| With its unique molecular structure and excellent performance,silicone rubber has been applied in many fields of military and civil.The structure and properties of functional fillers are important to enhance the comprehensive properties of silicone rubber materials.In order to enrich the application potential of silicone rubber,the traditional solution is to introduce single or multiple fillers into the matrix to improve a certain comprehensive performance of silicone rubber composites.The limitation is that the application of silicone rubber is limited because of the incompatibility between fillers and the poor dispersion and interfacial interaction of fillers in the matrix.This project designs a core-shell structure functional nanofiller（LM@Si O2-NH2）to prepare functional silicone rubber composites with high comprehensive performance.The main research contents are as follows:（1）Functional nanofillers with core-shell structure were prepared by coating nano-liquid metal droplets with silica,and then the shell was modified with 3-aminopropyl triethoxysilane（APTES）.The thickness of the shell can be controlled by changing the amount of silicon precursor,and the influence of its stability was explored.The thickness of the shell was controlled by adjusting the amount of silicon precursor,and the influence of its stability was explored.The experimental results show that the core-shell structure of functional nanofillers not only improves the stability of liquid metal droplet,but also improves the dispersion and interfacial force of functional nanofillers in the matrix.（2）LM@Si O2-NH2/PDMS composites were successfully prepared by using core-shell functional nanofillers to fabricate silicone rubber.The effects of fillers on the mechanical properties,dielectric properties and thermal properties of silicone rubber composites under different loading amounts were investigated experimentally.In the mass fraction of 0-40wt.%filler loading amount,the tensile strength of silicone rubber composites increased with the increasing loading amount,reaching 1.52MPa and the elongation at break was maintained at 130%.When the loading amount of LM@Si O2-NH2 nano-filler is 40 wt.%,the dielectric constant of the composite material at 103Hz frequency is significantly increased to 13.9,which is 340%higher than that of pure silicone rubber,and the tangent value of the dielectric loss is still less than 0.008.The results show that 40wt.%LM@Si O2-NH2/PDMS composite has the best thermal transfer performance.In addition,compared with the control LM NPs/PDMS composite,the stability was significantly increased and the weight loss rate was the lowest（28%）over a wide temperature range.It is noteworthy that the 40 wt.%LM@Si O2-NH2/PDMS composite also has good photothermal conversion performance.The temperature of the composite was increased to 61℃under infrared laser irradiation,and the temperature change was 37.6℃.It is far better than that for the simple PDMS composite material（8.7℃）. |
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