偶氮苯基小分子光控聚N-异丙基丙烯酰胺在离子液体中的自组装  

Azobenzene Molecules Switching Assemblies of Ploy(N-isopropylacrylamide)in Ionic Liquid

作　　者：李佩琪 王彩虹[2] Peiqi Li;Caihong Wang(United Technology Center of Western Metal Materials Co.,Ltd,Xi’an 710200,China;School of Chemical Engineering,Sichuan University,Chengdu 610065,China)

机构地区：[1]西部金属材料股份有限公司联合技术中心,陕西西安710200 [2]四川大学化学工程学院,四川成都610065

出　　处：《高分子材料科学与工程》2024年第2期32-38,共7页Polymer Materials Science & Engineering

基　　金：国家自然科学基金青年基金资助项目(21905184);博士后基金面上项目(2018M643473);博士后基金特别资助项目(2019T120837);四川大学博士后专项科研基金(20826041B4126)。

摘　　要：偶氮苯基材料因其具有可逆的光致顺反异构特性,可调控聚合物的自组装行为而受到广泛关注。采用不同结构且广泛商业化的偶氮苯基小分子(偶氮苯(AZO)、对羟基偶氮苯(AZO-OH)、对氨基偶氮苯(AZO-NH2)、二甲基黄[AZO-N(CH_(3))_(2)])作为光分子开关,控制聚N-异丙基丙烯酰胺(PNIPAm)在1-乙基-3-甲基咪唑双(三氟甲基磺酰基)亚胺([C2mim][NTf_(2)])离子液体中的自组装行为,探讨不同偶氮苯基末端基元对于PNIPAm自组装相行为的影响。结果表明,偶氮苯基小分子均能有效调控PNIPAm在[C2mim][NTf_(2)]离子液体中的相变响应行为,但不同的末端基元对于PNIPAm的相变温度及相变区间影响甚微。结合原位变温红外谱图分析可知,紫外光照强化了PNIPAm与离子液体之间的相互作用,从而抑制了PNIPAm侧链间的相互聚集,这将促进紫外光照条件下“溶剂化”效应的发生,可获得更低的相变温度。Azobenzene-based materials have attracted much attention because of their reversible light controlled assemblies of polymers.Here,different structural and widely commercialized azobenzene-based compounds(azobenzene(AZO),p-hydroxyazobenzene(AZO-OH),p-aminoazobenzene(AZO-NH2)and dimethyl yellow(AZO-N(CH_(3))_(2))were used as photomolecular trigger to control assemblies of poly(N-isopropylacrylamide)(PNIPAm)in 1-ethyl-3-methyl-imidazolium bis(trifluoromethylsulfonyl)amide([C2mim][NTf_(2)])ionic liquid and investigate the effect of different end-groups on the phase behavior of PNIPAm self-assembly.The results show that the photo-induced isomerization of azobenzene small molecules could effectively affect the phase transition of PNIPAm in[C2mim][NTf_(2)]ionic liquid.Meanwhile,various terminal groups attached on azobenzene moieties have little effect on the phase transition temperatures and phase transition interval of PNIPAm.Combined with the in situ FT-IR,the interaction between PNIPAm and ionic liquids was enhanced by UV irradiation,which inhibits the inter-aggregation between PNIPAm side chains,which promote the"solvation"effect under UV illumination conditions and a lower phase transition temperature could be obtained.

关 键 词：偶氮苯 聚N-异丙基丙烯酰胺 离子液体 自组装 分子开关 相变 响应行为 

分 类 号：TQ316.333[化学工程—高聚物工业]