CN102793947A - Degradable magnesium and surface modification method of alloy thereof - Google Patents
Degradable magnesium and surface modification method of alloy thereof Download PDFInfo
- Publication number
- CN102793947A CN102793947A CN2012103100036A CN201210310003A CN102793947A CN 102793947 A CN102793947 A CN 102793947A CN 2012103100036 A CN2012103100036 A CN 2012103100036A CN 201210310003 A CN201210310003 A CN 201210310003A CN 102793947 A CN102793947 A CN 102793947A
- Authority
- CN
- China
- Prior art keywords
- magnesium
- alloy
- coating
- sample
- degradable
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Abstract
The invention relates to degradable magnesium and a surface modification method of alloy thereof, which are characterized in that the surface modification method comprises the following steps: polishing the magnesium and an alloy sample of the magnesium to remove foreign substances on the surface, cleaning acetone, and cleaning and blowing-drying anhydrous ethanol and distilled water; dipping the processed sample into solution containing sodium hydroxide and/or potassium hydroxide and sodium carbonate, cleaning with the distilled water, blowing-drying for standby or re-heating and cooling in air for standby; and dipping the processed sample into chloroformic solution containing polylactic acid or polycaprolactone, coating the processed sample by adopting a dip-coating, spraying or spin-coating method, and heating, drying and removing chloroform to obtain a degradable polymer coating. The surface protection coating prepared by the method has the characteristics of zero toxicity, degradability, good biocompatibility and the like, and the initial corrosion rate of a magnesium alloy matrix can be relieved. The invention provides a new concept for the surface modification of the degradable magnesium alloy.
Description
Technical field
The present invention relates to a kind of metallic surface method of modifying, the surface modifying method of particularly a kind of magnesium and alloy thereof.
Background technology
The magnesium metal just has the clinical practice report as medical material as far back as 19 end of the centurys.Magnesium and alloy thereof have lower electrode potential, be prone to corrode/degrade in the internal milieu that contains chloride ion, and can be with the mode degraded fully in vivo of slow degraded, its catabolite is to organism nonhazardous effect simultaneously.Because magnesium and alloy thereof have These characteristics, the degradable embedded material is used it in people's expectation.
Yet, because that magnesium and alloy thereof corrode in the Human Physiology environment is too fast, particularly at the implantation initial stage; Fast corrosion rate cause the magnesium implant surfaces and around pH too high; Thereby cause magnesium implant surfaces biocompatibility poor, and the reaction that causes inflammation around, thereby wound healing hindered.Simultaneously, because corrosion rate is too fast, the hydrogen of generation can not in time be absorbed by body, thereby forms bubble coalescence in tissue, and this also is unfavorable for treatment.Therefore, the corrosion rate of selecting appropriate method to slow down magnesium and alloy thereof is particularly implanted the corrosion rate at initial stage, is that promotion medical degradable magnesium and alloy thereof are applied to clinical necessary ways early.
Surface modification is to improve the effective ways of magnesium and alloy corrosion resistance ability thereof.Relevant process for treating surface has a lot, like the chemical conversion process and anodic oxidation, differential arc oxidation, the plating nickel on surface that are treated to representative with chromate, stannate and cobaltatess, aluminize or surface modifying methods such as titanizing and organic coating.Yet there is the potential hazard to health in the section processes method, like chromate treating, plating nickel on surface or aluminum; The processing method that has can not satisfy degradable requirement, all is difficult in the human body environment, degrade like ceramic layer, titanium layer and most of organic coating of anodic oxidation or differential arc oxidation preparation.
CN200710157568.4 discloses a kind of method for preparing of magnesium alloy hydroxylapatite/polylactic acid composite biological coating.This invention organically combines the biological activity of hydroxyapatite and the biodegradability of polylactic acid, is used for the corrosion protection of magnesium alloy at biotic environment.Yet, can discharge calcium ion in the hydroxyapatite degradation process, calcium ion has the effect of blood coagulation, therefore should not contact for a long time with blood.In addition, often adhesion is relatively poor for the organic coating that directly prepares at Mg alloy surface.Owing to be that magnesium and alloy thereof are used as the degradable embedded material, thereby to develop nontoxic and have excellent biological compatibility, can in the human body environment, degrade, and the surface protecting layer of certain bond strength arranged with magnesium and alloy thereof.
