Xiong Xinbo

Preparation of hydroxyapatite coating using chemical liquid vaporization deposition on carbon/carbon composites

A new chemical liquid vaporization deposition (CLVD) is used on carbon–carbon (C/C) composites to prepare hydroxyapatite (HA) coating. The heating frequencies of the CLVD and induction heating method are 330 kHz and 30 kHz, respectively. The phases, morphologies, and compositions of these coatings are characterized using scanning electron microscopy, X-ray diffraction, and electronic data systems; the adhesion of the coatings to the C/C substrates was evaluated by a scratch test. The results demonstrate that the critical loads of HA coatings prepared through CLVD and induction are 47 N and 18 N, respectively. Although these coatings have no significant phase differences, the CLVD HA coating has abundant CO32−, which improves the adhesion, multiplication, and differentiation of external osteoblasts.

Individual humeral head replacement by C/C composite implants coated with hydroxyapatite via rotation plasma spraying

Abstract The humeral heads of rabbits were replaced with individualized C/C composite implants coated with hydroxyapatite (HA) via rotation plasma spraying. The effect of the implants was evaluated after 5 and 150 days by using histology, scanning electron microscopy, X-ray diffraction, and so on. Results showed that the coating interface of C/C composites facilitated phosphorite deposition and osseous tissue growth. Furthermore, the humeral bone and remaining bone tissues were morphologically similar and possessed enhanced bonding strength. These results indicated that individualized C/C composite implants with HA coatings enabled the humeral head to adapt to dynamic requirements and accelerate healing after bone transplantation.

Structure and oxidation behavior of a plasma sprayed yttrium silicates coated SiC-C/C with a glass outer sealant from 1 573K to 1 873K

Different compositions of yttrium silicates coatings were deposited on SiC-C/C by plasma spraying and an outer borosilicate glass was applied on the yttrium silicates coatings surfaces. The structure of the multi-layer coatings was characterized by XRD and SEM analyses. High temperature oxidation behavior of the multi-layer coatings coated C/C composites was investigated. Results show that SiC/2SiO2·Y2O3/1.5SiO2·Y2O3/ SiO2·Y2O3/glass multi-layer coating has better high temperature oxidation resistance, protecting carbon/ carbon composites from oxidation at 1 773 K in air for 164 h with the weight loss of 1.65%. The oxidation weight loss of the coated C/C with time accorded with parabolic rule in the temperature range 1 573 K–1 873 K; and the corresponding oxidation activation energy of the coated carbon/carbon composites is 132.2 kJ/mol.

Functions of the Mg–HA coating on carbon/carbon composite surface to promote the proliferation and osteogenic differentiation of mBMSCs

This study aims to evaluate the functions of the Mg–hydroxyapatite (Mg–HA) bio-coating on carbon/carbon composite (C/C) surface to promote the proliferation and osteogenic differentiation of bone mesenchymal stem cell (BMSCs). The Mg–HA-coated carbon/carbon composite was placed into a medium. The change of ion concentration in the solution and formation of bone-like apatite on the composite surface were observed. Thereafter, BMSCs of mice (mBMSCs) were cultivated on the coating surface for 4, 8, 24, 48, and 72 h. Finally, gene changes (i.e., Alp, OCN, Osx, and Runx2) related to cell proliferation and osteogenic differentiation were observed. The Mg–HA coating can form a bone-like apatite coating of high Mg concentration in the medium. After mBMSCs were cultivated on the Mg–HA coating for 72 h, mRNA of Alp, Osx, and Runx2 in Mg–HA was higher than that in the HA group (P 0.05). The Mg coating can significantly promote the proliferation and osteogenic differentiation of mBMSCs.