Hongen Nian

FTIR spectroscopic studies of lithium tetrafluoroborate in propylene carbonate + diethyl carbonate mixtures

FTIR (Fourier transformed infrared) spectra have been collected and analyzed for solutions of lithium tetrafluoroborate in propylene carbonate (PC), diethyl carbonate (DEC), and PC+DEC mixtures. It has been shown that the carbonyl stretch bands of PC and DEC, the ring of PC and the ether oxygen stretch bands of DEC are all very sensitive to the interaction between Li(+) and the solvent molecules. New shoulders appear and the original bands split with the addition of LiBF4, indicating that a strong interaction between Li(+) and molecules of PC and DEC exists through the oxygen group of C=O and ring of PC and both C=O oxygen and ether oxygen atoms of DEC. In addition, no preferential solvation of Li(+) in LiBF4/PC+DEC solutions was detected.

Investigation and Preparation of High Active Nano-MgO Thin SphericalMaterial

High active MgO precursor was prepared by high-temperature spray thermal decomposition method using saturated MgCl2 as raw materials. And high active nano-MgO thin spherical materials were prepared by MgO precursor being calcined at different temperatures after multiple hydration, purification, and filtration. The XRD, TG, DSC and SEM were employed to characterize the phase structure and micro-morphology of spherical materials whose formation mechanism was researched. And its activity (average pore size and surface area) was detected by using BET-BJH of N2 adsorption to get the optimum calcination temperature. The results showed that high active nano-MgO thin spherical material was periclase structure, its surface of nano-flake or rod-like, and thin sphere with diameter of 30∼100 nm and aperture of 10∼60 nm. The aperture was decreased while the surface area, microporous volume and surface activity were increased with preparation process were optimized, for example, calcination temperatures. Nano-MgO thin spherical material with a purity of 99.2 wt% was obtained at 900°C. And BET surface area of nano-sphere reached a maximum value of 31.6 m2/g with nest-like structure of particle uniform dispersion and average aperture of 11.2 nm. Meanwhile, the maximum absorption of N2 was gotten.