Adsorption of Linear Flexible Polymers and Globular Proteins on Nano-heterogeneous Surfaces
Department of Chemical and
Biomolecular Engineering
Adsorption of polymers and proteins is associated with numerous applications such as colloidal stabilization, making biocompatible materials and biosensor. The surfaces used in these applications are generally heterogeneous and yet quantitative experimental study about the effect of surface heterogeneity on adsorption is non-existent. Using the tools of molecular assembly, we have created surfaces that are heterogeneous on length-scales commensurate to typical polymer chains (Rg ~10-100nm). Physical heterogeneity is established using scanning probe microscopy. Chemical heterogeneity is established by electrochemical characterization on macroscopic length-scales and by scanning probe microscopy on microscopic length-scales. In the paper, results of adsorption of flexible polymers as well as globular proteins on the heterogeneous surfaces will be presented. The effects of parameters such as molecular weight, pH, flow, and concentration on the dynamics and static properties will be discussed. These experiments represent the first systematic experimental study of the impact of nanometer scale heterogeneity on adsorption of polymers.