CN101225181A - Y2O3 modified sulfonated polyetheretherketone proton exchange membrane and preparation method thereof - Google Patents

Abstract

The invention relates to an yttrium oxide (Y2O3)-modified sulfonated polyether ether ketone (SPEEK) proton exchange membrane and a preparation method. The proton exchange membrane comprises the following components in weight percentage: the SPEEK with sulfonation degrees between 30 and 95: 88.5to 99.9 percents, and the Y2O3 powders 0.1 to 10 percents. The preparation method comprises steps as follows: by adopting the SPEEK as the matrix and rare-earth metal oxide Y2O3 as the fillers, membrane casting solution uniformly stirred is prepared; flow-casting and membranes forming through pressing are then carried out; eventually inorganic-organic composite membranes are prepared through drying. The preparation method for the yttrium oxide (Y2O3)-modified sulfonated polyether ether ketone (SPEEK) proton exchange membrane has the advantages of low cost, high conductivity and excellent alcohol-rejecting ability in preparing the SPEEK/ Y2O3 proton exchange membranes. In addition, under the temperature from 20 to 100 centigrade, the conductivity ranges between 0.01 and 0.25 S/cm, the alcohol-rejecting coefficient reaches to an amount between 1.0 x 10<-2> and 1.0 x 10<-7> cm<2>/s, and the water absorption ranges between 5 and 150 percents.

Description

Y 2O 3Modification sulphonation polyetheretherketoneproton proton exchange film and preparation method thereof

Technical field

The present invention relates to a kind of direct methanol fuel cell sulfonated poly-ether-ether-ketone (SPEEK) proton exchange membrane (PEM) and preparation method thereof, particularly a kind of Y ₂O ₃Modification sulphonation polyetheretherketoneproton proton exchange film and preparation method thereof.

Background technology

Proton exchange membrane (PEM) is as the core of the focus direct methanol fuel cell (DMFC) of energy field research and development at present, and its material must have good proton conductive, and room-temperature conductivity should reach 10 at least ^-2Scm ^-1Methanol permeability is low, otherwise influences battery efficiency, work-ing life and cause wastage of material; Also to have sufficiently high stability of solution and chemical stability simultaneously, proton exchange membrane is had than the long life in DMFC.

Use the proton exchange membrane of perfluorinated ion polymer (PFI) as DMFC at present, this membrance chemistry stability is better, and its proton conductivity is stronger, but manufacturing cost height, high-temperature behavior is not good enough simultaneously, and especially the alcohol-rejecting ability deficiency of film has limited its application in DMFC.Therefore, the PEM of several no fluorine type polymers receives publicity in recent years, and wherein sulfonated polyether-ether-ketone (SPEEK) film is all comparatively outstanding at aspects such as chemical stability, hot properties, alcohol-rejecting abilities.The sulfonation degree of SPEEK film (DS) high-conductivity more is good more, but its alcohol-rejecting ability and stability of solution but decrease.For solving this contradiction, numerous investigators inorganic organic hybrid films of preparation such as heteropolyacid, phosphoric acid salt that in the SPEEK film, mix, this class modification improves the conductivity of PEM, but alcohol-rejecting ability decreases.Therefore press for and develop that a kind of cost is low, specific conductivity is high, the novel proton exchange membranes of features good methanol diffusion resistance.

Summary of the invention

One of purpose of the present invention is to provide a kind of Y ₂O ₃Modification sulphonation polyetheretherketoneproton proton exchange film.

Two of purpose of the present invention is to provide the preparation method of this proton exchange membrane.

For achieving the above object, the present invention adopts following technical scheme:

A kind of Y ₂O ₃Modification sulphonation polyetheretherketoneproton proton exchange film is characterized in that the composition and the mass percent thereof of this exchange membrane:

Sulfonation degree DS is 30～95 sulfonated polyether-ether-ketone SPEEK:88.5%～99.9%;

Y ₂O ₃Powder: 0.1%～10%.

Above-mentioned Y ₂O ₃The powder particle particle diameter is 1～1.5 micron.

Above-mentioned Y ₂O ₃The powder surface modification, its surface modification method is: with sulfonation degree DS greater than 85 SPEEK and Y ₂O ₃The ratio that powder in mass ratio is is dissolved in water or the ethanolic soln, stir 1～15h after, sedimentation and filtration places 90～150 ℃ of down dry 5～15h with throw out, obtains the Y after the finishing ₂O ₃Powder.

