Surfactant adsorption on a solid surface is a key issue in many different and diverse areas. For example, adsorption is a key and necessary step for the removal of particulate contaminates (e.g. dirt!) from clothes, dishes and hard surfaces. As another example, processes that are used to separate different minerals often use surfactant adsorption as the key separation vehicle. A final example is in recycling of paper; surfactant adsorption is used to remove ink particulates from the printed page. Surfactant adsorption is also very important in the semiconductor industry as well as enhanced oil recovery. Our group is interested primarily in the fundamentals of this process.
With Dr. Alberto Striolo, our group has an NSF-funded project to look at the effect of surface roughness on adsorption. Our efforts are both in the theoretical and experimental areas, and our goal is to understand how roughness affects adsorption; for example preliminary results suggest that a random roughness significantly reduces surfactant adsorption (by 100% or more) and also yields a film that can be much more flexible than that on a flat (e.g. almost molecularly smooth) surface. We will create surfaces with controlled roughnesses (both in a surface area and a morphological sense) and study the morphology of the adsorbed films using atomic force microscopy.
H. Gecol, J.F. Scamehorn, S.D. Christian, B.P. Grady, and F.E. Riddell, “Use of Surfactants to Remove Water Based Inks from Plastic Films”, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 189, 55 (2001).
A.D.W. Carswell, A.M. Lowe, X. Wei, B.P. Grady, “CMC Determination in the Presence of Surfactant-Adsorbing Inorganic Particulates”, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 212, 147 (2003).
C. Gutig, B.P. Grady, A. Striolo, “Experimental Studies on the Adsorption of Two Surfactants on Solid-Aqueous Interfaces: Adsorption Isotherms and Kinetics” Langmuir, 24, 4806 (2008); Correction: Langmuir, 24, 13814 (2008).
L. Shi, M. Ghezzi, G. Caminati, P. Lo Nostro, B.P. Grady, A. Striolo, “Adsorption Isotherms of Aqueous C12E6 and CTAB Surfactants on Solid Surfaces in the Presence of Low-Molecular-Weight Co-Adsorbents”, Langmuir, 25, 5536 (2009)
N.R. Tummala, B.P. Grady, A. Striolo, Lateral confinement effects on the structural properties of surfactant aggregates: SDS on graphene, Physical Chemistry Chemical Physics, 12, 13137 (2010)
J.L. Lopata, K.M. Werts, J.F. Scamehorn, B.P. Grady, “Thermodynamics of Mixed Anionic/Nonionic Surfactant Adsorption on Alumina”, Journal of Colloid and Interface Science, 342, 415 (2010).
S. Wu, L. Shi, L. B. Garfield, R.F. Tabor, A. Striolo, and B. P. Grady, Influence of Surface Roughness on Cetyltrimethylammonium Bromide (CTAB) Adsorption from Aqueous Solution, accepted Langmuir