェニレンジアミン、ジチオトレイトール、フェロシアン化合物、N1-ferrocenylmethyl-N1,N1,N2,N2,N2-pentamethylpropane-1,2-diaminium dibromide、メチルビオロゲン、ナフトキノン、メナジオン等も酸化還元活性種として好適に用い得る。 In the present embodiment, anthraquinone derivative, nicotinamide derivative, N-substituted nicotinamide, riboflavin derivative, and proflavine derivative are used as redox active species. In addition, methylene blue, N, N, N', N'-tetramethyl-p-phenylenediamine, dithiothreitol, ferrocyan compound, N1-ferrocenylmethyl-N1, N1, N2, N2, N2-pentamethylpropane-1,2- Diaminium dibromide, methyl viologen, naphthoquinone, menadione and the like can also be suitably used as redox active species.

<アントラキノン誘導体>
アントラキノン誘導体としては、例えば硫酸化アントラキノン(以下「AQDS」と略記する場合がある。)を用いることができる。硫酸化アントラキノンは、アントラキノンにスルホン基を導入して親水化した物質である。親水化により酸化還元活性種を電解液に均一分散でき好適である。すなわち、親水化アントラキノン誘導体は酸化還元活性種として好適に用い得る。
<Anthraquinone derivative>
As the anthraquinone derivative, for example, sulfated anthraquinone (hereinafter, may be abbreviated as "AQDS") can be used. Sulfated anthraquinone is a substance in which a sulfone group is introduced into anthraquinone to make it hydrophilic. Hydrophilization is suitable because redox active species can be uniformly dispersed in the electrolytic solution. That is, the hydrophilized anthraquinone derivative can be suitably used as a redox active species.

硫酸化アントラキノンの構造を化学式1に示し、その酸化還元反応式を化学式2に示す。pHの低い環境下では、酸化体(酸化還元反応式の左辺)の還元反応が進行し、平衡が右へ移動して、プロトンと電子が消費される。一方、pHの高い環境下では還元体(酸化還元反応式の右辺)の酸化反応が進行し、平衡が左へ移動して、プロトンと電子が放出される。 The structure of sulfated anthraquinone is shown in Chemical Formula 1, and its redox reaction formula is shown in Chemical Formula 2. In a low pH environment, the reduction reaction of the oxidant (the left side of the redox reaction formula) proceeds, the equilibrium shifts to the right, and protons and electrons are consumed. On the other hand, in an environment with a high pH, the oxidation reaction of the reducing agent (on the right side of the redox reaction formula) proceeds, the equilibrium shifts to the left, and protons and electrons are released.

Figure 0006847446
Figure 0006847446

Figure 0006847446
Figure 0006847446

<メチレンブルー>
メチレンブルー(以下「MB」と略記する場合がある。)の構造を化学式3に示し、その酸化還元反応式を化学式4に示す。pHの低い環境下では、酸化体(酸化還元反応式の左辺)の還元反応が進行し、平衡が右へ移動して、プロトンと電子が消費される。一方、pHの高い環境下では還元体(酸化還元反応式の右辺)の酸化反応が進行し、平衡が左へ移動して、プロトンと電子が放出される。
<Methylene blue>
The structure of methylene blue (hereinafter sometimes abbreviated as "MB") is shown in Chemical Formula 3, and its redox reaction formula is shown in Chemical Formula 4. In a low pH environment, the reduction reaction of the oxidant (the left side of the redox reaction formula) proceeds, the equilibrium shifts to the right, and protons and electrons are consumed. On the other hand, in an environment with a high pH, the oxidation reaction of the reducing agent (on the right side of the redox reaction formula) proceeds, the equilibrium shifts to the left, and protons and electrons are released.

Figure 0006847446
Figure 0006847446

Figure 0006847446
Figure 0006847446

<発電装置>
次に図1を参照して、上述した電解液を用いた発電装置について説明する。本実施形態に係る発電装置100は、正極槽1、負極槽2、正極3、負極4、冷却機構5、加熱機構6、循環機構7および熱交換機構8を有して構成される。
<Power generation device>
Next, with reference to FIG. 1, a power generation device using the above-mentioned electrolytic solution will be described. The power generation device 100 according to the present embodiment includes a positive electrode tank 1, a negative electrode tank 2, a positive electrode 3, a negative electrode 4, a cooling mechanism 5, a heating mechanism 6, a circulation mechanism 7, and a heat exchange mechanism 8.

正極槽1および負極槽2に、上述した電解液Sが収容される。正極3および負極4は、例えばカーボン製の電極である。正極3が、正極槽1の電解液Sに浸漬される。負極4が、負極槽2の電解液Sに浸漬される。 The above-mentioned electrolytic solution S is housed in the positive electrode tank 1 and the negative electrode tank 2. The positive electrode 3 and the negative electrode 4 are, for example, carbon electrodes. The positive electrode 3 is immersed in the electrolytic solution S of the positive electrode tank 1. The negative electrode 4 is immersed in the electrolytic solution S of the negative electrode tank 2.

冷却機構5は、正極槽1に収容された電解液Sを冷却する。すなわち冷却機構5は、正極3の近傍の電解液Sを冷却する。例えば冷却機構5は、正極槽1の電解液と海水とを熱交換させる熱交換器である。 The cooling mechanism 5 cools the electrolytic solution S housed in the positive electrode tank 1. That is, the cooling mechanism 5 cools the electrolytic solution S in the vicinity of the positive electrode 3. For example, the cooling mechanism 5 is a heat exchanger that exchanges heat between the electrolytic solution in the positive electrode tank 1 and seawater.

加熱機構6は、負極槽2に収容された電解液Sを加熱する。すなわち加熱機構6は、負極4の近傍の電解液Sを加熱する。例えば加熱機構6は、負極槽2の電解液と、工場や内燃機関、燃料電池等からの高温水とを熱交換させる熱交換器である。 The heating mechanism 6 heats the electrolytic solution S housed in the negative electrode tank 2. That is, the heating mechanism 6 heats the electrolytic solution S in the vicinity of the negative electrode 4. For example, the heating mechanism 6 is a heat exchanger that exchanges heat between the electrolytic solution in the negative electrode tank 2 and high-temperature water from a factory, an internal combustion engine, a fuel cell, or the like.

循環機構7は、正極槽1と負極槽2との間で電解液Sを循環させる機構である。循環機構7は、第1流路7a、第1ポンプ7b、第2流路7cおよび第2ポンプ7dを有して構成される。第1流路7aおよび第2流路7cは、電解液Sが通流可能流路であって、正極槽1と負極槽2とを接続する流路である。第1ポンプ7bは、第1流路7aに設けられたポンプであって、正極槽1の電解液Sを負極槽2へ向けて送出する。第2ポンプ7dは、第2流路7cに設けられたポンプであって、負極槽2の電解液Sを正極槽1へ向けて送出する。 The circulation mechanism 7 is a mechanism for circulating the electrolytic solution S between the positive electrode tank 1 and the negative electrode tank 2. The circulation mechanism 7 includes a first flow path 7a, a first pump 7b, a second flow path 7c, and a second pump 7d. The first flow path 7a and the second flow path 7c are flow paths through which the electrolytic solution S can flow, and are flow paths connecting the positive electrode tank 1 and the negative electrode tank 2. The first pump 7b is a pump provided in the first flow path 7a, and sends out the electrolytic solution S of the positive electrode tank 1 toward the negative electrode tank 2. The second pump 7d is a pump provided in the second flow path 7c, and sends out the electrolytic solution S of the negative electrode tank 2 toward the positive electrode tank 1.

