DEVELOPMENT OF INTELLIGENT ACTUATORS BASED ON CELLULOSE NANOFIBRIL HYDROGELS INTEGRATING RESPONSIVE POLYMERS AND AMYLOIDS WITH THERMAL AND PH SENSITIVITY

• Grant number: 25/04899-5
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: November 01, 2025
• End date: January 31, 2029
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Juliana da Silva Bernardes
• Grantee: Gustavo Oliva Amaral
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Campinas , SP, Brazil
• Associated research grant: 24/00989-7 - Research Center of Molecular Engineering for Advanced Materials (CEMol), AP.CEPID

Abstract

Nanocellulose, recognized as an advanced material, has garnered attention for its inherent properties, including biodegradability and its potential to serve as a substitute for synthetic polymers. Its combination with other polymeric materials allows the creation of smart actuators with characteristics responsive to temperature and pH stimuli, with applications in biomedicine and soft robotics. However, challenges such as balancing responsiveness and durability still need to be overcome. Thus, the proposed project aims to develop intelligent hydrogels that can be used as actuators by combining the thermoresponsiveness of poly(di(ethylene glycol) methyl ether methacrylate) (PDEGMA) and the pH-responsiveness of oxidized cellulose nanofibrils (CNFs) and oxidized CNFs (TO-CNFs) combined with amyloid fibrils (Afs), creating bilayer and gradient structures, with the objective of investigating and comparing their physicochemical characteristics, mechanical properties, and responsiveness to thermal and pH stimuli. To achieve this objective, hydrogels of CNFs + PDEGMA, TO-CNFs and TO-CNFs + amyloids will be prepared and characterized by the techniques of: Fourier-transform infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-Vis), atomic force microscopy (AFM), cryogenic transmission electron microscopy (Cryo-TEM), and rheology. Then, the manufacture of bilayer and gradient actuators will be carried out, in which it is planned to conduct analyses to characterize and measure the levels of response to thermal and pH stimuli of the structures. Such mechanical tests will be combined with structural mechanics simulations, allowing for the quantitative correlation of the physicochemical responses of hydrogel actuators to their mechanical deformations. The data will be analyzed and replicated for different synthesis routes, allowing for the statistical evaluation of the durability, reproducibility, and repeatability of the mechanical responses of intelligent nanocellulose hydrogels.