Guanghui Tian

Synthesis of C15 and C10 fuel precursors with cyclopentanone and furfural derived from hemicellulose

Fuel precursors 2,5-bis(2-furylmethylidene)cyclopentanone (F2Cp) and 2-(2-furylmethylidene)cyclopentanone (FCp) were obtained through aldol condensation of cyclopentanone and furfural over solid acid catalysts under solvent-free conditions. Nafion exhibited the best performance among the investigated catalysts (Nafion, Amberlyst-15, Amberlyst-36, H-USY, ZSM-5, H-β, and SiO2/Al2O3). Under optimized conditions, yields of F2Cp and FCp were 37.48% and 23.77%, respectively. Selectivities of F2Cp and FCp were 50.74% and 32.18%, respectively. Nafion showed good stability and did not deactivate during 4 runs. Meanwhile, a certain amount of humin was also generated during the reaction. The reaction mechanism for the aldol condensation of cyclopentanone and furfural and the formation mechanism of humin were also proposed.

Properties of magnetic carbon nanomaterials and application in removal organic dyes

Magnetic carbon nanomaterials were prepared facilely by one step hydrothermal synthesis method using biologically regenerated glucose as carbon sources and ferric ammonium citrate as iron sources. As-synthesized nanomaterials were characterized by means of SEM, TEM, XRD, N2 adsorption-desorption, VSM and XPS etc. techniques. Results show as-prepared magnetic nanomaterials are sphere particles with aggregation state and magnetic α-Fe particles are enclosed by carbon matrixes. With increase of calcination temperature, the degrees of the sample aggregation decrease, whereas the average particle sizes, BET specific surface areas and saturation magnetizations increase. The carbon with graphite structure has higher adsorption efficiency than that of amorphous carbon for organic dye rhodamine B in water. Whereas the iron with amorphous structure shows higher photocatalytic activity than that of the iron with crystalline structure for the degradation of rhodamine B. And rhodamine B in water can almost be degraded completely through the combination of adsorption and photocatalysis.

Changing molecular conjugation with a phenazine acceptor for improvement of small molecule-based organic electronic memory performance

Two conjugated small molecules with different molecular conjugation, 4′,4′′-(diazene-1,2-diyl)bis(2′,3′,5′,6′-tetrafluoro-N,N-diphenyl-[1,1′-biphenyl]-4-amine) (TPA-azo-TPA) and 4,4′-(perfluorophenazine-2,7-diyl)bis(N,N-diphenylaniline) (TPA-ph-TPA), in which the electron donor triphenylamine moiety is bridged using different electron-accepting azobenzene or phenazine blocks, were designed and synthesized. The TPA-ph-TPA molecule with a larger conjugation acceptor regularly formed a nanocrystalline film and the as-fabricated memory devices exhibited outstanding non-volatile write once read many (WORM) memory effects with an ON/OFF ratio ten times higher than that of TPA-azo-TPA. Using theoretical calculations, it was speculated that the memory performance is a result of an electric field induced charge transfer effect and the enhanced device performance of the acceptor molecular conjugation is because of the presence of a strong charge transfer effect. The experimental findings suggest that the strategy of molecular conjugation may promote the performance of small molecule-based organic electronic memory devices by an enhanced a strong charge transfer effect.