Atomic force microscopic studies of the influence of stretching on thin oriented films of ferroelectric liquid crystalline elastomers

Citation
Hm. Brodowsky et al., Atomic force microscopic studies of the influence of stretching on thin oriented films of ferroelectric liquid crystalline elastomers, FERROELECTR, 243(1-4), 2000, pp. 115-123
Citations number
14
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
FERROELECTRICS
ISSN journal
00150193 → ACNP
Volume
243
Issue
1-4
Year of publication
2000
Pages
115 - 123
Database
ISI
SICI code
0015-0193(2000)243:1-4<115:AFMSOT>2.0.ZU;2-S
Abstract
To analyze the impact of the molecular structure on the network formation i n ferroelectric liquid crystalline polymers, two copolymers are studied, wh ich are identical except for the molecular position of the cross-linkable g roup: (i) Polymer P1 with cross-linkable groups attached to the backbone vi a a short spacer and (ii) Polymer P2 with the cross-linkable group in termi nal position of a mesogenic side group. When mechanical stress is imposed o n thin films in homeotropic orientation through stretching, the two elastom ers react differently to the deformation, as seen by AFM imaging of the sur face topology: For Polymer P1, "intra-layer" cross-linking results in two d imensional networks in each backbone layer, separated by liquid-like FLC si degroup layers. As there are practically no vertical connections in this in tralayer network, no vertical distortions occur. In Polymer P2 a three dime nsional, "inter-layer" network is formed; the system reacts with a distorti on of the smectic layering.