Obtaining and characterizing IPMCs using triblock copolymers styrene-butadiene-styrene/cellulose nanocrystals nanocomposites as the electroactive material.

• Grant number: 22/14231-3
• Support Opportunities: Scholarships in Brazil - Master
• Start date: June 01, 2023
• End date: July 31, 2024
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Carlos Henrique Scuracchio
• Grantee: Paulo Oliveira Gall
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Ionomeric Polymer Metal Composite (or IPMC) stands out for their ability to act as mechanical actuators, being the subject of research in areas such as robotics and medicine, as well as electrical or deformation sensors. Its structure consists of a layer of electroactive polymer of the ionomeric type between two layers of metallic electrodes. This arrangement, when subjected to an electrical stimulus, undergoes a deformation relative to the applied voltage, and the inverse, the application of a deformation that results in an electrical response, is also possible. The material most used in IPMC studies is Nafion, a sulfonated polymer with a perfluorinated chain that, despite having excellent ionic conduction properties, brings with it some disadvantages such as high cost, low recyclability and biodegradability, and loss of conductivity in low humidity environments or at high temperatures. On the other hand, through the sulfonation of the polymer chain, we can achieve the conductive properties of interest with other polymers, including commercial ones, in addition to modifying the interaction between the constituent monomers in order to form nanostructures that help in the conduction process. The use of a block polymer such as SBS (styrene-butadiene-styrene) also adds to the mechanical properties of the composite, as it acts like an elastomer at room temperature, but can be manipulated like a thermoplastic at higher temperatures. Another point of interest is the study of the incorporation of fillers, especially from renewable sources, to modify both the mechanical properties and the ionic conduction mechanisms of the electroactive polymer. Thus, the use of cellulose nanocrystals, which have a high hydrophilic character, can help in the ionic conduction of the material as well as in the mechanical properties of the same, in addition to being a further step towards achieving sensors based on materials from renewable sources. In this context, the project proposes the sulfonation of a copolymer of the SBS type, the incorporation and dispersion of cellulose nanocrystals and the use of the resulting composite in the manufacturing of an IPMC and its characterization for use as a mechanical actuator.