Adhesion on polyethylene glycol and quaternary ammonium salt-grafted silicon surfaces: Influence of physicochemical properties

The aim of this work was to develop a new generation of antimicrobial materials. In order to restrict surface contamination by micro-organisms, the approach developed consisted in modifying the surface properties of a silicone wafer by grafting antimicrobial compounds such as quaternary ammonium salts (QAS) and polyethylene glycol (PEG). Under this approach, the grafted compound was endowed with a functionalised extremity which allowed it to react with the silicone wafer in order to form a covalent bond. The first part of this paper describes the synthesis of QAS and PEG molecules, and then the physicochemical characteristics of the modified silicon surfaces were determined. The second part concerned determination of the surface properties of the wafers and polystyrene beads used for adhesion tests. In line with the extended DLVO theory, it was thus possible to understand the mechanisms involved in the adhesion of polystyrene beads to the surface of QAS and PEG-modified silicon wafers.