熱交換機構8は、循環機構7が正極槽1に送る電解液Sと、循環機構7が負極槽2に送る電解液Sとの間で熱交換を行う熱交換器である。具体的には熱交換機構8は、第1流路7aを通流する電解液Sと、第2流路7cを通流する電解液Sとの間で熱交換を行う。 The heat exchange mechanism 8 is a heat exchanger that exchanges heat between the electrolytic solution S sent by the circulation mechanism 7 to the positive electrode tank 1 and the electrolytic solution S sent by the circulation mechanism 7 to the negative electrode tank 2. Specifically, the heat exchange mechanism 8 exchanges heat between the electrolytic solution S passing through the first flow path 7a and the electrolytic solution S passing through the second flow path 7c.

<発電装置の動作>
以上述べた発電装置100の動作について説明する。以下の説明では、温度応答性電解質のイオン化可能な官能基が、硫酸やカルボン酸等の酸(負電荷となり得る官能基)である場合について説明する。
<Operation of power generator>
The operation of the power generation device 100 described above will be described. In the following description, the case where the ionizable functional group of the temperature-responsive electrolyte is an acid (functional group that can be negatively charged) such as sulfuric acid or carboxylic acid will be described.

加熱機構6が負極槽2の電解液Sを加熱して、電解液Sの温度を高く、特に温度応答性電解質の相転移温度より高くする。そうすると、温度応答性電解質(分子)が脱水和・集合・収縮・凝集・ゲル化・沈殿等する。これにより温度応答性電解質の官能基の周囲の環境が疎水性(低極性)になり、または、官能基間の距離が近づくことにより、官能基がイオン化し難くなる。つまり、温度応答性電解質のpKa値が高くなり、負極槽2の水素イオン(プロトン)の濃度が減少する。もって負極槽2の電解液SのpHが増加する。同時に酸化還元活性種の酸化体、或いは還元体あるいはその両者と温度応答性電解質の相互作用が変化してもよい。 The heating mechanism 6 heats the electrolytic solution S in the negative electrode tank 2 to raise the temperature of the electrolytic solution S, particularly higher than the phase transition temperature of the temperature-responsive electrolyte. Then, the temperature-responsive electrolyte (numerator) is dehydrated, aggregated, contracted, aggregated, gelled, precipitated, etc. As a result, the environment around the functional groups of the temperature-responsive electrolyte becomes hydrophobic (low polarity), or the distances between the functional groups become closer, so that the functional groups are less likely to be ionized. That is, the pKa value of the temperature-responsive electrolyte increases, and the concentration of hydrogen ions (protons) in the negative electrode tank 2 decreases. Therefore, the pH of the electrolytic solution S in the negative electrode tank 2 increases. At the same time, the interaction between the redox active species oxide, the reduced product, or both of them and the temperature-responsive electrolyte may change.

そうすると、化学式2等に示した酸化還元活性種の酸化還元平衡は左へ移動する。つまり還元体の酸化反応が進行し、プロトンと電子が放出される。そして酸化還元活性種から放出された電子が、負極4から外部へ取り出される。 Then, the redox equilibrium of the redox active species represented by the chemical formula 2 or the like shifts to the left. That is, the oxidation reaction of the reducing body proceeds, and protons and electrons are released. Then, the electrons emitted from the redox active species are taken out from the negative electrode 4.

冷却機構5が正極槽1の電解液Sを冷却して、電解液Sの温度を(負極槽2の温度より)低く、特に温度応答性電解質の相転移温度より低くする。そうすると、温度応答性電解質(分子)が分散・膨潤・溶解等する。これにより温度応答性電解質の官能基の周囲の極性が高くなり、または、官能基間の距離が遠くなることにより、官能基がイオン化しやすくなる。つまり、温度応答性電解質のpKa値が低くなり、正極槽1の水素イオン(プロトン)の濃度が増加する。もって正極槽1の電解液SのpHが減少する。 The cooling mechanism 5 cools the electrolytic solution S in the positive electrode tank 1 to lower the temperature of the electrolytic solution S (lower than the temperature of the negative electrode tank 2), particularly lower than the phase transition temperature of the temperature-responsive electrolyte. Then, the temperature-responsive electrolyte (numerator) is dispersed, swollen, dissolved, etc. As a result, the polarity around the functional groups of the temperature-responsive electrolyte becomes high, or the distance between the functional groups becomes large, so that the functional groups are easily ionized. That is, the pKa value of the temperature-responsive electrolyte becomes low, and the concentration of hydrogen ions (protons) in the positive electrode tank 1 increases. Therefore, the pH of the electrolytic solution S in the positive electrode tank 1 decreases.

そうすると、化学式2等に示した酸化還元活性種の酸化還元平衡は右へ移動する。つまり周囲のプロトンと、正極3から供給される電子を用いて酸化体の還元反応が進行する。つまり、負極4からの電子が正極槽1にて消費される。 Then, the redox equilibrium of the redox active species represented by the chemical formula 2 or the like shifts to the right. That is, the reduction reaction of the oxidant proceeds using the surrounding protons and the electrons supplied from the positive electrode 3. That is, the electrons from the negative electrode 4 are consumed in the positive electrode tank 1.

以上の反応により、正極槽1では分散・膨潤・溶解等した温度応答性電解質(分子)と、酸化還元活性種の還元体の濃度が上昇する。負極槽2では集合・収縮・凝集・ゲル化・沈殿等した温度応答性電解質(分子)と、酸化還元活性種の酸化体の濃度が上昇する。循環機構7が、正極槽1と負極槽2との間で電解液Sを循環させることで、これら物質の濃度の均衡が保たれ、上述の反応が継続的に進行し、発電装置100による発電が継続的に行われる。 As a result of the above reaction, the concentrations of the temperature-responsive electrolyte (molecule) dispersed, swollen, dissolved, etc. and the reduced product of the redox active species increase in the positive electrode tank 1. In the negative electrode tank 2, the concentrations of the temperature-responsive electrolyte (molecule) that has aggregated, shrunk, agglutinated, gelled, precipitated, etc., and the oxide of the redox active species increase. The circulation mechanism 7 circulates the electrolytic solution S between the positive electrode tank 1 and the negative electrode tank 2, so that the concentration of these substances is balanced, the above-mentioned reaction continuously proceeds, and the power generation device 100 generates power. Is done continuously.

