Solid State Phenomena Vols. 121-123

Abstract: In situ UV-LIGA assembled robust micro check valves with large flow rates (>10 ml/s, displacement related), high-pressure support ability (>10 MPa) and high operational frequencies (>10 kHz) made of nano-structured nickel were presented in this paper. The microvalve consists of an array of 80 single micro valves to achieve the required flow rates. Test results show that the forward flow rate is about 19 ml/s under pressure of 90Psi. The backward flow rate is negligible. The reliability of the valve is ensured by the valve design and nanostructured nickel realized. The tested tensile strength of a nano structured nickel is about 1GPa. The strength of SU-8 is 50MPa, which is more than 50% higher that fabricated with a standard process.

Abstract: In order to achieve better photocatalytic performance, rutile dispersion in anatase was obtained from titanium isopropoxide (TIP) in a highly acidic solution at room temperature. Further hydrothermal treatment at 130 oC increased the crystallinity of titania. TEM revealed that the nanosized titania particles mainly consisted of granular anatase and rodlike rutile. These nanocrystals were applied onto cotton fabrics, and achieved a durable and satisfying protection against UV radiation. Preliminary experiments convinced us on the better photocatalytic behavior than the pure anatase phase.

Abstract: Ceria nanoparticles supported on aligned carbon nanotubes (CeO2/ACNTs), a novel adsorbent for fluoride from drinking water, were prepared by chemical reaction of CeCl3 with NaOH on aligned carbon nanotube solution and subsequent heat treatment. The best fluoride adsorption effect of CeO2/ACNTs occurs at pH 4.0 ~ 9.0. The largest adsorption capacity of CeO2/ACNTs reaches 33.7 mg g-1 at an equilibrium fluoride concentration of 18.0 mg l-1 at pH 7.0. The experiment results suggest that CeO2/ACNTs have great potential applications in environmental protection.

Abstract: The purpose of this study is to reveal the mechanism of wafer touch polishing by high purity colloidal silica slurry containing organic surfactants such as HEC (hydroxyl-ethyl cellulose). The effect of surfactant concentration on wafer touch polishing was studied with the aim of improving roughness on wafer surface after polishing. As a result, the level of haze and micro-roughness are decreased with the decrease of surfactant concentration.

Abstract: In this article, low-threshold random laser with one mirror and feedback is investigated in PMMA film containing Rhodamine 590 and TiO2 nano-particles. Incoherent and coherent laser emission is observed. Optics microscopy and Scanning Probe Microscopy are used to investigate the film structure and the principle of incoherent and coherent laser is analyzed.

Abstract: Functional core-shell structured composite nanofibers can be fabricated by means of electrospinning of two polymer solvents in a coaxial, two-capillary spinneret system. Three groups of composite nanofibers, Nylon-6(cell)/PVA(core), PC(cell)/ PU(core) and PU(cell)/Nylon-6(core), have been developed using this technique. Morphological, structural, and mechanical characterizations are conducted for the developed composite nanofibers and their applications as textile materials have been explored.

Abstract: In this study, it was demonstrated how second phases with small amount, which are hardly detected by XRD analysis, affect grain boundary dissolution and related mechanical properties of HA. All HA disks sintered at 1200 oC for 2 h in air with under moisture protection were phase pure and had Ca/P molar ratio of 1.67. Following certain period of exposure to the distilled water, the surface dissolution initiated at grain boundaries and particle loosening, subsequently resulting in decrease in mechanical properties of HA. In order to understand the dissolution mechanism, grain boundary structure of HA was identified by transmission electron microscopy (TEM) and high resolution TEM observation. From the analysis, it was found that the non-stoichiometric phase as α-tricalcium phosphate (TCP) transformed from β-TCP was existed at grain boundaries and caused surface dissolution of HA. From the XRD analysis, it was found that (211) and (112) planes of hydroxyapatite were susceptible to dissolution, whereas (300) plane was relatively stable.

Abstract: The intercalation of [Eu(2,2 bipyridine)2 ]3+ and [Eu(1,10 phenantroline)2]3+ into bentonite results in new nanocomposites which preserve the emission properties of the lanthanide. The exchange of sodium by lanthanide in the bentonite correlates with the host cation exchange capacity as well as with the guest molecular size and the interlaminar volume available in the clay. The intercalated complexes exhibit luminescence indicating an efficient protecting role of the matrix. This in turn points to lanthanide-clay nanocomposite as novel optical materials.