title: Thermally induced phase transformation of pearl powder.
abstract: The polymorphic phase transformation of thermally treated pearl powder was investigated by X-ray diffraction and thermoanalytical techniques. The phase transformation was based on quantification of the calcite content at various temperatures using Rietveld refinement analysis. The results show that the phase transformation of pearl aragonite occurred within a temperature range of 360-410 °C, which is 50-100 °C lower than the range for non-biomineralized aragonite. These thermoanalytical results suggest that the phase transformation of pearl aragonite may occur immediately after the thermal decomposition of the organic matrix in the pearl powder. An important finding is that decomposition of the organic matrix may greatly facilitate such transformation by releasing additional space for an easier structural reconstruction during the phase transformation process.
authors.affiliation: Key Laboratory of Advanced Textile Materials and Manufacturing Technology, Ministry of Education, Zhejiang Sci-Tech University, Hangzhou 310018, China. zgq@zstu.edu.cn
authors.forename: Guoqing
authors.initials: G
authors.lastname: Zhang
authors.forename: Yili
authors.initials: Y
authors.lastname: Guo
authors.forename: Ju
authors.initials: J
authors.lastname: Ao
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.forename: Guanglie
authors.initials: G
authors.lastname: Lv
authors.forename: Kaimin
authors.initials: K
authors.lastname: Shih
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry*; D002152:Calorimetry, Differential Scanning; D008958:Models, Molecular; D044367:Phase Transition; D011208:Powders; D013696:Temperature; D013818:Thermogravimetry; D013997:Time Factors
chemical_list: D011208:Powders; D002119:Calcium Carbonate