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Information × Registration Number 0210U005833, 0110U001976 , R & D reports Title Cyclic thermal analysis of melting and crystallization procceses of low-molrcular organic and non-organic crystall gydrates for the phase change materials (PCM) making popup.stage_title Head Postnikov Valeriy Anatolevich, Registration Date 18-01-2011 Organization Donbas national akadeny of civil engineering and architecture popup.description2 The paper reviews the current status of the kinetics and thermodynamics of melting and crystallization of inorganic and organic crystalline and their use as PSM. In studying the kinetics of crystallization and melting of substances were the main thermal analysis techniques: cyclic (CTA) and differential (DTA). Installation is made and the technique for a comprehensive study of substances by the CTA and DTA with automatic temperature control and analog output data via RS-232 interface on the PC. There has been investigated the effect of thermal history of the melt on the kinetic and thermodynamic parameters of crystallization . The conditions for the transfer of melts of pure substances and binary alloys in the supercooled state has been established. There has been identified the boundaries of metastability of the supercooled liquid phase for pure substances and binary alloys. There has been fixed an abrupt transition from a quasi-non-equilibrium crystallization to explosive type one on clean substances and smooth transition onf alloys. There has been investigated the regularities of melting and crystallization of mixtures in the sodium acetate trihydrate - sodium sulfate decahydrate bynary system. For this system, first constructed phase diagram, covering the region of melting and crystallization of mixtures. There has been determined thermal endo-and exothermic effect of phase transformations of alloys in the systems NaCH3COO · 3H2O - Na2SO4 · 10H2O and benzene - naphthalene by DTA. There has been investigated the dependence of the linear velocity v advancing crystallization front on the supercooling of the liquid phase for sodium acetate trihydrate and naphthalene by visual polyterm. There has been analized the thermodynamic parameters of phase equilibria, the supercooled state and the parameters of the nucleation for the system benzene - naphthalene based on actual supercoolings. The research results are interpreted from the perspective of the cluster-coagulation crystallization model in the light of molecular structure, the type and nature of intermolecular interactions. Key words: crystallization, crystalline hydrates, aromatic hydrocarbons, Phase Change Materials (PSM), a solution, melt, supercooling of the liquid phase, heating the melt, the melting temperature, heat of fusion, exo- and endothermic effects of phase transformations, thermal history of the melt, the binary systems, liquidus, solidus, eutectic, phase diagram, clusters, nuclei, the Gibbs free energy, the degree of transformation during melting and crystallization, the Avrami equation, sodium sulfate decahydrate, sodium acetate trihydrate, water, benzene, naphthalene, thermal analysis, visual polyterm, optical microscopy, X-ray analysis . Product Description popup.authors Постніков Валерій Анатолійович popup.nrat_date 2020-04-02 Close