Above-mentioned Y ₂O ₃The preparation method of modification sulphonation polyetheretherketoneproton proton exchange film is characterized in that the concrete steps of this method are:

A. be that 30～95 sulfonated polyether-ether-ketone is dissolved in the system membrane solvent with DS, be mixed with mass percent concentration and be 5%～40% preparation liquid;

B. in the preparation liquid of above-mentioned steps a gained, add Y ₂O ₃Powder, its consumption are 0.1%～10% of SPEEK quality; Under 20 ℃～80 ℃, stir and make Y ₂O ₃Powder is uniformly dispersed in preparation liquid, obtains mixing preparation liquid;

C. with step b gained mixing preparation liquid curtain coating or compacting film forming, at 10 ℃～80 ℃ following solvent flashings, obtain wet film then;

D. with step c gained wet film at 30 ℃～170 ℃ following freeze-day with constant temperature 0.5h～72h; Perhaps the dry 4h～72h under 30 ℃～100 ℃ of elder generation is warming up to 100 ℃～170 ℃ dry 0.5h～6h again, obtains Y ₂O ₃Modification SPEEK proton exchange membrane.

Above-mentioned system membrane solvent is: N, dinethylformamide DMF, N,N-dimethylacetamide DMAc or dimethyl sulfoxide (DMSO) DMSo.。

The inventive method preparation cost is low, prepared proton exchange membrane conductivity height, features good methanol diffusion resistance, and the specific conductivity under 20 ℃～100 ℃ is 1.00 * 10 ^-2～2.50 * 10 ^-1Scm ^-1Hinder pure coefficient and reach 1.00 * 10 ^-7～6.50 * 10 ^-7Cm ²s ^-1Water-intake rate is 5%～150%.

Embodiment

Embodiment one: present embodiment is used is the Y of surface modification not ₂O ₃Powder.

The technological process and the step of present embodiment are as follows:

1.SPEEK the preparation of preparation liquid: adopt DMAc as the system membrane solvent, with the DS that grinds be 48.3 SPEEK material dissolves in the system membrane solvent, be mixed with the SPEEK mass percent at 10% preparation liquid.

2.SPEEK/Y ₂O ₃The preparation of preparation liquid: in the SPEEK of step 1 gained preparation liquid, be that 8% dosage adds the not Y of surface modification by mass percentage ₂O ₃Powder, Y ₂O ₃The powder particle particle diameter is 1～1.5 micron.Use magnetic stirrer 4h down for 25 ℃, 75 ℃ are stirred 6h down, make Y ₂O ₃Powder is uniformly dispersed in preparation liquid, obtains SPEEK/Y ₂O ₃Preparation liquid.

3.SPEEK/Y ₂O ₃The preparation of proton exchange membrane:, pour casting film-forming in the clean flat plate mold into the mixing preparation liquid of step 2 gained.Mixing preparation liquid in the mould obtains SPEEK/Y at 25 ℃ of following solvent flashings ₂O ₃Wet film.Wet film is dry 48h under 60 ℃ earlier, is warming up to 120 ℃ of dry 4h again, obtains SPEEK/Y ₂O ₃Dry film.

To the prepared SPEEK/Y of the foregoing description ₂O ₃The proton exchange membrane application experiment, its process and result are as described below:

(1) SPEEK/Y ₂O ₃The test of proton exchange membrane conductivity:

On the basis of the two electrode methods of interchange, improve, design and set up a cover Simple and Reliable membrane resistance test set voluntarily.Detected temperatures is 30 ℃～90 ℃.SPEEK/Y ₂O ₃Specific conductivity during 30 ℃ of films is 1.53 * 10 ^-2S.cm ^-1, 70 ℃ reach maximum value 3.74 * 10 ^-2S.cm ^-1

(2) SPEEK/Y ₂O ₃The test of proton exchange membrane alcohol-rejecting ability:

Adopt the alcohol-rejecting ability of barrier film diffusion cell evaluated for film.Before the test film sample was soaked in deionized water one day, and under probe temperature, test after more than the stable 1h.Film is sandwiched in the middle of the two halves chamber, injects the 5mol/L methanol solution of 70ml in a side, the pure water that opposite side injects suitable volume makes its liquid level equal with the liquid level of methyl alcohol.Adopt in the gas chromatographic measurement pure water methanol concentration situation over time.Decide rate by Fick diffusion second and can get methanol permeability:

p＝(sV ₂l)/(AC ₁₀)

S ... methanol concentration is the slope of change curve in time

V ₂The volume of pure water

L ... wet-film thickness

A ... membrane area

C ₁₀The methanol solution initial concentration

By test, under reaction conditions as mentioned above, SPEEK/Y ₂O ₃The resistance alcohol coefficient of film is 3.09 * 10 ^-7Cm ²s ^-1

(3) SPEEK/Y ₂O ₃The test of proton exchange membrane water-intake rate:

Earlier with the SPEEK film in 90 ℃ of dry 24h down, claim dry film weight (M _d).Then film is immersed in the deionized water, soaking at room temperature 48h makes its abundant swelling.Take out wet film, inhale and remove surperficial moisture content, claim to such an extent that wet film weighs (Mw).The water-intake rate of film is:

By test, under reaction conditions as mentioned above, SPEEK/Y ₂O ₃The water-intake rate of film is 11.8%.

Embodiment two: that present embodiment is used is the Y of surface modification ₂O ₃Powder, its concrete modifying method is:

Adding DS is 90 SPEEK in deionized water, and the SPEEK aqueous solution is prepared in dissolving, with Y ₂O ₃Powder is put into and is wherein constantly stirred the 6h postprecipitation and filter, and throw out is placed 120 ℃ of dry 6h down, obtains the Y after the finishing ₂O ₃Powder.

