臺灣博碩士論文加值系統

PART I
雙溫敏性兩性離子高分子聚合物
本研究第一部分先分別以自由基聚合法聚合兩性離子單體[3-Dimethyl(methylmethacryloylethy1) Ammonium Propane sulfonate] (DMAPS) 及 N-Isopropylacrylamide (NIPAAm) 製備具有不同UCST與LCST之高分子聚合物。DMAPS自聚合後成 poly(DMAPS) [PDMAPS]，其具有高臨界溶液溫度(Upper Critical Solution Temperature，UCST) 之溫度敏感性。同時，PDMAPS聚合物之UCST也受離子濃度所影響，當離子濃度提高時DMAPS之磺酸基會受離子影響而展開變得更親水，使得UCST溫度降低，當達到一定的離子濃度時，UCST之現象也會逐漸消失，使其與水溶液成均一相；NIPAAm自聚合後成poly(NIPAAm) [PNIAAm]，同樣屬於具有低臨界溶液溫度(Lower Critical Solution Temperature，LCST) 溫度敏感性之材料，其結構中具有-CONH2 (醯胺基)官能基，能分別與水中的氫及氧產生氫鍵，結構中的疏水基在溫度大於32℃時，產生的熱能會破壞醯胺基與水之間的氫鍵，使異丙基之結構往外伸展而形成立體障礙，使其疏水性增加。因此PNIPAAm在低於低臨界溶液溫度為均一溶解狀態，但當溫度高於32℃時則發生不溶的兩相分離現象，而變成不透明之混濁狀態。
其次將NIPAAm分別與Acrylamide及DMAPS依不同比例共聚，形成各種不同組成的poly(NIPAAm-co-Acrylamide) 共聚體和poly(NIPAAm-co-DMAPS) 共聚體探討其是否具有雙溫度敏感性。初步實驗結果顯示，以此聚合方法無法得到雙溫度敏感性共聚體，只能改變聚合物之原始LCST或UCST。NIPAAm與親水性單體Acrylamide共聚之LCST溫度隨著Acrylamide單體比例增加而升高；與DMAPS共聚之LCST與UCST溫度則取決於NIPAAm和DMAPS單體比例之多寡，當NIPAAm莫耳比大於DMAPS則傾向於LCST；而NIPAAm莫耳比小於DMAPS則傾向於UCST。將NIPAAm與DMAPS共聚形成水凝膠，NIPAAm和DMAPS單體比例之多寡，則會影響膠體之平衡膨潤度。
為製備具雙溫度敏感性共聚物，本研究第二部分利用可逆加成-斷裂鏈轉移（Reversible Addition-Fragmentation Chain Transfer, RAFT）聚合法。第一階段先將NIPAAm單體聚合並接上鏈轉移試劑2-(Dodecylthiocarbonothioylthio)-2-methylpropionic acid (DMP)形成poly(NIPAAm)-CTA [PNIPAAm-CTA]，作為下一段使用之鏈轉移試劑﹔第二階段則以相同手法將DMAPS接上PNIAAm-CTA，製備出poly(NIPAAm-b-DAMPS) [P(NIPAAm-b-DMAPS)] 嵌段共聚物，此嵌段共聚物可同時展現PNIPAAm之LCST與PDMAPS之UCST雙溫度敏感特性。最後，我們針對帶有兩性離子嵌段共聚物探討在去離子水中與在NaCl、KCl和KBr水溶液中的相變化溫度，了解鹽類溶液對其溫度敏感性的影響。
PART II
雙溫敏兩性離子共聚水凝膠之製備及其性質之研究
本研究以兩性離子單體(DMAPS) 之電荷作用力及聚(乙二醇)甲基丙烯酸酯(PEGMA) 的氫鍵作用力作為主軸，以不添加交聯劑之方式製備出具有延展性及自修復功能之水凝膠。並透過拉伸材料至斷裂前、後之應力–應變曲線，觀察其自修復效果。DMAPS單體自聚合成PDMAPS後會形成側鏈上帶有正負電荷之梳狀結構高分子鏈，分子鏈間之正負電荷會互相吸引而形成網狀結構，因此在一定濃度下能以不加交聯劑之情況形成具有自修復功能之水凝膠，但膠體本身性質較軟爛不易成形。
為提升膠體的強度並保有自修復之能力，故選擇將聚(乙二醇)甲基丙烯酸酯(PEGMA)與兩性離子單體(DMAPS)共聚希望能提升其剛性和延展性。PEGMA主鏈上的羰基 (C=O) 與羥基(-OH) 能夠提供分子間的氫鍵，同樣的，能在低濃度不加交聯劑之情況下形成形態完整之水凝膠，但膠體本身容易脆裂且不具自修復功能。
將DMAPS與PEGMA兩種單體之特性結合，製備出具氫鍵複合電荷作用力之智慧型水凝膠，利用萬能測試儀以單軸拉伸方式測量水凝膠之機械強度，將討論不同濃度下各組成之應力與應變關係。測試之過程將膠體以緩慢之速率拉伸至樣本斷裂，將膠體斷裂面接觸24小時，再利用萬能測試儀以拉伸測量自修復後樣本機械強度之應力與應變關係，觀察是否修復至樣本初始之機械強度。
從初步的實驗結果得知，我們將DMAPS濃度度提高之組成，是期望分子鏈上之正負電荷能增加自修復之效果，但相對的PEGMA單體含量也增加，使2M之組成完全沒有自修復之，0.5M之膠體組成具有較明顯之自修復能力，其結果不如預期。最後將製備DMAPS、PEGMA與第一部分合成之PNIPAAm-CTA 共聚之水凝膠，並觀察其是否具有雙溫度敏感性，並保有自修復之效果。

PART I
Dual Temperature Sensitive Zwitterionic Polymers
