High-specific-surface-area magnetic porous carbon microspheres (MPCMSs) were fabricated by annealing Fe(2+)-treated porous polystyrene (PS) microspheres, which were prepared using a two-step seed emulsion polymerization process. The resulting porous microspheres were then sulfonated, and Fe(2+) was loaded by ion exchange, followed by annealing at 250 °C for 1 h under an ambient atmosphere to obtain the PS-250 composite. The MPCMS-500 and MPCMS-800 composites were obtained by annealing PS-250 at 500 and 800 °C for 1 h, respectively. The iron oxide in MPCMS-500 mainly existed in the form of Fe3O4, which was concluded by characterization. The MPCMS-500 carbon microspheres were used as catalysts in heterogeneous Fenton reactions to remove methylene blue (MB) from wastewater with the help of H2O2 and NH2OH. The results indicated that this catalytic system has a good performance in terms of removal of MB; it could remove 40 mg L(-1) of MB within 40 min. After the reaction, the catalyst was conveniently separated from the media within several seconds using an external magnetic field, and the catalytic activity was still viable even after 10 removal cycles. The good catalytic performance of the composites could be attributed to synergy between the functions of the porous carbon support and the Fe3O4 nanoparticles embedded in the carrier. This work indicates that porous carbon spheres provide good support for the development of a highly efficient heterogeneous Fenton catalyst useful for environmental pollution cleanup.

No abstract

No abstract

Developing hydrogel wound dressings with antibacterial activity and reproducible adhesion ability is an urgent need in biomaterial sciences. However, present hydrogel wound dressings either employ inorganic antibacterial agents such as Ag and metallic oxide nanoparticles, which have dosage dependence and unsatisfactory biocompatibility, or load antibiotics, evolving drug-resistant bacteria. Here a nucleobase-inspired self-adhesive and inherently antibacterial hydrogel is reported as a wound dressing. The hydrogel was developed from poly­(3-dimethyl­(methacryloyloxyethyl)­ammonium propanesulfonate)-co-poly­(methacryloylamidoadenine) (PDMAPS-co-PMA-Ade) and chitosan. The DMAPS moieties endow the hydrogel with an anti-fouling property, while special interactions between nucleobase-modified MA-Ade provide facile molecular recognition with corresponding groups on the surface of tissues. In vivo cutaneous wound repair determination demonstrated that the hydrogel-treated mice showed no hemorrhage, less inflammation, and fewer neovessels than the control after 14 days. This achievement offers an opportunity to facilitate significant wound healing without the aid of other antibiotics.