Hierarchical self-assembly structures of POSS-containing polypeptide block copolymers synthesized using a combination of ATRP, ROP and click chemistry
Hierarchical self-assembly structures of POSS-containing polypeptide block copolymers synthesized using a combination of ATRP, ROP and click chemistry
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DOI：
10.1039/c2py00574c
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发表时间：
2012-03
影响因子：
4.6
通讯作者：
Yun-Chih Lin;S. Kuo
中科院分区：
文献类型：
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作者：
Yun-Chih Lin;S. Kuo
本研究采用原子转移自由基聚合、开环聚合和点击化学相结合的方法合成了聚苯乙烯-b-聚（γ-炔丙基-L-谷氨酸酯-g-多面体低聚倍半硅氧烷）[PS-b-（PPLG-g-POSS）]的有机/无机大分子自组装结构单元。采用傅里叶变换红外光谱（FTIR）和广角X射线衍射（WAXD）测定，PS和POSS单元的掺入增强了固态下的α-螺旋构象。PS-b-的分级自组装（PPLG-g-POSS）二嵌段共聚物，我们用WAXD、小角X射线散射和透射电子显微镜表征，由于二嵌段共聚物的微相分离，导致了圆柱形结构的形成;六方柱堆积纳米结构以多肽片段的α-螺旋构象为特征，其取向垂直于二嵌段共聚物的圆柱方向; POSS部分的聚集诱导了六方晶格结构的堆积。通过温度依赖性FTIR光谱分析确定，相对于纯PPLG和PS-b-PPLG，POSS单元连接到PPLG的侧链上在升高的温度下稳定了α-螺旋二级结构。
In this study, we used a combination of atom transfer radical polymerization, ring opening polymerization, and click chemistry to synthesize new organic/inorganic macromolecular self-assembling building blocks of polystyrene-b-poly(γ-propargyl-L-glutamate-g-polyhedral oligomeric silsesquioxane) [PS-b-(PPLG-g-POSS)]. The incorporation of the PS and POSS units enhanced the α-helical conformation in the solid state, as determined using Fourier transform infrared (FTIR) spectroscopy and wide-angle X-ray diffraction (WAXD). Hierarchical self-assembly of the PS-b-(PPLG-g-POSS) diblock copolymers, which we characterized using WAXD, small-angle X-ray scattering, and transmission electron microscopy, led to the formation of cylindrical structures as a result of microphase separation of the diblock copolymer; the hexagonal cylinder packing nanostructure featured α-helical conformations of polypeptide segments, which were oriented perpendicular to the direction of the cylinder column from diblock copolymers; aggregation of the POSS moieties induced the packing into hexagonal lattice structures. The attachment of POSS units onto the side chains of PPLG stabilized the α-helical secondary structures at elevated temperature, relative to those of pure PPLG and PS-b-PPLG, as determined through temperature-dependent FTIR spectroscopic analyses.