BK21 Plus Haptic Polymer Composite Research Team & Department of Polymer-Nano Science and Technology, Chonbuk National University, Jeonju 54896, Korea.
Soft Matter. 2017 Aug 30;13(34):5759-5766. doi: 10.1039/c7sm01166k.
Herein, we have synthesized novel photopolymerizable dumbbell-shaped diacetylene liquid crystal (LC) monomers by locating a diacetylene dicarboxylic acid group at the center and chemically connecting swallow-tails, such as hydrophobic alkyl chains (abbreviated as ATDI) and amphiphilic biphenyl mesogens (abbreviated as BPDI), with bisamide groups. Major phase transitions of dumbbell-shaped diacetylene monomers were identified using differential scanning calorimetry (DSC), polarized optical microscopy (POM), and Fourier transform infrared spectroscopy (FT IR). Molecular packing structures were studied based on structure-sensitive wide-angle X-ray diffraction (WAXD) and small-angle X-ray scattering (SAXS) analyses. Mainly, due to nanophase separations and strong intermolecular hydrogen bonding, ATDI formed a low-ordered lamellar LC phase at room temperature. BPDI self-assembled into highly-ordered crystal phases (K and K) at lower temperatures below a low-ordered lamellar LC phase, in which BPDI were intercalated with each other to compensate the mutual volume differences. From the photopolymerization of ATDI and BPDI, it was realized that the topochemical reactions of dumbbell-shaped diacetylene monomers were closely related to their chemical structures as well as molecular packing structures.
在此，我们通过双酰胺基团将二乙炔二羧酸基团定位在中心，并将燕尾形（如疏水性烷基链（简称 ATDI）和两亲性联苯介晶（简称 BPDI））化学连接，合成了新型的光聚合哑铃形二乙炔液晶（LC）单体。使用差示扫描量热法（DSC）、偏光显微镜（POM）和傅里叶变换红外光谱（FTIR）确定了哑铃形二乙炔单体的主要相变。根据结构敏感广角 X 射线衍射（WAXD）和小角 X 射线散射（SAXS）分析研究了分子堆积结构。主要是由于纳米相分离和强分子间氢键，ATDI 在室温下形成低序层状 LC 相。BPDI 在较低温度下低于低序层状 LC 相自组装成高度有序的晶体相（K 和 K），其中 BPDI 相互嵌入以补偿相互的体积差异。从 ATDI 和 BPDI 的光聚合反应可以看出，哑铃形二乙炔单体的拓扑化学反应与其化学结构以及分子堆积结构密切相关。