In part I, we prepared the high molecular weight polymers with different Upper Critical Solution Temperature (UCST) and Lower Critical Solution Temperature (LCST) via free radical polymerization of N-Isopropylacrylamide (NIPAAm) and zwitterionic monomer, [3-Dimethyl(methylmethacryloylethy1) Ammonium Propane sulfonate] (DMAPS). Poly(DMAPS) [PDMAPS], which has a temperature sensitivity of UCST. Polymeric betaines are a class of zwitterionic polymers in which the cationic and anionic functional groups are linked on the same monomer unit. Thus the UCST of PDMAPS is also affected by the salt ion concentration. When the salt ion concentration is increased, the sulfonic group of DMAPS will be more hydrophilic by the influence of ions, which the UCST will be lower. When a certain ion concentration is reached, the phenomenon of UCST will gradually disappear and make it homogeneous in the aqueous salt solution. Poly(NIPAAm) [PNIAAm] is one of the well-known member of the temperature sensitive polymer materials‚ which has LCST‚ as it undergoes a hydrophilic-hydrophobic transition in water at LCST (32°C). Therefore, PNIPAAm is dissolved in an aqueous system and completely miscible at normal temperature, but its solubility decreases with increasing of temperature and show phase separation above the LCST (32°C).
Then, NIPAAm was copolymerized with acrylamide and DMAPS in different proportions to form poly(NIPAAm-co-Acrylamide) copolymer and poly(NIPAAm-co-DMAPS) copolymer with different compositions to investigate whether they have dual temperature sensitivity. The experimental results show that the doubly temperature sensitive copolymer can’t be obtained by this polymerization method. It’s can only change the original LCST or UCST of the polymer. The LCST of the copolymerization of NIPAAm with the hydrophilic monomer acrylamide increases with the proportion of acrylamide monomer. The poly(NIPAAm-co-DMAPS) copolymer , its LCST and UCST are dependent on the ratio of NIPAAm and DMAPS monomers. We also synthesis the poly(NIPAAm-co-DMAPS) copolymer hydrogel with different compositions. The equilibrium swelling ratio of the hydrogel is affected by the molar ratio of NIPAAm and DMAPS monomer.
