Advanced Materials Research Vols. 233-235

Abstract: The solid state reaction method, coprecipitation method and citric acid method were employed for the preparation of Cr-Mn mixed-oxide catalysts. Experimental results showed that this catalytic system has good selective catalytic reduction (SCR) properties of NO_x by ammonia in the presence of excess oxygen at low temperature (80-220°C). 97.8% conversion of NO_x with 100% selectivity of N₂ had been achieved on Cr-MnO_x mixed oxide prepared by the citric acid method at 120°C with the space velocity of 30,000 h^-1. X-ray diffraction, BET were adopted for the characterization of the active phase. The characterization results showed that a new crystal phase CrMn_1.5O₄ generated in mixed oxides which was the active center of the Cr-Mn catalysts.

Abstract: MgCl₂/alcohol complex treated with various Al-alkyl in preparing Ziegler-Natta catalyst and its precursors for polymerization of ethylene have been studied by XPS, SEM, and EDS. With different treatments, their different morphology and various structures were discussed in details. As a result, Al-alkyl treatment for MgCl₂/alcohol complex plays a dominant role in dispersing active titanium on surface of catalyst. The proper species and concentration of Al-alkyl were confirmed to have high performance in dispersing titanium species in treatment of MgCl₂/ alcohol complex. With lower concentration of TEA treatment, Ti distribution in catalyst was even with surface and body Ti/Mg ratio 0.04 and 0.03 respectively. In comparison, with higher concentration of TEA treatment, more Ti would be loaded on surface of catalyst. Ti distribution became to be uneven to form clubbed crystals on the surface. EDS results showed that Ti/Mg ratio was up to 6.2 on the clubbed crystals.

Abstract: Phthalocyanine catalysts were synthesized and supported matel phthalocyanines were found to be good catalysts for benzene hydroxylation to phenol. Matel phthalocyanines were characterized by N₂ absorption-desorption, FT-IR spectroscopy, and tranmsission electron microscopy. The experimental results suggested that the supported matel phthalocyanines were good catalysts for benzene hydoxylation reaction. Supported vanadium phthalocyanine performed the best catalytic activity, on which 11.6% of phenol yield and 100% of selectivity were obtained. And it was proved to be reusable in this reaction.

Abstract: The catalytic activity in NO+CO reaction was investigated, and the structure and reductive properties of various CuO/TiO₂-g-Al₂O₃ catalysts were characterized by means of BET, XRD, NO-TPD and DRIFTS technologies. The NO-TPD profile showed that peak temperatures of NO desorption by the 12Cu15TA were lower than that by the 15TA, and no N₂ desorption species detected on 15TA, indicating that the NO decomposition activity of the catalysts was higher than that of the supports. DRIFTS analysis showed the N₂O adsorption peaks appeared at 150for 12Cu15TA. And a peak for Cu⁺-NCO^- species at 2205cm^-1 was detected on 12Cu15TA.

Abstract: The impact of highly cationic density polymers such as modified poly-ethyleneimine(PEI), as anionic trash catcher(ATC) on the drainage and retention properties of aspen alkaline hydrogen peroxide mechanical pulp(APMP) in different CPAM(/bentonite) systems was studied. The results showed that Modified PEI could improve the retention and drainage properties of CPAM/ bentonite systems; when adding 0.02% dosage of PEI, the drainage and retention rate were increased by 16.0% and 1.9% respectively as compared to control with 0.03% dosage of the CPAM with 1.55 meq/g cationic charge density and 4.9 million molecular weight, which denoted by CPAM(W/W); the drainage and retention rate were increased by 28.6% and 3.0% respectively as compared to the control with 0.03% dosage of CPAM(W/W) and 0.3% dosage of bentonite. The CPAM with more cationic charge density and higher molecular weight than the CPAM(W/W) is denoted by CPAM(W/O) in this paper. The microparticle system which consisted with PEI and the CPAM(W/O)(/bentonite) was slightly superior to the PEI/CPAM(W/W)/bentonite system. When 0.02% dosage of PEI and 0.03% dosage of CPAM were added respectively, PEI/CPAM(W/O) made the drainage and retention rate increased by 9.5% and 1.9% respectively as compared with PEI/CPAM(W/W).

Abstract: By pretreatment of Pt/CeO₂ catalysts with high temperature reduction and subsequent low temperature reoxidation, the concentration of Ce³⁺ species in the Pt/CeO₂ catalysts could be adjusted, while at the same time the Pt particle size remained constant. Thus the pure effect of Ce³⁺/Ce⁴⁺ couples on the selective hydrogenation of crotonaldehdye could be explored. The investigation provided direct proofs supporting that Ce³⁺ species favors the crotyl alcohol selectivity.

Abstract: PDADMAC fixing agents with different characteristics were used to control dissolved and colloidal substances in P-RC APMP fiber suspension. Results showed that PDADMAC with higher charge density was easier to interact with anionic trash, resulting in better removal of suspended solid materials and chemical oxygen demand(COD). The PDADMAC achieved 78% removal of chemical oxygen demand. PDADMAC with higher molecular weight could easily be adsorbed onto fibers and fines, and had good removal for anionic trash. It was also found that PDADMAC with higher molecular weight was better to remove suspended solid substances, while PDADMAC with lower molecular weight was more effective for removing chemical oxygen demand(COD).

Abstract: Despite the widening use of the carbon fiber wound composite gas cylinder, the research on its structure is mainly focused on the experiment method. In this paper, the APDL language in ANSYS was used to create a model of carbon fiber wound aluminum alloy liner composite gas cylinders with the thickness and the wound angle of both heads varied. The autofrettage process of the cylinder was analyzed and the range of autofrettage pressure value was determined by the DOT CFFC standard. It is expected that the finite element analysis results would be conducive to the engineering practice.

Abstract: The main objective of this study was to investigate the effect of drying condition on the binder distribution and characterize the binder migration in the method of numerical and visual analysis by Scanning Electrical Microscopy (SEM), Atomic Force Microscopy (AFM), and Laser Scanning Confocal Microscope (LSCM). In this study, Rhodamine B was used to stain the binder and as the probe to characterize z-directional distribution of the binder using LSCM. The results implied that it was reliable and effective method using LSCM to characterize the z- directional distribution of binder and analyze the influence of dry condition on binder migration. It could be concluded that the dry temperature played an important effect on binder distribution in coated paper and high dry temperature accelerated binder migration to the coating surface, however low drying temperature made binder migrate towards the interior of base paper. Moderate drying is good to binder distribution and coating layer forming.

Abstract: The physical structure and chemical properties of coating layer have an important influence on transferring and setting of the printing ink. The typical objective of coating is to improve the appearance and printing properties of paper. In this study, the effect of drying condition on coating layer structure, surface properties, and print quality was investigated. The relationship between surface topography and drying condition was explored using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The conclusions were drawn that high and low drying temperature were not good to the paper properties, which resulted in high roughness, low paper gloss, high ink absorption, low print gloss and paper surface efficiency. The findings indicated that the coating drying temperature affected the pore size, depth and distribution of the coated paper surface. Moderate temperature was benefit to pigment particles and binder arranging orderly, which made the coating surface had high smoothness, gloss, paper surface efficiency, and modest ink absorption.