Co-reporter:Lijun Ji, Ge Liang, Yunfeng Si, Wei Qiao, Yuheng Zhang, Aiping Zhu, Dong Qiu
Materials Letters 2017 Volume 190(Volume 190) pp:
Publication Date(Web):1 March 2017
DOI:10.1016/j.matlet.2016.12.133
•A porous carbon was confirmed suitable microreactor for engineering silica based colloids.•Colloids could be synthesized by multistep chemical reactions.•High magnetic mesoporous BG and Fe2O3/SiO2 hollow microspheres were prepared.•SiO2/Ag spherical crowns were prepared.•The colloid synthesis process was controlled by various mechanisms.A three dimensional ordered macroporous carbon (OMC) was confirmed a proper microreactor for engineering silica based colloids by synthesizing magnetic mesoporous bioactive glass microspheres, Fe2O3/SiO2 hollow microspheres and SiO2/Ag spherical crowns. The OMC was much more chemically inert and heat resistant than the ordered macroporous polymer (OMP), thus multistep synthesis processes were carried out inside the OMC to engineer the composition, shape and structure of the silica based colloids. This work suggested that the OMC had more advantages in synthesizing colloids than the OMP, and the mechanism of engineering colloidal structures based on material wetting to the OMP was extended to designing multistep chemical reactions, limiting reaction in a closed room and material wetting to the OMC.Colloids of varied structures could be prepared by one- or multi-step synthesis process by using an ordered macroporous carbon as a microreactor.Download high-res image (129KB)Download full-size image
Co-reporter:Lijun Ji, Wei Qiao, Yuheng Zhang, Huayu Wu, Shiyong Miao, Zhilin Cheng, Qianming Gong, Ji Liang, Aiping Zhu
Materials Science and Engineering: C 2017 Volume 78(Volume 78) pp:
Publication Date(Web):1 September 2017
DOI:10.1016/j.msec.2017.04.070
•Halloysite nanotubes were used to strengthen a gelatin scaffold.•The mechanical properties of the gelatin scaffold were enhanced significantly.•Long-time drug release to fight infection and pain.•The obtained composite scaffold was suitable for bone treatment.Mechanical properties and anti-infection are two of the most concerned issues for artificial bone grafting materials. Bone regeneration porous scaffolds with sustained drug release were developed by freeze-drying the mixture of nanosized drug-loaded halloysite nanotubes (HNTs) and gelatin. The scaffolds showed porous structure and excellent biocompatibility. The mechanical properties of the obtained composite scaffolds were enhanced significantly by HNTs to > 300%, comparing to those of gelatin scaffold, and match to those of natural cancellous bones. The ibuprofen-loaded HNTs incorporated in the scaffolds allowed extended drug release over 100 h, comparing to 8 h when directly mixed the drug into the gelatin scaffold. The biological properties of the composite scaffolds were investigated by culturing MG63 cells on them. The HNTs/gelatin scaffolds with excellent mechanical properties and sustained drug release could be a promising artificial bone grating material.The addition of HNT can strengthen the gelatin scaffold obviously, and provide a persistent drug release.Download high-res image (153KB)Download full-size image
Co-reporter:Lijun Ji, Yuheng Zhang, Shiyong Miao, Mindong Gong, Xi Liu
Carbon 2017 Volume 125(Volume 125) pp:
Publication Date(Web):1 December 2017
DOI:10.1016/j.carbon.2017.09.094