In the second part, Reversible Addition-Fragmentation Chain Transfer (RAFT) polymerization was used to prepare the copolymer with dual-temperature sensitivity. In the first stage, the NIPAAm monomer was polymerized with the chain transfer reagent 2-(Dodecylthiocarbonothioylthio)-2-methylpropionic acid (DMP) to form poly(NIPAAm)-CTA [PNIPAAm-CTA], which is used as a chain transfer reagent for the next stage. In the second stage, DMAPS was polymerized with PNIAAm-CTA in the same manner to prepare poly(NIPAAm-b-DAMPS) [P(NIPAAm-b-DMAPS)] block copolymer which can simultaneously exhibit a UCST from DMAPS and a LCST from NIPAAm of dual-temperature sensitive characteristics. Finally, we investigated the phase transition temperature of the zwitterionic block copolymer in deionized water and the NaCl, KCl, and KBr aqueous solutions to understand its sensitivity to aqueous salt solutions.
PART II
Preparation and Properties of Zwitterionic Copolymer Hydrogels
In Part II, DMAPS with electrostatic interaction and poly(ethylene glycol) methacrylate (PEGMA) with hydrogen bonds are used as the main monomers. The hydrogels having ductility and self-healing ability were prepared without adding a crosslinker. By stretching the sample hydrogel to fracture, their stress-strain curves before and after the fracture were used to evaluate the self-healing efficiency of the hydrogel. The poly(DMAPS) [PDMAPS] will form a polymer chain which the cationic and anionic functional groups are located on the side chain. The cationic and anionic functional groups between the polymer chains will attract each other to form the three-dimensional network structure. In certain concentration is possible to prepare the hydrogel by not adding crosslinker, a hydrogel having a self-healing ability is formed, but the hydrogel itself is soft and not easily formed.
In order to enhance the strength of the hydrogel and maintain its self-healing ability, PEGMA was copolymerized with DMAPS to increase its rigidity and ductility. The carbonyl (C=O) and hydroxyl (-OH) groups on the PEGMA polymer chain provide a large amount of intermolecular hydrogen bonds. The hydrogel can be prepared at the low concentrations and without adding crosslinker. But the sample is brittle and does not have a self-healing ability.
A smart hydrogel with hydrogen bond complexing electrostatic interaction was prepared through combining the characteristics of DMAPS and PEGMA monomers. Mechanical strengths of these hydrogels were measured by uniaxial stretching experiment with universal tester. The stress-strain curves of the poly(DMAPS-co-PEGMA) hydrogels with different proportions were discussed.
Based on preliminary results, increasing the composition of the DMAPS concentration is to expect that the cationic and anionic functional groups on the polymer chain can increase the self-healing efficiency. But the result is not as expected.

