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At present, the use of hydrotalcite-like materials to remove fluoride from water is a relatively popular research topic. Herein, an experimental and theoretical study on the adsorption of F− on the surface of hydrotalcite was reported. The experiments indicate that adsorption reached equilibrium in 2 minutes. The experimental results of adsorption thermodynamics show that adsorption is spontaneous and endothermic. Calculations based on Density Functional Theory (DFT) and Molecular Dynamics (MD) simulation were used to research the adsorption of F− on the (0 0 3) crystal face of Cl−-hydrotalcite. The optimal geometric configuration of the adsorption of F− on different sites of the hydrotalcite surface was established. F− has the lowest adsorption energy (−300.565 kJ mol−1) at the vacancy above the aluminum atom and this configuration is the most stable. The analysis of the HOMO and LUMO and Fukui function results show that F− is more susceptible to electrophilic attack and adsorbed on the surface of hydrotalcite than Cl−. The calculation results of charge population and Partial Density Of States (PDOS) show that electron transfer occurred between F− and H on the surface of hydrotalcite laminates, and the strong hybridization of the F− 2p orbital with the H 1s orbital on the surface shows the formation of hydrogen bonds between them. The simulation results of adsorption thermodynamics are the same as the experimental results and the correctness of the experiment is verified. Finally, MD simulation was carried out to explain the effect of water on adsorption and confirmed the bonding mechanism. [ABSTRACT FROM AUTHOR]

The transformation of the piroxicam monohydrate to form I or form II could be achieved precisely by adjusting the particle size itself in a 99% acetone-1% H2O solvent at 31 °C. Mechanistic studies have demonstrated that the particle size could affect both the maximum concentration of piroxicam and the heterogeneous nucleation of form II during the solution-mediated phase transformation (SMPT) process, finally determining the polymorph outcome. [ABSTRACT FROM AUTHOR]

The practicality of portable fluorescent detectors has attracted widespread attention. Herein, a series of luminogens was obtained via integrating pyrrole/fluorinated-pyrrole with triphenylamine in high yield. The emission performance was modified via varying the F and CN substituents on the pyrrole ring. The compounds TPACHO and TPAFCHO, with aldehyde-group-substituted pyrrole, exhibit significant mechanochromic luminescence (MCL) behavior and typical AIEE properties. The compounds TPA2CN and TPA2FCN can efficiently detect liquid and gaseous hydrazine hydrate, and they can achieve paper-based detection through visually clear emission color switching from yellow/orange to blue. The minimum detectable concentration of hydrazine was 10 mM. Moreover, TPA2CN exhibits good inhibitory activity toward human nasopharyngeal tumor cells (CNE1) and it has application prospects in tumor cell detection and biological cell monitoring. Thus, such functionalized paper can be applied as highly selective discriminating test strips for hydrazine hydrate. [ABSTRACT FROM AUTHOR]