Schwann cell-matrix coated PCL-MWCNT multifunctional nanofibrous scaffolds for neural regeneration.

Nerve tissue engineering aims to create scaffolds that promote nerve regeneration in the damaged peripheral nervous system. However, there remain some challenges in the construction of scaffolds in terms of mechanical properties and cellular behaviour. The present work aims to develop multifunctional implantable nanofibrous scaffolds for nerve regeneration. Using electrospinning, nanofibrous neat polycaprolactone (PCL) and PCL/multiwalled carbon nanotubes (PCL-MWCNT) composite scaffolds were prepared in random and aligned morphology. Schwann cells and their secreted biochemical factors are responsible for neuronal survival in the peripheral nervous system. Therefore, the acellular matrix of Schwann cells was spin-coated on the PCL-MWCNT scaffolds to aid nerve regeneration. Physicochemical and mechanical properties, and the in vitro cellular response of the developed nanofibrous were investigated. We observed no significant change in fibre diameter between neat PCL and PCL-MWCNT scaffolds regardless of the morphology. However, the inclusion of MWCNT reduced the mechanical strength of nanocomposite scaffolds compared to neat PCL. In vitro study revealed biocompatibility of the developed scaffolds both with and without an acellular matrix. Gene expression study revealed a significant increase in peripheral myelin protein (PMP22) expression on acellular matrix-coated PCL-MWCNT scaffolds compared to neat PCL counterparts. Overall, the results suggested Schwann cell matrix-coated PCL-MWCNT nanofibers as a promising conduit for peripheral nerve regeneration.

Optimization of Sb2S3 Nanocrystal Concentrations in P3HT: PCBM Layers to Improve the Performance of Polymer Solar Cells.

In this study, polymer solar cells were synthesized by adding Sb2S3 nanocrystals (NCs) to thin blended films with polymer poly(3-hexylthiophene)(P3HT) and [6,6]-phenyl-C61-butyric-acid-methyl-ester (PCBM) as the p-type material prepared via the spin-coating method. The purpose of this study is to investigate the dependence of polymer solar cells' performance on the concentration of Sb2S3 nanocrystals. The effect of the Sb2S3 nanocrystal concentrations (0.01, 0.02, 0.03, and 0.04 mg/mL) in the polymer's active layer was determined using different characterization techniques. X-ray diffraction (XRD) displayed doped ratio dependences of P3HT crystallite orientations of P3HT crystallites inside a block polymer film. Introducing Sb2S3 NCs increased the light harvesting and regulated the energy levels, improving the electronic parameters. Considerable photoluminescence quenching was observed due to additional excited electron pathways through the Sb2S3 NCs. A UV-visible absorption spectra measurement showed the relationship between the optoelectronic properties and improved surface morphology, and this enhancement was detected by a red shift in the absorption spectrum. The absorber layer's doping concentration played a definitive role in improving the device's performance. Using a 0.04 mg/mL doping concentration, a solar cell device with a glass /ITO/PEDOT:PSS/P3HT-PCBM: Sb2S3:NC/MoO3/Ag structure achieved a maximum power conversion efficiency of 2.72%. These Sb2S3 NCs obtained by solvothermal fabrication blended with a P3HT: PCBM polymer, would pave the way for a more effective design of organic photovoltaic devices.

State of the Art and New Directions on Electrospun Lignin/Cellulose Nanofibers for Supercapacitor Application: A Systematic Literature Review.

Supercapacitors are energy storage devices with high power density, rapid charge/discharge rate, and excellent cycle stability. Carbon-based supercapacitors are increasingly attracting attention because of their large surface area and high porosity. Carbon-based materials research has been recently centered on biomass-based materials due to the rising need to maintain a sustainable environment. Cellulose and lignin constitute the major components of lignocellulose biomass. Since they are renewable, sustainable, and readily accessible, lignin and cellulose-based supercapacitors are economically viable and environmentally friendly. This review aims to systematically analyze published research findings on electrospun lignin, cellulose, and lignin/cellulose nanofibers for use as supercapacitor electrode materials. A rigorous scientific approach was employed to screen the eligibility of relevant articles to be included in this study. The research questions and the inclusion criteria were clearly defined. The included articles were used to draw up the research framework and develop coherent taxonomy of literature. Taxonomy of research literature generated from the included articles was classified into review papers, electrospun lignin, cellulose, and lignin/cellulose nanofibers for use as supercapacitor electrode materials. Furthermore, challenges, recommendations, and research directions for future studies were equally discussed extensively. Before this study, no review on electrospun lignin/cellulose nanofiber-based supercapacitors has been reported. Thus, this systematic review will provide a reference for other researchers interested in developing biomass-based supercapacitors as an alternative to conventional supercapacitors based on petroleum products.

