Datong Wu,Qiuhong Yin,Pengfei Cai,Xiaoyong Zhao,Yuanjiang Pan
Novel task-specific ionic liquids derived from (S)-phenyl amino acid were prepared as a chiral sensor for the first time. It was found that the ionic liquids exhibited different chiral visual responses to the enantiomers . When (S)-tryptophan was treated with the sensor and Cu(II) in water, the clear solution would change to a sapphire suspension. Differently, another enantiomer could not produce the precipitate. Furthermore, the enantiomers could generate different colors in DMSO under the same conditions. The substantial difference contributes to the easy discrimination with visual determination. Four racemates were successfully tested with this strategy. The precipitation was isolated in the range of 90–94% yields after complete formation of the coordinative bonds, which could be as a simple way for enantioseparation. The responsive mechanism of the sensor was studied by NMR spectroscopy , FTIR and SEM . UV-vis spectrophotometer was used to monitor the colorimetric signal of the racemate with different e.e. values.
Xing Ming,Qing Liu,Miaomiao Wang,Yongqing Cai,Binmeng Chen,Zongjin Li
Chloride-induced corrosion in reinforced concrete is a primary durability issue that causes large economic loss every year. To improve the intrinsic chloride binding capacity and realize a favorable corrosion protection of cement-based materials are thus crucial to prolong the service life of concrete structures. Here, alumina nano particles (ANPs) were incorporated to improve the chloride binding capacity of cement pastes in chloride solutions and the anti-corrosion performance of mortars under accelerated corrosion process. The ANPs facilitated the formation of alumino-ferrite-mono (AFm)-type phases, thereby improved the content of chemically bound chlorides. Solution calcium (Ca) ions benefited the chloride captured by calcium-(alumino-)silicate-hydrates (C-(A-)S-H) in the assistance of ANPs, especially at high initial chloride concentrations , and further evoked a pH-related chloride binding response. Moreover, the enhanced corrosion resistance was finally realized by incorporating appropriate amount of ANPs because of the filling and chemical effects induced low permeability of mortars. In general, the ANPs possess dual functions in the aspects of chloride binding and corrosion inhibition . These findings are expected to advance the design of high-durable cement-based materials serviced in the marine environment.
危险品化学品经营许可证（带存储）