Кінетика кристалізації низькомолекулярних органічних речовин

Розробка методики досліджень кінетики кристалізації і аналіз впливу різних чинників на неї за методами комплексних циклічного та диференціального термічних аналізів. Термодинамічний аналіз параметрів зародкоутворення при формуванні реальних кристалів.

Рубрика Химия
Вид автореферат
Язык украинский
Дата добавления 07.08.2014
Размер файла 2,8 M

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The thesis to a candidate's degree in chemistry, namely 02.00.04 -physical chemistry. - The Donbas National Academy of Civil Engineering and Architectuire, Makeevka, 1005.

The thesis is devoted to the research of the crystallization kinetics of the low-molecular organic matters: benzene, phenol, resorcinol, pyrocatechol, hydroquinone, pyrogallol, naphthalene, a-naphtol, benzoic acid. There have been developed and manufactured a device for a complex cyclic (CTA) and differential thermal (DTA) analyses, an apparatus to accomplish external actions on the melt. The technique for experimental researches of the influence of a thermal prehistory and external actions on the crystallization kinetics of melts has been created. With the help of the CTA and DTA the crysrtallization kinetics of benzene, phenol, resorcinol, pyrocatechol, hydroquinone, pyrogallol, naphthalene, a-naphtol, benzoic acid and binary mixtures in the system resorcinol-pyrocathehol and benzoic acid-naphthalene has been studied. We pioneered to fix a jump-like dependence of a pre-crystallization overcooling of the melt ДT? on the overheating Т+ about the melting temperature TL for benzene, phenol, resorcinol, pyrocatechol, hydroquinone, pyrogallol, naphthalene, a-naphtol, benzoic acid. There has been fixed that the physical overcooling depended neither one further melt overheating by 100 K higher than TL, nor on the isothermal holding time, nor on the cooling rate from 0,002 up to 8 K/c. There have been plotted the constitution diagrams of resorcinol-pyrocatechol and benzoic acid-naphthalene, pre-crystallization overcoolings being shown. On the base of the experimental data there has been carried out a mathematical analysis of a temperature curve run at a melt crystallization with regard to the cluster-coagulation mechanism of crystallization. An expression for a transformation degree з at various kinds of crystallization has been obtained. The kinetic parameters of crystallization have been analyzed. There has been analyzed an influence of the electromagnetic fields on the quantity of Gibb's free energy change ДG under nucleation. There has been suggested a scheme of calculating entropy changes as crystallization passes from a quasi-balance to a nonbalance-explosive one.

The key words: crystallization kinetics, benzene, phenol, resorcinol, pyrocatechol, hydroquinone, pyrogallol, naphthalene, a-naphtol, benzoic acid, melts, mixtures, thermal analysis, overcooling, overheating, Gibb's free energy, cluster, nucleus, coagulation, nucleation.

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