Double in-situ synthesis method for preparing carbon nanotube-reinforced hydroxyapatite composites

Abstract

The invention relates to composite materials for prosthesis materials, in particular to a double in-situ synthesis method for preparing carbon nano tube reinforced hydroxyapatite composite materials. The method comprises the steps that 1, in-situ synthesis of carbon nano tube-hydroxyapatite in-situ mixed powder is carried out; 2, double in-situ synthesis of carbon nano tube-hydroxyapatite in-situ composite powder is carried out; 3, the carbon nano tube reinforced hydroxyapatite composite materials are prepared. On the basis of preparing the carbon nano tube-hydroxyapatite in-situ composite powder, a hydroxyapatite layer which is dense in coating and controllable in structure is synthesized on the surface of the carbon nano tube through a sol-gel process, the carbon nano tube reinforced hydroxyapatite composite materials are prepared, the prefect structure of a carbon nano tube and the good biocompatibility of the hydroxyapatite composite materials are both achieved, meanwhile, the dispersion effect of the carbon nano tube and the interface combination effect are obviously improved, the carbon nano tube reinforced hydroxyapatite composite materials with the excellent mechanical property and the biocompatibility are made, and the carbon nano tube reinforced hydroxyapatite composite materials are widely applied to the bio-medical field.

Description

technical field [0001] The technical solution of the invention relates to a composite material used for prosthetic materials, in particular to a double in-situ synthesis method for preparing a carbon nanotube reinforced hydroxyapatite composite material. Background technique [0002] Due to its good biocompatibility, osteoconductivity and bioactivity, hydroxyapatite has broad application prospects as hard tissue implants and has attracted great attention. However, pure hydroxyapatite materials have poor mechanical properties and reliability, especially high brittleness, low flexural strength and fracture toughness, and are difficult to be directly used as load-bearing implants. Since carbon nanotubes were discovered by Iijima, due to their extremely high strength, toughness, and excellent electrical, magnetic, and thermal properties, they have become a recognized super-strong one-dimensional reinforcement material. The use of carbon nanotubes to strengthen hydroxyapatite co...

AI Technical Summary

Problems solved by technology

CN201210555876 is a technology developed by the inventor team earlier. Through practical application, it is found that this prior art has the following defects: After a large number of studies, it has been shown that the toxicity of carbon nanotubes in the body is mainly caused by lung inflammation and fibrosis, circulatory system Oxidative damage, atherosclerosis and systemic immune system abnormalities, etc. Therefore, in the preparation process of such composite materials, it is often necessary to take necessary technological measures to reduce the toxicity of carbon nanotubes and improve the biocompatibility of composite materials

The process method adopted in CN201210555876 is that after carbon nanotube-hydroxyapatite powder is put into deionized water, various raw materials such as sodium chloride and sodium bicarbonate are sequentially dissolved into the above-mentioned deionized water to make hydroxyapatite The defects of forming and modifying the surface of carbon nanotubes in a solution are as follows: First, through the liquid-phase chemical reactions of the above-mentioned various raw materials, the formed product is nano-particle hydroxyapatite, and this Only a very small amount of hydroxyapatite in shape and particle size can be attached to the surface of carbon nanotubes by physical adsorption. The patent specification is attached image 3 speaks volumes for this

As we all know, the physical adsorption force between carbon nanotubes and nano-hydroxyapatite particles belongs to the category of van der Waals force, therefore, the interfacial bonding force between the two is very small, and it is difficult to achieve the effect of transferring load and inhibiting crack growth. effect; in the subsequent process of making the above powder into a bulk composite material by pressing in the patent, chemical bonding cannot occur between carbon nanotubes and hydroxyapatite, and the original physical bonding state is still maintained. Therefore, the same as the traditional Similar to the external addition method, the interfacial binding effect between carbon nanotubes and hydroxyapatite has not changed substantially

As a result, although the mechanical properties of the composite material prepared by this patent have been improved, the fracture toughness is 1.4-3.6MPa·m 1 / 2 , still comparable to the fracture toughness of human bones 4~12MPa·m 1 / 2 There is a large gap, and the low fracture toughness is the main reason why hydroxyapatite composites are difficult to apply clinically

It can be seen that the carbon nanotube-hydroxyapatite interface bonding strength in the composite material prepared by this patent is low, which makes it difficult for the mechanical properties of the composite material to meet the requirements of hard tissue implants

[0004] Although there are many prior art methods for preparing carbon nanotube-reinforced hydroxyapatite composite materials, the existing methods for preparing carbon nanotube-reinforced hydroxyapatite composite materials, in the prepared carbon nanotube-reinforced hydroxyapatite In composite materials, some of the carbon nanotubes are exposed on the surface of the material and may be in contact with human tissue. It is difficult to avoid the toxicity caused by the dissolution of carbon nanotubes and cause harm to the human body. Therefore, it is difficult to take into account the perfect structure of carbon nanotubes and hydroxyapatite. Stone-based composite materials have good biocompatibility, and it is difficult to significantly improve the dispersion effect and interface bonding effect of carbon nanotubes, which affects the wide application of this material in the biomedical field.

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