Acquisition of a Scanning Probe Microscope for Liquids Material Research and Student Training

Kansas State University, Manhattan KS

Investigators

Abstract

This grant is for the acquisition of a scanning probe microscope (SPM) possessing both good temperature control and a sealed sample cell for the study of liquid samples. The instrument will be used to provide the first SPM study of surface behavior of liquids near either a wetting transition or a bulk critical point. These measurements will complement ongoing optical studies of these phenomena and provide a new perspective on these topics. Some subjects to be studied include droplet shapes, line tensions, and surface interaction potentials. Droplets on both homogeneous silane-coated and hydrophilic/hydrophobic silane-patterned silicon substrates will be studied to ascertain the interactions between the line tension and the surface potential. Other factors considered include the influence of molecular-scale surface roughness and heterogeneity on the contact angle and line tension. The study will significantly enhance understanding of the wettability of surfaces. Surface phenomena, such as adsorption and wetting, play extremely important roles in many physical, chemical and biological processes. Important information about the processes of adsorption and wetting, and how they are influenced by surface interactions and by processes occurring simultaneously in the bulk, can be deduced by studying these phenomena near either a surface or bulk transition point, such as a wetting transition or a bulk critical point. The SPM should have significant impact on the education and training of graduate and undergraduate students by enabling them to conduct both optical and SPM measurements of the same or similar phenomena.