CN-118421270-B - Plastic composite shaping phase change material and preparation method and application thereof

CN118421270BCN 118421270 BCN118421270 BCN 118421270BCN-118421270-B

Abstract

A plastic composite shaping phase change material and a preparation method and application thereof belong to the technical field of building energy-saving materials. Consists of solid-liquid phase material, expanded graphite and calcium ion crosslinked sodium alginate three-dimensional porous support material. The invention constructs a three-dimensional cross-linked network in-situ load phase-change material through coordination chelation of calcium ions and carboxyl functional groups on a sodium alginate G unit block, and simultaneously prepares the plastic composite shaping phase-change material by combining a cold drying technology. The calcium ion crosslinked sodium alginate three-dimensional porous network structure improves the mechanical property of the composite material, the composite material can be shaped and the volume of the composite material can be regulated and controlled under the heating condition, and the shape of the composite material is kept unchanged after cooling. The composite material has the functions of light-heat energy conversion and heat energy storage, is suitable for heat preservation of buildings in environments with larger day-night temperature difference, can slow down indoor temperature fluctuation range at night, saves building operation energy consumption, is convenient to apply, has low cost, and has wide application prospect in the field of building energy conservation.

Inventors

TANG BINGTAO
HAO YUPENG
ZHANG YUANG
PENG CHONG
ZHANG SHUFEN

Assignees

大连理工大学

Dates

Publication Date: 20260508
Application Date: 20240425
Priority Date: 20231225

Claims (3)

1. A plastic composite shaping phase change material is characterized in that the solid-liquid phase change material in the composite shaping phase change material accounts for 75-90wt%, the expanded graphite accounts for 3-15wt% and the calcium ion crosslinked sodium alginate accounts for 2-10wt%; The calcium ion crosslinked sodium alginate is formed by coordination crosslinking of calcium ions and carboxyl groups on a sodium alginate G unit block through cold drying, wherein the mass ratio of the sodium alginate to the calcium ions is 1:6-1:5; the preparation method of the phase change material comprises the following steps: (1) Adding the expanded graphite into the solid-liquid phase change material, stirring and mixing, wherein the solid-liquid phase change material is adsorbed on the expanded graphite In the pore structure, the solid-liquid phase change material/expanded graphite composite phase change material is obtained and ground into powder with the particle size of 0.2-0.3mm, wherein the mass ratio of the solid-liquid phase change material to the expanded graphite is 9:1-19:1; (2) Dissolving sodium alginate in water to obtain sodium alginate aqueous solution, wherein the mass ratio of sodium alginate to water is 1: (60-80); (3) Mixing the solid-liquid phase change material/expanded graphite composite phase change material with sodium alginate aqueous solution, stirring and mixing uniformly, dropwise adding calcium chloride solution, and standing for 10-12h to form composite hydrogel, wherein the mass ratio of the solid-liquid phase change material/expanded graphite composite phase change material to the sodium alginate is 10:1-20:1; (4) And freeze-drying to remove water to obtain the plastic composite shaping phase change material.
2. The plastic composite setting phase change material according to claim 1, wherein the solid-liquid phase change material is at least one of paraffin, n-octadecane, n-eicosane, n-dodecanol, n-tetradecanol, n-hexadecanol, palmitic acid, stearic acid, butyl stearate, methyl palmitate, methyl stearate, and polyethylene glycol.
3. The application of the plastic composite shaping phase change material as claimed in claim 1 or 2, wherein the plastic composite shaping phase change material is used for buildings or greenhouses.

Description

Plastic composite shaping phase change material and preparation method and application thereof Technical Field The invention relates to a plastic composite shaping phase change material, a preparation method and application thereof, and belongs to the technical field of building energy-saving materials. Background According to the statistics of the international energy agency, the running energy consumption of the global architecture is more than 30% of the total social energy consumption at present, and is continuously increased along with climate change and population growth. Thus, intelligent thermal management architecture has led to extensive research in the scientific and industrial world. The phase change material has the characteristics of isothermal phase change characteristic and higher energy storage density, can strengthen building thermal inertia, reduce maximum heat flow, transfer energy peak demand, reduce air temperature fluctuation and the like, is widely researched in the aspect of thermal management in the field of building energy conservation, and research results show that proper amount of phase change material is added into the building, and proper packaging method and position deployment are adopted, so that indoor comfort condition can be obviously improved, and energy demand of a heating ventilation air conditioning system is reduced (B.R.Sahar,A.Amani,B.K.Rim.M.S.Nejla and J.Abdelmajid,Journal of Building Engineering,2020,32,101563.). The single phase change material is directly added to building materials or directly mixed into concrete to generate the problems of phase change liquid leakage, poor thermal conductivity and the like, if the phase change material is deformed under backlog or other external force, the liquid leakage problem is further aggravated, and the defects of inherent rigidity, easy brittle failure and the like of the phase change material severely limit the practical application scene. Up to the present, the research and development of the plastic phase change material are less, so that the development and preparation of the plastic composite phase change energy storage material have important significance. Disclosure of Invention Aiming at the key problems of phase change liquid leakage, inherent rigidity, brittle fracture and the like of an organic solid-liquid phase change material, the invention aims at designing and preparing a plastic composite shaping phase change material, coating paraffin/expanded graphite in a gel system by an in-situ loading method, forming a three-dimensional porous cross-linked network by utilizing coordination chelation between calcium ions and sodium alginate carboxyl, building a porous airflow channel by depending on a three-dimensional supporting framework in combination with a freeze drying technology, endowing a processable space of the composite material, and realizing the shape plasticity and volume adjustable function of the composite material. Meanwhile, the solar radiation phenomenon is combined with the phase change heat collection characteristic of the phase change material, so that the low-cost processable composite shaping phase change material integrating light absorption, heat generation and heat storage is constructed, and is applied to heat preservation of a greenhouse in a building housing or in an environment with larger day-night temperature difference and out-of-season environment, so that the energy consumption for building operation is saved, and the production and life costs are reduced. The invention aims to provide a plastic composite shaping phase change material. The material is rich in pores, has certain compressibility and flexibility, integrates light-heat energy conversion and heat energy storage and utilization, has good heat management capability, simple synthesis process and convenient application, and has wide application prospect. The shaping phase change material is composed of paraffin/expanded graphite and a three-dimensional porous network support material, wherein the three-dimensional porous network support material is formed by coordination and cross-linking of calcium ions and carboxyl groups on sodium alginate G unit blocks, and under the chelation of coordination bonds, sodium alginate G units are mutually stacked to form a three-dimensional porous network and simultaneously load phase change components in situ, and a freeze drying technology is combined to form a three-dimensional sponge-like structure, so that the composite material has excellent mechanical properties, and can be processed and shaped under the heating condition. The composite shaping phase change material is composed of 75-90wt% of paraffin, 3-15wt% of expanded graphite and 2-10wt% of calcium ion crosslinked sodium alginate. The mass ratio of the sodium alginate to the calcium ions in the calcium ion crosslinked sodium alginate is 1:6-1:5. The organic solid-liquid phase-change material is at least one of paraffin (