Yao Li,Jingran Bi,Shan Liu,Haitao Wang,Chenxu Yu,Dongmei Li,Bei-Wei Zhu,Mingqian Tan
The presence of nanomaterials during food processing has attracted significant concern due to the physicochemical properties of nanomaterials. In this study, the presence and formation of nitrogen-containing fluorescence carbon dots (C-dots) in a grilled hamburger at different temperatures (220, 260, and 300 °C) were investigated during the pyrolysis process. The size and morphology of the C-dots were found to be highly dependent on the heating temperatures, which again affected the functional groups on their surface. The C-dots are strongly fluorescent with multicolor emission accompanied by a gradual decrease in fluorescence intensity. The fluorescence quantum yield of the C-dots produced at 260 °C was measured to be 23.25%. The potential cytotoxicity and biodistribution of the C-dots within live organisms were examined with the mouse osteoblasts cell line and mung bean sprout, respectively. The cell viability after 24 h incubation remained 79% for the C-dots obtained at 300 °C at a concentration of 3.2 mg mL−1, and no obvious phytotoxicity in the growing mung bean sprout was observed. The results showed an increased cytotoxicity of the C-dots formed at higher temperatures.
With the intention of improving the comprehensive performance of anion exchange membranes (AEMs), a series of hamburger-structure AEMs based on triple-ammonium side chain poly(2,6-dimethyl-1,4-phenylene oxide) (TA-PPO) membrane were prepared. 1, 2-dimetylimidazolium-modified silica (Im-SiO 2 ) was introducing to the surface of the TA-PPO membrane to fabricate a hamburger structure of Im-SiO 2 /TA-PPO membrane. The hamburger structure of the Im-SiO 2 /TA-PPO membrane is clearly observed by scanning electron microscope (SEM) and energy dispersive X-ray (EDX) linear scanning. Surprisingly, the Im-SiO 2 layer on the surface of TA-PPO shows many valuable properties. Such as impressive ion conduction ability, water retaining capacity, and swelling resistance. Besides, the Im-SiO 2 layer serves as a preserver to protect the TA-PPO membrane from being attacked by hydroxide and oxygen radical. Compared with TA-PPO membrane, the Im-SiO 2 /TA-PPO composite membrane exhibits the higher hydroxide conductivity and dimensional stability, and even higher alkaline stability and oxidation resistance. Typically, the Im-SiO 2 /TA-PPO composite membrane exhibits a maximum hydroxide conductivity of 105 mS/cm at 80 °C with a swelling ratio of 8.2%. Therefore, the hamburger structure of the Im-SiO 2 /TA-PPO membranes provides a new and reliable method to improve the comprehensive performance of AEM.
危险品化学品经营许可证（带存储）