以上述べた通り、本実施形態に係る発電装置100は、上述の電解液を用いて発電を行う発電装置であって、正極3と負極4と加熱機構6と冷却機構5とを有し、正極3および負極4は電解液に浸漬される。加熱機構6は、負極4の近傍の電解液を、温度応答性電解質の相転移温度より高い温度に加熱する。冷却機構5は、正極3の近傍の電解液を、温度応答性電解質の相転移温度より低い温度に冷却する。 As described above, the power generation device 100 according to the present embodiment is a power generation device that generates power using the above-mentioned electrolytic solution, and has a positive electrode 3, a negative electrode 4, a heating mechanism 6, and a cooling mechanism 5, and has a positive electrode. 3 and the negative electrode 4 are immersed in the electrolytic solution. The heating mechanism 6 heats the electrolytic solution in the vicinity of the negative electrode 4 to a temperature higher than the phase transition temperature of the temperature-responsive electrolyte. The cooling mechanism 5 cools the electrolytic solution in the vicinity of the positive electrode 3 to a temperature lower than the phase transition temperature of the temperature-responsive electrolyte.

<発電装置の動作(他の形態)>
ここで、温度応答性電解質のイオン化可能な官能基が、アミンの様な塩基(正電荷となり得る官能基)である場合について説明する。この場合、温度応答性電解質のアンモニウム基は低温においては高いpKaを有するが高温域においてはpKaの値が低くなる。このような温度応答性電解質を発電装置100に用いる場合には、冷却機構5と加熱機構6の配置を入れ替える。すなわち、冷却機構5が負極槽2の電解液Sを冷却し、加熱機構6が正極槽1の電解液Sを加熱するよう、発電装置100を構成する。
<Operation of power generator (other form)>
Here, the case where the ionizable functional group of the temperature-responsive electrolyte is a base such as amine (a functional group that can be a positive charge) will be described. In this case, the ammonium group of the temperature-responsive electrolyte has a high pKa at low temperatures, but the pKa value is low at high temperatures. When such a temperature-responsive electrolyte is used in the power generation device 100, the arrangements of the cooling mechanism 5 and the heating mechanism 6 are exchanged. That is, the power generation device 100 is configured so that the cooling mechanism 5 cools the electrolytic solution S in the negative electrode tank 2 and the heating mechanism 6 heats the electrolytic solution S in the positive electrode tank 1.

冷却機構5が負極槽2の電解液Sを冷却して、電解液Sの温度を低く、特に温度応答性電解質の相転移温度より低くする。そうすると、温度応答性電解質(分子)が分散・膨潤・溶解等する。これにより温度応答性電解質の官能基の周囲の極性が高くなり、または、官能基間の距離が遠くなることにより、官能基がイオン化しやすくなる。つまり、温度応答性電解質のpKa値が高くなり、負極槽2の水素イオン(プロトン)の濃度が減少する。もって負極槽2の電解液SのpHが増加する。 The cooling mechanism 5 cools the electrolytic solution S in the negative electrode tank 2 to lower the temperature of the electrolytic solution S, particularly lower than the phase transition temperature of the temperature-responsive electrolyte. Then, the temperature-responsive electrolyte (numerator) is dispersed, swollen, dissolved, etc. As a result, the polarity around the functional groups of the temperature-responsive electrolyte becomes high, or the distance between the functional groups becomes large, so that the functional groups are easily ionized. That is, the pKa value of the temperature-responsive electrolyte increases, and the concentration of hydrogen ions (protons) in the negative electrode tank 2 decreases. Therefore, the pH of the electrolytic solution S in the negative electrode tank 2 increases.

そうすると、化学式2等に示した酸化還元活性種の酸化還元平衡は、化学式2等の式で左へ移動する。つまり還元体の酸化反応が進行し、プロトンと電子が放出される。酸化還元活性種から放出された電子が、負極4から外部へ取り出される。 Then, the redox equilibrium of the redox active species shown in the chemical formula 2 or the like moves to the left by the formula of the chemical formula 2 or the like. That is, the oxidation reaction of the reducing body proceeds, and protons and electrons are released. The electrons emitted from the redox active species are taken out from the negative electrode 4.

加熱機構6が正極槽1の電解液Sを加熱して、電解液Sの温度を(負極槽2の温度より)高く、特に温度応答性電解質の相転移温度より高くする。そうすると、温度応答性電解質(分子)が集合・収縮・凝集・ゲル化・沈殿等する。これにより温度応答性電解質の官能基の周囲の環境が疎水性(低極性)になり、または、官能基間の距離が近づくことにより、官能基がイオン化し難くなる。つまり、温度応答性電解質のpKa値が低くなり、正極槽1の水素イオン(プロトン)の濃度が増加する。もって正極槽1の電解液SのpHが減少する。 The heating mechanism 6 heats the electrolytic solution S in the positive electrode tank 1 to raise the temperature of the electrolytic solution S (higher than the temperature of the negative electrode tank 2), particularly higher than the phase transition temperature of the temperature-responsive electrolyte. Then, the temperature-responsive electrolyte (molecule) aggregates, shrinks, aggregates, gels, precipitates, and the like. As a result, the environment around the functional groups of the temperature-responsive electrolyte becomes hydrophobic (low polarity), or the distances between the functional groups become closer, so that the functional groups are less likely to be ionized. That is, the pKa value of the temperature-responsive electrolyte becomes low, and the concentration of hydrogen ions (protons) in the positive electrode tank 1 increases. Therefore, the pH of the electrolytic solution S in the positive electrode tank 1 decreases.

そうすると、化学式2等に示した酸化還元活性種の酸化還元平衡は、化2の式で右へ移動する。つまり周囲のプロトンと、正極3から供給される電子を用いて酸化体の還元反応が進行する。つまり、負極4からの電子が正極槽1にて消費される。 Then, the redox equilibrium of the redox active species shown in the chemical formula 2 or the like shifts to the right by the formula of the chemical formula 2. That is, the reduction reaction of the oxidant proceeds using the surrounding protons and the electrons supplied from the positive electrode 3. That is, the electrons from the negative electrode 4 are consumed in the positive electrode tank 1.

以上の反応により、正極槽1では集合・収縮・凝集・ゲル化・沈殿等した温度応答性電解質(分子)と、酸化還元活性種の還元体の濃度が上昇する。負極槽2では分散・膨潤・溶解等した温度応答性電解質(分子)と、酸化還元活性種の酸化体の濃度が上昇する。循環機構7が、正極槽1と負極槽2との間で電解液Sを循環させることで、これら物質の濃度の均衡が保たれ、上述の反応が継続的に進行し、発電装置100による発電が継続的に行われる。 As a result of the above reaction, the concentrations of the temperature-responsive electrolyte (molecule) that has aggregated, shrunk, agglutinated, gelled, precipitated, etc., and the reduced product of the redox active species increase in the positive electrode tank 1. In the negative electrode tank 2, the concentrations of the temperature-responsive electrolyte (molecule) dispersed, swollen, and dissolved, and the oxide of the redox active species increase. The circulation mechanism 7 circulates the electrolytic solution S between the positive electrode tank 1 and the negative electrode tank 2, so that the concentration of these substances is balanced, the above-mentioned reaction continuously proceeds, and the power generation device 100 generates power. Is done continuously.