Acetone Vapor-Sensing Properties of Chitosan-Polyethylene Glycol Using Surface Plasmon Resonance Technique.

To non-invasively monitor and screen for diabetes in patients, there is need to detect low concentration of acetone vapor in the range from 1.8 ppm to 5 ppm, which is the concentration range of acetone vapor in diabetic patients. This work presents an investigation for the utilization of chitosan-polyethylene glycol (PEG)-based surface plasmon resonance (SPR) sensor in the detection of trace concentration acetone vapor in the range of breath acetone in diabetic subjects. The structure, morphology, and elemental composition of the chitosan-PEG sensing layer were characterized using FTIR, UV-VIS, FESEM, EDX, AFM, and XPS methods. Response testing was conducted using low concentration of acetone vapor in the range of 0.5 ppm to 5 ppm using SPR technique. All the measurements were conducted at room temperature and 50 mL/min gas flow rate. The sensor showed good sensitivity, linearity, repeatability, reversibility, stability, and high affinity toward acetone vapor. The sensor also showed better selectivity to acetone compared to methanol, ethanol, and propanol vapors. More importantly, the lowest detection limit (LOD) of about 0.96 ppb confirmed the applicability of the sensor for the non-invasive monitoring and screening of diabetes.

Investigation of Acetone Vapour Sensing Properties of a Ternary Composite of Doped Polyaniline, Reduced Graphene Oxide and Chitosan Using Surface Plasmon Resonance Biosensor.

This work reports the use of a ternary composite that integrates p-Toluene sulfonic acid doped polyaniline (PANI), chitosan, and reduced graphene oxide (RGO) as the active sensing layer of a surface plasmon resonance (SPR) sensor. The SPR sensor is intended for application in the non-invasive monitoring and screening of diabetes through the detection of low concentrations of acetone vapour of less than or equal to 5 ppm, which falls within the range of breath acetone concentration in diabetic patients. The ternary composite film was spin-coated on a 50-nm-thick gold layer at 6000 rpm for 30 s. The structure, morphology and chemical composition of the ternary composite samples were characterized by FTIR, UV-VIS, FESEM, EDX, AFM, XPS, and TGA and the response to acetone vapour at different concentrations in the range of 0.5 ppm to 5 ppm was measured at room temperature using SPR technique. The ternary composite-based SPR sensor showed good sensitivity and linearity towards acetone vapour in the range considered. It was determined that the sensor could detect acetone vapour down to 0.88 ppb with a sensitivity of 0.69 degree/ppm with a linearity correlation coefficient of 0.997 in the average SPR angular shift as a function of the acetone vapour concentration in air. The selectivity, repeatability, reversibility, and stability of the sensor were also studied. The acetone response was 87%, 94%, and 99% higher compared to common interfering volatile organic compounds such as propanol, methanol, and ethanol, respectively. The attained lowest detection limit (LOD) of 0.88 ppb confirms the potential for the utilisation of the sensor in the non-invasive monitoring and screening of diabetes.

Effect of sulfurization time on the properties of copper zinc tin sulfide thin films grown by electrochemical deposition.

We report growth of quaternary Cu2 ZnSnS4 (CZTS) thin films prepared by the electrochemical deposition from salt precursors containing Cu (II), Zn (II) and Sn (IV) metals. The influence of different sulfurization times t (t = 75, 90, 105, and 120 min) on the structural, compositional, morphological, and optical properties, as well as on the electrical properties is studied. The films sulfurized 2 hours showed a prominent kesterite phase with a nearly stoichiometric composition. Samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and Raman and UV-VIS-NIR spectrometer at different stages of work. X-ray diffraction and Raman spectroscopy analyses confirmed the formation of phase-pure CZTS films. (FESEM) shows that compact and dense morphology and enhanced photo-sensitivity. STEM - EDS elemental map of CZTS cross-section confirms homogeneous distribution. From optical study, energy gap was enlarged with a changed sulfurization times in the range of 1.37-1.47 eV.