title: Colloidal stability of negatively charged cellulose nanocrystalline in aqueous systems.
abstract: Colloidal stability of negatively charged cellulose nanocrystalline (CNC) in the presence of inorganic and organic electrolytes was investigated by means of dynamic light scattering and atomic force microscopy. CNC could be well dispersed in distilled water due to the electrostatic repulsion among negatively charged sulfate ester groups. Increasing the concentration of inorganic cation ions (Na(+) and Ca(2+)) resulted in CNC aggregation. CNC in divalent cation ion Ca(2+) solution exhibited less stability than that in monovalent cation ion Na(+) solution. Organic low-molecular-weight electrolyte sodium dodecyl sulfate (SDS) favored the stability of CNC suspension, whereas organic high-molecular-weight electrolyte sodium carboxymethyl cellulose (CMC) induced CNC particle aggregation due to intermolecular bridging interaction or entanglement. Cationic polyacrylamide (CPAM) caused a serious aggregation of CNC particles even at low concentration of CPAM. At low ionic strength (Na(+), 1 mM), CNC were stable in aqueous solution at the pH range of 2-11.
authors.affiliation: College of Material Science and Technology, Beijing Forestry University, Beijing, China.
authors.forename: Linxin
authors.initials: L
authors.lastname: Zhong
authors.affiliation: State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China.
authors.forename: Shiyu
authors.initials: S
authors.lastname: Fu
authors.affiliation: State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China.
authors.forename: Xinwen
authors.initials: X
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou 510640, China.
authors.forename: Huaiyu
authors.initials: H
authors.lastname: Zhan
authors.affiliation: College of Material Science and Technology, Beijing Forestry University, Beijing, China.
authors.forename: Runcang
authors.initials: R
authors.lastname: Sun