Advanced Materials Research Vols. 239-242

Abstract: The membrane emulsification-suspension polymerization (MESP) method was used to synthesize hypercrosslinked microspheres with a narrow size distribution. The resulting polymers possessed large specific surface area (over 1300 m²/g) and their particle size was controllable. The particles were more hydrophilic when using nitrobenzene as solvent instead of 1, 2-dichloroethane in the postcrosslinking process.

Abstract: In this paper the fluid flow and temperature are used together to optimize the 40 tons six strand tundish. Fluid flows in a six strand tundish have been investigated with physical modeling, then steady, three-dimensional temperature fields inside the six strand tundish are obtained. The physical modeling experiments give two optimal integrated tundish structural parameters of baffle holes. From the further study of temperature fields, the tundish should be optimized in the structural parameters of baffle holes in the condition of height 300mm, angel 30° and diameter 20mm.

Abstract: A series of TiO₂ thin films with and without Ce³⁺ doping were successfully obtained on microscope glass slides by sol-gel method. The photocatalytic activities of the pure TiO₂ and Ce³⁺-doped TiO₂ thin films were evaluated by the degradation of rhodamine B solution. The effects of both Ce³⁺ contents and annealing temperatures on the photocatalytic activities of the samples were examined. The results indicated that the TiO₂ thin film with an atomic ratio of Ti:Ce=5:1 annealed at 300°C had a higher photocatalytic activity among the samples.

Abstract: The aqueous solution polymerization methods were carried out using microwave heating for the superabsorbent synthesis experiment. The differences between reaction temperatures and reaction times were compared respectively under the same conventional heating conditions. The results showed that microwave heating can generate better results: The maximum of distilled water absorbency is 711 times, and the maximum of 0.9% saline water absorbency is 86 times when the polymerization temperature is at 35 °C and the reaction time is 1.5 h. Water absorbency of the superabsorbent obtained using microwave heating is better than that of conventional heating. Analysis of FTIR and SEM showed that starch grafting with acrylic acid and acrylamide was successful, and a three-dimensional network structure was formed in superabsorbent. The causes of organic reactions accelerated using microwave heating were also discussed in this paper.

Abstract: On the purpose of investigating the influence of calcinations temperature on crystallization and synthesis process of Li₄Ti₅O₁₂, Li₂CO₃ and amorphous TiO₂ were used as raw materials to synthesize phase Li₄Ti₅O₁₂ at different calcinations temperatures. TG-DSC showed that the crystallization of the products was more integrated along as temperatures increased. Both anatase and rutile TiO₂ would form phase Li₂TiO₃ by reacting with Li₂CO₃ primarily before synthesis of phase Li₄Ti₅O₁₂, and phase Li₂TiO₃ was formed as mid-phase from 700°C and 750°C revealed in the XRD pattern. SEM demonstrated that the particle size increased as temperature decreased, the particles were agglomerated together especially at 900°C. The samples displayed poor discharge capacity just because of Li₂TiO₃ phase and large size particles.

Abstract: Computational studies have been carried out on the LiNi_1-xCo_xO₂ compounds based on density-functional theory. Quantum-mechanical calculations are performed using a total-energy pseudopotential code. Density of states and partial density of states are calculated with the considering the spin state of Ni and Co. Electronic structure calculations suggest that the exchange splitting is controlled by Co content. As the Co content increased, the exchange splitting decreased. Electronic structure calculations show that the crystal field splitting is controlled by the second content. With Co contents increasing, the crystal field splitting decreased for LiNi_1-xCo_xO₂ with x=0, 1/3 and 2/3. The study also shows that the interaction of Ni ion with surrounding O ions and Li ions will be changed and prevents Li ions from leaving LiNiO₂ with the increasing substitution Co for Ni in LiNiO_2.

Abstract: The capacity of sewage sludge carbon (SSC) for the removal of lead ion from aqueous solution has been studied under different conditions,namely SSC particle size,initial pH,initial Pb²⁺ ion concentration and solution temperature.The results show that equilibrium data obtained fit the Langmuir adsorption isotherms,this SSC is an efficient adsorbent for removing lead ion.The finer the SSC particle used,the higher the metal adsorption capacity.An initial solution pH ≥4.5 is favourable for obtaining high metal removal.

Abstract: The derivation of effective thermal conductivity (ETC) for composite materials is a long-standing thermal transport problem. Based on the thermal resistance model and integration method, two analytical solutions of the ETC of composite materials, in which the dispersed phase consists of spheres in cubic arrangements, were derived either neglecting or considering the effect of radiation. As the effect of radiation in porous composite materials is considered, the theoretical result indicates that the effect of radiation cannot be neglected as the temperature or porosity of composite materials is high. The differences between the theoretical results and experimental data of the ETC of porous composite materials are acceptable.

Abstract: A novel reagentless H₂O₂ biosensor based on ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF₆) functionalized nano-gold as the biocompatible interface of Cytochrome C (Cyt c) by self-assembled method was proposed. The immobilized Cyt c showed direct electrochemistry and displayed an excellent electrocatalytic response to the reduction of H₂O₂ without the aid of any electron mediator. Under optimal experimental conditions, the as-prepared biosensor showed a wide linear response to H₂O₂ in the range of 0.23 µM to 3.0 mM with a detection limit of 0.12 µM (S/N = 3). The resulting biosensor can reached 95% of steady-state current within 5 s. The K^app_m value for H₂O₂ was found to be 1.2 mM.

Abstract: The inclusion complex of dibenzoylmathane(DBM)with β-cyclodextrin(β-CD)was studied. UV-spectrophotometer was used to investigate the complexation behaviour in liquid medium, and to demonstrate that the DBM aqueous solubility increased 7.27times due to complexation with β-CD and the inclusion rate of DBM was high to 95.92 percent and the drug-loading constant is also high to 37.86ug/g. Solid samples prepared by solution-agitating method. FT-IR was employed to assess the formation of the inclusion complex. Dissolution analysis indicated that dissolution properties of DBM/β-CD complex were superior compared to both pure DBM and the corresponding physical mixture of DBM and β-CD.