Ordering kinetic in two-dimensional hexagonal pattern of cylinder-forming PS-b-PMMA block copolymer thin films: dependence on the segregation strength

TL;DR

This study experimentally investigates how the ordering kinetics of cylinder-forming PS-b-PMMA block copolymer thin films depend on segregation strength, revealing that growth exponents and activation enthalpies decrease exponentially with increasing segregation strength.

Contribution

It provides the first experimental analysis of the relationship between segregation strength and ordering kinetics in PS-b-PMMA thin films.

Findings

Maximum growth exponent of 1/3 at the order-disorder transition

Growth exponents and activation enthalpies decrease exponentially with segregation strength

Diffusivity follows the same exponential trend as these kinetic parameters

Abstract

This paper reports the experimental determination of the growth exponents and activation enthalpies for the ordering process of standing cylinder-forming all-organic polystyrene-block-poly (methyl methacrylate) (PS-b-PMMA) block copolymer (BCP) thin films as a function of the BCP degree of polymerization (N). The maximum growth exponent of 1/3 is observed for the smallest BCP at the border of the order disorder transition. Both the growth exponents and the activation enthalpies exponentially decrease with the BCP segregation strength (chi N) following the same path of the diffusivity.