title: Surface plasmon resonance studies of pullulan and pullulan cinnamate adsorption onto cellulose.
abstract: Surface plasmon resonance studies showed pullulan cinnamates (PCs) with varying degrees of substitution (DS) adsorbed onto regenerated cellulose surfaces from aqueous solutions below their critical aggregation concentrations. Results on cellulose were compared to PC adsorption onto hydrophilic and hydrophobic self-assembled thiol monolayers (SAMs) on gold to probe how different interactions affected PC adsorption. PC adsorbed onto methyl-terminated SAMs (SAM-CH(3)) > cellulose > hydroxyl-terminated SAMs (SAM-OH) for high DS and increased with DS for each surface. Data for PC adsorption onto cellulose and SAM-OH surfaces were effectively fit by Langmuir isotherms; however, Freundlich isotherms were required to fit PC adsorption isotherms for SAM-CH(3) surfaces. Atomic force microscopy images from the solid/liquid interfaces revealed PC coatings were uniform with surface roughnesses <2 nm for all surfaces. This study revealed hydrogen bonding alone could not explain PC adsorption onto cellulose and hydrophobic modification of water-soluble polysaccharides was a facile strategy for their conversion into surface modifying agents.
authors.affiliation: Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, USA.
authors.forename: Abdulaziz
authors.initials: A
authors.lastname: Kaya
authors.forename: Xiaosong
authors.initials: X
authors.lastname: Du
authors.forename: Zelin
authors.initials: Z
authors.lastname: Liu
authors.forename: Jessica W
authors.initials: JW
authors.lastname: Lu
authors.forename: John R
authors.initials: JR
authors.lastname: Morris
authors.forename: Wolfgang G
authors.initials: WG
authors.lastname: Glasser
authors.forename: Thomas
authors.initials: T
authors.lastname: Heinze
authors.forename: Alan R
authors.initials: AR
authors.lastname: Esker
mesh_terms: D000327:Adsorption; D002482:Cellulose / Q000737:chemistry*; D002934:Cinnamates / Q000737:chemistry*; D005936:Glucans / Q000737:chemistry*; D011485:Protein Binding; D013438:Sulfhydryl Compounds / Q000737:chemistry; D020349:Surface Plasmon Resonance / Q000379:methods*; D013499:Surface Properties
chemical_list: D002934:Cinnamates; D005936:Glucans; D013438:Sulfhydryl Compounds; C009109:pullulan; D002482:Cellulose