Table of Contents
International Journal of Carbohydrate Chemistry
Volume 2013 (2013), Article ID 242684, 8 pages
http://dx.doi.org/10.1155/2013/242684
Research Article

Combination of Natural and Thermosensitive Polymers in Flocculation of Fine Silica Dispersions

1Instituto Tecnológico de Tijuana, Centro de Graduados e Investigación, Apartado Postal 1166, 22000 Tijuana, BC, Mexico
2Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Straβe 6, 01069 Dresden, Germany

Received 16 July 2013; Accepted 12 September 2013

Academic Editor: Jianjun Li

Copyright © 2013 Angel Licea-Claverie et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

A novel strategy for faster and better flocculation in solid-liquid separation processes is reported: the use of the natural polyelectrolyte chitosan (CH2500) in combination with the biocompatible thermosensitive polymer poly(N-vinylcaprolactam) (PNVCL). Silica dispersions (Aerosil OX50) were used as model and evaluated by means of analytical centrifuge, laser diffraction, and turbidimetry studies. Results show that the sedimentation velocity is doubled by addition of PNVCL and that at 45°C the density of the sediment is 33% higher, as compared to the use of CH2500 only. This results from the temperature sensitive behavior of PNVCL that phase-separate expelling water at temperatures higher than its LCST (32–34°C) leading to compaction of the flocs. By using this strategy the sediment is more compact, contains less water, and contains a very small amount of biodegradable CH2500 and biocompatible PNVCL.