Effect of additives on the biological properties of titanium oxide silicate materials

The sol-gel method derived bioactive silicate thin film materials synthesized from film-forming solutions based tetroetoksisilana, calcium chloride, phosphoric acid, ethanol in a total concentration of 0.4 mol/l and tetrabutoxytitanium a concentration of 0.3 mol/l pre-dissolved in butanol. Thin films obtained from the film forming solutions (ERP) on a substrate of monocrystalline silicon (model substrate) by extrusion stretching with speed of 5 mm/s, followed by heat treatment at 60-80°C for 20 minutes and at 600°C for 1 hour. The influence of titanium oxide on bio properties of materials obtained on the basis of the system SiO ₂-P ₂O ₅-CaO was revealed. When adding the titanium oxide in the ERP system has stabilized for 5 days. Upon reaching viscosity 3.7 mm /s is the formation of films when applied surface pore substrate, the film-forming solution viscosity above 4.4 mm /s, and the films are peeled offfrom the uneven surface of the substrate. With the use of thermal and IR - spectroscopic analysis traced the main stages of the formation of oxide systems. At temperatures up to 400 ° C are removed physically bound and chemically bound water. The second step in the temperature range 400-600°C due to the combustion of the alcohol and the products of thermal degradation ethoxy. crystallization processes do not occur until 700°C. The third stage is developed at temperatures above 700°C and is associated with polymorphic transformations SiO ₂. According to the results of X-ray analysis, the crystallization products were defined. When adding the titanium oxide in fixed phase hydroxyapatite Ca ₁g(PO ₄) ₅. ₅₂(HPO ₄)o. ₁₅(SiO ₄)o. ₃₃(OH)i ₆₆Oo. ₁₉, CaSiO ₃, anatase TiO ₂, Ca ₃(PO ₄) ₂, calcium silicate Ca ₅(PO ₄) ₂. ₈₅(SiO ₄)o. ₁₅O, but it is necessary to raise the processing temperature of the material to 800°C. In the study of the bioactive properties of the samples were immersed in the SBF solution for 14 days. For a sample containing titanium oxide in the system for 14 days the mass of the samples increased at 29 % and for the sample without the titanium oxide at 16%. For samples containing titanium oxide in the surface after immersion in SBF solution yields large, loose particles with a high content of Ca and P on the surface. Such material is extensively exchanged with calcium ions and phosphate ions with a solution of silanol groups bind calcium ions, contributing to the formation of a layer of amorphous calcium phosphates gradually crystallize into HA and other calcium phosphates. The presence of sodium and magnesium on the surface of the samples after immersion in SBF solution indicates deposition SBF solution components to the surface of the film. Titanium oxide increases the bioactivity of the material and accelerates the regeneration process.

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