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Process of epitaxial crystal growth for CaSO4 center dot 0.5H(2)O on a surface of dissolving fluorapatite crystals studied by scanning electron microscopyстатья
Информация о цитировании статьи получена из
Scopus,
Web of Science
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
- Автор: Dorozhkin S.V.
- Журнал: Scanning
- Том: 18
- Номер: 2
- Год издания: 1996
- Издательство: FAMS Inc.
- Местоположение издательства: United States
- Первая страница: 119
- Последняя страница: 124
- Аннотация: A process for the epitaxial crystal growth for CaSO4 . 0.5H(2)O on a surface of dissolving natural fluorapatite (FAP) crystals under conditions of wet-process phosphoric acid production has been studied by scanning electron microscopy (SEM). With the SEM working in a secondary electron mode, we were able to establish the main stages of the coating formation, including direct measurements of its thickness and growing rate values for individual needle-like CaSO4 . 0.5H(2)O crystals. Confirmation of an aggregate mechanism for CaSO4 . 0.5H(2)O epitaxial crystals growth, established earlier under conditions of chemical crystallization, was achieved for the first time. The mechanism includes the following steps: (1) ultramicrocrystals of CaSO4 . 0.5H(2)O were formed, (2) they coalesced into needlelike crystals by means of mutual aggregation, (3) the needle-like crystals united into star-like and besom-like aggregates, and (4) the latter formed macro-aggregates. We have found that these steps occur simultaneously, resulting in multilayer coating formation. During the investigation, the phenomenon of FAP crystals aggregation by means of mutual intergrowing of epitaxial CaSO4 . 0.5H(2)O coatings and the peculiarities of the etching process for the FAP crystal surface under conditions of CaSO4 . 0.5H(2)O coatings formation were also studied.
- Добавил в систему: Дорожкин Сергей Вениаминович