Cellulose nanocrystals and nanofibrils grafted with poly(2-alkyl-oxazolines)

• Grant number: 23/07122-6
• Support Opportunities: Scholarships in Brazil - Doctorate (Direct)
• Start date: August 01, 2023
• End date: June 30, 2027
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Camila Alves de Rezende
• Grantee: João Pedro Gumiero Rodrigues
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Associated research grant: 21/12071-6 - Tailoring colloids through supramolecular interactions: from fundamentals to applications, AP.TEM

Abstract

In this DSc project, the focus lies on exploring hybrid materials comprising of cellulose nanocrystals (CNC) and nanofibrils (CNF) modified with poly(2-alkyl-2-oxazolines) (POx) to create responsive hydrogels and aerogels. By grafting responsive polymers onto the cellulose nanoparticles, innovative properties can be imparted, making them suitable for various biomedical applications. The advantageous features of these hybrid systems include low toxicity, easy surface functionalization, and responsiveness to external stimuli like temperature, pH, ionic force, and UV radiation. The alkyl groups in the POx can be tailored to achieve the desired lower critical solution temperature (LCST) behavior in aqueous solutions and the responsiveness of the (co)polymers can be controlled by composition, post-functionalization, and hydrolysis. Moreover, the colloidal properties of the hybrid materials can be fine-tuned by adjusting the polymer/nanocellulose ratios, CNC/CNF ratios, monomer combinations, hydrolysis degree, molar mass, and molar mass dispersity. This combination of POx with nanocelluloses allows for the preparation of reinforced hydrogels with customizable properties such as swelling degree and mesh size, regulated by temperature or pH. Interestingly, limited research exists on the combination of nanocellulose and POx, making this project a significant contribution to the field. The resulting hydrogel and aerogel forms of these hybrid materials hold immense potential for applications in drug delivery systems and tissue engineering. (AU)