以上述べた通り、この形態に係る発電装置100は、上述の電解液を用いて発電を行う発電装置であって、正極3と負極4と加熱機構6と冷却機構5とを有し、正極3および負極4は電解液に浸漬される。加熱機構6は、正極3の近傍の電解液を、温度応答性電解質の相転移温度より高い温度に加熱する。冷却機構5は、負極4の近傍の電解液を、温度応答性電解質の相転移温度より低い温度に冷却する。 As described above, the power generation device 100 according to this embodiment is a power generation device that generates power using the above-mentioned electrolytic solution, and has a positive electrode 3, a negative electrode 4, a heating mechanism 6, and a cooling mechanism 5, and is a positive electrode 3. And the negative electrode 4 is immersed in the electrolytic solution. The heating mechanism 6 heats the electrolytic solution in the vicinity of the positive electrode 3 to a temperature higher than the phase transition temperature of the temperature-responsive electrolyte. The cooling mechanism 5 cools the electrolytic solution in the vicinity of the negative electrode 4 to a temperature lower than the phase transition temperature of the temperature-responsive electrolyte.

<試験1:発電原理確認試験>
本実施形態に係る電解液によって発電が可能であることを確認するため、図2に示す試験器具にて発電原理確認試験を行った。
<Test 1: Power generation principle confirmation test>
In order to confirm that power generation is possible with the electrolytic solution according to the present embodiment, a power generation principle confirmation test was conducted with the test instrument shown in FIG.

試験器具は、図2に示すように、水溶液槽11、冷却水循環槽12、高温水循環槽13、低温側電極14、高温側電極15、低温熱源16、高温熱源17、電流電圧計18(Keithley社、2401SourceMeter)、整流板19、伝熱板20を有して構成される。水溶液槽11に、試験用試料が満たされる。
低温側電極14および高温側電極15は、水溶液槽11内部の試験用試料と接触した状態とされる。低温側電極14は、白金のワイヤーであって、太さは1mmであり、試験用試料と接触する部位の長さは22mmである。高温側電極15は、白金のワイヤーであって、太さは1mmであり、試験用試料と接触する部位の長さは18mmである。低温側電水溶液槽と高温側水溶液槽は厚み0.2mmの整流板で部分的に区切られており効果的に熱対流が維持されるように設計されている。低温側電水溶液槽と高温側水溶液槽の厚みは3mmであり、直径が30mmの円筒形である。低温側電極14と高温側電極15との間に、電流計18が接続される。
低温側水槽12は、厚み0.1mmの伝熱板を介して水槽と接触しており、低温熱源16から温度を制御した湯水が供給される。高温側水槽13は、厚み0.1mmの伝熱板を介して水槽と接触しており、高温熱源17から温度を制御した湯水が供給される。そうすると水溶液槽11では、低温側電極14の近傍の試験用試料は冷却され、高温側電極15の近傍の試験用試料は加熱されて、水溶液槽11の試験用試料の内部で温度差(温度傾斜)が生じる。また、水溶液槽11内には対流により低温側電極14と高温側電極15の間を試験用試料が循環する。
As shown in FIG. 2, the test instruments include an aqueous solution tank 11, a cooling water circulation tank 12, a high temperature water circulation tank 13, a low temperature side electrode 14, a high temperature side electrode 15, a low temperature heat source 16, a high temperature heat source 17, and a current voltmeter 18 (Keythley). , 2401SourceMeter), a rectifying plate 19, and a heat transfer plate 20. The aqueous solution tank 11 is filled with a test sample.
The low temperature side electrode 14 and the high temperature side electrode 15 are in contact with the test sample inside the aqueous solution tank 11. The low temperature side electrode 14 is a platinum wire, has a thickness of 1 mm, and has a length of a portion in contact with the test sample of 22 mm. The high temperature side electrode 15 is a platinum wire, has a thickness of 1 mm, and has a length of a portion in contact with the test sample of 18 mm. The low-temperature side electric aqueous solution tank and the high-temperature side aqueous solution tank are partially separated by a straightening vane having a thickness of 0.2 mm, and are designed to effectively maintain heat convection. The thickness of the low-temperature side electric aqueous solution tank and the high-temperature side aqueous solution tank is 3 mm, and the diameter is 30 mm in a cylindrical shape. An ammeter 18 is connected between the low temperature side electrode 14 and the high temperature side electrode 15.
The low temperature side water tank 12 is in contact with the water tank via a heat transfer plate having a thickness of 0.1 mm, and hot water whose temperature is controlled is supplied from the low temperature heat source 16. The high temperature side water tank 13 is in contact with the water tank via a heat transfer plate having a thickness of 0.1 mm, and hot water whose temperature is controlled is supplied from the high temperature heat source 17. Then, in the aqueous solution tank 11, the test sample in the vicinity of the low temperature side electrode 14 is cooled, the test sample in the vicinity of the high temperature side electrode 15 is heated, and the temperature difference (temperature gradient) inside the test sample in the aqueous solution tank 11 is reached. ) Occurs. Further, the test sample circulates in the aqueous solution tank 11 between the low temperature side electrode 14 and the high temperature side electrode 15 by convection.

以上のように構成した試験器具にて、低温側電極14、高温側電極15の間に生じる電圧および電流の大きさを測定した。また電極の代わりに直径1mmの熱電対を挿入し温度差の計測も行うこともできる。 With the test instrument configured as described above, the magnitudes of the voltage and current generated between the low temperature side electrode 14 and the high temperature side electrode 15 were measured. Further, a thermocouple having a diameter of 1 mm can be inserted instead of the electrode to measure the temperature difference.

<試験用試料>
以下に示す水溶液を調整して試験用試料(電解液)とし、上述の試験器具にて試験を行った。
硫酸化アントラキノン 1mmol/L
還元剤(亜ジチオン酸ナトリウム) 0.5mmol/L
KCl 30mmol/L
NaOH 2mmol/L
温度応答性電解質(Nps(COO)) 4mmol/L
<Test sample>
The following aqueous solution was adjusted to prepare a test sample (electrolyte solution), and the test was conducted with the above-mentioned test equipment.
Sulfated anthraquinone 1 mmol / L
Reducing agent (sodium dithionite) 0.5 mmol / L
KCl 30 mmol / L
NaOH 2 mmol / L
Temperature-responsive electrolyte (Nps (COO )) 4 mmol / L

ここで温度応答性電解質(Nps)としては、カルボン酸を有するアクリル酸とNイソプロピルアクリルアミドを共重合体した温度応答性ナノ微粒子電解質を用いた。電解質中のカルボン酸の濃度が4 mmol/Lとなるように濃度を調整した。ナノ粒子電解質としては詳しくは、N−イソプロリルアクリルアミドを93mol%、アクリル酸を5mol%、架橋剤のN,N‘−メチレンビスアクリルアミドを2mol%共重合したナノ微粒子である。当該微粒子(以下「Nps」と表記する場合がある。)は以下の様にして作成した。 Here, as the temperature-responsive electrolyte (Nps), a temperature-responsive nanoparticles electrolyte obtained by copolymerizing acrylic acid having a carboxylic acid and Nisopropylacrylamide was used. The concentration was adjusted so that the concentration of carboxylic acid in the electrolyte was 4 mmol / L. More specifically, the nanoparticle electrolyte is nanoparticles obtained by copolymerizing 93 mol% of N-isoprolyl acrylamide, 5 mol% of acrylic acid, and 2 mol% of N, N'-methylenebisacrylamide as a cross-linking agent. The fine particles (hereinafter sometimes referred to as "Nps") were prepared as follows.