PART I
雙溫敏性兩性離子高分子聚合物
第一章2
序論2
第二章4
實驗4
2.1 藥品4
2.2 兩性離子單體 3-Dimethyl(methylmethacryloylethy1) Ammonium Propane sulfonate (DMAPS) 之合成 6
2.3兩性離子聚合物 Poly [3-Dimethyl(methylmethacryloylethy1) Ammonium Propane sulfonate] (PDMAPS) 之合成8
2.4溫度敏感性共聚物之合成10
2.4.1 Poly(NIPAAm-co-Acrylamide)共聚物之合成10
2.4.2 Poly(NIPAAm-co-DMAPS)共聚物之合成12
2.5 Poly(NIPAAm-co-DMAPS)之智慧型水凝膠之製備14
2.6 RAFT聚合法合成poly(NIPAAm-b-DMAPS) 嵌段共聚物17
2.7平衡膨潤度量測 22
2.8 可見光範圍穿透度量測22
第三章23
結果與討論23
3.1兩性離子單體 3-Dimethyl(methylmethacryloylethy1) Ammonium Propane sulfonate (DMAPS) 結構鑑定23
3.2溫度敏感性高分子聚合物25
3.2.1 Poly[3-Dimethyl(methylmethacryloylethy1) Ammonium Propane sulfonate] (PDMAPS) 之結構鑑定25
3.2.2 Poly(DMAPS) 水溶液濃度對UCST之影響27
3.2.3 不同濃度NaCl水溶液對poly(DMAPS) 之UCST影響29
3.3共聚物之LCST與UCST31
3.3.1 Poly(NIPAAm-co-Acrylamide)共聚物31
3.3.2 摻混 PNIPAAm、Poly(NIPAAm-co-AAm)與PDMAPS33
3.3.3 Poly(NIPAAm-co-DMAPS) 共聚物35
3.4 Poly(NIPAAm-co-DMAPS)之智慧型水凝膠37
3.4.1不同組成之Poly(NIPAAm-co-DMAPS) 水凝膠平衡膨潤度37
3.4.2不同溫度下對Poly(NIPAAm-co-DMAPS)膠體膨潤度之影響39
3.5 Poly(NIPAAm-b-DMAPS) 溫度敏感性嵌段共聚物41
3.5.1 Poly(NIPAAm-b-DMAPS) 之結構鑑定41
3.5.2 Poly(NIPAAm-b-DMAPS) 水溶液之LCST與UCST45
3.5.3 Poly(NIPAAm-b-DMAPS)對鹽類水溶液之相變化47
第四章51
結論51
參考文獻52
PART II
兩性離子單體共聚物水凝膠之製備及其性質之研究
第一章57
序論57
第二章59
實驗59
2.1 藥品59
2.2 電荷作用力之水凝膠製備方法60
2.3 氫鍵作用力之水凝膠製備方法62
2.4 氫鍵複合電荷作用力-智慧型水凝膠之製備方法64
2.4.1 Poly(DMAPS-co-PEGMA) 共聚物水凝膠64
2.5 自修復拉伸測試67
第三章69
結果與討論69
3.1電荷作用力之水凝膠製備方法69
3.2 氫鍵複合電荷作用力-智慧型水凝膠72
3.2.1智慧型水凝膠之機械強度72
3.2.2智慧型水凝膠之自修復能力80
第四章83
 結論與未來工作83
4.1 結論83
4.2 未來工作83
參考文獻85

PART I
1.M. A. C. Stuart, W. T. S. Huck, J. Genzer, M. Müller, C. Ober, M. Stamm, G. B. Sukhorukov, I. Szleifer, V. V. Tsukruk, M. Urban, Emerging applications of stimuli-responsive polymer materials. Nat. Mater., 9, 101–13, 2010.
2.A. S. Hoffman, Stimuli-responsive polymers: Biomedical applications and challenges for clinical translation. Adv. Drug Deliv. Rev., 65, 10–16, 2013.
3.M. Elsabahy, K. L. Wooley, Design of polymeric nanoparticles for biomedical delivery applications. Chem. Soc. Rev., 41, 2545–2561, 2012.
4.Y. Yu, Y. Li, C. Zhu, and L. Liu, Synthesis and characterization of temperature sensitive and biodegradable hydrogel based on N -isopropylacrylamide. Cent. Eur. J. Chem., 8, 426–433, 2010.
5.D. Roy, W. L. A. Brooks, B. S. Sumerlin, New directions in thermoresponsive polymers. Chem. Soc. Rev., 42, 7214–7243, 2013.
6.H. G. Schild, Poly(N-isopropylacrylamide): experiment, theory and application. Prog. Polym. Sci., 17, 163–249, 1992.
7.H. Ivan Meléndez-Ortiz and E. Bucio, Stimuli-Sensitive Behaviour of Binary Graft Co-polymers (PP-g-DMAEMA)-g-NIPAAm and (PP-g-4VP)-g-NIPAAm in Acidic and Basic Medium. Des. Monomers Polym. 12, 99–108, 2009.
