Effect of processing parameters on the morphology of hydrothermally synthesized calcium borate powders
AMERICAN CERAMIC SOCIETY, JOURNAL, vol.106, pp.3188-3198, 2023 (SCI-Expanded, Scopus)
- Publication Type: Article / Article
- Volume: 106
- Publication Date: 2023
- Journal Name: AMERICAN CERAMIC SOCIETY, JOURNAL
- Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Periodicals Index Online, Aerospace Database, Applied Science & Technology Source, Art Source, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, Computer & Applied Sciences, EBSCO Education Source, INSPEC, Metadex, Civil Engineering Abstracts
- Page Numbers: pp.3188-3198
- Ankara Yıldırım Beyazıt University Affiliated: Yes
Abstract
The present study aimed to examine the effect of pH and time on the finalmorphology of calcium borate powders. Primarily, aqueous solutions thatmainly consisted of borax and calcium chloride were prepared with fivedifferent pH values varying between 2 and 15. Hydrothermal synthesis tem-perature was determined as 200◦C, and four different times from 30 min to24 h were selected. Phase formation and powder morphology were exam-ined via an X-ray diffractometer and scanning electron microscopy. Fouriertransform infrared spectroscopy was used to identify the type of borategroups. Results revealed that pH directly determines the growth mechanismof calcium borate crystals. Lower pH induced nonclassical growth by form-ing self-assembled nano-plates. Individual, rodlike particles were observedfor alkali solution. At weak basic conditions, priceite (4CaO⋅5B2O3⋅7H2O)and alkali condition parasibirskite (2CaO⋅B2O3⋅H2O) phases wereobtained.