Author(s): Souza, Reinaldo ; Nobrega, Glauco ; Afonso, Inês Santos ; Pereira, José ; Cardoso, Elaine ; Marques, Filipe ; Vilarinho, Cândida ; Moita, Ana ; Lima, Rui A.
Date: 2025
Persistent ID: http://hdl.handle.net/10198/35127
Origin: Biblioteca Digital do IPB
Subject(s): PDMS heat exchanger; Polymeric matrix composites; Waste particle; Thermal conductivity; Heat transfer
This study investigates the heat transfer performance of three types of heat exchangers: one made of pure polydimethylsiloxane (PDMS), another incorporating recycled graphite (PDMS + Graphite 30 mass%), and a third using commercial aluminium nanoparticles (PDMS + Aluminium 30 mass%). Thermal performance was evaluated by measuring the thermal conductivity of the materials, analysing experimental convection tests with deionized water in a single-phase regime and using a thermal camera to obtain temperature profiles of the different surfaces. The results revealed that the composites formed with PDMS matrix and recycled graphite showed elevated thermal conductivity, approximately 2.7 times higher than pure PDMS. The heat transfer coefficient performance was 2.5 times superior to that of the heat exchanger made with commercial aluminium nanoparticles and up to 5 times higher compared to pure PDMS. The thermal analysis highlighted the benefits of the composites, showing a more uniform temperature distribution both in the serpentine channel and along the sides of the PDMS. The study aimed to provide an economical alternative that also contributes to waste valorisation. These findings validate the effectiveness of recycled particles in improving heat transfer performance in heat exchangers made from a combination of PDMS matrix and recycled, economical materials.