•Carbon-TiO2 nanotubes are prepared by using surface-sulfonated PS fibers as templates.•Carbon doping lowers the bandgap energy of TiO2.•Carbon doping extends the visible light adsorption of TiO2 to a longer wavelength.•The carbon-TiO2 nanotubes separate and transfer electron-hole pairs high efficiently.•The carbon-TiO2 nanotubes show excellent property in photodegrading UDMH solution.Titanium dioxide (TiO2) has been widely investigated as a photocatalytic material. However, the photocatalytic activity of TiO2 is suppressed by the large band gap and the recombination rate of the electron-hole pairs. Here, we propose an in situ synthetic strategy for the construct of carbon doped TiO2 (carbon-TiO2) nanotubes using surface-sulfonated layer of polystyrene fibers/titania composites as the precursors of TiO2 and carbon source via a facile route of calcination. This technique involves the preparation of morphology well controlled polystyrene fibers, sulfonation of PS fibers, sol-gel synthetic process of TiO2 and the pyrolysis of SSPS fibers in a N2 atmosphere at 450 °C. The morphology and structure of as-prepared carbon-TiO2 nanotubes are mainly characterized by SEM, TEM, XRD, Raman spectroscopy, XPS and UV–vis spectroscopy. All results confirm the carbon doping in the as-prepared carbon-TiO2 nanotubes. As a result of the unique microstructure, this composite exhibits remarkable photocatalytic efficiency for the degradation of unsymmetrical dimethylhydrazine under visible light irradiation, indicating great potential for dealing with waste water containing organic pollutant.Carbon doped TiO2 nanotubes with an enhanced photocatalytic performance under UV and visible light were prepared by an in situ synthetic strategy. Carbon doping into TiO2 lattice lowered the band gap energy of TiO2 and improved visible light absorption, indicating great potential for dealing with waste water containing organic pollutant.Download high-res image (191KB)Download full-size image
Co-reporter:Lijun Ji, Wenjun Wang, Duo Jin, Songtao Zhou, Xiaoli Song
Materials Science and Engineering: C 2015 Volume 46() pp:1-9
Publication Date(Web):1 January 2015
DOI:10.1016/j.msec.2014.09.041
•Bioactive glass nanoparticles were synthesized and confirmed excellent bioactivity.•NBG/PCL composites with a high NBG content were prepared by melt blending method.•The NBG/PCL composites were confirmed excellent bioactivity.•The NBG/PCL composites presented excellent mechanical property after soaking in SBF.Nanoparticles of bioactive glass (NBG) with a diameter of 50–90 nm were synthesized using the Stöber method. NBG/PCL composites with different NBG contents (0 wt.%, 10 wt.%, 20 wt.%, 30 wt.% and 40 wt.%) were prepared by a melt blending and thermal injection moulding technique, and characterized with XRD, FTIR, and SEM to study the effect of NBG on the mechanical properties and in vitro bioactivity of the NBG/PCL composites. In spite of the high addition up to 40 wt.%, the NBG could be dispersed homogeneously in the PCL matrix. The elastic modulus of the NBG/PCL composites was improved remarkably from 198 ± 13 MPa to 851 ± 43 MPa, meanwhile the tensile strength was retained in the range of 19–21.5 MPa. The hydrophilic property and degradation behavior of the NBG/PCL composites were also improved with the addition of the NBG. Moreover, the composites with high NBG content showed outstanding in vitro bioactivity after being immersed in simulated body fluid, which could be attributed to the excellent bioactivity of the synthesized NBG.
