Synthesis of white cement bonded porous fumed silica-based composite for thermal insulation with low thermal conductivity via a facile cast-in-place approach

High performance thermal insulation material was prepared by fumed silica as thermal insulation matrix, white cement as binder. SiC powder was incorporated as an opacifier. Short glass fibers were added to increase stiffness and minimize contraction. The samples were produced within 4 days under ambient pressure with no complicated equipment. The influences caused by white cement amount on the properties were investigated to achieve the optimal performance. A low thermal conductivity 0.033 W·m−1·K−1 at 25 °C and a low thermal conductivity 0.038 W·m−1·K−1 at 800 °C were achieved based on the experimental results. The linear shrinkage of the insulation up to 800 °C in air for 30 min was 7.54%. In addition, the insulation exhibited a compression stress above 0.15 MPa (3% strain). The relation between structure and performances was revealed. That we here publicly reported thermal insulation materials synthetized by nano-powder and inorganic binder might reveal a new method for synthesis high performance thermal insulation materials. Based on the simplicity of the manufacturing process, the optimized material properties and cheap cost of raw materials, we believe this technology can act as an effective thermal insulation material for buildings and myriad applications requiring improved thermal efficiency.