title: Sodium lignosulfonate as a renewable stabilizing agent for aqueous alumina suspensions.
abstract: The macromolecule sodium lignosulfonate (SL) has been investigated as dispersing agent for aqueous alumina colloids as a renewable alternative to usual petrochemical stabilizing agents. Optimization of the SL concentration necessary to stabilize the alumina suspension at different pH values was determined by viscometer. The results showed that addition of 250 ppm of the total suspension mass led to about 70% viscosity reduction of the suspension, whereas zeta potential analysis revealed negative values for the SL suspensions throughout the pH range investigated, suggesting that the alumina particles were covered by negatively charged SL molecules. Particle size investigation informed that the average particle diameter of the SL suspensions was smaller compared to that of the pristine particles. Sedimentation time for the SL suspensions was dramatically longer than that for the pristine one. The reported data strongly corroborated that SL is a suitable renewable dispersing agent for aqueous alumina colloids.
authors.affiliation: Institute of Chemistry, University of Campinas (UNICAMP), PO Box 6154, Campinas, SP 13083-970 Brazil.
authors.forename: Jackson D
authors.initials: JD
authors.lastname: Megiatto
authors.affiliation: Macromolecular Materials and Lignocellulosic Fibers Group, Center for Science and Technology of BioResources, Institute of Chemistry of São Carlos, University of São Paulo, CP 780, 13560-970 São Carlos, São Paulo, Brazil.
authors.forename: Bianca M
authors.initials: BM
authors.lastname: Cerrutti
authors.affiliation: Macromolecular Materials and Lignocellulosic Fibers Group, Center for Science and Technology of BioResources, Institute of Chemistry of São Carlos, University of São Paulo, CP 780, 13560-970 São Carlos, São Paulo, Brazil. Electronic address: elisabete@iqsc.usp.br.
authors.forename: Elisabete
authors.initials: E
authors.lastname: Frollini
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008031:Lignin / Q000031:analogs & derivatives* / Q000737:chemistry; D010316:Particle Size; D016062:Porosity; D014783:Viscosity
chemical_list: C001545:lignosulfuric acid; D008031:Lignin; D000537:Aluminum Oxide
keywords: Colloidal alumina; FOQELS; Sodium lignosulfonate