Novel thermal conductivity and anti-corrosion coating with hydrophobic properties for heat exchanger applications

Industrial heat exchangers commonly encounter the issue of metal corrosion. Conventional anti-corrosion coatings typically exhibit poor heat conduction, leading to diminished heat exchange efficiency. This study presents a novel coating that combines high thermal conductivity with enduring anti-corrosion performance. The interfacial compatibility between the boron nitride (BN) / silicon carbide (SiC) and fluorosilicone resin (FSR) is effectively enhanced through fluorosilane modification. This improvement, in conjunction with the superior thermal conductivity of the BN/SiC composite filler and the multi-barrier effects of the two-dimensional BN material, results in the composite coating with a high thermal conductivity of 1.65 W/(m·K). After 60 days of immersion in 3.5 wt% NaCl solution, the coating maintains a low-frequency impedance exceeding 1011 Ω·cm2. Good hydrophobicity can promote the long-term anti-corrosion performance of the coating. Thanks to the inherent hydrophobicity of FSR and the reduced surface energy of the filler due to fluorosilane modification, the coating also exhibits hydrophobic characteristics, evidenced by a water contact angle of 109.69°. The development of this novel multifunctional coating holds significant implications for heat exchangers and other applications requiring a balance between thermal conductivity and anti-corrosion performance.