Summary of the invention
Characteristics such as that the surface modifying method that the purpose of this invention is to provide a kind of degradable magnesium and alloy thereof, the surface protecting layer of this method preparation have is nontoxic, degradable, excellent biological compatibility, and the initial stage corrosion rate that can slow down magnesium alloy substrate.
The surface modifying method of magnesium of the present invention and alloy thereof is following:
1. polishing magnesium and alloy sample thereof removed Superficial Foreign Body, and ultrasonic cleaning 5～15 minutes in acetone then is more respectively with dehydrated alcohol and distilled water cleaning and dry up;
2. the sample after the above-mentioned processing is immersed and contain in the solution of sodium hydroxide and/or potassium hydroxide and sodium carbonate; Wherein sodium hydroxide is or/and the mass concentration of potassium hydroxide is 20～80g/L; The mass concentration of sodium carbonate is 5～15g/L, is heated to 40～90 ℃, 2～20 hours time; Take out sample and clean, dry up subsequent use with distilled water; Or heated 2～12 hours down at 60～140 ℃ again, the cooling back is subsequent use in the air;
3. the sample after the polylactic acid (PLLA) of the sample immersion 3～10% after step 2 being handled or the chloroformic solution of polycaprolactone (PCL) are handled with the method coating step 2 of dip-coating, spraying or spin coating, heat drying is removed chloroform, obtains the degradable polymer coating.The method of molecular weight, solution concentration and spraying or spin coating that can be through the adjustment polymer obtains the degradable polymer coating of different-thickness.
Described degradable polymer for obtained at present FDA or SFDA authentication can clinical use the degradable polymer material with good biocompatibility, include but not limited to polylactic acid or polycaprolactone.
After above-mentioned steps 2 is handled, form transition zone on the surface of magnesium and alloy thereof, its phase composition is a magnesium hydroxide, sees Fig. 1; Be microcosmic porous pattern, see Fig. 2.On the one hand, adhesion is preferably arranged between magnesium hydroxide itself and polymer, simultaneously microcosmic porous pattern can further improve the bond strength of itself and polymer coating; On the other hand, research shows that magnesium hydroxide can slow down the initial stage corrosion rate of magnesium and alloy thereof to a certain extent.Therefore, the magnesium hydroxide transition zone can play and improve the effect that slows down magnesium and alloy substrate initial stage corrosion rate and raising and polymer coating bond strength.The more important thing is that the catabolite of magnesium hydroxide is harmless to body fluid or blood.
Degradable polymer coating on the transition zone can further be slowed down the corrosion rate of magnesium and alloy substrate thereof; And can obtain the degradable polymer coating of variety classes, thickness, thereby realize the purpose of control magnesium and alloy substrate corrosion rate thereof through kind, molecular weight, the method for preparing of adjustment degradable polymer.In addition, also can in the process of preparation degradable polymer coating, be written into medicine, promptly prepare medicine carrying degradable polymer coating according to actual user demand.Optional medicine comprises antithrombotic reagent, anti-inflammatory medicaments, anti-proliferative drugs etc.
Characteristics of the present invention are:
1. the present invention is directed to the too fast deficiency of initial stage corrosion rate that degradable magnesium and alloy thereof exist; In conjunction with its handling characteristics, a kind of method for preparing that reduces magnesium alloy initial stage corrosion rate and have the coating of good biocompatibility has been proposed as medical embedded material.Adopt two-step method to carry out surface modification treatment; Reach the purpose of slowing down magnesium alloy initial stage corrosion rate through transition zone and degradable polymer coating; Simultaneously because the microcosmic porous pattern of transition zone and the characteristic of itself, can play the effect that improves itself and degradable polymer coating adhesion.
