Electric field alignment of asymmetric diblock copolymer thin films
Abstract
Electric field alignment of asymmetric diblock copolymer polystyrene-block-polymethyl methacrylate forming cylindrical microdomains, PS-b-PMMA, thin films was studied using small angle neutron scattering, grazing incidence small angle x-ray scattering and transmission electron microscopy. Effect of electric field strength, interfacial interactions, film thickness and pathway dependence were investigated. Interfacial interactions dissipate away from the interface and it is easier to achieve alignment with increasing film thickness. Stronger interfacial interactions slow domain alignment, particularly the reorientation of the microdomains adjacent to polymer/substrate interface. Starting from poorly ordered state, PS-b-PMMA form cylindrical microdomains that break up into spheres or ellipsoids locally and with time, reconnect to form cylinders aligned in the direction of applied electric field. Starting from well-ordered state with cylinders parallel to the surface, the applied field enhances the fluctuations having a wavelength comparable to the equilibrium period. The cylindrical microdomains then break up into spheres that reconnect to form oriented cylinders. This latter reorientation is much slower than that form the poorly ordered state.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2004
- Bibcode:
- 2004APS..MARW31012X