アクリル酸(AAc)、N-Isopropylacrylamide(NIPAm)、N,N'-Methylenebisacrylamide(BIS)およびsodium dodecyl sulfate(SDS)をMiliQ水300 mL に溶解させ、総モノマー濃度が312mMになるようにした。組成はNIPAm 93mol%、BIS 2mol%、AAc 5mol%、SDS 6.21mM、V−501 19.3mg/1.96mL DMSOにした。重合前のpHは1M HClおよび1M NaOHによって3.5に調節した。その後Nを30分間混合溶液中でバブリングさせた。開始剤V−501をDMSOに溶解させ、混合溶液に加えることで重合を開始させた。重合はN雰囲気かつ70℃で3時間攪拌して行った。反応後の溶液は透析膜(MWCO 12,000−14,000)を用いて界面活性剤の量が総モノマー濃度の0.25%以下になるまで水を交換し、透析することで精製した。対アニオンは陽イオン交換樹脂(Muromac C1002−H)によって除去した。陽イオン交換樹脂は濾過することで分離した。Nps水溶液の濃度は透析した水溶液の5mLを凍結乾燥することによってNpsの重量から求めた。導入されたAAc量は酸塩基中和滴定により定量し、滴定曲線から膨潤時と収縮時でのpKaを得た。 Acrylic acid (AAc), N-Isopropyl azine (NIPAm), N, N'-Methylenebis azine (BIS) and sodium dodecyl sulfate (SDS) were dissolved in 300 mL of MiliQ water to bring the total monomer concentration to 312 mM. The composition was NIPAm 93 mol%, BIS 2 mol%, AAc 5 mol%, SDS 6.21 mM, V-501 19.3 mg / 1.96 mL DMSO. The pH before polymerization was adjusted to 3.5 with 1M HCl and 1M NaOH. Followed by the N 2 was bubbled for 30 minutes mixed solution. Polymerization was initiated by dissolving the initiator V-501 in DMSO and adding it to the mixed solution. Polymerization was carried out for 3 hours in an N 2 atmosphere and 70 ° C.. The solution after the reaction was purified by using a dialysis membrane (MWCO 12,000-14,000), exchanging water until the amount of the surfactant became 0.25% or less of the total monomer concentration, and dialyzing. The counter anion was removed with a cation exchange resin (Muromac C1002-H). The cation exchange resin was separated by filtration. The concentration of the Nps aqueous solution was determined from the weight of Nps by freeze-drying 5 mL of the dialyzed aqueous solution. The amount of AAc introduced was quantified by acid-base neutralization titration, and pKa at the time of swelling and contraction was obtained from the titration curve.

なお硫酸化アントラキノンは、1:1の還元体との混合物となるように事前に還元剤(亜ジチオン酸ナトリウム)と混合したものを用いた。 The sulfated anthraquinone used was previously mixed with a reducing agent (sodium dithionite) so as to be a mixture with a 1: 1 reduced product.

水溶液槽11内に温度勾配を生じないように同じ温度(20℃)の水を冷却水循環槽12、高温水循環槽13に流通した場合は、電圧が40mV以下で有り、電流が0.003μA以下であることが確認された。次に冷却水循環槽12に約10℃の水を流通し、高温水循環槽13に約70℃の水を循環したところ水溶液槽11内の低温側の電解質温度が20℃であり高温側の電解質温度が58℃であることを確認した。この状態で白金電極を用いて電位差測定を行ったところ295mVの電位差が観察された。また、電流計測を行ったところ最大0.2μA程度の電流が観察された。この値は徐々に減少したが0.063μAで定常となった。以上の結果から温度応答性電解質と硫酸化アントラキノンを含有する電解液により発電が可能であることが確認された。なお電流値が低下した理由としては整流板の構造により対流が抑制されたためだと考えられた。 When water of the same temperature (20 ° C.) is circulated in the cooling water circulation tank 12 and the high temperature water circulation tank 13 so as not to generate a temperature gradient in the aqueous solution tank 11, the voltage is 40 mV or less and the current is 0.003 μA or less. It was confirmed that there was. Next, when water at about 10 ° C. was circulated in the cooling water circulation tank 12 and water at about 70 ° C. was circulated in the high temperature water circulation tank 13, the electrolyte temperature on the low temperature side in the aqueous solution tank 11 was 20 ° C. and the electrolyte temperature on the high temperature side. Was confirmed to be 58 ° C. When the potential difference was measured using a platinum electrode in this state, a potential difference of 295 mV was observed. Moreover, when the current was measured, a maximum current of about 0.2 μA was observed. This value gradually decreased, but became steady at 0.063 μA. From the above results, it was confirmed that power generation is possible with an electrolytic solution containing a temperature-responsive electrolyte and sulfated anthraquinone. It was considered that the reason why the current value decreased was that the convection was suppressed by the structure of the straightening vane.

<試験2:2槽電位差測定試験1>
本実施形態に係る発電装置100のように、2つの槽を用いる構成で発電が可能であることを確認するため、図3に示す試験器具にて2槽電位差測定試験を行った。
<Test 2: Two-tank potentiometric test 1>
In order to confirm that power generation is possible in a configuration using two tanks as in the power generation device 100 according to the present embodiment, a two-tank potentiometric test was performed with the test instrument shown in FIG.

試験器具は、図3に示すように、低温側槽21、高温側槽22、低温浴23、高温浴24、低温側電極25、高温側電極26、塩橋27を有して構成される。低温側槽21および高温側槽22に、試験用試料が収容される。そして低温側槽21の試験用試料と、高温側槽22の試験用試料とが、塩橋27により電気的に連結される。 As shown in FIG. 3, the test instrument includes a low temperature side tank 21, a high temperature side tank 22, a low temperature bath 23, a high temperature bath 24, a low temperature side electrode 25, a high temperature side electrode 26, and a salt bridge 27. The test sample is housed in the low temperature side tank 21 and the high temperature side tank 22. Then, the test sample of the low temperature side tank 21 and the test sample of the high temperature side tank 22 are electrically connected by the salt bridge 27.

低温側電極25および高温側電極26は、試験用試料に浸漬された状態とされる。低温側電極25および高温側電極26は、ガラス状カーボン電極を用いた。低温側電極25と高温側電極26との間に、電圧計28が接続される。また、塩橋27は、メチレンビスアクリルアミドで架橋したアクリルアミドのハイドロゲル(KCl含有)を用いた。 The low temperature side electrode 25 and the high temperature side electrode 26 are in a state of being immersed in the test sample. As the low temperature side electrode 25 and the high temperature side electrode 26, a glassy carbon electrode was used. A voltmeter 28 is connected between the low temperature side electrode 25 and the high temperature side electrode 26. Further, as the salt bridge 27, an acrylamide hydrogel (containing KCl) crosslinked with methylenebisacrylamide was used.

