Preparation of thermally conductive flexible liquid silicone rubber composites by magnetic field-induced self-assembly of Fe3O4@C

Efficient heat dissipation is very crucial for the performance, service life, and reliability of modern electronic devices. It is very challenging to improve heat dissipation efficiency through innovative material structure design. Therefore, in the work, dopamine (PDA) is used to coat the surface of graphite (C) with its excellent surface coating modification ability, so that the C surface has oxygen-containing groups to change its electronegativity, and Fe 2+ and Fe 3+ in the solution are attracted to the surface of C, and then in situ redox reaction occurs on the surface of C to generate magnetic graphite (Fe 3 O 4 @C). Fe 3 O 4 @C is uniformly dispersed into liquid silicone rubber (LSR) by solution blending, and Fe 3 O 4 @C performs integral directional filling in the LSR under the action of magnetic field ( B = 140 mT), thus preparing Fe 3 O 4 @C/LSR composites. Through magnetic field orientation, the thermal conductivity of Fe 3 O 4 @C/LSR composites reach 1.25 W/m·K when the content of Fe 3 O 4 @C is 100 phr, which is 410% higher than that of pure LSR (0.2447 W/m·K). Infrared thermal imaging test shows that Fe 3 O 4 @C/LSR composites has good heat dissipation performance, Fe 3 O 4 @C/LSR composites have shown great potential in terms of flexibility and high thermal conductivity.