Self-assembly and molecular dynamics of copolymers of gamma-methyl-(L)-glutamate and stearyl-(L)-glutamate
Self-assembly and molecular dynamics of copolymers of gamma-methyl-(L)-glutamate and stearyl-(L)-glutamate
复制标题
DOI：
10.1021/ma070792i
复制
发表时间：
2007-10
期刊：
影响因子：
5.5
通讯作者：
A. Gitsas;G. Floudas;M. Dietz;M. Mondeshki;H. Spiess;G. Wegner
中科院分区：
文献类型：
--
作者：
A. Gitsas;G. Floudas;M. Dietz;M. Mondeshki;H. Spiess;G. Wegner
我们利用热力学（差示扫描量热法）、结构（广角x射线散射和13C固体核磁共振）以及动力学（介电光谱和定点固体核磁共振）技术报道了一系列聚（γ-甲基-l-谷氨酸-co-γ-硬脂酰-l-谷氨酸）[poly(MLG-co-SLG)]的自组装和分子动力学。当wPSLG≥18%时，共聚物发生硬脂基结晶，反映了烃侧链构象的变化。该共聚物的挤出纤维由α-螺旋和β-片状两种二级结构组成，沿纤维轴取向，形成瓶颈结构，MLG/SLG序列形成颈部，较远的SLG序列形成瓶状。这种超分子组织对动力学有直接影响。发现了两个具有强烈温度依赖性的介电活性过程。特定位置的核磁共振允许识别运动的几何形状。一个与…的小振幅运动有关。
We report on the self-assembly and molecular dynamics in a series of poly(γ-methyl-l-glutamate-co-γ-stearyl-l-glutamate) [poly(MLG-co-SLG)] using thermodynamic (differential scanning calorimetry), structural (wide-angle X-ray scattering and 13C solid-state NMR), as well as dynamic (dielectric spectroscopy and site-specific solid-state NMR) techniques. Stearyl crystallization takes place in the copolymers with wPSLG ≥ 18% which reflects changes of the hydrocarbon side chains conformation. Extruded fibers of the copolymers are composed of both α-helical and β-sheet secondary structures oriented along the fiber axis with a bottleneck structure with MLG/SLG sequences forming the neck and more distant SLG sequences forming the bottle. This supramolecular organization has direct consequences on the dynamics. Two dielectrically active processes with strong temperature dependences were found. Site-specific NMR allowed the identification of the geometry of motions. One is associated with small-amplitude motions of...