Advanced Materials Research Vols. 512-515

Abstract: Chitosanase was immobilized on CSG hybrid material by cross-linking reaction and the immobilization conditions and characterization of the immobilized enzyme were carried out. The optimal conditions for immobilization were as follows: 0.1 g carrier material was treated with 2.5 ml 5% solution of glutaraldehyde and 2 ml chitosanase was immobilized on the carrier. Optimal temperature and pH for the immobilized enzyme were 60°C and 7.0, respectively. Kinetic parameter Km was10.64 g/l. The immobilized enzyme showed better operation and storage stability than the free enzyme.

Abstract: In this paper, metallocene based LLDPE (mLLDPE) extra-fine fiber , which can not be processed by a common solution electrospinning method.was successfully prepared via a melt electrospinning method. First, a self-designed melt electrospinning device was manufctured and it was used to produce mLLDPE fibers . Then LLDPE extra-fine fiber was successfully prepared by addition of viscosity-reducing additive such as wax, and the resulted fiber was charctered by SEM. Last, the optimal parameters for the preparation of mLLDPE fiber was determined. The experimental results show that commercial mLLDPE can hardly be processed to fibers because of its high viscosity. The diameter and morphology of resulted mLLDPE electrospun fibers depend on the electrospinning parameters such as electric field strength and collecting distance.

Abstract: In this paper amorphous silica powder properties are analyzed and studied. It shows that precipitated silica has larger specific surface area, higher absorption value, higher whiteness and lower bulk density. Different usage of amorphous silica has different properties and different particle size. The order of particle size is that precipitation silica for rubber is bigger than precipitated silica for filler, and the smallest is precipitated silica for coating. XRD, FTIR, SEM and TEM show that precipitated silica is amorphous silica which has wealthy hydroxyl and porous properties and chain branched structure.

Abstract: In this paper the comparison among some papermaking powder properties are studied. It shows that the properties of different powders are different because of different chemical composition and different preparation method and their particle size is different for different purpose such as filler and pigment. The particle size of powder for pigment powder is smaller than that for filler. The specific surface area of papermaking filler is lower than 20m²/g, the absorption value of DBP is about 45cm³/100g, the whiteness is up to 90%, and the particle size is about 3µm. The specific surface area of papermaking pigment is lower than 25m²/g, the absorption value of DBP is from 40 cm³/100g to100cm³/100g, the whiteness of clay is up to 50%, the whiteness of GCC and PCC is up to 90%, and the particle size is lower than 2µm. The specific surface area of silica is up to 100m²/g, the absorption value of DBP is up to 100cm³/100g, the whiteness is up to 97%, and the particle size is around 5µm.

Abstract: Polyacrylamide (PAM) is an important polymer for oilfield flooding. The viscosity of PAM solution is very significant for polymer flooding to enhance oil recovery. The main factors which influence viscosity of PAM solution including polymer concentration, temperature, stirring rate, TDS and divalent cation ions were studied. The results showed that high stirring rate will reduce the viscosity of PAM solution; and the viscosity decreases gradually with temperature increasing; TDS and divalent cation ions also affect the viscosity of polymer solution greatly, the viscosity loss is more than 3% with the TDS increases by 1000 mg/L under the same concentration of divalent cation ions; the viscosity loss is around 20% with the concentration of divalent cation ions increase by 100 mg/L.

Abstract: Multiplayer core-shell TiO₂/PSt/PVP hybrid microspheres were successfully synthesized by the copolymerization of vinylpyrrolidone in the solution of ethyl acetate with TiO₂/PSt core-shell hybrid microspheres which were formed through the encapsulation of KH570-g-TiO₂ sol particles with styrene, while the active KH570-g-TiO₂ sol particles were prepared by the hydrolysis condensation of KH-570 with tetrabutyl titanate. Characterization technologies of FT-IR and TGA were applied to investigate the structure and the thermal stability of the product. The results showed that the hydroxyl groups from the hydrolysis of KH-570 condensed with the surface hydroxyl groups of TiO₂, as well as PSt and PVP were grafted successively onto the surface of KH570-g-TiO₂ sol particles. The thermal decomposition temperature of TiO2/PSt/PVP was higher than TiO₂/PSt, which also indicated that the obtained product was the final objective product.

Abstract: O-cresol was mixed and reacted with camphene in the presence of the H-mordenite as catalysts to form the alkylation products named terpenophenol, and the terpenophenol was hydrogenated with the help of the catalyst to form a perfume intermediates of terpenylcyclohexanol. In this paper, the influence of reaction temperature and material ratio on alkylation and the hydrogenation were investigated.

Abstract: The urea dosing unit in the diesel engine SCR system, real-time calculates and delivers the quantitative urea , which is vital to the reduction of the NOx emission. Considering the practical condition, according to the function of the urea dosing unit, based on the pump controlling quantitative and air assisted atomization principle, the mechanical part of dosing unit is designed. Also based on the consideration with versatility and openness of the unit, the control part of dosing unit is designed. At last, based on the the common and open platform founded by designed urea dosing unit, which is composed of mechanical part and control part, the SCR control module and dosing module are developed. At last, the designed dosing unit is examined by the engine ETC test. The ETC test results indicate the design achieves the intended purpose.

Abstract: With the increasing concentration of CO₂ in the atmosphere, climate change has been prominent and brought a series of disasters to human being. In China, the important aspect to control CO₂ concentration is to decrease its emission of coal-fuel power plant. The engineering application of chemical absorption technology and economic analysis of the Beijing Gao Bei-dian and the second unit of Shanghai Shi Dong-kou power plants built by China Hua Neng Electric Group is introduced. The achievements of CO₂ engineering capture and the effort direction we will towards in the future is also summarized.

Abstract: In the research of bio-disinfector, it needs neutralizers to eliminate the antibacterial activity of disinfector during the disinfection experiment. But there was no report about the appropriate neutralizer of antibacterial peptides. In this paper, we study the neutralizer suitable for ε-polylysine by using the orthogonal design and optimize the combination of neutralizers. Then we performed the checkup experiment of neutralizer according to the method listed in Disinfection Technology Standard. Finally we successfully obtain the right neutralizer of ε-polylysine which is the combination of 0.5 M BSA and 0.5 M K₂HPO₄, This can provide a convenience for researchers to evaluate the disinfection effect of disinfector whose main component is ε-polylysine.