Pattern formation mechanisms in sphere-forming diblock copolymer thin films

Leopoldo R. Gómez; Nicolás A. García; Richard A. Register; Daniel A. Vega

doi:10.4279/pip.100001

Authors

Leopoldo R. Gómez Instituto de Física del Sur (IFISUR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional del Sur, 8000 Bahía Blanca, Argentina
Nicolás A. García Instituto de Física del Sur (IFISUR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional del Sur, 8000 Bahía Blanca, Argentina
Richard A. Register Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey, 08544, USA.
Daniel A. Vega Instituto de Física del Sur (IFISUR), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad Nacional del Sur, 8000 Bahía Blanca, Argentina

DOI:

https://doi.org/10.4279/pip.100001

Keywords:

Block Copolymer, Thin Films, Phase Transition, Self-assembly

Abstract

The order-disorder transition of a sphere-forming block copolymer thin film was numerically studied through a Cahn-Hilliard model. Simulations show that the fundamental mechanisms of pattern formation are spinodal decomposition and nucleation and growth. The range of validity of each relaxation process is controlled by the spinodal and order-disorder temperatures. The initial stages of spinodal decomposition are well approximated by a linear analysis of the evolution equation of the system. In the metastable region, the critical size for nucleation diverges upon approaching the order--disorder transition, and reduces to the size of a single domain as the spinodal is approached. Grain boundaries and topological defects inhibit the formation of superheated phases above the order--disorder temperature. The numerical results are in good qualitative agreement with experimental data on sphere-forming diblock copolymer thin films.

Received: 22 August 2017, Accepted: 12 December 2017; Edited by: R. Dickman; Reviewed by: A. Peters, Dept. Chemical Engineering, Louisiana Tech Univ., Ruston, USA; DOI: http://dx.doi.org/10.4279/PIP.100001

Cite as: L R Gómez, N A García, R A Register, D A Vega, Papers in Physics 10, 100001 (2018)

This paper, by L R Gómez, N A García, R A Register, D A Vega, is licensed under the Creative Commons Attribution License 4.0.