CN-121990801-A - Porous microstructure foaming white cement radiation refrigeration composite material and preparation method thereof

Abstract

The invention discloses a porous microstructure foaming white cement radiation refrigeration composite material and a preparation method thereof, belonging to the technical field of building energy-saving materials, wherein the material takes sulfoaluminate white cement as a base material, a uniformly distributed porous microstructure is formed in the preparation process by adding a foaming agent, and the high reflection characteristic of the sulfoaluminate white cement is utilized to realize the high-efficiency radiation refrigeration function by the synergistic effect of the enhanced scattering and heat insulation performance of the porous microstructure; the invention solves the problems of low radiation refrigeration efficiency and insufficient heat insulation performance of the traditional white cement material, has simple preparation process and controllable cost, can be widely applied to building exterior walls, roofs and other enclosure structures, and has remarkable energy-saving benefit and market application prospect.

Inventors

• WU SHUYI
• LIN JIANWEI

Assignees

• 福建农林大学

Dates

Publication Date

20260508

Application Date

20260126

Claims (7)

1. 1. The porous microstructure foaming white cement radiation refrigeration composite material is characterized by comprising the following raw materials in parts by weight: 100 parts of sulfoaluminate white cement; 0.2-0.5 part of foaming agent; 0-5 parts of functional filler; 40-50 parts of water; Wherein the composite material has an atmospheric window emissivity of greater than 90% and an overall solar reflectance of greater than 90%.
2. 2. The porous microstructured foaming white cement radiant refrigeration composite of claim 1, wherein the foaming agent comprises sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, sodium alpha-olefin sulfonate, hydrogen peroxide, and/or aluminum powder.
3. 3. The porous microstructured foaming white cement radiant refrigeration composite of claim 2, wherein the foaming agent is sodium dodecyl sulfate.
4. 4. A porous microstructured foaming white cement radiant refrigeration composite as in claim 2 or 3 wherein the foaming agent, when added, is pre-diluted with water at a mass ratio of foaming agent: water = 1:25.
5. 5. The porous microstructured foamed white cement radiant refrigeration composite of claim 1, wherein the functional filler comprises one or more of cellulose nanofibers, nano silica particles, polyester microfibers, cellulose nanowhiskers, attapulgite, bamboo fibers, water glass, and aqueous epoxy.
6. 6. The preparation method of the porous microstructure foaming white cement radiation refrigeration composite material is characterized by comprising the following steps: 1) The raw material composition of the composite material according to any one of claims 1 to 5, wherein sodium dodecyl sulfate and water are weighed, diluted according to a mass ratio of 1:25, and stirred for 3-5min at 400-500r/min to generate stable foam; 2) Weighing sulfoaluminate white cement powder and water, stirring for 2-3min at 200-300r/min to uniformly disperse the powder, and obtaining white cement paste; 3) Adding the functional filler cellulose nanofiber dispersion liquid into the cement paste, stirring for 2-3min at 200-300r/min, and stirring to fully mix the paste; 4) Adding the foam obtained in the step 1) into the white cement paste prepared in the step 2) twice, stirring for 2-3min at 200-300r/min after each addition, and uniformly stirring to fully mix the air bubbles and the white cement paste; 5) Pouring the cement paste obtained in the step 4) into a mould, and curing to obtain the porous microstructure foaming white cement radiation refrigeration composite material.
7. 7. The method for preparing the porous microstructure foaming white cement radiation refrigeration composite material according to claim 6, wherein the curing conditions adopted in the step 5) are that the temperature is 25+/-5 ℃ and the humidity is 90+/-10%, and the curing time is 7 days.

Description

Porous microstructure foaming white cement radiation refrigeration composite material and preparation method thereof Technical Field The invention relates to the technical field of radiation refrigeration materials, in particular to a porous microstructure foaming white cement radiation refrigeration composite material taking foaming white cement as a matrix and optimizing performance by adding functional materials and a preparation method thereof, which can be widely applied to the fields of building energy conservation, cold chain logistics, electronic equipment heat dissipation and the like. Background Along with the increasingly prominent global energy crisis and environmental problems, the refrigeration demand continuously grows in the fields of construction, industry, civilian life and the like, the traditional compression refrigeration technology depends on fossil energy consumption, so that the energy utilization rate is low, a large amount of greenhouse gases can be discharged, and the environmental burden is aggravated. Under the background, the radiation refrigeration technology is taken as a passive refrigeration technology, and becomes a research hot spot in the refrigeration field by virtue of no external energy input and zero pollution emission. The core principle of the radiation refrigeration technology is that the material radiates heat to the outer space in the form of electromagnetic wave with the wavelength of 8-13 mu m (atmospheric window wave band) through the infrared radiation characteristic of the material, and simultaneously reduces the absorption of solar radiation energy by optimizing the solar reflectivity of the material, thereby realizing the refrigeration effect lower than the ambient temperature. At present, a small amount of cement-based radiation refrigerating materials have been proposed, but are significantly different from the present invention. The prior published patent CN 120463466A mainly adopts white portland cement and high-proportion alumina, barium sulfate and other radiation refrigeration particles to realize solar reflectance and atmospheric window emissivity. But this patent does not contemplate reducing reliance on expensive functional particles by the microstructure design of the matrix itself. In contrast, the invention eliminates the dependence on high-proportion expensive functional particles and adopts a foaming process to construct a porous microstructure in a matrix. The controllable foaming process provided by the invention constructs a porous microstructure to realize an innovative thought of radiation refrigeration, can effectively improve solar reflectance through Mie scattering effect generated by bubbles, and has the advantages of light weight and lower cost. The prior published patent CN 115466086A mainly adopts white cement, quartz powder, titanium dioxide and other components and adopts a high-temperature autoclaved curing (180 ℃) process to induce and generate tobermorite and other crystals, thereby optimizing the optical performance and pore structure. However, the problems of complexity and energy consumption of the production process are not considered, and the high-temperature high-pressure maintenance condition has high equipment requirement and high energy consumption, and is unfavorable for low-cost and large-scale production. In contrast, the invention adopts standard curing technology of normal temperature and normal humidity. The innovative thought of constructing the porous microstructure by the controllable foaming technology can be completed by conventional stirring and maintenance, complicated high-temperature autoclaves are not needed, and the controllable foaming technology has the advantages of simple process, energy conservation, consumption reduction and easiness in industrialized popularization. The prior published patent CN 108975824A is mainly a cement-based foaming heat-insulating material, and the mechanical property of a pore structure is improved by using latex powder and a reinforcing material, so that the aim of realizing building heat insulation is fulfilled. But no material architecture and structural design is made for the high reflectivity and high emissivity required for radiation refrigeration. In contrast, the invention makes clear that the radiation refrigeration is used as the core function guide, the high whiteness sulphoaluminate cement is preferably used as the matrix, and the functional filler is scientifically added. The invention provides an innovative thought for realizing radiation refrigeration by using the porous microstructure, so that the porous microstructure is not only used for light heat insulation, but also used for enhancing light scattering to improve reflectivity, and has the advantage of multifunction integration. Therefore, development of a cement-based radiation refrigeration material with low cost, simple process and multifunctional integration is needed, and the cement-based radi