Liquid Crystalline Dendrimers
Abstract
The influence of molecular construction of LC dendrimers on their phase behavior and properties have been studied. First to five generations of carbosilane LC dendrimers with 8, 16, 32, 64 and 128 terminal mesogenic groups (cyanobiphenyl, methoxyphenyl benzoate, ethyl lactate derivatives, etc.) have been synthesized. Investigation of thermal behavior and structure of LC dendrimers reveals smectic mesophases over a wide temperature region. LC dendrimers with terminal ethyl-L-lactate-containing mesogenic groups exhibit a chiral smectic C mesophase possessing ferroelectricity. It was found for the first time that LC dendrimers of fifth generation have two levels of structural organization: smectic-like arrangement of mesogenic groups and supramolecular assembling of LC dendrimers in nanostructures of columnar type. Hydrodynamic and electrooptical properties of solutions of LC dendrimers synthesized have been studied. The results demonstrate, that hydrodynamic behavior of LC dendrimers is similar to the behavior of solid unpermeable particles, which radius of gyration is proportional to the molar mass to the power of 1/3. At the same time, the chain character of these dendrimers is exhibited in temperature dependence of viscosity and small-scale mechanism of their orientation in the electric field, that reflects their polymeric nature.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1999
- Accession Number
- ADA372433
Entities
People
- A. M. Muzafarov
- E. A. Rebrov
- N. I. Boiko
- S. A. Ponomarenko
- V. P. Shibaev
Organizations
- Moscow State University