Evolution of Surface Morphologies in Multivariant Assemblies of Surface-Tethered Diblock Copolymers after Selective Solvent Treatment

Abstract

We study systematically the topography behavior of PHEMA-b-PMMA block as a function of the PHEMA and PMMA block lengths after selectively collapsing the top (PMMA) block by using surface-anchored assemblies of poly(2-hydroxyethyl methacrylate-b-methyl methacrylate), PHEMA-b-PMMA, block copolymer with orthogonally varying lengths of each block. Our experimental results are in excellent qualitative agreement with topology diagrams predicted by self-consistent field calculations of Zhulina and co-workers.

Polymer Brushes with Nanometer‐Scale Gradients

“…[7,8] A special case that has attracted considerable interest lately, is the generation of molecular gradients in surface-attached polymer layers where parameters such as graft density, molecular weight, or composition of the surface-attached chains are varied laterally. [9][10][11][12][13][14][15] These so called 'gradient brushes' allow a systematic variation of surface properties across the substrate and can be used to influence the phase separation in diblock copolymer systems, [16,17] or to control the adhesion of biological cells. [18,19] They can also help to improve the understanding of the physics of brush systems, as they allow one to vary on a single substrate, for example, the graft density and/or the molecular weight.…”

Surface-chemical and -morphological gradients

“…Tomlinson and Genzer used gradual draining of a monomer solution from a vessel to generate brush-like polymer gradients with a gradually changing molecular weight, 65,66 Fig. 6a, step A.…”

“…(c-e) PHEMA (red squares) and total copolymer (blue circles) thicknesses along the directions depicted in the total thickness profile shown in part b. 66 2.2.1. Particles.…”

“…One widely used approach to create morphological gradients is to bind particles onto a smooth substrate. Genzer and his colleagues 62,66,[91][92][93] have established a simple but highly efficient procedure to create nanofeature gradients by creating gradients of polymers and then adsorbing gold particles. They have employed two basic principles to create one-dimensional gradients or a combination of both to prepare two-dimensional gradients.…”

Combinatorial and High‐Throughput Methods in Macromolecular Materials Research and Development

“…[74][75][76][77][78] Several researchers have made surface-grafted polymers that have gradients in variables such as polymer chain length, composition, and graft density. [79][80][81][82][83][84][85][86][87][88][89] …”