材料期刊网

真空等离子喷涂的钛涂层经5.0mol/L NaOH溶液处理后，将其浸泡在含Ca2+、HPO2 4-的模拟生理体液(FCS和SBF)中，考察涂层诱导羟基磷灰石生长过程，并评价其生物活性。用SEM观察碱处理前后和在模拟生理体液中浸泡后钛涂层的形貌，用AES分析了碱处理前后钛涂层的表面成分；用XRD、FT-IR和EDS表征浸泡后涂层表面生长物的结构和成分；并测量了处理后钛涂层在浸泡过程中溶液中离子浓度和pH值的变化。结果表明，经处理的钛涂层在模拟生理体液中能诱导羟基磷灰石在其表面生长；在SBF和FCS分别形成碳酸羟基磷灰石层和含氧磷灰石的羟基磷灰石层。钛涂层的活性是由于碱处理后表面形成了网状和纤维状结构的Na-Ti-O化合物。这种化合物在模拟生理溶液中释放Na+，吸收H+，形成水化钛酸盐，诱导羟基磷灰石成核生长。

Vacuum plasma sprayed Ti coatings were chemically treated with 5.0mol/L NaOH at 40℃ for 24h and immersed into two kinds of simulated physiological solutions containing Ca2+, HPO2 4- ions. The surface morphologies and compositions of Ti coating before and after alkali treatment were examined by SEM and AES respectively. The formation layers on the Ti coating after immersion in FCS and SBF were characterized by SEM, EDS, XRD and FT-IR. The changes of ion concentration and pH value of FCS after immersion were measured by ICP-AES and pH meter. The results obtained indicate that the fibrous and net-like surface structure forms on the surface of porous Ti coating by treatment of NaOH solution.which consists of Na, Ti and O element with the atom ratio nearly equal to that of Na2TiOa. After immersion in simulated physiological solutions, the treated Ti coating shows apatite-forming ability and the apatite formed in FCS is oriented crystallized, plate-like HA with trace of OCP whereas the apatite precipitated in SBF is needle-like carbonate-containing hydroxyapatite. The bioactivity of the alkali treated Ti coatings can be explained in terms of the formation of hydrated titanate which can induced apatite nucleation and growth in FCS and SBF.