Synthesis and Nanomorphology of Tethered Block Copolymer Brushes

University Of Akron, Akron OH

Investigators

Abstract

A systematic investigation into tethered block copolymer brushes is proposed. The impetus for this work stems from preliminary results where a polystyrene-block-poly(methyl methacrylate) polymer was created by the "grafting-from" approach on a silicate substrate. Treatment with block-selective solvents effected reversible contact changes that were interpreted in terms a model that placed either polystyrene or PMMA at the air interface. The purpose of the proposed research is to confirm the speculative models for this system. The 1st goal is to better characterize the PS-b-PMMA bush by correlating film thickness with Mp, determination of chain length dispersity, determination of percent PS homopolymer and a more complete characterization of nanostructure composition. The 2nd goal is to study the dynamics of surface reorganization by a systematic variation in temperature and solvent. The 3rd goal is to develop alternative polymerization methods for block copolymer brushes. A 4th goal is to expand the composition of the tethered block copolymers by including new monomers (e.g., fluorinated and water-soluble monomers) and the preparation of tethered triblock copolymers. The 5th goal is to control the distribution of tethered block copolymers by using mixed self-assembled monolayers, microcontact printing or stereolithography. Successful completion of this proposed research will have several potential benefits to society. The synthesis and characterization of polymer brushes will have a large impact on colloidal stabilization, which is critical for stable emulsion and latex formulations. Other applications include new adhesives, protein-resistance biosurfaces, chromatographic separation of biomolecules, lubricants and polymer blend compatibilization. ***