Preparation And Application Of Nano Calcium Phosphate Ceramic Powder

Calcium phosphate ceramics, like tri-calcium phosphate(β-TCP) and hydroxyapatite(HA) arebiologically active materials with structures and compositions similar to bone tissue. Due to thesebio-ceramics have perfect biocompatibility, biodegradability and osteoinductive characteristics, sothey can be used as various biomedical materials for hard tissue applications.In this thesis, the mesoporous calcium phosphate ceramic powders were prepared by bothco-precipitation and hydrothermal methods. By adjusting the concentration and kind of templates, thekind of additive and Ca/P molar ratio, the phase and morphology were regulated. Meanwhile themechanism of water-absorbent was studied. The morphologies, compositions, specific surface areas ofcalcium phosphate ceramic products were analyzed by SEM, XRD, FTIR and N2adsorption methods.The synthesized nano-hydroxyapatite was applied to prepare the composite adhesive. The preparationprocess, mechanical properties and influence factors on mechanical properties were investigated.It was found that the morphologies changed obviously with the changing template CTABconcentrations, CTAB/SDS ratios, additives and Ca/P mole ratios. The β-TCP was obtained easily atthe low temperature and high calcination temperature. Under slow dropping conditions, the mainproduct was HA, while β-TCP for the direct mixing conditions. Compared with the normal HA, themesoporous HA posses a higher water absorption rate. It is suggested that the high water absorptionwas affected by the interaction of the hydrogen bonding and capillary force.The mechanical property tests indicated that the compressive strength of n-HA reiforced epoxyresin matrixed composite increased and then decreased with increasing n-HA addition, the maximumof compressive strength was achieved at the n-HA content of10wt%. The adhesive property ofEasyOne resin matrixed composite decreased with increasing n-HA content, the maximum ofadhesive strength was achieved at the n-HA content of5wt%. The adhesive property of SuperBond matrixed composite increased firstly and decreased with incremental n-HA addition, the maximum ofcompressvie strength was achieved at n-HA content of10wt%. When the HA content is within acertain range, the filler particles can prevent the crack propagation effectively, therefore themechanical properties of the composite improved; Whereas the too high HA content leads toagglomeration of nano-particles, the mechanical properties of the composite adhesive decreased.