8.W. F. Lee, and Y. H. Lin, Swelling behavior and drug release of NIPAAm/ PEGMEA copolymeric hydrogels with different crosslinkers. J. Mater. Sci., 41, 7333–7340, 2006.
 9.S. R. Huang, K. F. Lin, T. M. Don, C. F. Lee, M. S. Wang and W. Y. Chiu, Thermoresponsive Conductive Polymer Composite Thin Film and Fiber Mat: Crosslinked PEDOT:PSS and P(NIPAAm-co-NMA) Composite. J. Polym. Sci. Part A Polym. Chem. 54, 1078–1087, 2016.
10.D. J. Liaw, and W. F. Lee, Thermal Degradation of Poly [ 3-Dimethyl(methylmethacryloylethy1) Ammonium Propanesulfonate]. Appl. Polym., 30, 4697–4706, 1985.
11.R. Zeng, S. Xu, J. Cheng, Z. Cai, P. Pi, and X. Wen, Thermoresponsive / low-fouling Zwitterionic Hydrogel for Controlled Drug Release. J. Appl. Polym. Sci., 131, 39816, 1–7, 2014.
12.L. Chen, Y. Honma, T. Mizutani, D. Liaw, J. P. Gong and Y. Osada, Effects of polyelectrolyte complexation on the UCST of zwitterionic polymer. Polymer, 41, 141–147, 2000.
13.Y. J. Shih, Y. Chang, A. Deratani and D. Quemener, “Schizophrenic” Hemocompatible Copolymers via Switchable Thermoresponsive Transition of Nonionic/ zwitterionic Block Self-Assembly in Human Blood. Biomacromolecules, 13, 2849–2858, 2012.
14.K. Haraguchi, J. Ning and G. Li, Changes in the Properties and Self-Healing Behaviors of Zwitterionic Nanocomposite Gels Across Their UCST Transition. Macromol. Symp., 358, 182–193, 2015.
15.D. N. Schulz, D. G. Peiffer, P. K. Agarwal, J. Larabee, J. J. Kaladas, L. Soni, B. Handwerker and R. T. Garner, Phase behaviour and solution properties of sulphobetaine polymers. Polymer, 27, 1734–1742, 1986.
16.M. Li, , X. He, , Y. Ling and H. Tang, Dual Thermoresponsive Homopolypeptide with LCST-Type Linkages and UCST-Type Pendants: Synthesis, Characterization, and Thermoresponsive Properties. Polymer, 132, 264–272, 2017.
17.L. Mäkinen, D. Varadharajan, H. Tenhu and S. Hietala, Triple Hydrophilic UCST-LCST Block Copolymers. Macromolecules, 49, 2016.
18.Y. Kotsuchibashi, M. Ebara, T. Aoyagi and R. Narain, Recent advances in dual temperature responsive block copolymers and their potential as biomedical applications. Polymers, 8, 380, 2016.
19.F. J. Xu, E. T. Kang and K. G. Neoh, pH- and temperature-responsive hydrogels from crosslinked triblock copolymers prepared via consecutive atom transfer radical polymerizations. Biomaterials, 27, 2787–2797, 2006.
20.H. Sun, J. Chen, X. Han and H. Liu, Multi-responsive hydrogels with UCST- and LCST-induced shrinking and controlled release behaviors of rhodamine B. Mater. Sci. Eng. C, 82, 284–290, 2018.
21.A. Kikuchi, T. Okano, Intelligent thermoresponsive polymeric stationary phases for aqueous chromatography of biological compounds. J. Control. Release, 193, 2–8, 2014.
22.H. Yagi, K. Yamamoto, T. Aoyagi, New liquid chromatography method combining thermo-responsive material and inductive heating via alternating magnetic field. J. Chromatogr. B Anal. Technol. Biomed. Life Sci., 876, 97–102, 2008.
23.F. Dai, P. Wang, Y. Wang, L. Tang, J. Yang, W. Liu, H. Li and G. Wang, Double thermoresponsive polybetaine-based ABA triblock copolymers with capability to condense DNA. Polymer, 49, 5322–5328, 2008.
