Advanced Materials Research Vols. 233-235

Abstract: Al-containing mesoporous molecular sieves(Al-MCM-41) were synthesized at ambient temperature. The structures of samples were characterized by XRD, N₂-adsorption/desorption isotherms and FT-IR, etc. The evaluation results showed that Al-MCM-41 had higher catalytic activity for isomerization conversion of endo-tetrahydrodicyclo-pentadiene (endo-TCD) into exo-tetrahydrodicyclo-pentadiene (exo-TCD) and adamantane (AdH). Loading inorganic acid on the surface of Al-MCM-41 led increase of its catalytic activity and the yield of adamantane.

Abstract: To develop the potential use of adamantane derivatives in surfactant field, the adamantyl residue was introduced into the quaternary ammonium salt. The method involved synthesizing N-(1-adamantyl)-N, N-dimethylamine from 1-adamantine and quaternizing with different alkylating agents. Eight adamantane-containing quaternary ammonium salts were prepared and their structures were identified by ¹H NMR and IR.

Abstract: A new tertiary amine derivative of adamantane —N,N,N’,N’-tetramethyl-1, 3-disaminomethyl adamantane dihydrochloride (1), which is a key intermediate for preparing Gemini surfactants and bola surfactants, has been synthesized in this paper. The target compound (1) can be synthesized in high yield by using 1-adamantanecarboxylic acid as raw material. The structure of these compounds has been identified.

Abstract: Acid-resistant ultramarine blue pigment with a silica shell was prepared by dense silica coating process. From X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM) analysis, it was confirmed that silica in the coating is attached on the ultramarine particles surface by characterizing the composition of elements and the microstructure on the surface of the silica coated particles. Orthogonal experimental design was applied to optimize the operating conditions of the coating process. The best acid resistance for the coated ultramarine blue reached the ninth grade under the following conditions: silica adding rate of 5 g/h, solid content of 6 g/l in the slurry and coating time of 2.5 h.

Abstract: UV curable vinylic polymethylsilane (v-PMS) was synthesized by a facile one-step Wurtz route, the products’ molecular structures were characterized by FT-IR and the mechanism of the chemical reactions was discussed in detail. The as-synthesized product was a promising candidate for the fabrication of micro ceramic structures for microfluidics by softlithography techniques.

Abstract: Alumina was modified by doping with metal oxide and then used as the support for depositing gold by an impregnation-ammonia washing method to obtain Au/M_xO_y/Al₂O₃ (M=Co, Zr and Ce) catalysts. These samples were characterized by inductively coupled plasma-atomic emission spectrometry (ICP-AES), transmission electron microscope (TEM) and X-ray diffraction (XRD). The effects of Co₃O₄ content, metal oxide and mixed metal oxides on the catalytic activity for the selective oxidation of cyclohexane to cyclohexanone and cyclohexanol using molecular oxygen as oxidant were studied. The results showed that better catalytic performance was obtained over Au/M_xO_y/Al₂O₃ catalysts compared with over Au/Al₂O₃ catalysts. 9.69% conversion of cyclohexane and 93.31% selectivity to cyclohexanone, cyclohexanol and cyclohexyl hydroperoxide, with 1.02 ratio of cyclohexanone to cyclohexanol were obtained over the Au/M_xO_y/Al₂O₃ catalyst at 150 , 1.5 MPa for 3 h. Moreover, according to the recycling test, the catalyst could be reused four times without remarkable loss of activity.

Abstract: A novel solid-liquid reaction route has been developed to synthesize rodlike submicron cobalt oxalate via dissolution of cobalt powders by oxalic acid. The rod diameter and length of the oxalate particles were found to be remarkably altered by using HCl or HNO₃ as additive. With HCl as additive rice-shaped particles were generated while with HNO₃ slender needlelike particles were created with an average aspect ratio up to 42. Furthermore, strings of Co₃O₄ nanobeads were obtained by calcination of the slender precursor particles in air. The CoC₂O₄·2H₂O submicron rods and Co₃O₄ nanobeads were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TG), and X-ray diffraction (XRD).

Abstract: A new compound, 2-carboxylbenzaldehyde-2-pyrroleformylhydrazone (C₁₃H₁₁N₃O₃), was synthesized by condensation of 2-carboxylbenzaldehyde (C₈H₆O₃) with 2-pyrroleformylhydrazine (C₅H₇N₃O). Its structure has been determined on the basis of elemental analysis, FTIR spectrum, UV-vis spectrum, ¹HNMR, ¹³CNMR, MS and X-ray single-crystal diffraction analysis.

Abstract: Magnetic mesoporous Mn-Fe oxide catalyst with high surface area was prepared by calcining the corresponding oxalate precursor. The calcined sample was characterized by XRD, FTIR, N₂ adsorption, TEM, and SEM. The catalytic property of the porous Mn-Fe oxide catalyst was evaluated by catalytic decolorization of methyl orange (MO). XRD, SEM, and TEM analysis and N₂ adsorption–desorption isotherm revealed mesoporous Mn-Fe oxide strucutre with high-surface area and uniform pore-size distribution. The results of catalytic performance measurements showed that the Mn-Fe binary oxide was an effective catalyst. The as-prepared catalyst could be recycled as a magnetically separatable catalyst to treat dye-containing wastewater.

Abstract: A simple synthesis of 3,4-dihydropyrimidinones from the aldehyde, 1,3-dicarbonyl compound, and urea (thiourea) using nanostructural zinc oxide hollow spheres as the catalyst under solvent-free conditions is described. Compared with traditional Biginelli reactions, this method has advantages of excellent yields and short reaction time.