School of Chemistry, University of Birmingham, Edgbaston, B15 2TT, Birmingham, UK.
Department of Chemistry, University of Warwick, Gibbet Hill Road, CV4 7AL, Coventry, UK.
Macromol Rapid Commun. 2020 Mar;41(6):e1900599. doi: 10.1002/marc.201900599. Epub 2020 Feb 4.
Understanding, predicting, and controlling the self-assembly behavior of stimuli-responsive block copolymers remains a pertinent challenge. As such, the copolymer blending protocol provides an accessible methodology for obtaining a range of intermediate polymeric nanostructures simply by blending two or more block copolymers in the desired molar ratio to target specific stimuli-responsiveness. Herein, thermoresponsive diblock copolymers are blended in various combinations to investigate whether the resultant cloud point temperature can be modulated by simple manipulation of the molar ratio. Thermoresponsive amphiphilic diblock copolymers composed of statistical poly(n-butyl acrylate-co-N,N-dimethylacrylamide) core-forming blocks and four different thermoresponsive corona-forming blocks, namely poly(diethylene glycol monomethyl ether methacrylate) (p(DEGMA)), poly(N-isopropylacrylamide), poly(N,N-diethylacrylamide), and poly(oligo(ethylene glycol) monomethyl ether methacrylate) (p(OEGMA)) are selected for evaluation. Using variable temperature turbidimetry, the thermoresponsive behavior of blended diblock copolymer self-assemblies is assessed and compared to the thermoresponsive behavior of the constituent pure diblock copolymer micelles to determine whether comicellization is achieved and more significantly, whether the two blended corona-forming thermoresponsive blocks exhibit cooperative behavior. Interestingly, blended diblock copolymer micelles composed of p(DEGMA)/p(OEGMA) mixed coronae display cooperative behavior, highlighting the potential of copolymer blending for the preparation of stimuli-responsive nanomaterials in applications such as oil recovery, drug delivery, biosensing, and catalysis.
理解、预测和控制刺激响应嵌段共聚物的自组装行为仍然是一个具有挑战性的问题。因此，共聚物共混策略为获得一系列中间聚合物纳米结构提供了一种可行的方法，只需将两种或更多嵌段共聚物按所需的摩尔比混合，以获得特定的刺激响应性。在此，通过不同组合混合热响应性两亲性嵌段共聚物，以研究是否可以通过简单地改变摩尔比来调节所得浊点温度。选择了由统计聚（n-丁基丙烯酰胺-co-N,N-二甲基丙烯酰胺）核形成嵌段和四种不同热响应性冠形成嵌段组成的热响应性两亲性嵌段共聚物，即聚（二乙二醇单甲醚甲基丙烯酸酯）（p（DEGMA））、聚（N-异丙基丙烯酰胺）、聚（N,N-二乙基丙烯酰胺）和聚（聚乙二醇单甲醚甲基丙烯酸酯）（p（OEGMA））用于评估。使用变温浊度法评估共混两亲性嵌段共聚物自组装体的热响应行为，并将其与组成纯两亲性嵌段共聚物胶束的热响应行为进行比较，以确定是否实现了共胶束化，更重要的是，两个混合的冠形成热响应性嵌段是否表现出协同行为。有趣的是，由 p（DEGMA）/p（OEGMA）混合冠组成的共混两亲性嵌段共聚物胶束表现出协同行为，突出了共聚物共混在诸如采油、药物输送、生物传感和催化等应用中制备刺激响应性纳米材料的潜力。