The technological process and the step of present embodiment are as follows:

1.SPEEK the preparation of preparation liquid: adopt DMAc as the system membrane solvent, with the DS that grinds be 82.6 SPEEK material dissolves in the system membrane solvent, be mixed with the SPEEK mass percent at 10% preparation liquid.

2.SPEEK/Y ₂O ₃The preparation of preparation liquid: in the SPEEK of step 1 gained preparation liquid, be the Y that 5% dosage adds surface modification by mass percentage ₂O ₃Powder, Y ₂O ₃The powder particle particle diameter is 1～1.5 micron.Use magnetic stirrer 4h down for 25 ℃, 75 ℃ are stirred 6h down, make Y ₂O ₃Powder is uniformly dispersed in preparation liquid, obtains SPEEK/Y ₂O ₃Preparation liquid.

3.SPEEK/Y ₂O ₃The preparation of proton exchange membrane:, pour casting film-forming in the clean flat plate mold into the mixing preparation liquid of step 2 gained.Mixing preparation liquid in the mould obtains SPEEK/Y at 25 ℃ of following solvent flashings ₂O ₃Wet film.Wet film is dry 48h under 60 ℃ earlier, is warming up to 120 ℃ of dry 4h again, obtains SPEEK/Y ₂O ₃Dry film.

To the prepared SPEEK/Y of the foregoing description ₂O ₃The proton exchange membrane application experiment, its process and result are as described below:

(1) SPEEK/Y ₂O ₃The test of proton exchange membrane conductivity:

Testing method is as described in the example 1.SPEEK/Y ₂O ₃Specific conductivity during 30 ℃ of films is 5.68 * 10 ^-2Scm ^-1, 70 ℃ reach maximum value 9.45 * 10 ^-2Scm ^-1

(2) SPEEK/Y ₂O ₃The test of proton exchange membrane alcohol-rejecting ability:

Testing method is as described in the example 1.SPEEK/Y ₂O ₃The resistance alcohol coefficient of film is 6.86 * 10 ^-7Cm ²s ^-1

(3) SPEEK/Y ₂O ₃The test of proton exchange membrane water-intake rate:

Testing method is as described in the example 1.SPEEK/Y ₂O ₃The water-intake rate of film is 37%.

Claims (5)

1. Y ₂O ₃Modification sulphonation polyetheretherketoneproton proton exchange film is characterized in that the composition and the mass percent thereof of this exchange membrane:

Sulfonation degree DS is 30～95 sulfonated polyether-ether-ketone SPEEK:88.5%～99.9%;

Y ₂O ₃Powder: 0.1%～10%.

2. Y according to claim 1 ₂O ₃Modification sulphonation polyetheretherketoneproton proton exchange film is characterized in that described Y ₂O ₃The powder particle particle diameter is 1～1.5 micron.

3. Y according to claim 1 and 2 ₂O ₃Modification sulphonation polyetheretherketoneproton proton exchange film is characterized in that described Y ₂O ₃The powder surface modification, its surface modification method is: with sulfonation degree DS greater than 85 SPEEK and Y ₂O ₃The ratio that powder in mass ratio is is dissolved in water or the ethanolic soln, stir 1～15h after, sedimentation and filtration places 90～150 ℃ of down dry 5～15h with throw out, obtains the Y after the finishing ₂O ₃Powder.

4. Y according to claim 1 ₂O ₃The preparation method of modification sulphonation polyetheretherketoneproton proton exchange film is characterized in that the concrete steps of this method are:

A. be that 30～95 sulfonated polyether-ether-ketone is dissolved in the system membrane solvent with sulfonation degree, be mixed with mass percent concentration and be 5%～40% preparation liquid;

B. in the preparation liquid of above-mentioned steps a gained, add Y ₂O ₃Powder, its consumption are 0.1%～10% of sulfonated polyether-ether-ketone quality; Under 20 ℃～80 ℃, stir and make Y ₂O ₃Powder is uniformly dispersed in preparation liquid, obtains mixing preparation liquid;

C. with step b gained mixing preparation liquid curtain coating or compacting film forming, at 10 ℃～80 ℃ following solvent flashings, obtain wet film then;

D. with step c gained wet film at 30 ℃～170 ℃ following freeze-day with constant temperature 0.5h～72h; Perhaps the dry 4h～72h under 30 ℃～100 ℃ of elder generation is warming up to 100 ℃～170 ℃ dry 0.5h～6h again, obtains Y ₂O ₃Modification SPEEK proton exchange membrane.

5. Y according to claim 4 ₂O ₃The preparation method of modification sulphonation polyetheretherketoneproton proton exchange film is characterized in that used system membrane solvent is: N, dinethylformamide DMF, N,N-dimethylacetamide DMAc or dimethyl sulfoxide (DMSO) DMSo.