Search

Indium oxide/polyaniline (In2O3/PANI) composite nanofibers with the solid or hollow structure of In2O3 were successfully synthesized via a facile and efficient combined method of electrospinning, high-temperature calcination, and in situ polymerization. Various techniques, including scanning electron microscopy, Brunauer–Emmett–Teller, Fourier transform infrared, transmission electron microscopy, and X-ray diffraction, were employed to acquire the morphological, structural, and crystalline information of the prepared samples. The gas sensing performances of the as-obtained composite nanofibers were investigated by a home-made gas sensing test system at room temperature. All the results demonstrated that both solid and hollow In2O3/PANI composite nanofibers had higher response values than those of pure PANI sensor. In addition, the ammonia sensing properties of hollow In2O3/PANI composite nanofibers were much better than that of the solid ones. Furthermore, hollow In2O3/PANI composite nanofibers also showed ideal repeatability and selectivity due to their more and different types of P-N heterojunctions.

Two types of SnO2 nanofibers were prepared by electrospinning and calcination of polyvinyl acetate/stannic chloride pentahydrate and polyvinyl pyrrolidone/stannic chloride pentahydrate precursors, respectively. Due to the different properties of polymer solutions and different decomposition mechanisms during calcination, the as-prepared SnO2 nanofibers showed different morphologies and crystal structures. As a result, they exhibited different performance when used as lithium-ion battery anodes and photocatalysts. In the lithium-ion battery test, the SnO2 nanofibers obtained from polyvinyl acetate/stannic chloride pentahydrate precursor showed a higher reversible specific capacity (871 mAh g−1) and better cycling performance (574 mAh g−1 after 20th cycles) because their cobweb-like structure and polycrystalline nature had better ability to accommodate the volume changes of SnO2. On the other hand, SnO2 nanofibers derived from polyvinyl pyrrolidone/stannic chloride pentahydrate precursor exhibited higher photocatalytic degradation of methylene blue (56 %) even at a low concentration of (10−5 M, 50 ml) because they provided higher surface area for absorbing and degrading methylene blue.

In the present work, Fe-montmorillonite (Fe-MMT) was synthesized by hydrothermal method, and then was modified by cetyltrimethyl ammonium bromide (CTAB). The polyamide6 (PA6)/organic-modified Fe-montmorillonite (Fe-OMT) composite nanofibers were prepared by facile compounding and electrospinning. Fe-OMT was first dispersed in N, N-dimethyl formamide and then compounded with PA6 which was dissolved in formic acid. The composite solutions were electrospun to form PA6/Fe-OMT composite nanofibers. The structure, morphology, thermal stability, and crystalline properties of the composite nanofibers were characterized by Fourier transfer infrared (FTIR) spectra, Energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), High-resolution electron microscopy (HREM), Scanning electron microscopy (SEM), and Thermogravimetric analyses (TGA), respectively. It was found that the silicate clay layers were well exfoliated within the composite nanofibers and were oriented along the fiber axis. The SEM images indicated that the loading of Fe-OMT decreased the diameters of composite nanofibers. TGA analyses revealed that the thermal stability was notably improved in the presence of silicate clay. It was also observed from wide-angle XRD analyses that the presence of nanoclays improved the γ-form crystals and induced the formations of α-form crystals of the PA6, attributed to effective nucleating effects of silicate clay platelets.

Titanium dioxide and polypropylene fibers were prepared by melt-compounding and sputter coating, respectively. Energy dispersive x-ray analysis (EDX) confirmed the presence of titanium dioxide in the fibers. Through the application of environmental scanning electron microscopy (ESEM) and scanning probe microscopy (SPM), it was found that incorporating the titanium dioxide by melt-compounding caused severe aggregation of the titanium dioxide nanoparticles at the polypropylene fiber surface. Indeed, coverage of the fiber surface by titanium dioxide was poor. By contrast, the coverage of the sputter coated fiber surfaces was much more consistent, although aggregation of the titanium dioxide nanoparticles still appeared quite extensive. The behavior of the nanocomposite fiber surfaces was investigated using dynamic contact angle measurements by the Wilhelmy technique. Only a small increase in hydrophilicity of the polypropylene fibers was observed after melt-compounding with titanium dioxide, but a larger increase was noted after sputter coating. UV irradiation appreciably enhanced the hydrophilicity of the fiber surfaces in both cases.

This paper describes the surface functionalization of woven silk fabric by magnetron sputter coating of PTFE (polytetrafluoroethylene). The PTFE sputter coating was applied to improve the hydrophobic property of silk fabric. The effects of PTFE sputter coating on surface morphology and surface chemical properties were characterized using atomic force microscopy (AFM) and ATR-FTIR (attenuated total reflection-Fourier transform infrared spectroscopy). The wettability of the fabric was characterized through measuring the surface contact angle by a dynamic sessile analysis (DSA) technique. The contact angle of the PTFE coated fabric showed a significant increase from 68° to about 138°. The experimental results also revealed that larger sputtering pressures brought less contact angle hysteresis.

Polypropylene (PP) fibres have an extensive range of applications, including filtration, composites, biomaterials and electronics. In these applications, the surface properties of the fibres are particularly important. This paper presents examples of the use of gas plasma technology to create functional nanostructures on PP fibre surfaces, which render the surfaces hydrophilic. It is also shown how these treatments can be regulated to produce the desired level of hydrophilicity for a given application. Three principal modifications have been performed, to create functional nanostructures: plasma activation with oxygen gas plasma, grafting of polyacrylic acid following argon gas plasma treatment, and plasma-enhanced deposition of silver. Atomic force microscopy (AFM) and environmental scanning electron microscopy (ESEM) were employed to characterise the morphology, surface structure and composition of the fibres treated by gas plasma.