Vapor Deposition In Presence Research Articles

Fabrication of electrically conductive superparamagnetic fabric with microwave attenuation, antibacterial properties and UV protection using PEDOT/magnetite nanoparticles

Incorporation of electrically conductive and magnetic materials to textiles creates flexible wearable substrates with numbers of functionality as attractive alternative in many applications. Herein, an electrically conductive fabric with superparamagnetic properties was fabricated utilizing PEDOT/magnetite nanoparticles. Nanoparticles synthesis and deposition was carried out on the flexible polyester fabric through facile chemical methods. Fe3O4 nanoparticles was in-situ synthesized and deposited using thiourea as the both reducing and complexing agents on PET fabric via enhanced chemical precipitation method. 3,4‑ethylene dioxythiophene (EDOT) was polymerized on the treated polyester fabric through chemical vapor deposition in presence of ferric (III) chloride as both oxidant and doping agents. The morphology and particles size and their distribution on the fabric, crystal phase, magnetization properties and chemical structure of the treated fabrics were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), vibrating sample magnetometry (VSM) and energy dispersive X-ray spectroscopy (EDS). The tensile and electrical properties of the treated fabrics were measured with Instron and two probe devices. The electrical resistivity of the fabric containing magnetite/PEDOT was measured to be lower than 1000 Ω cm−1. The significant UV protection, antibacterial activities against S. aureus and electromagnetic interference shielding behavior were obtained on the treated fabrics. The conductive superparamagnetic fabric can be applied in biomedical, separation, energy generation, sensor and smart textile applications due to the considerable fastness and nontoxic behavior.

The high-yield growth of Bi2Se3 nanostructures via facile physical vapor deposition

The growth of Bi2Se3 nanostructures by physical vapor deposition in presence or absence of Au catalysts on Si and mica substrates is investigated. In the presence of Au nanodroplets on substrate surfaces, the growth of Bi2Se3 nanostructures in diverse crystallographic orientations is initiated via a catalyst-assisted process at low source flux condition. At elevated flux supply, nearly free-standing vapor-solid growth dominates and an array consisting of dense inclined standing nanoribbons are achieved. The morphologies of the obtained Bi2Se3 nanoribbons can be easily manipulated by changing growth temperature.

FeCl 2-CVD production of carbon fibres with graphene layers nearly perpendicular to axis

We decomposed acetylene by chemical vapour deposition in presence of FeCl 2 vapours, which react with carbon radicals without thermal decomposition (500 °C). This produced a large volume of wool-like product around the FeCl 2 reservoir, composed of semi-crystalline carbon fibres, with high conversion rate (40 mass%). Fibres showed remarkable morphology, with iron nano-rings belting their centres and mirror symmetry. Fibres were mono or multi filament (each filament belted with metal). Semi-crystalline fibres were readily transformed by thermal treatment into a large-angle conical structure with turbostratic piling along fibre axis. These observations suggest a catalytic growth on the inner wall of iron rings.