title: Understanding the lateral movement of particles adsorbed at a solid-liquid interface.
abstract: In this paper we study the phenomenon of lateral movement of particles that are electrostatically adsorbed at a solid-liquid interface. The experimental system involves negatively charged silica particles of two different sizes (65 nm and 90 nm) that are exposed to the positively charged solid surface (silane coated silicon wafer) in sequential steps. The particle-adsorbed wafers are analyzed under a scanning electron microscope and the images are processed to determine the pair-correlation function for the particles adsorbed in the first step. From the pair correlation data and the particle surface coverage data we show that the adsorbed particles are mobile at the solid-liquid interface. In specific, we show that the adsorbed particles are mobile at the solid-liquid interface when there is a driving force for the adsorbed particles to move. The driving force in the scheme of experiments discussed in this paper is the reduction in the free energy of the system.
authors.affiliation: Department of Chemical Engineering, The City College of City University of New York, New York, NY 10031, United States.
authors.forename: Kunal
authors.initials: K
authors.lastname: Savaji
authors.affiliation: Department of Chemical Engineering, The City College of City University of New York, New York, NY 10031, United States.
authors.forename: Xue
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Chemical Engineering, The City College of City University of New York, New York, NY 10031, United States. Electronic address: couzis@ccny.cuny.edu.
authors.forename: Alexander
authors.initials: A
authors.lastname: Couzis
keywords: Free energy minimization; Lateral movement of adsorbed particles; Pair-correlation function; Salt concentration of suspension; Silica particles