Guorong Xu

Fabrication and characterisation of gelatin-hyaluronic acid/nanobioactive glass hybrid scaffolds for tissue engineering

Abstract Nanobioactive glass (NBG) particles were synthesised via sol–gel method and characterised by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The new composite biomaterial based on gelatin (Gel) conjugated with hyaluronic acid (HA) and NBG in the ternary SiO2–CaO–P2O5 system was prepared through freeze drying method. The composite scaffold was characterised by using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermal analyses. Mechanical properties and swelling behaviour of this composite are compared with properties of Gel-HA/NBG composite of similar material without NBG. The TEM results indicated that the prepared NBG particle size was ∼100 nm. The SEM studies showed that the NBG were homogenously distributed within the Gel/HA matrix and the composite scaffolds showed interconnected pores with a size varied from 50 to 200 μm. The Gel-HA/NBG composite scaffold showed higher compressive strength and better stability than the Gel/HA scaffold. These results indicate that composite scaffolds developed using NBG disseminated Gel/HA matrix as potential scaffolds for tissue engineering applications.

Study on Controlled Release of 5-Fluorouracil from Gelatin/Chitosan Microspheres

The microspheres based on gelatin (Gel) and chitosan (Cs) were prepared by a water-in-oil (W/O) emulsion crosslinking method using glutaraldehyde (GA) as a crosslinker. 5-Fluorouracil (5-FU), as an anticancer drug, was successfully loaded into the Gel/Cs microspheres. The release behavior of 5-FU was investigated with the microspheres acting as carriers for controlled release. Scanning electron microscopy (SEM) showed the formation of the microspheres is spherical with the size around 300 μm. The release patterns depend on the composition of Gel/Cs microspheres, content of crosslinker and drug content in the microspheres. The cumulative drug release of 5-FU from the microspheres decreased with increasing GA content; however, the cumulative drug release increased with increasing Gel mass ratio and 5-FU content in the microspheres. The results of 5-FU release kinetics for Gel/Cs microspheres indicated Fickian diffusion.

Spherical LiCoBO3 particles prepared via a molten salt method for lithium ion batteries

LiCoBO3/ketjen black composites were prepared at a moderate temperature of 450 °C by a molten salt method using eutectic mixtures of LiCl and KCl as the reaction medium and ketjen black as a carbon source. The monoclinic structure and spherical morphology are respectively confirmed by X-ray diffraction, scanning electron microscopy and transmission electron microscopy. The electrochemical behavior was studied by galvanostatic charge–discharge and cyclic voltammetry tests. At a rate of C/20, the composite delivered an initial specific capacity of 48 mA h g−1 and a discharge specific capacity of 40 mA h g−1 at the 25th cycle, indicating a stable cycling performance. However, rate capability for the composite needs to be further improved.

Electrochemical performance of porous α-LiVOPO4/C composite by solution combustion synthesis method

Porous α-LiVOPO4/C composite was prepared by the solution combustion synthesis method followed by annealing at 500°C for a short annealing duration of just 50 min. The synthesised material was characterised by XRD, SEM, TEM, N2 adsorption–desorption isotherms and charge–discharge tests. When tested at 0.05C rate for Li ion insertion properties, α-LiVOPO4/C composite exhibits good cycle capability with an negligible capacity degradation for the first 31 cycles. However, it shows poor rate capability with initial discharge specific capacities of 127.6 mAh g− 1 (0.05C), 109.1 mAh g− 1 (0.1C) and 74.9 mAh g− 1 (0.2C), respectively.

Effect of carbon sources on morphologies and electrochemical properties of MoS2/carbon composites

Molybdenum disulfide/reduced graphene oxide-carbon (MoS2/RGO-C) and molybdenum disulfide/reduced graphene oxide (MoS2/RGO) composites are synthesized using graphene oxide and glucose as carbon sources, and effects of carbon sources on morphologies and electrochemical properties of MoS2/carbon composites are studied in detail by comparing the materials with pristine MoS2. It demonstrates that after addition of glucose during the synthesis process, MoS2/RGO-C particles grow up due to coating of amorphous carbon on surface, and the coated carbon restrains nanosheet growth of MoS2 crystals. Electrochemical results indicate that incorporation of the reduced graphene oxide and interconnected conductive carbon network improve cycling stability of the MoS2/RGO-C composites, and a capacity retention of 80.5% is obtained after 250 charge/discharge cycles.