Advanced Materials Research Vol. 412

Abstract: In this paper, the catalyst precursors were coated on the surface of natural flake graphite with micron size by liquid coating method. Carbon with one-dimensional nanostructures formed on the surface of graphite after the heat treatment of the mixture of phenolic resin and coated graphite. The effects of the forms and amounts of catalyst precursors and the temperature on the formation of carbon with one-dimensional nanostructures were studied. And the thermal conductivities of the samples were measured. The results showed that the catalyst precursor with the form of NiO would be better. And the optimum amounts of the catalyst precursor were 1mass % ~2 mass % of resin. It was not conducive to the reaction when the temperature was too low or too high, but 1100°C was appropriate. The thermal conductivities of samples were increasing with the increase of the qualities of carbon with one-dimensional nanostructure.

Abstract: Type-A zeolites molecular sieve is prepared after crystallization of the type-A zeolites molecular sieve precursor, which is prepared from Stellerite, at temperature of 90 ~ 100°C for 6 hours. It has a complete structure, with crystallinity of 98%, volume average particle size of 3.72µm and particle size distribution which is less than 10µm over 90%. Multi-member rings structure in the type-A zeolites molecular sieve cover each other, forming the cage (β-cage, α-cage, octahedral cage) structure. Nuclei and nanometer particles are formed after the further congregation reaction, and then gather and grow, result in the formation of nanometer crystal particles and transformation to micrometer particles.

Abstract: To study the interaction between hydroxyapatite (HAP) and collagen in bone, we researched the phenomenon of collagen biomineralization and self-assembly in viro by uv-vis spectra and circular dichroism (CD) spectra. The materials prepared by self-assembly collagen and collagen-HAP showed layer structures. And the product prepared by collagen-HAP had better and more compact appearance. The decrease of speed of collagen self-assembly was caused by calcium ion or strontium ion added. The trough of CD spectra moved down in calcium-containing solution and moved up when forming precipitation of calcium phosphate from the solution. It indicated that the effect of collagen self-assembly was caused by calcium ions, strontium ions etc. in the solution. The IR spectrum proved that a coordinate bond formed between calcium ion and amide groups on collagen.

Abstract: The magnesium hydroxide (MH) whiskers were modified in micro-emulsion by introducing monomer that can polymerize. The SEM and FT-IR were used to analyze the structure after polymeration in whiskers surface. The results shows that there was flexible layer forming in the surface of whisker and the compatibility of whiskers in organic phase was improved. Get the MH/PE (polyethylene) composites by melt extrusion, study the compatibility of MH whiskers in organic phase. The results shows that MH whiskers after modification play a signification toughening effect in composites.

Abstract: The effect of liquid carboxyl terminated butadiene acrylonitrile copolymer (CTBN) on the properties of oxide graphene (OG) /epoxy resin (EP) composite has been studied. The results show that oscillations process can greatly increase the tensile strength, shear strength and hardness of the composites, for the compatibility between the EP and the OG can be greatly improved after oscillations. Infra-red analysis shows that CTBN reacts with EP to form ester group. The tensile strength of the EP decrease, and the elongation at break increase, as more and more CTBN added. The tensile strength of the OG/EP composite is 14.37 MPa, while that of CTBN/OG/EP (15/0.001/100) composite is 4.84 MPa.

Abstract: The influence of ultrasonic oscillation process on the performance of oxidized graphene (OG) /epoxy resin (EP) composite is studied. The results show that the oscillation process can greatly improve the tensile strength, shear strength and hardness of EP, as well as it’s morphology, for the compatibility of EP with OG is greatly improved after oscillation. OG can improve the dielectric constants of EP to some extent, while increase the tensile strength at low content, decrease with adding more OG. The tensile strength of EP is 19.32MPa and the dielectric constants 1.73 with 3/1000 content of OG. The morphology of the EP shows that the fracture surface of the composite is layer shape while the surface of EP is smooth, indicating OG change the structure of EP after cross-linking reaction.

Abstract: A porous biomorphic woodceramic was prepared from bagasse powders infiltrated with the epoxy resin followed by sintering in vacuum. The microstructures and chemical structures of the woodceramics were studied by SEM and FTIR, respectively. The effect of the sintering temperature and content of bagasse on the carbon yield ratio, volume shrinkage ratio, and volume electrical resistivity of the woodceramics were studied. Experimental results show that the pores in woodceramics present the irregular distribution but the main structural features of the tracheidal cell structures are retained. The woodceramic is a carbon material containing C–O–C, C=C, C=O and C–H bonds. The carbon yield ratio of the woodceramics decreases with the increase of the content of bagasse. While the volume shrinkage ratio and volume electrical resistivity increase with the increase of the content of bagasse.

Abstract: Using metallurgical grade aluminum hydroxide as the raw material self-dispersed g-AlOOH nanopowders were made by sol-hydrothermal crystallization and the charge process. The AlOOH/polyimide nanocomposite membrane was prepared by compounding soluble polyamide with AlOOH using sol dispersed quasi-homogeneous blending and compounding method. TEM, XRD, IR and other techniques were employed to characterize AlOOH nanopowders and AlOOH/polyimide nanocomposite membranes, respectively. The results showed that: the particle size of AlOOH crystal was about 70nm, with good self-dispersion in water and some organic solvents; in the polyimide matrix, the AlOOH was dispersed at nanoscale, without agglomeration; when its content in composite membrane reached 15 %, it still had a good dispersion and transmission property.

Abstract: In order to improve the dispersion of TiO₂, use the surface coating technology to form the aluminium ion film on the surface of TiO₂, so as to achieve the aim of modification. Use the aqueous solution sedimentary drying method to make the alumina coating experiment under as certain technical condition, use the test like the scanning electron microscopy and transmission electron microscope, etc to analyze the coating powder’s dispersive and coating situation. The paper started from the angle of ion sedimentary reaction equilibrium, made the thermodynamics analysis on the coating on the surface of TiO₂ and got the [Al]_T-pH relationship diagram about the aluminium ion, and then confirm the PH extent for the aluminium ion’s completed sedimentation. The result indicated that, when the PH value reached from 8 to 12, the aluminium ion would completely precipitate.

Abstract: On the basis of the mechanism of ions precipitation reaction equilibrium, the thermodynamic analysis of Meⁿ⁺(La³⁺, Ni²⁺, Fe³⁺, Al³⁺)-CO₃^2--NH₃•H₂O system was discussed in this paper. The relation curves between total concentrations of each metal ion and pH values at different total ammonia concentrations c_N and total carbon concentrations c_C were obtained. The suitable pH value of the complete precipitation reaction for all metal ions was also determined. It shows that when c_N = 0.010 mol•L^-1 and c_C = 1.000 mol•L^-1, the optimal pH is 9.0 to prepare the doped titanium dioxide powders by coprecipitation-coating process and using NaHCO₃ and NH₃•H₂O as the precipitants.