Temperature dependence of the structure of a carbosilane dendrimer with terminal cyanobiphenyl groups: Molecular-dynamics simulation

被引:14
作者
Markelov, D. A. [1 ,2 ]
Mazo, M. A. [3 ]
Balabaev, N. K. [4 ]
Gotlib, Yu. Ya. [1 ]
机构
[1] Russian Acad Sci, Inst Macromol Cpds, St Petersburg 199004, Russia
[2] St Petersburg State Univ, Fac Phys, St Petersburg 198504, Russia
[3] Russian Acad Sci, NN Semenov Chem Phys Inst, Moscow 119991, Russia
[4] Russian Acad Sci, Inst Math Problems Biol, Pushchino 142290, Moscow Oblast, Russia
基金
俄罗斯基础研究基金会;
关键词
LIQUID-CRYSTALLINE DENDRIMER; MESOGENIC GROUPS; FORCE-FIELD; MONTE-CARLO; BEHAVIOR; CHEMISTRY; MOBILITY; SOLVENTS; SIZE;
D O I
10.1134/S0965545X13010045
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
The molecular-dynamics simulation of the structure and molecular mobility of an individual macromolecule of a fourth-generation carbosilane dendrimer with terminal cyanobiphenyl groups in a highly diluted chloroform solution in the range 213-323 K is performed. Upon a change in temperature, the dendrimer undergoes structural rearrangement that depends on the ability of terminal segments to penetrate into the dendrimer. At temperatures close to the boiling point of the solvent, aliphatic spacers of terminal segments can penetrate deep into the dendrimer. As temperature decreases, the terminal segments are grouped only on the surface of the molecule; this leads to a 45% increase in the number of solvent molecules in the treelike part of the macromolecule. These results make it possible to give a new interpretation of temperature effects previously observed in NMR experiments for dilute solutions of these macromolecules.
引用
收藏
页码:53 / 60
页数:8
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