Micro-nano latent heat storage capsules suitable for cement-based materials and preparation method thereof

Abstract

The invention discloses a micro-nano latent heat storage capsule suitable for cement-based materials and a preparation method thereof, wherein sodium lauryl sulfate, deionized water and n-octadecane are stirred and mixed to obtain an oil phase; sodium silicate nonahydrate , deionized water, and nano-carbon dots are stirred evenly, and the pH is adjusted with ammonia water to obtain a water phase; the water phase is dispersed in the oil phase during the stirring process, and hydrochloric acid is added dropwise with stirring until the pH value drops to 7 to obtain micro-nano capsules ; Add vinyltriethoxysilane to the micro-nano capsules under heating conditions, heat crystallization treatment, and prepare micro-nano latent heat storage capsules suitable for cement-based materials. The phase change enthalpy of the capsule is 180-200J / g, the heat storage temperature is 21.5-23°C, the particle size of the capsule is 0.08-0.10μm, the thermal conductivity is 21-23W / mK, and the mechanical properties are 23-25μN. The preparation process of the invention is environment-friendly, has high capsule coating rate, high physical and chemical stability, and is suitable for cement-based materials.

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.