title: Internal surface polarity of regenerated cellulose gel depends on the species used as coagulant.
abstract: Cellulose gels regenerated from aqueous alkali-urea solvent were found to have different surface polarity depending on coagulant species. Gels coagulated by alcohols adsorbed Congo red about twice as much as those coagulated by aqueous coagulants. The difference was also noted in the iodine reaction; the alcohol-coagulated gels showed blue coloration similar to that of iodine-starch reaction in contrast to those from aqueous coagulants, which gave light yellow colors similar to that of the original iodine solution. These phenomena can be ascribed to the influence of coagulant species on the surface nature of cellulose fibrils internal to the gels. X-ray diffractometry indicated that the hydrophobicity was likely to result from exposure of glucopyranoside ring planes on the surface of cellulose fibrils. Scanning electron microscopy showed characteristic differences in nanometer-scale morphologies between the two types of cellulose gel.
authors.affiliation: Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan. eaab7154@nifty.com
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Isobe
authors.forename: Ung-Jin
authors.initials: UJ
authors.lastname: Kim
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kimura
authors.forename: Masahisa
authors.initials: M
authors.lastname: Wada
authors.forename: Shigenori
authors.initials: S
authors.lastname: Kuga
mesh_terms: D002482:Cellulose / Q000737:chemistry*; D003029:Coagulants / Q000737:chemistry*; D005782:Gels / Q000737:chemistry; D010316:Particle Size; D013499:Surface Properties
chemical_list: D003029:Coagulants; D005782:Gels; D002482:Cellulose