2. the present invention provides new thinking for the surface modification of medical degradable magnesium alloy.Described transition zone and degradable polymer coating not only can play slows down magnesium and the corrosive effect of alloy substrate thereof, also possesses the performance of degraded in vivo simultaneously.The application original intention of this and medical degradable magnesium alloy is consistent.
3. the present invention can reduce the initial stage corrosion rate of magnesium alloy, and coating has excellent biological compatibility, can prepare drug-carried coat according to actual needs simultaneously, thereby makes magnesium alloy after the modification more can satisfy the needs of actual therapeutic.
Description of drawings
Fig. 1 is the X-ray diffractogram of the transition zone of magnesium and alloy surface formation thereof;
Fig. 2 is the microcosmic porous pattern of the transition zone of magnesium and alloy surface formation thereof.
The specific embodiment
Embodiment 1
Sample is 99.95% magnesium metal.After sample ground with sand paper, ultrasonic cleaning 5 minutes in acetone and dehydrated alcohol respectively was with the distilled water cleaning and dry up; To contain Na0H40g/L and Na
2CO
3The solution of 6g/L is heated to 80 ℃, puts into sample and soaks 6 hours, and the taking-up back is cleaned with distilled water and dried up subsequent use; The mean molecule quantity that sample after alkali liquor handled immerses mass concentration 8g/L is 50,000 polylactic acid chloroformic solutions, slowly lifts out solution after 3 minutes, so repeat 3 times after, dry back gained polylactic acid coating layer thickness is about 30 microns.
After the said method surface modification, in 37 ℃ simulated body fluids (ion concentration: Na
+142.0mM/L, K
+5.0mM/L, Mg
2+1.5mM/L, Ca
2+2.5mM/L, Cl
-147.8mM/L, HCO
3 -4.2mM/L, HPO
4 2-1.0mM/L, SO
4 2-0.5mM/L; Original ph is 7.4) the middle immersion after 5 days, the pH of simulated body fluid is 8.2, is 9.6 and have only the pH of the simulated body fluid of magnesium hydroxide transition zone under the same terms; The pH of the simulated body fluid of 99.95% magnesium metal of long time without surface modification then is 10.9; Explanation is in immersion process, and this surface reforming layer effectively slows down pH value of solution and rises, and slows down degradation rate.
Sample is the AZ91 magnesium alloy.Dry up through polishing, sample after cleaning; To contain KOH30g/L and Na
2CO
3The solution of 10g/L is heated to 90 ℃, puts into sample immersion 8 hours, and the taking-up back is cleaned and dry up subsequent use with distilled water, heated 4 hours down at 80 ℃ then; Service property (quality) concentration is that the mean molecule quantity of 5g/L is that sample after 80,000 polycaprolactone chloroformic solution is handled alkali liquor sprays, and the spraying condition is nozzle liquid inventory 0.6mL/ hour, and spray time is 12 minutes; Dry back gained polycaprolactone coating layer thickness is about 70 microns.
AZ91 carries out cell culture experiments in vitro according to ISO10993-5 after the said method surface modification, cultivate after 3 days, has a large amount of cells and its growth conditions good through the AZ91 of modification surface adhesion, and cell quantity is about 85/mm
2, untreated AZ91 then has only on the surface only a few cell to exist under the same terms, and cell quantity is about 20/mm
2, explain that coating that this surface modifying method obtains improved the biocompatibility of magnesium and alloy substrate thereof.
