Effect of titanium addition on thermal stability of hydroxyapatite/zirconia nanocomposite

Abstract

HA/ZrO2 composite nanpowder with various addition of titanium (0.2-2.4wt%) were synthesized via wet chemical method using ZrOCl2.8H2O, H3PO4, Ca(OH)2 and tetraethylorthotitanate as precursor materials. The composites were then sintered at 900-1200?C for 2h, respectively. Effect of titanium addition to the composite on the phase composition and thermal stability during thermal treatment was investigated. The results suggested that as the sintering temperature increased from 900?C to 1200?C and with the addition of titanium to the composite below 0.8wt%, main phases were HA and ZrO2. As the sintering temperature increased to 1200?C and with the addition of titanium to the composite above 0.8wt%, main phases were HA, ZrO2 and a small amount of dicalcium phosphate (DCP). There were still no tricalcium phosphate (?-TCP) and CaZrO3 phases observed, which indicated that the addition of titanium restrained decomposition of HA and thermal reaction between HA and ZrO2. It also suggested that the addition of 0.8wt% titanium to the composite was optimum for producing HA/ZrO2 composite nanopowder with expected main phases. With the addition of 0.8wt% titanium to the composite, SEM images showed that the individual particles of the two materials were still visible, which also implied that the reaction between HA and ZrO2 did not occur.

Sinteran Hidroksiapatit dalam Atmosfera Nitrogen untuk Peningkatan Sifat Mikrokekerasan

“…Hal yang demikian adalah kerana pembentukan fasa kedua semasa penguraian HA, contohnya TCP (tetrakalsium fosfat) akan mengurangkan sifat mekanik HA Wang et al 2015). Oleh itu, penguraian HA hendaklah dielakkan bagi penghasilan HA tersinter yang mempunyai sifat mekanik tinggi untuk aplikasi pergigian.…”

“…Oleh itu, penguraian HA hendaklah dielakkan bagi penghasilan HA tersinter yang mempunyai sifat mekanik tinggi untuk aplikasi pergigian. Secara umum, HA tulen terurai pada suhu 1300°C (Wang et al 2015). Kalsium disingkirkan daripada struktur HA semasa penguraian HA.…”

“…Suhu sinteran 1300°C dipilih kerana suhu ini merupakan suhu kritikal kerana penguraian HA berlaku (Wang et al 2015). Relau (Bole LK/1862) digunakan untuk menjalankan sinteran sampel dengan menggunakan gas N 2 .…”

“…Suhu sinteran pada 1300°C merupakan suhu kritikal berlakunya penguraian HA (Wang et al 2015). Namun begitu, atmosfera sinteran yang digunakan dalam kajian ini tidak memberi kesan ke atas kestabilan fasa sampel HA tulen yang terbentuk pada suhu 1300°C.…”

Preparation of inverse opal zirconia

“…One of the simplest ways to make photonic crystals structures is the self-assembly technique, which assemblies monodisperse colloidal spheres [10]. Polystyrene (PS) photonic crystals based on selfassembly method was widely used to generate a photonic crystal and due to the low fabrication costs, easily obtained raw materials and mild processing conditions [11][12][13].…”