Controlling the Interactions between Cationic Nanocellulose and Other Colloids for the Design of Functional Materials

• Grant number: 24/20969-0
• Support Opportunities: Regular Research Grants
• Start date: April 01, 2025
• End date: March 31, 2028
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Juliana da Silva Bernardes
• Grantee: Juliana da Silva Bernardes
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia e Inovação (Brasil). Campinas , SP, Brazil
• Associated researchers: Diego Magalhães do Nascimento ; Elisa Silva Ferreira
• Associated scholarship(s): 25/07212-0 - Elucidating the structure of cellulose nanofibril networks by Cryogenic Transmission Electron Microscopy, BP.TT

Abstract

There has been growing interest in producing materials from cellulose nanofibrils (CNFs) extracted from biomass, aiming for environmentally low-impact alternatives. To develop functional materials, combining CNFs in water with other colloids is generally necessary to add specific functionalities. In most reported studies, cellulose nanofibrils have negative electrostatic charges and are combined with similarly charged colloids to prevent aggregation. However, the possibility of extracting cationic CNFs, still scarcely reported in the literature, broadens the applications of these nanomaterials by allowing attractive electrostatic interactions with negatively charged colloids. These interactions can destabilize colloidal systems, presenting a challenge in the production of materials. However, controlling the aggregation can lead to materials with enhanced mechanical, barrier, and adhesion properties. This control is an innovative tool in the design of cellulosic materials, as colloidal stability is generally required in the preparation of homogeneous or organized materials. Besides the attractive interactions between CNFs and other colloids, network formation is crucial in developing materials containing these nanofibrils. CNFs form gels at low concentrations, which is advantageous for applications such as thickeners and stabilizers in formulations. However, network formation can negatively affect materials with strong barriers and adhesion properties. Preparing dispersions with high solid content and increasing viscosity is challenging, which limits the application of these materials on various substrates. This project proposes using attractive forces to prepare functional materials from cationic cellulose nanofibrils, aiming at the decontamination of effluents and coating and adhesion of substrates. In addition to controlling the interactions between cationic CNFs and other colloids, network formation will be adjusted according to the desired application. The expected results will expand knowledge about CNF colloids in aqueous media and enable the production of new cellulosic materials prepared in water using non-toxic chemicals and scalable methods. (AU)