Impact of Cellulose Additives on the Macro- and Nanotribology of Surfactant Lamellar Phases

• Grant number: 24/06709-6
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate (Direct)
• Start date: November 01, 2024
• End date: July 03, 2025
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Watson Loh
• Grantee: Carla Manuela Sganzerla Sabino
• Supervisor: Emily Cranston
• Host Institution: Instituto de Química (IQ). Universidade Estadual de Campinas (UNICAMP). Campinas , SP, Brazil
• Institution abroad: University of British Columbia, Vancouver (UBC), Canada
• Associated to the scholarship: 21/13195-0 - Relationship between microstructure and macroscopic properties of materials formed by nanocelluloses and self-assembled surfactant aggregates, BP.DD

Abstract

Petroleum-based polymers are commonly used as additives to tailor specific properties or functionalities in formulations. Bio-based biodegradable polymers, such as polysaccharides, have been proposed as an alternative to preparing more sustainable formulations, including, in this scenario, the use of nanocelluloses. On the other hand, surfactants are molecules highly present in different products, and the lamellar phases are especially important in topical formulation thanks to their capacity to adsorb hydrophilic and hydrophobic additives and their lubrication properties. As observed in the ongoing project, the colloidal behaviour of these two components in suspension differs from their pure counterparts. In order to understand the surface forces that drive the interaction of these two components, nanocelluloses and surfactant lamellar phases, in solution, in this proposal, we aim to perform force-distance measurements by Atomic Force Microscopy. Moreover, Friction Force Microscopy (FFM) could provide information about the nanotribology mechanisms in a topical application and complement the force-distance measurements. The interaction forces could be measured between a colloidal probe modified with nanocelluloses and a supported surfactant bilayer. In contrast, the friction forces could be measured between a spherical silica particle and a substrate covered with the nanocellulose-surfactant samples. Macro tribology tests would also be performed with a tribometer, and the samples would be deposited in artificial skin to evaluate the sample's lubricant properties. While the AFM/FFM studies would help understand fundamental aspects of the nanocellulose surfactant interactions that are not consensual in the literature, the macro tribology tests would permit evaluate the practical application of the system as a lubricant.