Guangqi Hu,Yuqiong Sun,Yixuan Xie,Shuangshuang Wu,Xuejie Zhang,Jianle Zhuang,Chaofan Hu,Bingfu Lei,Yingliang Liu
UV absorbers are very effective in the fields of antiyellowing, resistance of photocatalytic degradation, and sunscreen cosmetics. However, commercialized UV absorbers have the drawbacks of toxicity, low absorption efficiency, transparency, etc. Here, we report for the first time silicon quantum dots as full-band UV absorbers. The NH-refunctionalized silicon quantum dots with high-performance UV absorption were successfully synthesized under the synergistic effect of sodium citrate and ethanediamine, and the (NH, OH)-functionalized silicon quantum dots (SiQDs) with full-band UV absorption can be achieved by reregulating −NH2 and −OH groups on the surface. The as-prepared (NH, OH)-functionalized SiQDs exhibited good stability and underwent treatment of varying pH and temperature. Furthermore, experimental results demonstrated that compared to commercial water-soluble organic UV absorbers, the (NH, OH)-functionalized SiQDs showed better antiyellowing performance for polyurethane and resistance of photocatalytic degradation for rhodamine B, and presented huge application potential in sunscreen cosmetics. Finally, the UV absorption mechanism of SiQDs was explained to be mainly related to Γ → Γ direct band gap transition, which absorb UV light and release it as thermal radiation.
At present, nanofiber antibacterial materials, especially silver antibacterial materials, are one of the most popular antibacterial materials. Nanofiber antibacterial materials are the most widely used materials due to their antibacterial spectrum and persistence. In fact, the storage and anti-yellowing properties of nanofiber antibacterial materials are of great concern in the application of industrial and consumer goods. However, there are few studies on the uniform preparation, storage, and anti-yellowing properties of antibacterial materials. Thus, we prepared nanofiber antibacterial materials by adding surfactants and studied the dispersion and storage time of the spinning solution. After spinning and forming the membrane, we tried to study the fiber morphology and environmental factors prepared by different proportions. Finally, we also tried to study the properties of the nanofiber membrane, such as contact angle, anti-yellowing, and antibacterial property. In a word, we explored the basic rules of material preparation, storage, and yellowing resistance so as to provide guidance for nanofiber antibacterial material industrial production.
Bioderived polycarbonate (ISB-PC) was synthesized via transesterification and polycondensation of isosorbide (ISB) and diphenyl carbonate (DPC) using lithium acetoacetone as a catalyst. The resulting ISB-PC exhibited high glass transition temperatures similar to bisphenol A polycarbonate (BPA-PC) and was thermally stable up to 350 ℃. The incorporation of isosorbitol into the polymer chain imparted an improved mechanical property of ISB-PC, such as a higher bending and tensile modulus and higher elongation at break. ISB-PC can be readily cast into transparent films with a tensile strength of 73.3 MPa and a tensile modulus of 534 MPa. ISB-PC displayed high UV transmittance and possessed blue fluorescence under UV irradiation. At the same time, ISB-PC also has strong anti-yellowing ability.
危险品化学品经营许可证（带存储）