Claims (1)
1. the surface modifying method of degradable magnesium and alloy thereof is characterized in that being made up of following steps:
1) polishing magnesium and alloy sample thereof removed Superficial Foreign Body, and ultrasonic cleaning 5～15 minutes in acetone then is more respectively with dehydrated alcohol and distilled water cleaning and dry up;
2) immersion of the sample after the above-mentioned processing is contained in the solution of sodium hydroxide and/or potassium hydroxide and sodium carbonate; Wherein sodium hydroxide is or/and the mass concentration of potassium hydroxide is 20～80g/L; The mass concentration of sodium carbonate is 5～15g/L, is heated to 40～90 ℃, 2～20 hours time; Take out sample and clean, dry up subsequent use with distilled water; Or heated 2～12 hours down at 60～140 ℃ again, the cooling back is subsequent use in the air;
3) with step 2) sample after handling immerses the method coating step 2 of the chloroformic solution of 3～10% polylactic acid (PLLA) or polycaprolactone (PCL) with dip-coating, spraying or spin coating) sample after handling, heat drying is removed chloroform, acquisition degradable polymer coating.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210310003.6A CN102793947B (en) | 2012-08-28 | 2012-08-28 | Degradable magnesium and surface modification method of alloy thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201210310003.6A CN102793947B (en) | 2012-08-28 | 2012-08-28 | Degradable magnesium and surface modification method of alloy thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN102793947A true CN102793947A (en) | 2012-11-28 |
| CN102793947B CN102793947B (en) | 2015-05-20 |
Family
ID=47193412
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201210310003.6A Active CN102793947B (en) | 2012-08-28 | 2012-08-28 | Degradable magnesium and surface modification method of alloy thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN102793947B (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103934184A (en) * | 2014-03-27 | 2014-07-23 | 同济大学 | Method for preparing degradable magnesium alloy and modified polylactic acid coating composite material |
| CN105536045A (en) * | 2016-02-03 | 2016-05-04 | 江苏时空涂料有限公司 | Method for preparing fibroin modified magnesium polylactate alloy active coating |
| EP3144018A4 (en) * | 2014-05-13 | 2017-05-31 | Jiangsu Fengyuan Medical Devices Co., Ltd. | Method for preparing surface coating with reduced degradation rate of biodegradable magnesium alloy vascular stent |
| CN108159507A (en) * | 2018-01-24 | 2018-06-15 | 太原科技大学 | A kind of antibiotic property magnesium alloy materials and preparation method for short-term intrauterine device |
| CN108660494A (en) * | 2018-03-23 | 2018-10-16 | 郑州大学 | The polymer compound film layer and preparation process of a kind of magnesium and Mg alloy surface Covalent bonding together |
| CN111012955A (en) * | 2019-11-04 | 2020-04-17 | 南京大学 | Modified medical magnesium alloy material and preparation method thereof |
| CN111893534A (en) * | 2020-06-13 | 2020-11-06 | 郑州大学 | Preparation method of polycaprolactone coating on surface of biological magnesium alloy |
| CN115708896A (en) * | 2022-11-16 | 2023-02-24 | 南京友德邦医疗科技有限公司 | Degradable magnesium alloy composite material and preparation method thereof |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001021326A1 (en) * | 1999-09-22 | 2001-03-29 | Surmodics, Inc. | Water-soluble coating agents bearing initiator groups and coating process |
| WO2007139931A2 (en) * | 2006-05-26 | 2007-12-06 | Abbott Cardiovascular Systems Inc. | Bioabsorbable stent with radiopaque coating |
| CN101214396A (en) * | 2008-01-03 | 2008-07-09 | 乐普（北京）医疗器械股份有限公司 | Controlled degradation magnesium alloy coating bracket and preparation thereof |
| CN101249286A (en) * | 2008-03-31 | 2008-08-27 | 乐普（北京）医疗器械股份有限公司 | Degradable chemical bitter earth alloy bracket and method of preparing the same |
