Electrospinning of Carboxymethyl Chitosan/Polyoxyethylene Oxide Nanofibers for Fruit Fresh-Keeping

Electrospinning provides an effective method for generating nanofibers from solution of carboxymethyl chitosan/polyoxyethylene oxide (CMCS/PEO). The goal of this work is to explore the potential application of electrospun CMCS/PEO nanofiber membrane in fruit fresh-keeping. The microstructure, antibacterial activity, hydrophilia, and air permeability of the nanofiber membrane have been tested. For comparison, the fresh-keeping effects of commercial cling wrap and CMCS/PEO nanofiber membranes on strawberries’ rotting rate and weight loss rate have been studied. The results indicate that the electrospun CMCS/PEO membrane could effectively avoid water loss in strawberries and has a remarkable effect to prolong strawberries’ shelf life due to its breathability and antibacterial activity. In addition, the composite CMCS/PEO, nanofiber membrane is non-poisonous and edible, which can be used in food industry

A Three-Dimensional Porous Conducting Polymer Composite with Ultralow Density and Highly Sensitive Pressure Sensing Properties

An ultralight conducting polyaniline/SiC/polyacrylonitrile (PANI/SiC/PAN) composite was fabricated by in situ polymerization of aniline monomer on the surface of fibers in SiC/PAN aerogel. The SiC/PAN aerogel was obtained by electrospinning, freeze-drying, and heat treatment. The ingredient, morphology, structure, and electrical properties of the aerogel before and after in situ polymerization were investigated by X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and voltage-current characteristic measurement. The thermostability of PANI/SiC/PAN composite was investigated by thermogravimetric analysis (TGA) and electrical resistance measured at different temperatures. The density of the PANI/SiC/PAN composite was approximately 0.211 g cm−3, the porosity was 76.44%, and the conductivity was 0.013 S m−1. The pressure sensing properties were evaluated at room temperature. The electrical resistance of as-prepared sample decreased gradually with the increase of pressure. Furthermore, the pressure sensing process was reversible and the response time was short (about 1 s). This composite may have application in pressure sensor field

Colorful Hydrophobic Poly(Vinyl Butyral)/Cationic Dye Fibrous Membranes via a Colored Solution Electrospinning Process

Supplementary Materials. (DOCX 3474 kb

Graphene Quantum Dots Doped PVDF(TBT)/PVP(TBT) Fiber Film with Enhanced Photocatalytic Performance

We report the fabrication of polyvinylidene fluoride (tetrabutyl titanate)/polyvinyl pyrrolidone ((tetrabutyl titanate))-graphene quantum dots [PVDF(TBT)/PVP(TBT)-GQDs] film photocatalyst with enhanced photocatalytic performance. The polyvinylidene fluoride (tetrabutyl titanate)/polyvinyl pyrrolidone ((tetrabutyl titanate)) [PVDF(TBT)/PVP(TBT)] film was first prepared with a dual-electrospinning method and then followed by attaching graphene quantum dots (GQDs) to the surface of the composite film through a hydrothermal method. Later, part of the PVP in the composite film was dissolved by a hydrothermal method. As a result, a PVDF(TBT)/PVP(TBT)-GQDs film photocatalyst with a larger specific surface area was achieved. The photocatalytic degradation behavior of the PVDF(TBT)/PVP(TBT)-GQDs film photocatalyst was examined by using Rhodamine B as the target contaminant. The PVDF(TBT)/PVP(TBT)-GQDs photocatalyst showed a higher photocatalytic efficiency than PVDF(TBT)-H2O, PVDF(TBT)/PVP(TBT)-H2O, and PVDF(TBT)-GQDs, respectively. The enhanced photocatalytic efficiency can be attributed to the broader optical response range of the PVDF(TBT)/PVP(TBT)-GQDs photocatalyst, which makes it useful as an effective photocatalyst under white light irradiation

Electrospun PEDOT:PSS/PVP Nanofibers for CO Gas Sensing with Quartz Crystal Microbalance Technique

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/polyvinylpyrrolidone (PEDOT:PSS/PVP) composite nanofibers were successfully fabricated via electrospinning and used as a quartz crystal microbalance (QCM) sensor for detecting CO gas. The electrical property of individual PEDOT:PSS/PVP nanofibers was characterized and the room temperature resistivity was at the magnitude of 105 Ω·m. The QCM sensor based on PEDOT:PSS/PVP nanofibers was sensitive to low concentration (5–50 ppm) CO. In the range of 5–50 ppm CO, the relationship between the response of PEDOT:PSS nanofibers and the CO concentration was linear. Nevertheless, when the concentration exceeded 50 ppm, the adsorption of the nanofiber membrane for CO gas reached saturation and the resonant frequency range had no change. Therefore, the results open an approach to create electrospun PEDOT:PSS/PVP for gas sensing applications

Current–Voltage Characteristics in Individual Polypyrrole Nanotube, Poly(3,4-ethylenedioxythiophene) Nanowire, Polyaniline Nanotube, and CdS Nanorope

In this paper, we focus on current–voltage (I–V) characteristics in several kinds of quasi-one-dimensional (quasi-1D) nanofibers to investigate their electronic transport properties covering a wide temperature range from 300 down to 2 K. Since the complex structures composed of ordered conductive regions in series with disordered barriers in conducting polymer nanotubes/wires and CdS nanowires, all measured nonlinearI–Vcharacteristics show temperature and field-dependent features and are well fitted to the extended fluctuation-induced tunneling and thermal excitation model (Kaiser expression). However, we find that there are surprisingly similar deviations emerged between theI–Vdata and fitting curves at the low bias voltages and low temperatures, which can be possibly ascribed to the electron–electron interaction in such quasi-1D systems with inhomogeneous nanostructures

Electrical transport properties of an isolated CdS microrope composed of twisted nanowires

CdS is one of the important II-VI group semiconductors. In this paper, the electrical transport behavior of an individual CdS microrope composed of twisted nanowires is studied. It is found that the current–voltage (I-V) characteristics show two distinct power law regions from 360 down to 60 K. Space-charge-limited current (SCLC) theory is used to explain these temperature- and electric-field-dependent I-V curves. The I-V data can be well fitted by this theory above 100 K, and the corresponding carrier mobility, trap energy, and trap concentration are also obtained. However, the I-V data exhibit some features of the Coulomb blockade effect below 80 K