Dual Stimuli-Responsive P(NIPAAm-co-SPA) Copolymers: Synthesis and Response in Solution and in Films
Dual Stimuli-Responsive P(NIPAAm-co-SPA) Copolymers: Synthesis and Response in Solution and in Films
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DOI：
10.3390/polym10060645
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发表时间：
2018-06-01
期刊：
影响因子：
5
通讯作者：
Schacher, Felix H.
中科院分区：
文献类型：
--
作者：
Grimm, Oliver;Schacher, Felix H.
我们提出了双刺激响应性聚（N-异丙基丙烯酰胺-co-螺吡喃丙烯酸酯）（P（NIPAAm-co-SPA））共聚物的合成和溶液性质的不同组成通过氮氧自由基介导的共聚反应制备。所得共聚物的特征在于根据静态光散射的摩尔质量为40，000至100，000 g/mol，并且SPA含量高达5.3%。后者通过H-1 NMR光谱和UV-Vis光谱测定。这些材料在聚合物膜中照射最少三个循环后表现出可逆响应;还在TRIS缓冲液（pH 8）水溶液中研究了它们在溶液中对光和温度的响应。使用波长为365和590 nm的LED装置进行照射。在水溶液中，使用具有340和540 nm滤光器的光纤耦合的200 W Hg（Hg）灯的定制设置，并且在照射期间对共聚物溶液进行额外加热，以研究螺吡喃或汞形式的存在对浊点温度的影响。由此，发现增加SPA含量导致两种状态之间的更显著差异，并且通常降低浊点。
We present the synthesis and solution properties of dual stimuli-responsive poly(N-isopropylacrylamide-co-spiropyran acrylate) (P(NIPAAm-co-SPA)) copolymers of varying composition prepared via nitroxide-mediated copolymerization. The resulting copolymers feature molar masses from 40,000 to 100,000 g/mol according to static light scattering and an SPA content of up to 5.3%. The latter was determined by H-1 NMR spectroscopy and UV-Vis spectroscopy. These materials exhibit reversible response upon irradiation in polymeric films for a minimum of three cycles; their response in solution to both light and temperature was also investigated in an aqueous TRIS buffer (pH 8). Irradiation was carried out using LED setups with wavelengths of 365 and 590 nm. In aqueous solution, a custom-made setup using a fiber-coupled 200 W Hg(Xe) lamp with 340 and 540 nm filters was used and additional heating of the copolymer solutions during irradiation allowed to study influence of the presence of either the spiropyran or merocyanine form on the cloud point temperature. Hereby, it was found that increasing the SPA content leads to a more pronounced difference between both states and decreasing cloud points in general.