Advanced Materials Research Vols. 557-559

Abstract: N-methyl-N-hexadecylpyrrolidinium bromide (IL) was synthesized for the design of ionic liquid crystals which is a fascinating class of molecular materials, offering the combination of order and mobility. In binary mixtures with water, lyotropic liquid crystalline phase appears in the range of IL content from 35% to 70% and the temperature range from -1.1 to 24 °C in the heating run. The SAXS curves explored the self-assembly processes and hexagonal phase of the IL apparent sol. The saturated aliphatic ionic liquid in water assemble less tightly compared with aromatic ionic liquid based on imidazolium in water, which is due to the absence of aromatic package effect.

Abstract: A diblock copolymer template of nonbornene derivatives was employed to prepare Bi2O3 nanoparticles. The precursor formed within the nano-size micelles of diblock copolymer after introducing BiCl3 into the template. The precursor was calcined to produce Bi2O3 nano particles, XRD and TEM show that these nanoparticles are the α-Bi2O3 phase and have an average size from 10 to 30 nm. The photocatalytic performance of Bi2O3 particles has been tested in the degradation of methyl orange solution at visible light condition.

Abstract: Microencapsulating ionic liquid is an effective way to overcome the loss of ionic liquid in the extraction process. A phase inversion method was used to form microcapsules containing 1-butyl-3-methylimidazolium hexafluorophosphate [BMIM] [PF6]. The oil phase, composed of [BMIM][PF6], polysulfone and dichloromethane, was dropped into the 0.2 wt% gelatin aqueous solution using nitrogen gas pressure to form droplets. As dichloromethane evaporated completely, polysulfone microcapsules containing [BMIM] [PF6] were obtained. The microcapsules were characterized using a polarizing microscope, a laser particle size analyzer and a thermogravimetric analyzer. Moreover the microcapsules were performed some effect on caprolactam extraction from water.

Abstract: Silver nanoparticles have been synthesized in 3-(aminopropyl)triethoxysilane (KH-550) solution using DMF (N, N-dimethylformamide) as both solvent and reductant at room temperature and 120°C. A characteristic surface plasmon band can be observed for the obtained silver nanoparticles from UV-vis absorption spectra, which indicate that KH-550 can serve as stabilizing agent for the formation of silver nanoparticles. Transmission electron microscopy (TEM) results show that silver nanoparticles with different sizes were obtained by simply controlling the reaction temperature.

Abstract: Monodispersed porous cubic nickel oxide nanostructures have been synthesized by a simple method. TEM have been employed for the morphology and structure characterization. Electrochemical data prove that the monodispersed porous cubic nickel oxide nanostructures contain a good specific capacitance.

Abstract: PEDOT nanotubes were prepared by a template synthesis method. Based on our template, it was deduced that there are two successive processes in the formation of nanotubes. The first step is soakage of the porous templates by a polymer solution, and the second step is adsorption of free charged cationic groups and doped PEDOT onto the template surface with negative charges. XRD results showed that well orientated PEDOT chain were formed during the synthesis, moreover the arrange conductivity of molecular chains strongly affect the structures of PEDOT nanotubes. The nanotubes were measured to be about 5.5~17.6 S/cm, which is higher than that of nanotube pellet due to the high contact resistance between the adjacent nanotubes.

Abstract: With the increasing use of nano-SiO₂ and nano-kaolinite, it is imperative to investigate their effect on the transport of aqueous contaminants. In this study, the extent and reversibility of sorption of AT on nano-SiO₂ and nano-kaolinite were examined using batch sorption experiments. Influence of ionic strength, pH and temperature was investigated. Sorption data were well fitted with Freundlich models. The sorption capacities were larger at low ionc strengths and low pHs. Nano-particle aggregate size is an important factor for the pH influencing process, which increase as the pH approach pHzpc. The sorption of AT on the two nano-particles is spontaneous.

Abstract: Nano-sized aluminum nitride (AlN) powders were synthesized through a carbothermal reduction nitridation (CRN) route from a sol-gel low temperature combustion precursor. The precursor was precalcined at 600-1200 °C and then nitrided at 1400-1550 °C for different holding time to obtain AlN powders. During the whole preparation process, the amorphous alumina in the precursors first transformed to γ-Al₂O₃, then to α-Al₂O₃, and AlN was obtained through the nitridation of α-Al₂O₃ with the reduction of carbon. The results show that the appropriate precalcination benefits the activity of precursors and promotes the formation of AlN phase due to the transition of amorphous alumina to γ-Al₂O₃, and the optimum precalcination temperature is 1000 °C. The effects of different nitridation parameters on the microstructure of AlN powders were also investigated. By being nitrided at 1500-1550 °C for 2 h, the AlN powders present a good distribution and small particle size of 30-90 nm from the precursor precalcinated at 1000 °C.

Abstract: A realistic quantum magnetic disk structure formed by a nanowire array is studied. The length fluctuation of the nanowires is described with Gaussian distributions. The magnetostatic interaction between two nanowires with different length and radius is derived. Based on that, we study the thermal stability of the nanowire array analytically and numerically by the damage spreading technique. The results show that when the magnetic cell’s spacing reduces (the storage density increases) or the nanowire length increases, damage spreading becomes difficult and the system stability is enhanced. In addition, the long-range magnetostatic interaction and the shape anisotropy make the system more stable and the nanowire length fluctuation influence is comparatively small.

Abstract: Selective localization of carbon nanotubes (CNTs) at the interface of immiscible polymer blend was achieved by the method that poly(styrene-co-maleic anhydride) (SMA) was first reacted with CNTs, and then blended with nylon6/polystyrene (PA6/PS). In the PA6/PS blends, CNTs was localized in PA6 phase and the percolation threshold was 2wt%. However, for the PA6/PS/(SMA- CNTs) composites, TEM results showed that most of CNTs were selectively localized in matrix, but some of tubes were induced by SMA to disperse at the interface. The localization of CNTs at the interface caused the percolation threshold of PA6/PS/(SMA- CNTs) was only 0.33 wt%, which is much lower than that of PA6/PS/ CNTs.