Amphiphilic block copolymers are usually used as compatibilizer for polymers blends or as surfactant for emulsions. The organization and conformation of each block can be influenced by the interfacial interactions, especially if the blocks are able to crystallize. The objective of this work is focused on the effect of interface on the organization and crystallization of thin films of diblock copolymers deposited on model substrates.Polyethylene-b-Polyethylene glycol (PE-b-PEG) diblock copolymers have been deposited on aluminum and model substrates (hydrophilic and hydrophobic surface obtained by a chemical grafting of a gold layer deposited on a silicon wafer). Each block is able to crystallize. PE block is apolar (hydrophobic character), while PEG block is polar (hydrophilic character). The aim is therefore to understand how the affinity of each block towards a given surface can govern the copolymer organization and crystallization. Polarization-Modulation Infrared Reflection Absorption Spectroscopy (PM-IRRAS) is used to characterize PE-b-PEG thin films, in order to get information about the organization of both blocks. These results will be compared with bulk analyses performed by Attenuated Total Reflection Infrared Spectroscopy (ATR) in order to evidence specific chains organization in thin films. Atomic Force Microscopy (AFM) analyses were also performed on thin polymer layer in order to characterize the morphology and nanostructuration.Various PE-b-PEG copolymers (different compositions) have been deposited on substrates and studied by PM-IRRAS and AFM.   IR results have evidenced major differences in peaks intensities and positions between the thin films deposited on the various substrates.Influence on chains organization of both substrate surface chemistry and copolymers composition will be discussed in terms of molecular orientations that can be probed by PM-IRRAS specific selection rules. AFM imaging will allow us to confirm the copolymers organization.

Nanostructuration of diblock copolymers at interface

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.