文献类型：会议论文

英文题名：Effect of crystal seeding on the hydration of calcium phosphate cement

作者：Liu, Changsheng[1]; Shen, Wei[1]

机构：[1] Natl. Eng. Res. Ctr. Ultrafine P., E. China Univ. of Sci. and Technol., P.O. Box 258, Shanghai 200237, China

会议论文集：13th European Conference on Biomaterials

会议日期：1997

会议地点：GOTHENBURG, SWEDEN

语种：英文

外文关键词：Calorimetry - Compressive strength - Dissolution - Hydration - Nucleation - Phosphate minerals - Porosity - Reaction kinetics - Substrates

摘要：In this paper, the effect of crystal seeding on the hydration of calcium phosphate cement (CPC) has been carefully investigated. The setting time of the CPC slurry not containing any crystal seeds was 150 min, while the setting time for the specimen containing 5 wt% low crystallinity hydroxyapatite used as a crystal seed was 7 min. This improvement in the setting time was due to HAP serving as a substrate for heterogeneous nucleation which accelerated nucleation. In addition, the compressive strength of the specimen containing the crystal seeding was deduced and we report values different from those previously reported in the literature. The calorimetric curve indicated that crystal seeding could reduce the induction period. A.c. impedance spectroscopy revealed that at the beginning of hydration, the rate of reaction increased and also that the mean diameter and porosity decreased as the seed content increased. At the end of the hydration reaction the situation was changed with the mean diameter and porosity in the sample without any seeds being a minimum, which indicated that the compressive strength was a maximum. This result could be explained by the dissolution and reprecipitation of small hydration products produced by the high rate of reaction produced by the introduction of the crystal seeds.