Bacterial infectious diseases and bacterial‐infected environments have been threatening the health of human beings all over the world. In view of the increased bacteria resistance caused by overuse or improper use of antibiotics, antibacterial biomaterials are developed as the substitutes for antibiotics in some cases. Among them, antibacterial hydrogels are attracting more and more attention due to easy preparation process and diversity of structures by changing their chemical cross‐linkers via covalent bonds or noncovalent physical interactions, which can endow them with various specific functions such as high toughness and stretchability, injectability, self‐healing, tissue adhesiveness and rapid hemostasis, easy loading and controlled drug release, superior biocompatibility and antioxidation as well as good conductivity. In this review, the recent progress of antibacterial hydrogel including the fabrication methodologies, interior structures, performances, antibacterial mechanisms, and applications of various antibacterial hydrogels is summarized. According to the bacteria‐killing modes of hydrogels, several representative hydrogels such as silver nanoparticles‐based hydrogel, photoresponsive hydrogel including photothermal and photocatalytic, self‐bacteria‐killing hydrogel such as inherent antibacterial peptides and cationic polymers, and antibiotics‐loading hydrogel are focused on. Furthermore, current challenges of antibacterial hydrogels are discussed and future perspectives in this field are also proposed.

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The vacuum-based magnetron sputtering was utilized to the fabrication of Cu 2 ZnSnS 4 (CZTS) thin films on flexible Al, Mo, and stainless steel foil substrates. The structural, compositional, and morphological properties of prepared thin films were investigated. According to the XRD and Raman results, for Al and Mo foil substrates, the structures of thin films are major CZTS and tiny secondary phase of Cu 2 SnS 3 . The preferred orientation of CZTS is along the (112) plane. The XRD peaks and Raman peaks of CZTS on Mo foil substrate are stronger than those on Al foil substrate. The calculated grain sizes are 33.6 and 39.0 nm for the thin films on Al and Mo foil substrates, respectively, indicating the higher crystallinity for Mo foil substrate samples. The compositions of thin films are near the stoichiometry of CZTS and show Cu-poor and Zn-rich properties. The surfaces of thin films are composed of compact grains. When using stainless steel foil as substrate, the fabricated thin films are composed of Cu 2 SnS 3 , FeS, and Zn, revealing the existence of sulfurization of Fe. The reaction between Fe and S inhibits the full sulfurization of Cu-Zn-Sn precursor, resulting in the absence of CZTS in the fabricated thin films. The composition of thin films is far from the stoichiometry of CZTS. In order to get desired properties of CZTS thin films, the inhibition of reaction between Fe and S is needed for stainless steel foil substrate.

The effects of mix activated fluxes on the penetrations, microstructures and mechanical properties of tungsten inert gas (TIG) welded AZ31 magnesium alloy joints were studied. The results showed that an increase in the amount of TiO 2 coating improved the weld penetration and depth/width ratio of the TIG welded AZ31 magnesium alloy seams. The a-Mg grains of the fusion zone (FZ) became fine gradually with the addition of CaF 2 coating but coarsened sharply when the amount of TiO 2 coating was over 70%. In addition, the porosities and total length of solidification cracks in the FZ were reduced by the CaF 2 and TiO 2 coatings. The ultimate tensile strength value of the welded joints increased with the addition of TiO 2 coating but decreased sharply when more TiO 2 coating was adopted.

Flexible Cu2ZnSnS4 (CZTS) thin films are more advantageous than those on rigid glass substrates. In this study, vacuum-based magnetron sputtering was utilized to fabricate CZTS thin films on flexible polyimide substrates. Zn/Sn/Cu precursors were sputtered and then sulfurized. The influences of sulfurization temperature on the structural, compositional, morphological, electrical, and optical properties of the fabricated thin films were analyzed. The experimental results show that the CZTS structures form on the polyimide substrates after sulfurization. The crystallinity of CZTS enhances and the secondary phases in the thin films decrease with increasing sulfurization temperature. Single-phase CZTS thin films are obtained for sulfurization temperatures reaching 450 °C. The compositions of the fabricated thin films are Cu-poor and Zn-rich. The fabricated CZTS thin films show p-type conductivity. The direct optical band gaps of the thin films range from 1.51 eV to 1.55 eV. The absorption coefficients of these films are larger than 1 × 104 cm−1 above the band gap edge. The experimental results reveal the feasibility of the deposition of CZTS thin films on polyimide substrates by vacuum-based methods. The fabricated thin films can suitably function as absorbers for solar cell applications.