Thermal Analysis Assesses the Hydroxyl Concentration in Hydroxyapatite

摘要

Modification of the chemical composition provides a simple, but powerful approach in tailoring the properties of hydroxyapatite (HAp). To date, activity has been directed to measuring the Ca/P ratio, and substitution of calcium or phosphate. Less attention has been directed to the quantity and alignment of hydroxyl groups (OH') in hydroxyapatite. This is an issue with thermally processed HAp, where the OH' content may be depleted and lead to changes in properties. For synthesized apatites, the structure may be modified with chemical groups from the reaction. The OH* groups in both synthesized and heat treated apatites' may not be aligned in the same direction within a single column, or be aligned in the same direction as the neighbouring column. Alignment can produce a charged apatite that has been shown to play an important role in attracting cells and providing an improved bone contact.