Road to Disorder in Smectic Elastomers

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Physical Review E, Statistical, Nonlinear, and Soft Matter Physics

DOI:https://doi.org/10.1103/PhysRevE.77.021706· OSTI ID:960174

Obraztsov, E; Muresan, A; Ostrovskii, B; de Jeu, W

We present a high-resolution x-ray study of the effects of disorder induced by random cross-linking side-chain smectic elastomers. The influence of variation of the concentration and stiffness of the cross-link units on the disruption of the one-dimensional translational order is reported in detail. Precise analysis of the line shape of the quasi-Bragg peaks associated with the smectic layering indicates a transition from algebraic decaying ordering to disorder. The smectic line shapes can be described by the Caille correlation function convoluted with a finite-size factor represented by a stretched Gaussian (compressed exponential). The transition to disorder is signaled by a change in the exponent of the stretched Gaussian from 1 (simple Gaussian describing finite-size domains) via 0.5 (Lorentzian describing exponentially decaying short-range correlations) to <0.5 (stretched exponential correlations). For a flexible cross linker the changeover occurs for concentration between 0.15 and 0.20, for a stiff cross linker below about 0.10. Broadening of the higher harmonics of the x-ray peak indicates strong nonuniform strain within finite-size domains and local deformations induced by randomly distributed dislocations.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 960174
• Report Number(s): BNL--83160-2009-JA
• Journal Information: Physical Review E, Statistical, Nonlinear, and Soft Matter Physics, Journal Name: Physical Review E, Statistical, Nonlinear, and Soft Matter Physics Vol. 77
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CORRELATION FUNCTIONS
CROSS-LINKING
DISLOCATIONS
ELASTOMERS
FLEXIBILITY
HARMONICS
SHAPE
STRAINS
national synchrotron light source