HR: 1340h
AN: B33C-1038    [Abstracts]
TI: Polysaccharide Adsorption to Alumina and Silica Surfaces: Quartz Crystal Microbalance with Dissipation and Molecular Dynamics Simulations Studies
AU: * Kwon, K D
EM: kkwon@geosc.psu.edu
AF: Department of Geosciences, The Pennsylvania State University, University Park, PA 16802 United States
AU: Green, H
EM: hans.green@q-sense.com
AF: Q-Sense AB, Redegatan 13, Västra Frolunda, SE-426 77 Sweden
AU: Bjöörn, P
EM: patrik.bjoorn@q-sense.com
AF: Q-Sense Inc., 1200 Quail Street, Newport Beach, CA 92660 United States
AU: Kubicki, J D
EM: kubicki@geosc.psu.edu
AF: Earth & Environmental Systems Institute, The Pennsylvania State University, University Park, PA 16802 United States
AB: Quartz Crystal Microbalance with Dissipation (QCM-D) was used to investigate kinetics of dextran adsorption to alumina and silica surfaces. The adsorbed amount of dextran and its conformations were determined on Al2O3-coated and SiO2-coated quartz crystals by real-time monitoring resonance frequency change and energy dissipation change of the coated crystals. After rinse of the crystals in a flow-through cell at pH 6 and 22 °C, the apparent mass of retained dextran was 83 ng/cm² on the alumina surface and 30 ng/cm² on the silica surface based on the linear relationship between the frequency change and adsorbed mass. The ratios of frequency change and dissipation change, which are related to the conformation of the polymers on the surfaces, suggest significantly different adsorption behaviors of dextran on alumina and silica surfaces. The different adsorption behaviors are likely to affect the distribution of pollutants in soils and aquifers. Molecular dynamics simulations of 10 monomeric units of dextran on a silica slab illustrate that H2O molecules leads to loosely bound dextran structure onto SiO2 surface, which was reflected as high energy dissipation in the QCM-D experiments. This study shows that QCM-D technique is very promising in diverse environmental and biogeochemical studies due to its high sensitivity (ng/cm²) of adsorbed mass and long-range structural (viscoelastic) information with real time.
DE: 0400 BIOGEOSCIENCES
DE: 0409 Bioavailability: chemical speciation and complexation
DE: 0412 Biogeochemical kinetics and reaction modeling (0414, 0793, 1615, 4805, 4912)
DE: 1000 GEOCHEMISTRY
SC: Biogeosciences [B]
MN: Fall Meeting 2005