Jianing Zhang,Junjun Zhang,Xinai Zhang,Xiaowei Huang,Jiyong Shi,Remah Sobhy,Ibrahim Khalifa,Xiaobo Zou
In this study, we devised a photothermally stable phytochemical dye by leveraging alizarin in conjunction with the metal–organic framework ZIF-8 (AL@ZIF-8). The approach involved grafting alizarin into the microporous structure of ZIF-8 through physical adsorption and hydrogen-bonding interactions. AL@ZIF-8 significantly enhanced the photostability and thermostability of alizarin. The nanoparticles demonstrate substantial color changes in various pH environments, showcasing their potential for meat freshness monitoring. Furthermore, we introduced an intelligent film utilizing poly(vinyl alcohol)-sodium alginate-AL@ZIF-8 (PA-SA-ZA) for detecting beef freshness. The sensor exhibited a superior water contact angle (52.34°) compared to the alizarin indicator. The color stability of the film was significantly enhanced under visible and UV light (ΔE < 5). During beef storage, the film displayed significant color fluctuations correlating with TVB-N (R2=0.9067), providing precise early warning signals for assessing beef freshness.
Wenjing Ma,Sangram Keshari Samal,Zhongche Liu,Ranhua Xiong,Stefaan C. De Smedt,Bharat Bhushan,Qilu Zhang,Chaobo Huang
In the last few years, the amount of industrial oily wastewater discharge and number of oil spill accidents have increased exponentially, spurring the development of highly efficient, cost-effective oil-water separation technologies. In this study, a dual pH- and ammonia-vapor-responsive polyimide (PI)-based nanofibrous membrane with high permeate flux and stability was developed for oil-water separations. The membrane was prepared by successively dip-coating electrospun PI in decanoic acid (DA)-TiO 2 and silica nanoparticles (SNPs). The novel SNP/DA-TiO 2 /PI membrane exhibits superhydrophobicity in air and superoleophilicity in neutral aqueous environments (e.g., at pH 6.5). However, the membrane becomes hydrophilic and superoleophobic in basic aqueous environments (e.g., at pH 12), resulting in only water permeation during oil-water separations. The oil-water separation potential of this innovative dual-responsive membrane was investigated using several model oil-water mixtures. The membrane has extremely high flux (6500±100 L m −2 h −1 ) and separation efficiency (>99%) and is reusable. In addition, thermal stability and abrasion resistance tests show that the membrane is highly stable under extreme conditions. This dual-responsive electrospun nanofibrous membrane has potential for use in industrial oil-polluted water and oil spill treatment and in systems that require selective oil-water permeation. Furthermore, changes in the surface wettability can also be induced by exposure to ammonia vapor, which might facilitate remote-controlled oil-water separations.
In the work, rGO nanosheet is synthesized using the typical Hummer’s method, then Cu 12 Sb 4 S 13 quantum dots@rGO composites are prepared by solvent thermal method, and Cu 12 Sb 4 S 13 quantum dots with the average size of 5 nm are densely distributed on the surface of rGO sheet. NH 3 gas response of Cu 12 Sb 4 S 13 quantum dots@rGO nanosheet composites at room temperature of 25 °C is enhanced compared with the pure Cu 12 Sb 4 S 13 quantum dots and rGO nanosheet, and the composites possess an excellent stability during the humidity range of 45%–80% with a low detection limit of 1 ppm, which is related with the intrinsic hydrophobicity characteristic of Cu 12 Sb 4 S 13 quantum dots. It also proves that Cu 12 Sb 4 S 13 quantum dots@rGO nanosheet composites have a quite high selectivity towards ammonia compared with ethanol, methanol, acetone, toluene, hydrogen sulfide and nitrogen dioxide at room temperature. The gas sensing mechanism of the composites is discussed primarily.
Zirconia slurry aimed to apply in digital light process (DLP) printing technology were made of the 3 mol% yttrium oxide (Y2O3) stabilized micro-nano zirconium dioxide (3YSZ) powders. An overall mechanical strength can be obtained via a precise control of two-step sintering process. The results show that Y2O3 in 3YSZ would diffuses into the ceramic lattice, further stabilizing the metastable tetragonal zirconia (t-ZrO2) toughening phase in sub-micro sized grains with nearly 100% crystal phase transition ratio. The Vickers hardness of sintered ceramic parts reaches 12.94 ± 0.186 GPa. The fracture toughness (KIC) of sintered ceramics is 5.63 ± 0.015 MPa·m1/2. The propagation law of Vickers crack reveals the mechanism of strengthening and toughening of fine grains on matrix fracture toughness. Due to the uniform crystals also can make the corrosion better to construct a three-phase boundary sensitive process, the response of the T-ZrO2-SnO2 to 30 ppm NH3 is 15.7 mV which is 2 times more than the commercial ZrO2. A relative short response and recovery times of 6 s and 33 s can achieve with a good reproducibility of continuous response and recovery transients.
危险品化学品经营许可证（带存储）