24.R. T. A. Mayadunne, J. Jeffery, G. Moad and E. Rizzardo, Living Free Radical Polymerization with Reversible Addition−Fragmentation Chain Transfer (RAFT Polymerization): Approaches to Star Polymers. Macromolecules, 36, 1505–1513, 2003.
25.G. Moad, E. Rizzardo and S. H. Thang, A. Living Free-Radical Polymerization by Reversible Addition - Fragmentation Chain Transfer: The RAFT Process, Macromolecules, 31, 5559–5562, 1998.
26.C. L. McCormick, A. B. Lowe, Aqueous RAFT polymerization: recent developments in synthesis of functional water-soluble (co)polymers with controlled structures. Acc. Chem. Res., 37, 312–325, 2004.
27.F. Xu, D.Wu, Y. Huang, H. Wei, Y. Gao, X. Feng, D. Yan and Y. Mai, Multi-Dimensional Self-Assembly of a Dual-Responsive ABC Miktoarm Star Terpolymer. ACS Macro Lett., 6, 426–430, 2017.
28.C. Y. Kuo, T. M. Don, S. C. Hsu, C. F. Lee, W. Y. Chiu and C. Y. Huang, Thermo- and pH-induced self-assembly of P(AA-b-NIPAAm-b-AA) triblock copolymers synthesized via RAFT polymerization. J. Polym. Sci. Part A Polym. Chem., 54, 1109–1118, 2016.
29.K. E. B. Doncom, H. Willcock and R. K. O'Reilly, The direct synthesis of sulfobetaine-containing amphiphilic block copolymers and their self-assembly behavior. Eur. Polym. J., 87, 497–507, 2017.
30.G. Moad, E. Rizzardo and S.H. Thang, Living Radical Polymerization by the RAFT Process - A Third Update. Australian Journal of Chemistry, 65, 985–1076, 2012.
PART II
1.M. A. Ramin, L. Latxague, K. R. Sindhu, O. Chassande and P. Barthélémy, Low molecular weight hydrogels derived from urea based-bolaamphiphiles as new injectable biomaterials. Biomaterials, 145, 72–80, 2017.
2.Y. Wang, A. Guan, I. Isayeva, K. Vorvolakos, S. Das, Z. Li and K. S. Phillips, Interactions of Staphylococcus aureus with ultrasoft hydrogel biomaterials. Biomaterials, 95, 74–85, 2016.
3.J. Kopeček, Hydrogel biomaterials: A smart future? Biomaterials, 28, 5185–5192, 2007.
4.F. J. Xu, E. T. Kang and K. G. Neoh, pH- and temperature-responsive hydrogels from crosslinked triblock copolymers prepared via consecutive atom transfer radical polymerizations. Biomaterials, 27, 2787–2797, 2006.
5.L. Li, B. Yan, J. Yang, W. Huang, L. Chen and H. Zeng, Injectable Self-Healing Hydrogel with Antimicrobial and Antifouling Properties. ACS Appl. Mater. Interfaces, 9, 9221–9225, 2017.
6.Q. Yang, P. Wang, C. Zhao, W. Wang, J. Yang and Q. Liu, Light-Switchable Self-Healing Hydrogel Based on Host–Guest Macro-Crosslinking. Macromol. Rapid Commun., 38, 1600741, 2017.
7.X. Zhao, H. Wu, B. Guo, R. Dong, Y. Qiu and P. X. Ma, Antibacterial anti-oxidant electroactive injectable hydrogel as self-healing wound dressing with hemostasis and adhesiveness for cutaneous wound healing. Biomaterials, 122, 34–47, 2017.
8.Z. Gong, G. Zhang, X. Zeng, J. Li, G. Li, W. Huang, R. Sun and C. Wong, High-Strength, Tough, Fatigue Resistant, and Self-Healing Hydrogel Based on Dual Physically Cross-Linked Network. ACS Appl. Mater. Interfaces, 8, 24030–24037, 2016. 