低温側槽21は、低温浴23の湯水に浸漬された状態とされる。低温浴23には、図示しない低温熱源から温度を制御した湯水が供給される。高温側槽22は、高温浴24の湯水に浸漬された状態とされる。高温浴24には、図示しない高温熱源から温度を制御した湯水が供給される。以上の構成により、低温側槽21の試験用試料が冷却され、高温側槽22の試験用試料が加熱され、低温側槽21の試験用試料と高温側槽22の試験用試料との間に温度差が生じる。 The low temperature side tank 21 is in a state of being immersed in the hot water of the low temperature bath 23. Hot water whose temperature is controlled is supplied to the low temperature bath 23 from a low temperature heat source (not shown). The high temperature side tank 22 is in a state of being immersed in the hot water of the high temperature bath 24. Hot water whose temperature is controlled is supplied to the high temperature bath 24 from a high temperature heat source (not shown). With the above configuration, the test sample in the low temperature side tank 21 is cooled, the test sample in the high temperature side tank 22 is heated, and between the test sample in the low temperature side tank 21 and the test sample in the high temperature side tank 22. There is a temperature difference.

以上のように構成した試験器具にて、低温側槽21の試験用試料と高温側槽22の試験用試料との間に温度差を発生させ、低温側電極25と高温側電極26との間に生じる電圧の大きさを電圧計28で測定した。電圧は、温度差を0℃から50℃まで変化させて測定した。
<試験用試料>
以下の表に示す水溶液を調整して試験用試料とし、上述の試験器具にて試験を行った。

Figure 0006847446
試料は、AQDS(硫酸化アントラキノン)、DITH(亜ジチオン酸ナトリウム)、Nps(試験1と同じナノ微粒子(温度応答性電解質))、水酸化ナトリウムおよび塩化カリウムを表1の比率で混合して作成した。Npsの濃度はカルボン酸当量で示している。 With the test equipment configured as described above, a temperature difference is generated between the test sample in the low temperature side tank 21 and the test sample in the high temperature side tank 22, and the temperature difference is generated between the low temperature side electrode 25 and the high temperature side electrode 26. The magnitude of the voltage generated in the above was measured with a voltmeter 28. The voltage was measured by changing the temperature difference from 0 ° C. to 50 ° C.
<Test sample>
The aqueous solution shown in the table below was prepared as a test sample, and the test was conducted using the above-mentioned test equipment.
Figure 0006847446
The sample was prepared by mixing AQDS (sulfated anthraquinone), DITH (sodium dithionite), Nps (same nanoparticles as in Test 1 (temperature-responsive electrolyte)), sodium hydroxide and potassium chloride in the ratio shown in Table 1. did. The concentration of Nps is indicated by the carboxylic acid equivalent.

試料「Nps Blank」は、酸化還元活性種を含まない、比較用の試料である。試料「AQDS」は、AQDSに対して過量のNps(4倍)を含有する。試料「AQDS half-reduced」は、AQDSの半量を還元する還元剤(DITH)を混合した試料である。試料「AH2DS」は、AQDSの全量を還元する還元剤(DITH)を混合した試料である。 The sample "Nps Blank" is a comparative sample that does not contain redox active species. The sample "AQDS" contains an excessive amount of Nps (4 times) with respect to AQDS. The sample "AQDS half-reduced" is a sample mixed with a reducing agent (DITH) that reduces half of AQDS. The sample "AH2DS" is a sample mixed with a reducing agent (DITH) that reduces the total amount of AQDS.

2槽電位差測定試験1の結果を図4のグラフに示す。4種の試料のいずれも、温度差10℃から20℃で電位差が大きく増加している。この領域は、電解液の温度が30℃〜40℃の領域であり、ナノ微粒子の相転移によりpHが大きく変化する温度域であるから、ナノ微粒子の相転移が電位差に直接的に影響していると考えられる。 The result of the two-tank potentiometric test 1 is shown in the graph of FIG. In all four types of samples, the potential difference is greatly increased when the temperature difference is 10 ° C. to 20 ° C. In this region, the temperature of the electrolytic solution is in the region of 30 ° C. to 40 ° C., and the pH changes significantly due to the phase transition of the nanoparticles. Therefore, the phase transition of the nanoparticles directly affects the potential difference. It is thought that there is.

試料組成の違いによって電位差生成の結果も相応に変化している。試料「Nps Blank」は、温度差の増加に伴って電位差が増加しているが、電位差は最大でも54.95mV(50℃)であった。これに対して、酸化還元活性種であるAQDSを混合した試料は、より大きな電位差を生成した。試料「AQDS half-reduced」は、温度差50℃にて、本試験で最大となる225.41mVの電位差を生成した。試料「AQDS」は温度差50℃にて189.50mV、試料「AH2DS」は温度差50℃にて193.33mVの温度差を生成した。 The result of potential difference generation also changes accordingly due to the difference in sample composition. In the sample "Nps Blank", the potential difference increased as the temperature difference increased, but the potential difference was 54.95 mV (50 ° C.) at the maximum. On the other hand, the sample mixed with the redox active species AQDS produced a larger potential difference. The sample "AQDS half-reduced" generated a potential difference of 225.41 mV, which was the maximum in this test, at a temperature difference of 50 ° C. The sample "AQDS" produced a temperature difference of 189.50 mV at a temperature difference of 50 ° C., and the sample "AH2DS" produced a temperature difference of 193.33 mV at a temperature difference of 50 ° C.

以上の試験により、温度応答性電解質を単独で発電に用いる場合(試料「Nps Blank」)よりも、温度応答性電解質と酸化還元活性種(AQDS)とを併用する場合の方が、大きな電位差を生成できることが確認された。 According to the above test, the potential difference is larger when the temperature-responsive electrolyte and the redox active species (AQDS) are used in combination than when the temperature-responsive electrolyte is used alone for power generation (sample "Nps Blank"). It was confirmed that it can be generated.

<試験3:2槽電位差測定試験2>
本実施形態に係る発電装置100のように、2つの槽を用いる構成で発電が可能であることを確認すると同時に様々な酸化還元活性種を用いることができることを実証するため、様々な試料を用いて試験2と同様の試験を行った。
<Test 3: Two-tank potentiometric test 2>
Various samples are used in order to confirm that power generation is possible in a configuration using two tanks as in the power generation device 100 according to the present embodiment and at the same time to demonstrate that various redox active species can be used. The same test as in Test 2 was performed.

<試験用試料>
以下の表2および表3に示す水溶液を調整して試験用試料とし、他は試験2と同様に試験を行った。

Figure 0006847446
※1:試料「NA(half)」は、酸化型ニコチンアミドと還元型ニコチンアミドとをモル比1:1で混合し、総量を1.0mmol/Lとした。 <Test sample>
The aqueous solutions shown in Tables 2 and 3 below were prepared as test samples, and the others were tested in the same manner as in Test 2.
Figure 0006847446
* 1: In the sample "NA (half)", oxidized nicotinamide and reduced nicotinamide were mixed at a molar ratio of 1: 1 to give a total amount of 1.0 mmol / L.

