Diblock copolymer lamellae on sinusoidal and fractal surfaces

Ranjan, Amit ; Kulkarni, Manish ; Karim, Alamgir ; Sharma, Ashutosh (2012) Diblock copolymer lamellae on sinusoidal and fractal surfaces The Journal of Chemical Physics, 136 (9). 094903_1-094903_9. ISSN 0021-9606

Full text not available from this repository.

Official URL: http://jcp.aip.org/resource/1/jcpsa6/v136/i9/p0949...

Related URL: http://dx.doi.org/10.1063/1.3685223

Abstract

A scaling analysis of equilibrium orientation of diblock copolymer molecules on fractal surfaces and a brief comparison with a particular experiment is presented in this paper. This work is motivated by a recent experimental finding that a diblock copolymer film of polystyrene-PMMA, when deposited on a rough substrate, can orient its lamellae from a parallel to a perpendicular configuration depending on the topographical characteristics of the substrate surface. It was found that the RMS height itself is not enough to effect the equilibrium configuration, but the fractal dimension of the surface is also important. In general, the orientation of lamellae is a function of the the power spectral density (PSD) curves of the underlying substrate surface. Assuming the diblock lamellae to behave like an Alexander-deGennes brush, we obtain the free energy expressions for this brush in both parallel and perpendicular orientations in various asymptotic regimes. Comparison of their free energy expressions predicts the equilibrium configuration. By examining the PSD curves and using our scaling results, we are able to qualitatively explain some aspects of the experimental observations regarding the equilibrium orientation of the diblock copolymer lamellae on rough surfaces.

Item Type:Article
Source:Copyright of this article belongs to American Institute of Physics.
Keywords:Fractals; Free Energy; Polymer Blends; Polymer Films; Rough Surfaces; Surface Energy; Surface Roughness; Thin Films
ID Code:96545
Deposited On:02 Jan 2013 10:44
Last Modified:02 Jan 2013 10:45

Repository Staff Only: item control page