Supercooling phase change-inhibiting alkane microcapsule and preparation and application thereof

Abstract

The invention discloses a supercooling phase change-inhibiting alkane microcapsule and preparation and application thereof. The size of the alkane microcapsule is within a range from 0.1Mu m to 100Mu m, the alkane microcapsule consists of shell materials and core materials, the shell materials are melamine resin, the core materials are n-alkane phase change agent and n-alkane nucleating agent, the carbon atom number of the n-alkane phase change agent is twelve to twenty eight, and the carbon atom number of the n-alkane nucleating agent is twenty two to forty. The preparation method for the alkane microcapsule, which is disclosed by the invention, is an in-situ polymerization method, and the preparation process includes core material emulsion preparation, shell material prepolymer preparation and alkane microcapsule preparation. For the same type of alkane microcapsule, the carbon atom number of the nucleating agent is greater than the carbon atom number of the phase change agent, and the nucleating agent and the phase change agent can be formed into gel. The invention has the advantages that: the alkane microcapsule has the characteristics of supercooling phase change inhibition, smooth surface and aggregation resistance, the preparation process for the alkane microcapsule is simple, and the application range is wide.

Description

technical field [0001] The invention relates to an alkane microcapsule capable of inhibiting supercooled phase transition and its preparation and application, belonging to phase change material technology. Background technique [0002] Organic alkanes are a kind of phase change materials used in a certain temperature environment. Encapsulate organic alkanes in microcapsules to obtain alkane microcapsules. Phase change microcapsules have been widely used in aerospace, textile and other fields. However, there is supercooling phenomenon in alkane microcapsules, and its degree of supercooling (the difference between the melting temperature and the crystallization temperature) increases with the particle size of the microcapsules (Y.Yamagishi, T.Sugeno, T.Ishige. "Anevaluation of microencapsulated PCM for use in cold energy transportation medium", IEEE 1996, 3: 2077-2083), so that it cannot undergo phase change at a specific temperature and absorb / release phase change heat, whi...

AI Technical Summary

Problems solved by technology

However, there is supercooling phenomenon in alkane microcapsules, and its degree of supercooling (the difference between the melting temperature and the crystallization temperature) increases with the particle size of the microcapsules (Y.Yamagishi, T.Sugeno, T.Ishige. "Anevaluation of microencapsulated PCM for use in cold energy transportation medium", IEEE 1996, 3: 2077-2083), so that it cannot undergo phase transition at a specific temperature and absorb / release phase transition heat, hindering its practical application

[0003] U.S. Patent US 2004 / 0076826 pointed out that for phase-change microcapsules whose core material is n-tridecane to n-octadecane organic alkanes with a carbon number of 13 to 28, a relative content of 0.1% is added to the core material To 15% monovalent n-alkanols or monovalent n-alkylamine derivatives of organic alkanes as nucleating agents can inhibit the supercooling of microcapsules, but studies have shown that adding a small amount of alcohol to the core material of organic alkanes microcapsules Alkaline derivatives are used as nucleating agents, although it can inhibit the supercooling of organic alkanes microcapsules, but the addition of these substances will make the microcapsules easy to agglomerate, and the surface becomes very rough. This may be due to the occurrence of hydroxyl groups on alcohols and microcapsule wall materials Reaction caused by (Y.F.Fan, X.X.Zhang, X.C.Wang, J.Li, Q.B.Zhu. "Super-cooling prevention of microencapsulated phase change material", Thermochimica Acta, 2004, 413 (1-2): 1-6; Xing- Xiang Zhang, Yao-feng Fan, Xiao-ming Tao, Kit-lun Yick. "Crystallization and prevention of supercooling of microencapsulated n-alkanes", Journal of Colloid and Interface Science, 2005, 281(2): 299-306)

In addition, the amino groups on the amine derivatives also make the surface of the prepared phase change microcapsules very rough, and the microcapsules are agglomerated together, making it difficult to disperse, which is not conducive to the further industrial application of the microcapsules. One of the reasons is that the agglomeration Microcapsules with a very rough surface are difficult to disperse evenly in a continuous phase with high viscosity as a dispersed phase; the second reason is that the uneven surface of the microcapsules will hardly be in full contact with the continuous phase

Above-mentioned article has also studied the situation of sodium chloride as nucleating agent, the surface of the microcapsules prepared by this method is also rough and easy to agglomerate; For paraffin as nucleating agent, although it has been proved in the above research that paraffin will not make the surface of microcapsules It becomes rough and does not make the microcapsules easy to agglomerate, but since the paraffin itself is a mixture, the phase transition temperature range is relatively large, so while suppressing the supercooling of the organic alkanes, it also increases the phase transition temperature range of the microcapsules, Therefore, the relative heat absorption / release of the microcapsules in a fixed temperature range is reduced. At the same time, because the content of each component of paraffin wax is not fixed, it is impossible to quantitatively adjust the supercooling of the microcapsules.

[0004] In the existing method for suppressing the supercooling phenomenon of organic alkane microcapsules, there is no use of gel factor as a nucleating agent for phase change materials to quantitatively control the supercooling phenomenon of phase change microcapsules, and to avoid destroying the morphology of microcapsules Research report or invention patent

Images