جستجوی مقالات مرتبط با کلیدواژه « Electrospinning » در نشریات گروه « شیمی »

Ag-doped TiO2/PVA nanofibers have many potential applications as a photoanode of dye-sensitized solar cells (DSSCs). In this study, we report the fabrication of DSSCs based on Ag-doped TiO2/PVA nanofibers as photoanode, graphene oxide as a Pt-free counter electrode catalyst, and natural dye sensitizer. Ag-doped TiO2/PVA nanofibers were fabricated using an electrospinning method. The electrospun nanofibers were characterized by a scanning electron microscope, X-ray diffraction, Fourier transform infrared spectroscopy and thermogravimetric analysis. The nanoparticle content of lower 100 mg/mL, and the electrospun nanofibers were uniform. Based on the results of the characterization analysis, the electrospun Ag-doped TiO2/PVA nanofibers were successfully prepared with diameters from 100 to 400 nm. They were used as photoanodes of DSSCs using a natural dye sensitizer extracted from the leaf of the magenta plant. The highest power conversion efficiency of DSSCs with Ag-doped TiO2/PVA nanofibers was 0.6% from the J-V curves. This approach would be a potential application for fabricating a solar cell based on composite fiber, Pt-free catalyst, and natural dye sensitizer.

Electrospun NanoFibers (ENFs) were fabricated from the mixture of Cellulose Acetate (CA), chitosan (CHI), and poly (ethylene oxide) using an acetic acid solution. The impact of CA/CHI ratio (0.5, 1, 1.5 wt %), CHI/PEO ratio (1, 1.5, 2 wt%), Sodium Dodecyl Sulfate (SDS) (0, 1.5, 3% w/w) and ammonium oxalate (3%, w/w) on the diameter, tensile strength, elongation, and porosity of the ENFs were optimized using Response Surface Methodology-Central Composite Rotatable Design (RSM-CCRD). The results revealed that ENFs were formed of non-woven fibers with a maximum diameter of 113 nm. Second-order polynomial models with high R2 values (0.996–0.99) were developed using Cubic analysis. The optimum condition was identified to be at the compounded level of CA/CHI 1.5 wt%, CHI/PEO 1 wt%, and SDS 3% (w/v). At the best point, the diameter, surface tension, elongation, and porosity of the fabricated ENFs were 96.07 nm, 0.054 N/mm2, 13.09 mm, and 52.29 respectively.

In this work, the optimization of the synthesis of PAN/Ag nanofiber composites via electrospinning was investigated via Taguchi's experimental design approach. The adsorption capacity of sulfur compounds from natural gas condensate was considered an objective function. The PAN/Ag nanofiber with 11 wt% PAN, 45 wt% AgNO3, 15 kV applied voltage, and 15 cm for a distance of a needle to a collector showed the highest adsorption capacity. The SEM, EDX, TEM, XRD, and FT-IR techniques were employed to elucidate the optimized PAN/Ag nanofiber structure. The results showed the successful synthesis of PAN/Ag nanofibers with diameters in 100-300 nm range and well distribution of Ag nanoparticles in the polymeric matrix. In addition, optimization of the adsorption capacity of PAN/Ag nanofiber in desulfurization of natural gas condensate in batch mode was performed via central composite design. Four factors including adsorbent weight, sulfur concentration in the natural gas condensate, the volume of the sample, and the adsorption time were considered effective factors each in three levels. The ANOVA analysis showed the more important factor in adsorbent performance is the concentration of sulfur in gas condensate and the weight of the adsorbent. The interaction terms between time and concentration and between volume and concentration are also important in response. Moreover, the response surface analysis of interaction terms showed the adsorptive nature of desulfurization.