Co-reporter:Lijun Ji, Wenjun Wang, Molly M. Stevens, Songtao Zhou, Aiping Zhu, Ji Liang
Materials Research Bulletin 2015 61() pp: 453-458
Publication Date(Web):
DOI:10.1016/j.materresbull.2014.10.060
Co-reporter:Lijun Ji, Yunfeng Si, Hongfei Liu, Xiaoli Song, Wei Zhu, Aiping Zhu
Microporous and Mesoporous Materials 2014 Volume 184() pp:122-126
Publication Date(Web):15 January 2014
DOI:10.1016/j.micromeso.2013.10.007
•A method combining orthogonal design and quantitive analysis of SAXS was proposed.•An efficient method to evaluate the impact of multifactor to mesoporous structure.•The optimum formula of a MBG with complex components was revealed.An orthogonal experimental design method combining with quantitive analysis of small-angle X-ray scattering (SAXS) pattern was applied to optimize the synthesis of bioactive glasses with highly ordered mesoporous structure (MBGs). The quantitive analysis of SAXS pattern allows a quantified evaluation of the ordering of the mesoporous structure, which makes it possible to tailoring the mesoporous structure of the MBGs with complex component by a traditional orthogonal experimental design method. The number of trials for preparing MBGs can be greatly reduced and the primary factors affecting the formation of mesoporous structure and the properties of MBGs can be easily found out by this orthogonal experimental design method. MBGs containing SiO2, CaO, Fe2O3 were prepared as an example to present the way to obtain optimized ordered mesoporous structure. It confirmed that Fe2O3 was the primary factor influencing the mesoporous structure of the MBGs. The ordering of the mesopores increased in the first and then decreased with the increase of F127 content.A novel method combining an orthogonal experiment (L16) and a quantitive analysis of SAXS patterns was proposed to reveal the impact degree of multifactor to pore ordering of mesoporous bioactive glasses and determine the optimum synthesis formula of the MBGs with complicated multicomponent. The verification experiment showing the highly ordered mesoporous structure of the optimum MBGs confirmed the rationality and validity of the method.
Co-reporter:Lijun Ji;Yunfeng Si;Ailing Li;Wenjun Wang
Frontiers of Chemical Science and Engineering 2012 Volume 6( Issue 4) pp:470-483
Publication Date(Web):2012 December
DOI:10.1007/s11705-012-1217-1
Bioactive glasses (BGs) are ideal materials for macroporous scaffolds due to their excellent osteoconductive, osteoinductive, biocompatible and biodegradable properties, and their high bone bonding rates. Macroporous scaffolds made from BGs are in high demand for bone regeneration because they can stimulate vascularized bone ingrowth and they enhance bonding between scaffolds and surrounding tissues. Engineering BG/biopolymers (BP) composites or hybrids may be a good way to prepare macroporous scaffolds with excellent properties. This paper summarizes the progress in the past few years in preparing three-dimensional macroporous BG and BG/BP scaffolds for bone regeneration. Since the brittleness of BGs is a major problem in developing macroporous scaffolds and this limits their use in load bearing applications, the mechanical properties of macroporous scaffolds are particularly emphasized in this review.
Co-reporter:Lijun Ji, Wei Qiao, Kai Huang, Yuheng Zhang, Huayu Wu, Shiyong Miao, Hongfei Liu, Yixiang Dong, Aiping Zhu, Dong Qiu
Materials Science and Engineering: C (1 June 2017) Volume 75() pp:
Publication Date(Web):1 June 2017
DOI:10.1016/j.msec.2017.02.107
•Nanosized 58S BG particles were prepared by using a MOC template.•The 58S particles possessed narrow size distribution and spherical morphology.•The narrow size distribution was confirmed crucial to gelatin composite.•The mechanical properties of the gelatin composite were improved significantly.•The outstanding bioactivity of the 58S BG particles was confirmed.Nanosized 58S bioactive glass (BG) particles were synthesized by using a three-dimensional ordered macroporous carbon template (OMC) with a pore size of 400 nm. The obtained 58S BG particles possessed a diameter of 300 nm, narrow size distribution and uniform spherical morphology. 58S/gelatin composites were prepared and showed much better mechanical properties than pure gelatin. The narrow size distribution of the 58S particles replicated from OMC was confirmed crucial to the mechanical properties of the 58S/gelatin composite, comparing to the contrast sample prepared with polydispersed particles. The outstanding bioactivity of the 58S BG particles was confirmed by inducing the formation of carbonated hydroxyapatite on the 58S/gelatin composite surface. This work showed a successful example that OMC template could be used to synthesize particles requiring a robust reaction condition, and a particle synthesis method that could well control particle size distribution was important for preparing materials with outstanding mechanical properties.