9.D. L. Taylor and M. in het Panhuis, Self-Healing Hydrogels. Adv. Mater. 28, 9060–9093, 2016.
10.H. U. Rehman, Y. Chen, Y. Guo, Q. Du, J. Zhou, Y. Guo, H. Duan, H. Li and H. Liu, Stretchable, strong and self-healing hydrogel by oxidized CNT-polymer composite. Compos. Part A Appl. Sci. Manuf., 90, 250–260, 2016.
11.H. Yu, Y. Liu, H. Yang, K. Peng and X. Zhang, An Injectable Self-Healing Hydrogel Based on Chain-Extended PEO-PPO-PEO Multiblock Copolymer. Macromol. Rapid Commun., 37, 1723–1728, 2016.
12.L. Shi, Y. Han, J. Hilborn and D. Ossipov, ‘Smart’ drug loaded nanoparticle delivery from a self-healing hydrogel enabled by dynamic magnesium-biopolymer chemistry. Chem. Commun., 52, 11151–11154, 2016.
13.S. Maity, A. Datta, S. Lahiri and J.Ganguly, A dynamic chitosan-based self-healing hydrogel with tunable morphology and its application as an isolating agent. RSC Adv., 6, 81060–81068, 2016.
14.H. Hong, H. Liao, S. Chen and H. Zhang, Facile method to prepare self-healable PVA hydrogels with high water stability. Mater. Lett., 122, 227–229, 2014.
15.Y. Fang, C. F. Wang, Z. H. Zhang, H. Shao and S. Chen, Robust self-healing hydrogels assisted by cross-linked nanofiber networks. Sci. Rep., 3, 2811, 2013.
16.H. Liu, C. Xiong, Z. Tao, Y. Fan, X. Tang and H. Yang, Zwitterionic copolymer-based and hydrogen bonding-strengthened self-healing hydrogel. RSC Adv., 5, 33083–33088, 2015.
17.K. Haraguchi, J. Ning and G. Li, Changes in the Properties and Self-Healing Behaviors of Zwitterionic Nanocomposite Gels Across Their UCST Transition. Macromol. Symp., 358, 182–193, 2015. 
18.Z. Ye, P. Zhang, J. Zhang, L. Deng, J. Zhang, C. Lin, R. Guo and A. Dong, Novel dual-functional coating with underwater self-healing and anti-protein-fouling properties by combining two kinds of microcapsules and a zwitterionic copolymer. Prog. Org. Coatings, 127, 211–221, 2019.
19.D. J. Liaw and W. F. Lee, Thermal Degradation of Poly [ 3-Dimethyl(methylmethacryloylethy1) Ammonium Propanesulfonate]. Appl. Polym., 30, 4697–4706, 1985.
20.K. E. B. Doncom, H. Willcock and R. K. O’Reilly, The direct synthesis of sulfobetaine-containing amphiphilic block copolymers and their self-assembly behavior. Eur. Polym. J., 87, 497–507, 2017.
21.B. Zhou, C. Zuo, Z. Xiao, X. Zhou, D. He, X. Xie and Z. Xue, Self-Healing Polymer Electrolytes Formed via Dual-Networks: A New Strategy for Flexible Lithium Metal Batteries. Chemistry - A European Journal, 24, 19200–19207, 2018.
22.J. Wu, Z. Xiao, A. Chen, H. He, C. He, X. Shuai, X. Li, S. Chen, Y. Zhang, B. Ren, J. Zheng and J. Xiao, Sulfated zwitterionic poly(sulfobetaine methacrylate) hydrogels promote complete skin regeneration. Acta. Biomater., 71, 293–305, 2018.
23.S. Chen, F. Mo, Y. Yang, F. J. Stadler, S. Chen, H. Yang and Z. Ge, Development of zwitterionic polyurethanes with multi-shape memory effects and self-healing properties. J. Mater. Chem. A, 3, 2924–2933, 2015.