Method for preparing calcium silicate/beta- tricalcium phosphate composite powder by in situ chemical precipitation method

Abstract

The invention relates to a method of preparing composite powder of calcium metasilicate / beta-tricalcium phosphate by in-situ chemical precipitation, belonging to biomedical material field; which is characterized by: take calcium nitrate, mammonium phosphate dibasic and sodium silicate as raw material; prepare settled miscible liquids of mammonium phosphate dibasic and sodium silicate, calcium nitrate liquids, adjust the pH to 10-12; add the calcium nitrate liquids drop by drop into the miscible liquids of mammonium phosphate dibasic and sodium silicate to occur in-situ chemical precipitation, settle metasilicate and beta-tricalcium phosphate through one-step chemical reaction at the same time to accomplish the even composition of said two component and produce composite powder of calcium metasilicate / beta-tricalcium phosphate. The crystal size of composite powder of calcium metasilicate / beta-tricalcium phosphate produced in said invention could be controlled between 50 nanometers and 2 micrometres following the preparing technique; said invention is characterized by: preparing technique is easy to accomplish and convenient to spread with less preparing operating steps and lower cost, etc.

Description

technical field [0001] The invention relates to a method for preparing calcium silicate / β-tricalcium phosphate composite powder by an in-situ chemical precipitation method, which belongs to the field of biomedical materials. Background technique [0002] Inorganic biomedical hard tissue repair and replacement materials mainly include calcium-phosphorus-based biomaterials and calcium-silicon-based biomaterials. Among them, the research on calcium-phosphorus-based biomaterials has a long history. Past studies have found that hydroxyapatite has good bioactivity among calcium-phosphorus-based materials, but poor biodegradability, while β-tricalcium phosphate biomaterials have good biodegradability but low bioactivity. In recent years, calcium-silicon-based biomaterials such as bioactive glass and calcium silicate have attracted more and more attention due to their excellent bioactivity and degradability. In addition to the composition of the material, the structure of the mate...

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Problems solved by technology

However, this method has the following disadvantages: due to the high temperature (1390-1500 ° C) and long time (more than 40 hours) in the sintering process of ceramics, the preparation process consumes a lot of energy and costs high

This method for preparing powder also has the following disadvantages: first, before preparing the composite powder, it is necessary to prepare a well-dispersed β-tricalcium phosphate powder, otherwise it will cause uneven mixing of the prepared composite powder, And affect the mechanical strength of the ceramic sintered body; second, the preparation of β-tricalcium phosphate powder also needs to go through processes such as precipitation, aging, multiple times of full washing, filtration, and drying, and then in the suspension of β-tricalcium phosphate powder After the calcium silicate powder is precipitated in the liquid, the same process of precipitation, aging, multiple times of full washing, filtration, and drying must be carried out again; third, due to the precipitation in the suspension of β-tricalcium phosphate powder Calcium silicate powder is generated and compounded with the β-tricalcium phosphate powder in the suspension at the same time. Due to the conventional stirring process conditions, the two components of β-tricalcium phosphate and calcium silicate will not be uniform. The shortcomings of composites, which further affect the mechanical strength of ceramic sintered bodies; Fourth, when preparing composite ceramics, sintering is carried out at 1300-1400 ° C, which is much higher than the sintering temperature of calcium silicate and β-tricalcium phosphate , and inevitably lead to the transformation of all the phases of the β-tricalcium phosphate component into the α-tricalcium phosphate phase. As already described above, the rapid degradation rate of α-tricalcium phosphate also limits the use of this type of material in Clinical application; Fifth, due to the uneven composite degree of the powder, poor sintering activity, phase transition caused by high temperature during sintering, etc., the mechanical strength of the prepared composite ceramics is not good, which affects more Wide range of clinical applications, especially limited in occasions with high mechanical load requirements

Although this method of mechanical ball milling and mixing is simple in process, its fatal disadvantages are: firstly, it is necessary to prepare different single ceramic powders, and the preparation process of each single ceramic powder requires complicated and cumbersome washing, filtering, and drying. , calcination and other processes; secondly, the application of mechanical ball milling mixing method must introduce ball milling media, the usual ball milling media is alumina or zirconia and other substances, so it is very easy to introduce impurities as ball milling media during the ball milling mixing process, and the field of biological materials The purity requirements of the material are very high, so the ball milling mixing process is a non-ideal technology for preparing biological materials

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