Micro-nano latent heat storage capsule applicable to cement-based material and preparation method thereof

Abstract

The invention discloses a micro-nano latent heat storage capsule applicable to a cement-based material and a preparation method thereof. The preparation method comprises the following steps: mixing sodium dodecyl sulfate, deionized water and n-octadecane by stirring to obtain an oil phase; uniformly stirring sodium silicate nonahydrate, deionized water and nanocarbon dots, and adjusting pH by using ammonia water to obtain an aqueous phase; dispersing the aqueous phase in the oil phase in the stirring process, and dropwise adding hydrochloric acid while stirring until the pH value is lowered to7 to obtain a micro-nano capsule; adding vinyl triethoxysilane into the micro-nano capsule under a heating condition, and heating for crystallization to obtain the micro-nano latent heat storage capsule applicable to the cement-based material. The capsule has the phase change enthalpy of 180-200J / g, the heat storage temperature of 21.5-23 DEG C, the particle size of 0.08-0.10 microns, the heat conductivity of 21-23W / mK and the mechanical property of 23-25[mu]N. The capsule is environment-friendly in preparation process, high in capsule coverage rate and high in physical and chemical stability, and is applicable to the cement-based material.

Description

technical field [0001] The invention belongs to the technical field of building materials, and in particular relates to a preparation method of micro-nano latent heat storage capsules suitable for cement-based materials. Background technique [0002] Latent heat storage materials can store or release a large amount of latent heat during the phase transition process, and have high thermophysical properties. Different from traditional sensible heat storage, phase change energy storage materials can provide higher energy storage density, and heat storage is an approximately isothermal process. At the same time, its materials are sustainable, so it has broad application prospects in building energy conservation. In addition, as the most widely used building structure material, cement-based materials can effectively compound other materials and have a high heat exchange area, which has great potential in solving the increasingly prominent problem of building energy consumption gr...

AI Technical Summary

Problems solved by technology

The prepared phase change microcapsule wall material has a poor shaping effect, and there is a problem of incomplete coating of the graphene oxide coating of the sheet, and there are safety hazards such as liquid leakage and flammability in application.

[0006] The existing existing technology of preparing microcapsules by coating organic phase change materials with inorganic wall materials has a shortcoming mainly because the thermal conductivity of the inorganic wall materials is not high, resulting in a slight phase change after coating with inorganic wall materials. The heat exchange rate between the capsule and the outside world is reduced, and the cost of using graphene and other materials is very expensive. Moreover, the mechanical properties and chemical stability of the inorganic wall materials that have not been crystallized cannot be guaranteed, and they cannot be applied in cement-based materials at all.