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    Quartz Crystal Microbalance with Dissipation Monitoring and Surface Plasmon Resonance Studies of Carboxymethyl Cellulose Adsorption onto Regenerated Cellulose Surfaces

    Year: 2011

    Journal: Langmuir, 2011, 27 (14), pp 8718–8728, 20110906

    Authors: Liu Z. †, Choi H. †, Gatenholm P., Esker A.R.*†

    Last authors: Alan R. Esker

    Organizations: Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, United States Department of Chemical and Biological Engineering, Biopolymer Technology, Chalmers University of Technology, SE-412 96 Göteborg, Sweden

    Country: Sweden, Sverige, USA, US, United States, United States of America, America

    Adsorption of anionic polyelectrolytes, sodium salts of carboxymethyl celluloses (CMCs) with different degrees of substitution (DS = 0.9 and 1.2), from aqueous electrolyte solutions onto regenerated cellulose surfaces was studied using quartz crystal microbalance with dissipation monitoring (QCM-D) and surface plasmon resonance (SPR) experiments. The influence of both calcium chloride (CaCl2) and sodium chloride (NaCl) on CMC adsorption was examined. The QCM-D results demonstrated that CaCl2 (divalent cation) caused significantly greater CMC adsorption onto regenerated cellulose surfaces than NaCl (monovalent cation) at the same ionic strength. The CMC layers adsorbed onto regenerated cellulose surfaces from CaCl2 solutions exhibited greater stability upon exposure to flowing water than layers adsorbed from NaCl solutions. Both QCM-D and SPR results showed that CMC adsorption onto regenerated cellulose surfaces from CaCl2 solutions increased with increasing CaCl2 concentration up to the solubility limit (10 mM). Voigt-based viscoelastic modeling of the QCM-D data indicated that the CMC layers adsorbed onto regenerated cellulose surfaces had shear viscosities of ηf ≈ 10–3 N·s·m–2 and elastic shear moduli of μf ≈ 105 N·m–2. Furthermore, the combination of SPR spectroscopy and QCM-D showed that the CMC layers contained 90–95% water. Adsorption isotherms for CMCs in CaCl2 solutions were also obtained from QCM-D and were fit by Freundlich isotherms. This study demonstrated that CMC adsorption from CaCl2 solutions is useful for the modification of cellulose surfaces.