title: Reliable dn/dc Values of Cellulose, Chitin, and Cellulose Triacetate Dissolved in LiCl/N,N-Dimethylacetamide for Molecular Mass Analysis.
abstract: Freeze-dried microfibrillated cellulose (MFC) was directly dissolved in 8.0% w/w lithium chloride/N,N-dimethylacetamide (LiCl/DMAc), and MFC/LiCl/DMAc solutions with accurate MFC concentrations were prepared. The different MFC solutions were diluted to 1.0% and 0.5% w/v LiCl/DMAc, and subjected to size-exclusion chromatography with multiangle laser-light scattering and refractive index analyses (SEC/MALLS/RI), and off-line RI analysis to determine their refractive index increments (dn/dc). Chitin, cellulose triacetate, a poly(styrene) standard, and cellobiose were used for comparison. Each of the two determination methods gave different dn/dc values for MFC and chitin but similar dn/dc values for cellulose triacetate and poly(styrene). The anomalously small dn/dc values of MFC and chitin were explainable in terms of stable cellulose-LiCl and chitin-LiCl structures (i.e., formation of apparent covalent bonds between hydroxyl groups and LiCl) in the solutions. Thus, the SEC/MALLS/RI method provides reliable molecular mass parameters for cellulose and chitin.
authors.affiliation: Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo 113-8657, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Ono
authors.affiliation: Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo 113-8657, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Ishida
authors.affiliation: Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo 113-8657, Japan.
authors.forename: Hiroto
authors.initials: H
authors.lastname: Soeta
authors.affiliation: Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo 113-8657, Japan.
authors.forename: Tsuguyuki
authors.initials: T
authors.lastname: Saito
authors.affiliation: Department of Biomaterials Science, Graduate School of Agricultural and Life Sciences, The University of Tokyo , Tokyo 113-8657, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Isogai
mesh_terms: D000081:Acetamides / Q000737:chemistry*; D002475:Cellobiose / Q000737:chemistry; D002482:Cellulose / Q000031:analogs & derivatives* / Q000032:analysis / Q000737:chemistry*; D002686:Chitin / Q000032:analysis / Q000737:chemistry*; D002850:Chromatography, Gel; D018021:Lithium Chloride / Q000737:chemistry*; D008970:Molecular Weight; D011137:Polystyrenes / Q000737:chemistry; D012031:Refractometry / Q000379:methods; D012995:Solubility; D012997:Solvents / Q000737:chemistry
chemical_list: D000081:Acetamides; D011137:Polystyrenes; D012997:Solvents; D002686:Chitin; D002475:Cellobiose; D002482:Cellulose; C024671:cellulose triacetate; D018021:Lithium Chloride; C013959:dimethylacetamide