Figure 0006847446
Figure 0006847446

表2の試料の結果を図5のグラフに示す。表3の試料の結果を図6のグラフに示す。何れの試料も、酸化還元活性種を含まない資料「Nps Blank」よりも大きな電位差を生成した。50℃の温度差による最大電位差は、試料「NA(half)」(酸化型ニコチンアミドと還元型ニコチンアミド(モル比1:1)および四等量のNpsの混合溶液)を用いて得られた254mVであった。試料「NA(half)」は、酸化還元活性種の混合により、試料「Nps Blank」(54.95mV)に比べ約4.6倍もの電位差を生成した。 The results of the samples in Table 2 are shown in the graph of FIG. The results of the samples in Table 3 are shown in the graph of FIG. All samples produced a larger potential difference than the data "Nps Blank" which did not contain redox active species. The maximum potential difference due to a temperature difference of 50 ° C. was obtained using a sample "NA (half)" (a mixed solution of oxidized nicotinamide and reduced nicotinamide (molar ratio 1: 1) and four equivalents of Nps). It was 254 mV. The sample "NA (half)" produced a potential difference of about 4.6 times that of the sample "Nps Blank" (54.95 mV) by mixing redox active species.

以上の試験により、温度応答性電解質であるNpsと、AQDS(硫酸化アントラキノン)、NA(ニコチンアミド)、MB(メチレンブルー)、TMPD(N,N,N’,N’−テトラメチル−p−フェニレンジアミン)、PPH(プロフラビンヘミ硫酸塩水和物)またはRiboflavin(リボフラビン)とを併用することにより、温度応答性電解質を単独で発電に用いる場合(試料「Nps Blank」)よりも大きな電位差を生成できることが確認された。 Based on the above tests, Nps, which is a temperature-responsive electrolyte, and AQDS (sulfated anthraquinone), NA (nicotinamide), MB (methylene blue), TMPD (N, N, N', N'-tetramethyl-p-phenylene) By using diamine), PPH (proflavine hemisulfate hydrate) or Riboflavin (riboflavin) in combination, a larger potential difference can be generated than when the temperature-responsive electrolyte is used alone for power generation (sample "Nps Blank"). Was confirmed.

(他の実施形態)
(1)上述の実施形態では、温度に応じてpH変化を生じさせる温度応答性電解質と、酸化還元活性種とを、電解液に含有させる場合について説明した。温度応答性電解質に替えて、その他の刺激、例えば光によりpH変化を生じさせる物質を用いて、電解液および発電装置を構成することも可能である。
(Other embodiments)
(1) In the above-described embodiment, a case where a temperature-responsive electrolyte that causes a pH change depending on the temperature and a redox-active species are contained in the electrolytic solution has been described. Instead of the temperature responsive electrolyte, other stimuli, such as substances that cause a pH change due to light, can be used to construct the electrolyte and the power generator.

光によりpH変化を生じさせる物質としては、例えばメタクリル酸共重合体とアゾ色素の複合溶液などがあり、文献「高分子カルボン酸−アゾ色素コンプレックス系の光による可逆的pH変化」(高分子論文集、Vol.37, No.4, pp.293-298(Apr.,1980))にて報告されている。また、文献「A photoinduced pH jump applied to drug release from cucurbit[7]uril」(Chem. Commun., 2011, 47,8793-8795)でも、光照射でpH変化するホスト−ゲスト分子が示されている。また、スピロピラン誘導体およびスピロピラン誘導体を含有した高分子微粒子を用いてもpH変化を生じる事が報告されている(J. Am. Chem. Soc., 2011, 133 (37), pp 14699-14703)。このような光応答性物質と酸化還元活性種を含有する水溶液を用いて、発電装置を構成することが可能である。 Examples of substances that cause a pH change due to light include a composite solution of a methacrylic acid copolymer and an azo dye, and the literature "Reversible pH change due to light of a polymer carboxylic acid-azo dye complex system" (Polymer paper) It is reported in Shu, Vol.37, No.4, pp.293-298 (Apr., 1980)). In addition, the document "A photoinduced pH jump applied to drug release from cucurbit [7] uril" (Chem. Commun., 2011, 47,8793-8795) also shows host-guest molecules whose pH changes with light irradiation. .. It has also been reported that pH changes occur even when polymer fine particles containing a spiropirane derivative and a spiropirane derivative are used (J. Am. Chem. Soc., 2011, 133 (37), pp 14699-14703). It is possible to construct a power generation device by using an aqueous solution containing such a photoresponsive substance and a redox active species.

(2)上述の実施形態では、冷却機構5および加熱機構6の具体例として熱交換器を挙げ、海水や高温水と電解液Sとを熱交換させて電解液Sを加熱・冷却する形態を説明した。冷却機構5および加熱機構6としては、正極槽1および負極槽2の電解液Sの加熱・冷却が可能であればよい。正極槽1および負極槽2の壁面を加熱・冷却する形態も可能であるし、電極(正極3または負極4)を加熱・冷却して電解液Sの加熱・冷却を行う形態も可能である。 (2) In the above-described embodiment, a heat exchanger is given as a specific example of the cooling mechanism 5 and the heating mechanism 6, and a mode in which the electrolytic solution S is heated and cooled by heat exchange between seawater or high-temperature water and the electrolytic solution S is used. explained. As the cooling mechanism 5 and the heating mechanism 6, it is sufficient that the electrolytic solution S in the positive electrode tank 1 and the negative electrode tank 2 can be heated and cooled. The wall surfaces of the positive electrode tank 1 and the negative electrode tank 2 can be heated and cooled, or the electrodes (positive electrode 3 or negative electrode 4) can be heated and cooled to heat and cool the electrolytic solution S.

なお上述の実施形態(他の実施形態を含む、以下同じ)で開示される構成は、矛盾が生じない限り、他の実施形態で開示される構成と組み合わせて適用することが可能であり、また、本明細書において開示された実施形態は例示であって、本発明の実施形態はこれに限定されず、本発明の目的を逸脱しない範囲内で適宜改変することが可能である。 The configurations disclosed in the above-described embodiments (including other embodiments, the same shall apply hereinafter) can be applied in combination with the configurations disclosed in the other embodiments as long as there is no contradiction. , The embodiments disclosed in the present specification are examples, and the embodiments of the present invention are not limited thereto, and can be appropriately modified without departing from the object of the present invention.

