Synthesis of Polyaniline–Cerium Oxide Nanocomposite for Photodetector Application

In this paper nanocomposites materials of Polyaniline (PAni) nano-fiber (NFs) and Cerium oxide (CeO2) nanoparticles (NPs) were prepared by two method; hydrothermal and chemical method respectively. The spin coating method was used to prepare PAni and Pani/CeO2 on Si and glass substrates and then screened with XRD, FE-SEM, UV-Vis and as-prepared thin-film photodetectors. The X-ray diffraction pattern of all the prepared films showed the presence of crystalline nature. It was found that the PAni/CeO2 films have a cubic crystal structure.. FESEM results proved that the PAni film prepared have nanofiber like structure, while the PAni/CeO2 films proved that CeO2 NPs fully caped with PAni nanofiber. The UV-Vis spectra showed peaks of PAni 340nm, 651nm and PAni/CeO2 320nm, 620 nm and in the energy gap it is noticed that the band gap value decreases as the CeO2 ratios increases where the maximum values of energy gap of B-band and Q-band (1.65 – 2.74) eV. The maximum sensitivity values of the photoconductive detectors were observed at PAni/CeO2 (2 vol.%) nanoparticles deposited on n-Si substrate which were approximately (2696.5%, 946.15%, 1402.2%, 1613.9%3837.9%, and 2700%) for wavelengths 360, 465, 510, 595,660 and 965 nm respectively.

Carbon Nano-Fiber/PDMS Composite Used as Corrosion-Resistant Coating for Copper Anodes in Microbial Fuel Cells

The development of high-performance anode materials is one of the greatest challenges for the practical implementation of Microbial Fuel Cell (MFC) technology. Copper (Cu) has a much higher electrical conductivity than carbon-based materials usually used as anodes in MFCs. However, it is an unsuitable anode material, in raw state, for MFC application due to its corrosion and its toxicity to microorganisms. In this paper, we report the development of a Cu anode material coated with a corrosion-resistant composite made of Polydimethylsiloxane (PDMS) doped with carbon nanofiber (CNF). The surface modification method was optimized for improving the interfacial electron transfer of Cu anodes for use in MFCs. Characterization of CNF-PDMS composites doped at different weight ratios demonstrated that the best electrical conductivity and electrochemical properties are obtained at 8 % weight ratio of CNF/PDMS mixture. Electrochemical characterization showed that the corrosion rate of Cu electrode in acidified solution decreased from (17 ± 6) × 103 μm y−1 to 93 ± 23 μm y−1 after CNF-PDMS coating. The performance of Cu anodes coated with different layer thicknesses of CNF-PDMS (250 µm, 500 µm, and 1000 µm), was evaluated in MFC. The highest power density of 70 ± 8 mW m−2 obtained with 500 µm CNF-PDMS was about 8-times higher and more stable than that obtained through galvanic corrosion of unmodified Cu. Consequently, the followed process improves the performance of Cu anode for MFC applications.

Application of Polystyrene Nanofiber in Detection of Anxiety-Related Bio-Marker Cortisol

This work aimed to explore the correlation between plasma cortisol level and the occurrence of anxiety through the polystyrene (PS) nano-fiber solid phase extraction technology. The PS nano-fibers were prepared, and its characterization was performed to detect its adsorption selectivity and blood compatibility. 32 anxiety patients treated in the hospital were recruited as the research subjects, with another 35 mentally healthy people as controls. The Hamilton Anxiety (HAMA) Scale, Symptom checklist-90 (SCL-90) scale, and Eysenck personality questionnaire (EPQ) were used to analyze the anxiety degree, psychological disorder degree, and personality of the two groups. The plasma cortisol level was detected by PS nano-fiber solid phase extraction technology. Finally, the Pearson correlation test was performed to analyze the correlation between the plasma cortisol level and the scores of HAMA scale, SCL-90 scale, and EPQ scale in anxiety patients. It was revealed that the HAMA scale and SCL-90 scale scores of anxiety patients were superior to those of healthy subjects (P < 0.05). The “neuroticism” factor score in EPQ were obviously higher than that of healthy subjects (P < 0.05). The diameter of the prepared PS nano-fiber was within 200~900 nm, with a small specific surface area (BET), pore volume, and pore size, and the cellular structure was noted on the fiber surface. The PS nano-fiber demonstrated relatively good adsorption performance for benzene hydrocarbon compounds and had excellent anti-protein adsorption capacity. It was found that the plasma cortisol level of anxiety patients was higher than that of healthy subjects (P < 0.05), and the plasma cortisol level was positively correlated with HAMA scale, SCL-90 scale, and EPQ scale scores (r = 0.996, 0.993, and 0.971, respectively; P < 0.05). In conclusion, the PS nano-fiber solid phase extraction technology can be applied to identify the plasma cortisol level, which was with a good anti-interference property. An increased plasma cortisol level can be used as an indicator for auxiliary diagnosis of anxiety.

Development of polyvinyl alcohol-based carbon nano fiber sheet for thermal interface material

Polyvinyl alcohol (PVA)-based carbon nanofiber (CNF) sheets are fabricated as an innovative thermal interface material (TIM), which is a potential substitute for traditional TIMs. Five types of PVA-based CNF sheets were fabricated at different mass ratios of PVA:vapor-grown carbon fiber (VGCF) (1:0.100, 1:0.070, 1:0.050, 1:0.030, 1:0.025). The thickness of the PVA-based CNF sheets was 30–50 µm, which was controlled by the amount of VGCF. The microstructure of the CNF sheets indicated that VGCFs were arranged in random directions inside the sheet, and PVA was formed as a membrane between two VGCFs. However, many pores were found to exist between the VGCFs. The porosity of the PVA-based CNF sheets decreased from 25 to 13% upon decreasing the mass ratio of VGCF from 43.38 to 16.13%. The density and Shore hardness of all CNF sheets were 1.03–1.15 × 106 g m−3 and 82.4–85.0 HS, respectively. The highest thermal conductivity, measured as the mass ratio of PVA:VGCF, was achieved at 1:0.05, with the in-plane thermal conductivity of the fabricated sheet being 14.3 W m−1 k−1.

Electro-spun nano fiber of carboxymethyl cellulose – curcumin and its applications

Cellulose is a prominent scaffolding polysaccharide found in plants as micro fibrils which form the structurally strong framework in the cell walls. It has wide variety of uses such as attacking agent, emulsifier, stabilizer etc. Its use can be further enhanced by converting cellulose into cellulose derivatives. One of the most important cellulose derivatives is carboxy methyl cellulose (CMC). In the present study, cellulose is converted to CMC thereby preparing CMC – curcumin nanofiber by using electro spinning method. The functional groups identification was done by using UV Visible spectroscopy and FT-IR. Surface structure was analyzed by using Scanning Electron Microscopy. The antifungal activity was studied against Aspergillus niger and Candida albicans. . The antibacterial activities also studied for the samples against E.coli, Klebsiella pneumonia, Streptococcus mutans and Staphylococcus aureus.