Dispersion of cellulose nanocrystals in aqueous media

• Grant number: 19/00584-9
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2019
• End date: August 31, 2022
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Agreement: Consortium of Alberta, Laval, Dalhousie and Ottawa (CALDO)
• Mobility Program: SPRINT - Projetos de pesquisa - Mobilidade
• Principal Investigator: Watson Loh
• Grantee: Watson Loh
• Principal researcher abroad: Michael KC Tam
• Institution abroad: University of Waterloo, Canada
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated researchers: Juliana da Silva Bernardes
• Associated research grant: 15/25406-5 - Organizing matter: colloids formed by association of surfactants, polymers and nanoparticles, AP.TEM

Abstract

In order to produce stable and processable cellulose nanocrystals (CNCs), fundamental understanding of the relationship between the surface chemistry, interaction forces and colloidal stability of CNCs is necessary. We will develop analytical tools for the quantification of interaction forces, macroscopic evaluation of the stability of CNCs, and chemical modification of CNCs. By careful analysis of the structural-property relationship between the surface properties of CNCs and their interactions in aqueous solution, critical factors controlling the stability of CNCs will be identified. Based on this knowledge, we will develop protocols for the manufacture of stable CNCs. We will also evaluate and elucidate the impact of additives on the colloidal stability of CNCs. The impact of drying and modes of removal of hydration water on the dispersibility of CNC in water will be examined. The role of functionalization of CNC with oligomers or polymers on the colloidal stability of CNCs will be pursued. The dual purposes of functionalization are to introduce electrostatic and steric stabilization to the CNC. Strategies to perform such modification within the current manufacturing process would be explored. Functionalization not only enhances the stability of CNCs, but it can also be used to impart new properties and functionalities that may be critical for CNC incorporation in product formulations. It is hoped that this research will advance our understanding of the behaviour of CNC in aqueous solution that will enhance the application and use of CNC in new applications. We will further conduct a comprehensive study of several factors known or believed to influence agglomerate formation in aqueous dispersions, and to examine the effects of varying multiple factors simultaneously. We will study the process and kinetics of CNC agglomeration under various conditions, but primarily focused on those present in the final stages of CNC manufacturing. Such scientific knowledge and development will be relevant to our industrial partners in Canada (CelluForce Inc.), and in Brazil (Suzano & Fibria). (AU)