100 :発電装置
1 :正極槽
2 :負極槽
3 :正極
4 :負極
5 :冷却機構
6 :加熱機構
7 :循環機構
7a :第1流路
7b :第1ポンプ
7c :第2流路
7d :第2ポンプ
8 :熱交換機構
11 :水溶液槽
12 :冷却水循環槽
13 :高温水循環槽
14 :低温側電極
15 :高温側電極
16 :低温熱源
17 :高温熱源
18 :電流電圧計
19 :整流板
20 :伝熱板
21 :低温側槽
22 :高温側槽
23 :低温浴
24 :高温浴
25 :低温側電極
26 :高温側電極
27 :塩橋
28 :電圧計
S :電解液
100: Power generation device 1: Positive electrode tank 2: Negative electrode tank 3: Positive electrode 4: Negative electrode 5: Cooling mechanism 6: Heating mechanism 7: Circulation mechanism 7a: First flow path 7b: First pump 7c: Second flow path 7d: First 2 pump 8: heat exchange mechanism 11: aqueous solution tank 12: cooling water circulation tank 13: high temperature water circulation tank 14: low temperature side electrode 15: high temperature side electrode 16: low temperature heat source 17: high temperature heat source 18: current voltmeter 19: rectifying plate 20: Heat transfer plate 21: Low temperature side tank 22: High temperature side tank
23: Low temperature bath 24: High temperature bath
25: Low temperature side electrode 26: High temperature side electrode
27: Shiohashi 28: Voltmeter S: Electrolyte

Claims (13)

温度に応じてpKaが変化する電解質である温度応答性電解質と、酸化還元活性種(ヒドロキノン誘導体を除く)とを含有する電解液。 An electrolytic solution containing a temperature-responsive electrolyte, which is an electrolyte whose pKa changes with temperature, and redox-active species (excluding hydroquinone derivatives). 温度に応じてpKaが変化する電解質である温度応答性電解質と、酸化還元活性種であるN,N,N’,N’−テトラメチル−p−フェニレンジアミンあるいはその誘導体とを含有する電解液。 An electrolytic solution containing a temperature-responsive electrolyte, which is an electrolyte whose pKa changes with temperature, and N, N, N', N'-tetramethyl-p-phenylenediamine or a derivative thereof, which are redox active species. 温度に応じてpKaが変化する電解質である温度応答性電解質と、酸化還元活性種であるニコチンアミドあるいはその誘導体とを含有する電解液。 An electrolytic solution containing a temperature-responsive electrolyte, which is an electrolyte whose pKa changes with temperature, and nicotinamide, which is a redox active species, or a derivative thereof. 温度に応じてpKaが変化する電解質である温度応答性電解質と、酸化還元活性種であるプロフラビンヘミ硫酸塩水和物あるいはその誘導体とを含有する電解液。 An electrolytic solution containing a temperature-responsive electrolyte, which is an electrolyte whose pKa changes with temperature, and proflavine hemisulfate hydrate, which is a redox active species, or a derivative thereof. 温度に応じてpKaが変化する電解質である温度応答性電解質と、酸化還元活性種であるリボフラビンあるいはその誘導体とを含有する電解液。 An electrolytic solution containing a temperature-responsive electrolyte, which is an electrolyte whose pKa changes with temperature, and riboflavin, which is a redox active species, or a derivative thereof. 温度に応じてpKaが変化する電解質である温度応答性電解質と、酸化還元活性種である硫酸化アントラキノンあるいはその誘導体とを含有する電解液。 An electrolytic solution containing a temperature-responsive electrolyte, which is an electrolyte whose pKa changes with temperature, and sulfated anthraquinone, which is a redox active species, or a derivative thereof. 温度に応じてpKaが変化する電解質である温度応答性電解質と、酸化還元活性種であるナフトキノンあるいはその誘導体とを含有する電解液。 An electrolytic solution containing a temperature-responsive electrolyte, which is an electrolyte whose pKa changes with temperature, and naphthoquinone, which is a redox active species, or a derivative thereof. 温度に応じてpKaが変化する電解質である温度応答性電解質と、酸化還元活性種であるメチレンブルーあるいはその誘導体とを含有する電解液。 An electrolytic solution containing a temperature-responsive electrolyte, which is an electrolyte whose pKa changes with temperature, and methylene blue, which is a redox active species, or a derivative thereof. 前記温度応答性電解質は、極性基と、疎水性基と、イオン化可能な官能基とを有する分子である請求項1から8のいずれか1項に記載の電解液。 The electrolytic solution according to any one of claims 1 to 8, wherein the temperature-responsive electrolyte is a molecule having a polar group, a hydrophobic group, and an ionizable functional group. 請求項1から9のいずれか1項に記載の電解液を用いて発電を行う発電装置であって、
正極と負極と加熱機構と冷却機構とを有し、前記正極および前記負極は前記電解液に浸漬され、
前記加熱機構は、前記正極と前記負極のうち一方の近傍の前記電解液を加熱し、
前記冷却機構は、前記正極と前記負極のうち他方の近傍の前記電解液を冷却する、発電装置。
A power generation device that generates power using the electrolytic solution according to any one of claims 1 to 9.
It has a positive electrode, a negative electrode, a heating mechanism, and a cooling mechanism, and the positive electrode and the negative electrode are immersed in the electrolytic solution.
The heating mechanism heats the electrolytic solution in the vicinity of one of the positive electrode and the negative electrode.
The cooling mechanism is a power generation device that cools the electrolytic solution in the vicinity of the other of the positive electrode and the negative electrode.
前記加熱機構は、前記温度応答性電解質の相転移温度より高い温度に前記電解液を加熱し、
前記冷却機構は、前記温度応答性電解質の相転移温度より低い温度に前記電解液を冷却する請求項10に記載の発電装置。
The heating mechanism heats the electrolytic solution to a temperature higher than the phase transition temperature of the temperature-responsive electrolyte.
The power generation device according to claim 10, wherein the cooling mechanism cools the electrolytic solution to a temperature lower than the phase transition temperature of the temperature-responsive electrolyte.
正極槽と負極槽と循環機構とを有し、前記電解液が前記正極槽および前記負極槽に収容され、前記正極が前記正極槽の前記電解液に接触し、前記負極が前記負極槽の前記電解液に接触し、前記加熱機構が前記正極槽と前記負極槽のうち一方の前記電解液を加熱し、前記冷却機構が前記正極槽と前記負極槽のうち他方の前記電解液を冷却し、前記循環機構が前記正極槽と前記負極槽との間で前記電解液を循環させる請求項10または11に記載の発電装置。 It has a positive electrode tank, a negative electrode tank, and a circulation mechanism, and the electrolytic solution is housed in the positive electrode tank and the negative electrode tank, the positive electrode comes into contact with the electrolytic solution in the positive electrode tank, and the negative electrode is the negative electrode tank. Upon contact with the electrolytic solution, the heating mechanism heats the electrolytic solution of one of the positive electrode tank and the negative electrode tank, and the cooling mechanism cools the electrolytic solution of the other of the positive electrode tank and the negative electrode tank. The power generation device according to claim 10 or 11, wherein the circulation mechanism circulates the electrolytic solution between the positive electrode tank and the negative electrode tank. 熱交換機構を有し、前記熱交換機構は、前記循環機構が前記正極槽に送る前記電解液と、前記循環機構が前記負極槽に送る前記電解液との間で熱交換を行う請求項12に記載の発電装置。 12. The heat exchange mechanism has a heat exchange mechanism, and the heat exchange mechanism exchanges heat between the electrolytic solution sent by the circulation mechanism to the positive electrode tank and the electrolytic solution sent by the circulation mechanism to the negative electrode tank. The power generation device described in.
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