Self-organization of amphiphilic liquid-crystalline dendrimers in bulk and at the interface

Abstract

A comparative analysis of the structure and phase behavior of synthesized carbosilane amphiphilic LC dendrimers of the third generation containing mesogenic phenyl and oligo(ethylene glycol) fragments is performed. When phenol groups are replaced with oligo(ethylene glycol) moieties, the temperature interval of the existence of the LC phase in the mesogen-containing dendrimers decreases. The chemical nature of hydrophilic terminal groups is found to control the organization of dendrimers in the smectic mesophase. Structural models for their packing are proposed. Amphiphilic dendrimers are shown to form stable Langmuir films at the water/air interface. Surface-pressure-surface area-isotherms are constructed. The effect of the chemical nature of hydrophilic groups on the formation of a monolayer at the interface and on the packing density of dendrimer molecules in the monolayer is discussed.