| CN101264351A (en) * | 2008-04-07 | 2008-09-17 | 易生科技(北京)有限公司 | Composite coating cardiovascular medicaments elution stent and preparation thereof |
| CN101337090A (en) * | 2008-08-29 | 2009-01-07 | 乐普（北京）医疗器械股份有限公司 | Composite coating magnesium/magnesium alloy biology device and preparation method thereof |
| EP2204196A1 (en) * | 2006-11-17 | 2010-07-07 | National Institute for Materials Science | Magnesium-based medical device and process for producing the same |
| CN102008751A (en) * | 2010-11-24 | 2011-04-13 | 北京道淼浩博科技发展有限公司 | Biodegradable stent composite material and preparation method thereof |
-
2012
- 2012-08-28 CN CN201210310003.6A patent/CN102793947B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2001021326A1 (en) * | 1999-09-22 | 2001-03-29 | Surmodics, Inc. | Water-soluble coating agents bearing initiator groups and coating process |
| WO2007139931A2 (en) * | 2006-05-26 | 2007-12-06 | Abbott Cardiovascular Systems Inc. | Bioabsorbable stent with radiopaque coating |
| EP2204196A1 (en) * | 2006-11-17 | 2010-07-07 | National Institute for Materials Science | Magnesium-based medical device and process for producing the same |
| CN101214396A (en) * | 2008-01-03 | 2008-07-09 | 乐普（北京）医疗器械股份有限公司 | Controlled degradation magnesium alloy coating bracket and preparation thereof |
| CN101249286A (en) * | 2008-03-31 | 2008-08-27 | 乐普（北京）医疗器械股份有限公司 | Degradable chemical bitter earth alloy bracket and method of preparing the same |
| CN101264351A (en) * | 2008-04-07 | 2008-09-17 | 易生科技(北京)有限公司 | Composite coating cardiovascular medicaments elution stent and preparation thereof |
| CN101337090A (en) * | 2008-08-29 | 2009-01-07 | 乐普（北京）医疗器械股份有限公司 | Composite coating magnesium/magnesium alloy biology device and preparation method thereof |
| CN102008751A (en) * | 2010-11-24 | 2011-04-13 | 北京道淼浩博科技发展有限公司 | Biodegradable stent composite material and preparation method thereof |
Non-Patent Citations (6)
| Title |
|---|
| ALYAA ALABBASI ET AL.: "Polylactic acid coating on a biodegradable magnesium alloy: An in vitro degradation study by electrochemical impedance spectroscopy", 《ALYAA ALABBASI,》 * |
| 曾荣昌，等: "医用镁合金表面改性研究进展", 《中国有色金属学报》 * |
| 李绮: "可降解镁合金表面载药涂层的制备和性能", 《材料研究学报》 * |
| 赵常利，等: "生物医用镁合金表面PLGA涂层研究", 《动能材料》 * |
| 郭洁，等: "表面改性在医用镁及镁合金材料研究中的应用", 《生物骨科材料与临床研究》 * |
| 高家诚，等: "碱热处理镁及其在仿生模拟体液中耐蚀性能", 《金属热处理》 * |
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103934184A (en) * | 2014-03-27 | 2014-07-23 | 同济大学 | Method for preparing degradable magnesium alloy and modified polylactic acid coating composite material |
| CN103934184B (en) * | 2014-03-27 | 2016-03-02 | 同济大学 | The preparation method of degradable magnesium alloy/polydactyl acid coating composite material |
| EP3144018A4 (en) * | 2014-05-13 | 2017-05-31 | Jiangsu Fengyuan Medical Devices Co., Ltd. | Method for preparing surface coating with reduced degradation rate of biodegradable magnesium alloy vascular stent |
| CN105536045A (en) * | 2016-02-03 | 2016-05-04 | 江苏时空涂料有限公司 | Method for preparing fibroin modified magnesium polylactate alloy active coating |
| CN105536045B (en) * | 2016-02-03 | 2018-11-30 | 东阳市特意新材料科技有限公司 | A kind of preparation method of silk-fibroin polydactyl acid magnesium alloy active coating |
| CN108159507A (en) * | 2018-01-24 | 2018-06-15 | 太原科技大学 | A kind of antibiotic property magnesium alloy materials and preparation method for short-term intrauterine device |
| CN108660494A (en) * | 2018-03-23 | 2018-10-16 | 郑州大学 | The polymer compound film layer and preparation process of a kind of magnesium and Mg alloy surface Covalent bonding together |
| CN108660494B (en) * | 2018-03-23 | 2020-04-24 | 郑州大学 | Macromolecular composite film layer with covalent bond combination on surface of magnesium and magnesium alloy and preparation process thereof |
| CN111012955A (en) * | 2019-11-04 | 2020-04-17 | 南京大学 | Modified medical magnesium alloy material and preparation method thereof |
