Laminated stone-inspired multi-layer crystal structure reinforced bamboo scrap/magnesium oxychloride lightweight composites

Abstract Magnesium-based aerated cement has the characteristics of noncombustibility and nontoxicity compared with traditional organic aerated materials, realizing low-carbon manufacturing and energy saving in building construction. However, the pore walls of ordinary magnesium-based aerated cement are thin and brittle and can easily collapse under force, limiting its application in energy saving. This study aimed to obtain low-cost, low-energy, lightweight, high-strength, flame-retardant, and heat-insulating thermal insulation materials. Inspired by the formation process of stacked stones, calcium stearate was adsorbed on solid particles, stabilizing the pore and forming independent lumps of gel-state crystals in this study. At the same time, the hydrogen bonds of hydroxyethyl cellulose were used to chemically stitch the dispersed crystals to form a dense laminated structure. The interfacial compatibility between bamboo scraps and magnesium oxychloride improved the load transfer efficiency. The results showed that the strength-to-weight ratio of the composites increased 2.5 times, and the softening coefficient increased about 2 times. In comparison, the mechanical properties and thermal insulation properties of the composites far exceeded those of most thermal insulation materials, providing a theoretical basis for their use in the field of multifunctional building materials.