A novel magnetic microsphere was prepared by simple microemulsion polymerization for protein drug delivery systems. The Fe3O4 magnetic nanoparticles were successfully encapsulated in chitosan microspheres, which endowed the chitosan microspheres with good magnetism. The drug loading performance results indicated that the prepared magnetic chitosan microspheres exhibited a superior drug loading capacity, and the drug loading amount reached 947.01 mg g−1. Furthermore, the magnetic chitosan microspheres also showed a higher drug release rate (87.8%) and evident sustained-release performance in vitro. The magnetic microsphere carrier will be widely used in the biomedical field as a promising drug carrier.
A highly active catalyst of molybdenum oxide supported on mesoporous alumina modified by Ca2+was synthesized by anin situmethod and applied in the catalytic oxidative desulfurization (CODS) system.
When ordinary wounds are infected, the skin's self-healing capacity declines; thus appropriate dressings with both antibacterial ability and healing ability for bacteria-associated wounds are indispensable. In this work, multifunctional chitin/ZnO composite hydrogels have been designed as an infected full-thickness skin wound-healing material. The hydrogels are fabricated by a facile one-pot strategy through the sequential addition of commercial ZnO powders into aqueous alkaline chitin solutions, crosslinking and regeneration. The regenerated nanoscale ZnO particles aggregate into microscale particles and are embedded in the chitin matrix with tight interactions, including hydrogen bonding and coordination interactions. The decoration of ZnO endows the chitin/ZnO composite hydrogels with excellent antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), with acceptable biocompatibility. More importantly, the chitin/ZnO composite hydrogels show an outstanding accelerated infectious full-thickness wound-healing performance with more fibroblast proliferation, more collagen deposition, and more neogenesis of the epithelium and granulation tissue. Therefore, it is expected that the chitin/ZnO composite hydrogels can serve as competitive skin wound dressings for the prevention and control of infections.
A highly-efficient graphitic carbon nitride (g-C3N4) photocatalyst for visible light photodegradation of rhodamine B (RhB) and methyl orange (MO) simulating dyeing wastewater was synthesized by the thermal polycondensation of melamine. The photocatalysts were characterized by TG-DTG-DSC, XRD, EA, XPS, FT-IR, SEM, TEM, BET, PL and UV-vis DRS. The results showed that the photocatalytic performance of g-C3N4 at a higher calcination temperature was significantly enhanced, and its photocatalytic activities for the photodegradation of RhB and MO were remarkably improved by 64.91% and 41.83%, respectively, which was mainly attributed to the satisfactory crystallinity, stable graphene-like structure, large surface area, and excellent optical properties. It was found that •O2− radicals and •OH radicals were the main active species for the photodegradation process by the free radicals trapping experiments and ESR analysis. The photodegradation mechanism of g-C3N4 was proposed predicated using the characterization results.
A nano-sized solid acid was synthesized from rice hull ash by acid activation. The solid acid was characterized by XRD, FT-IR, TEM and solid-state NMR spectroscopy. The characterization results show that the solid acid is amorphous silica with –OH and –SO3H functional acid groups. The TEM images show that the particle size range of the solid acid catalyst is 50–100 nm. In addition, the catalytic results indicate that the solid acid exhibits excellent activity and recyclability for the transesterification reaction of soybean oil with methanol, suggesting promising industrial applications in biodiesel production.