| CN111893534A (en) * | 2020-06-13 | 2020-11-06 | 郑州大学 | Preparation method of polycaprolactone coating on surface of biological magnesium alloy |
| CN115708896A (en) * | 2022-11-16 | 2023-02-24 | 南京友德邦医疗科技有限公司 | Degradable magnesium alloy composite material and preparation method thereof |
| CN115708896B (en) * | 2022-11-16 | 2024-03-19 | 南京友德邦医疗科技有限公司 | Degradable magnesium alloy composite material and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN102793947B (en) | 2015-05-20 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102793947B (en) | Degradable magnesium and surface modification method of alloy thereof | |
| CN103933611B (en) | The preparation method of medical magnesium alloy surface hydroxyapatite/polylactic acid composite coating | |
| CN104784750B (en) | Improve the corrosion proof surface modifying method of morphotropism Biological magnesium alloy implant devices | |
| CN101337090B (en) | Composite coating magnesium/magnesium alloy biology device and preparation method thereof | |
| CN101249286B (en) | Degradable chemical bitter earth alloy bracket and method of preparing the same | |
| CN107096068A (en) | A kind of preparation method of dentistry implant and its bioactivity antimicrobial surface | |
| CN103272269B (en) | Hydroxyapatite/chitosan composite coating and preparation method thereof | |
| CN103463681B (en) | Method for preparing biodegradable magnesium alloy surface modification fluoridated hydroxyapatite coating | |
| CN101214396A (en) | Controlled degradation magnesium alloy coating bracket and preparation thereof | |
| CN103110981A (en) | Method for preparing antibacterial active titanium oxide nanotube array composite coating material | |
| CN106606801B (en) | A kind of Zn-ZnO system kirsite and the preparation method and application thereof | |
| CN103934184B (en) | The preparation method of degradable magnesium alloy/polydactyl acid coating composite material | |
| CN103484845A (en) | Preparation method of biodegradable magnesium alloy/calcium phosphate coating composite material | |
| CN101642585A (en) | Biological activating solution for surface of magnesium alloy and application thereof | |
| Mousa et al. | Polycaprolactone tridentate ligand corrosion inhibitors coated on biodegradable Mg implant | |
| Bazaka et al. | Polymer encapsulation of magnesium to control biodegradability and biocompatibility | |
| CN101491692A (en) | Preparation method of calcium titanate nano-tube array biological coatings | |
| CN103628112B (en) | A kind of preparation method of titanium based titanium oxide silver chloride composite coating material | |
| CN106606806A (en) | Zn-Mg1Ca series zinc alloy and preparing method and application of Zn-Mg1Ca series zinc alloy | |
| CN106609327B (en) | A kind of Zn-HAP systems kirsite and preparation method and application | |
| CN101791435B (en) | Method of collagen modification of medical metal implant surface | |
| CN112121227A (en) | Preparation method of medical composite coating of strontium titanate/strontium hydroxyapatite on titanium metal surface | |
| CN101773412A (en) | Surface activation method of dental implant | |
| JP2010515513A (en) | Metal implant | |
| CN101161295A (en) | Method for modifying medical metallic grafting body surface collagen by galvano-chemistry method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20171207 Address after: 510651 Changxin Road, Guangzhou, Guangdong, No. 363, No. Patentee after: NEW MATERIALS RESEARCH INSTITUTE OF GUANGDONG PROVINCE Address before: 510651 Changxin Road, Guangzhou, Guangdong, No. 363, No. Patentee before: Guangzhou Research Institute of Non-ferrous Metals |
|
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: 510651 Changxin Road, Guangzhou, Guangdong, No. 363, No. Patentee after: Institute of new materials, Guangdong Academy of Sciences Address before: 510651 Changxin Road, Guangzhou, Guangdong, No. 363, No. Patentee before: GUANGDONG INSTITUTE OF NEW MATERIALS |