Abstract:In the present work, core TiO 2 and ZnO oxide nanofibers were prepared by electrospinning, then shell oxide (ZnO, TiO 2 ) layers were deposited on them by atomic layer deposition (ALD). The aim of preparing ZnO and TiO 2 nanofibers, as well as ZnO/TiO 2 and 3 TiO 2 /ZnO nanocomposites is to study the interaction between the oxide materials when a pure oxide fiber is covered with thin film of the other oxide, and explore the influence of exchanging the core and shell materials on their photocatalytic and gas sensing properties.The composition, structure and morphology of the pure and composite nanofibers were studied by SEM-EDX, TEM, XRD, FTIR, UV-Vis and Raman. The photocatalytic activity of the as-prepared materials was analyzed by UV-Vis spectroscopy through decomposing aqueous methyl orange under UV irradiation. The gas sensing of the nanofibers was investigated by detecting 100 ppm NH 3 at 150 and 220 °C using interdigital electrode based sensors.

Our study was directed to improve the residual flexural strength and the heat resistant properties of concrete exposed to high temperatures using different fiber cocktail loadings including steel, polymer or cellulose fibers. At first the morphology and the thermal properties of the fibers and the fiber/cement composites were investigated by SEM and TG/DTA-MS. Then the influence of fiber type and amount on residual flexural strength were tested after cooling back from 150, 500 or 800 °C temperature loadings. By adding steel, cellulose and polymer (polypropylene) fibers to cement, improvements both in post-cracking residual flexural strength and in insensitivity against explosive spalling were reached.

No abstract

TiO2/WO3 nanofibers were prepared in a one-step process by electrospinning. Titanium(IV) bis(ammonium lactato)dihydroxide (TiBALDH) and ammonium metatungstate (AMT) were used as water-soluble Ti and W precursors, respectively. Polyvinylpyrrolidone (PVP) and varying ratios of TiBALDH and AMT were dissolved in a mixture of H2O, EtOH and CH3COOH. The as-spun fibers were then heated in air at 1 °C min−1 until 600 °C to form TiO2/WO3 composite nanofibers. Fiber characterization was done using TG/DTA, SEM–EDX, FTIR, XRD, and Raman. The annealed composite nanofibers had a diameter range of 130–1940 nm, and the results showed a growth in the fiber diameter with an increasing amount of WO3. The photocatalytic property of the fibers was also checked for methyl orange bleaching in visible and UV light. In visible light, the photocatalytic activity increased with an increase in the ratio of AMT, while 50% TiBALDH composite fibers showed the highest activity among the as-prepared fibers in UV light.

Abstract. "Smart windows" are envisaged for future low-energy, high-efficient architectural buildings, as well as for the car industry. By switching from coloured to fully bleached state, these windows regulate the energy of solar flux entering the interior. Functional layers in these devices are the transition metals oxides. The materials (transitional metal oxides) used in smart windows can be also applied as photoelectrodes in water splitting photocells for hydrogen production or as photocatalytic materials for self-cleaning surfaces, waste water treatment and pollution removal. Solar energy utilization is recently in the main scope of numerous world research laboratories and energy organizations, working on protection against conventional fuel exhaustion. The paper presents results from research on transition metal oxide thin films, fabricated by different methods -atomic layer deposition, atmospheric pressure chemical vapour deposition, physical vapour deposition, and wet chemical methods, suitable for flowthrough production process. The lower price of the chemical deposition processes is especially important when the method is related to large-scale glazing applications. Conclusions are derived about which processes are recently considered as most prospective, related to electrochromic materials and devices manufacturing. Transition metal oxidesTransition metal oxides (TMO) are claimed to be one of the most interesting classes of solids, exhibiting varieties of properties, structures and applications [1]. Their properties are determined by the unique nature of their outer d-electrons. Transition-metal oxides can be insulators, semiconductors, metals, or undergo semiconductor-metal transitions. Transition metal oxides possess unusual and useful electronic, optical and magnetic properties. Many of these properties strongly depend on materials defects like vacancies, dislocations, stacking faults and grain boundaries [2].