title: Fabrication of cationic cellulosic nanofibrils through aqueous quaternization pretreatment and their use in colloid aggregation.
abstract: The aqueous pre-treatment of cellulose with periodate and Girard' reagent T was employed as a novel and promising method to promote nanofibrillation of wood pulp and to obtain cellulosic nanofibrils with cationic functionality (CNFC). To demonstrate the feasibility of CNFCs in particle aggregation, a kaolin clay model suspension was aggregated by the CNFCs. Direct high-pressure homogenization of cationized cellulose resulted in nanofibrils exhibiting typical widths of 10-50 nm and cationic charge densities ranging from 1.10 to 2.13 mequiv.g(-1). The nanofibril suspensions existed in the form of highly transparent gels and possessed cellulose I crystalline structures. All of the CNFCs promoted strong aggregation of kaolin and produced voluminous kaolin-CNFC aggregates with lateral dimensions of several millimeters. Moreover, the CNFCs maintained good aggregation performance through wide pH (3-9) and temperature (25-60 °C) ranges. Thus, CNFCs were shown to be highly potential candidates for replacement of present synthetic soluble flocculation and coagulation aids.
authors: Fibre and Particle Engineering Laboratory, P.O. Box 4300, FI-90014, University of Oulu, Finland. Electronic address: Henrikki.Liimatainen@Oulu.fi.
authors: Henrikki
authors: H
authors: Liimatainen
authors: Fibre and Particle Engineering Laboratory, P.O. Box 4300, FI-90014, University of Oulu, Finland. Electronic address: Terhi.Suopajarvi@Oulu.fi.
authors: Terhi
authors: T
authors: Suopajärvi
authors: Fibre and Particle Engineering Laboratory, P.O. Box 4300, FI-90014, University of Oulu, Finland. Electronic address: Juho.Sirvio@Oulu.fi.
authors: Juho
authors: J
authors: Sirviö
authors: Department of Chemistry, P.O. Box 3000, FI-90014, University of Oulu, Finland. Electronic address: Osmo.Hormi@Oulu.fi.
authors: Osmo
authors: O
authors: Hormi
authors: Fibre and Particle Engineering Laboratory, P.O. Box 4300, FI-90014, University of Oulu, Finland. Electronic address: Jouko.Niinimaki@Oulu.fi.
authors: Jouko
authors: J
authors: Niinimäki
keywords: Dialdehyde cellulose; Girard’ reagent T; Kaolin clay; Nanocellulose; Nanofibrillation