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In this article, the space-time fractional perturbed nonlinear Schrödinger equation (NLSE) in nanofibers is studied using the improved $tan(\varphi (\xi )/2)$ expansion method (ITEM) to explore new exact solutions. The perturbed nonlinear Schrodinger equation is a nonlinear model that occurs in nanofibers. The ITEM is an efficient method to obtain the exact solutions for nonlinear differential equations. With the help of the modified Riemann–Liouville derivative, an equivalent ordinary differential equation has been obtained from the nonlinear fractional differential equation. Several new exact solutions to the fractional perturbed NLSE have been devised using the ITEM, which is the latest proficient method for analyzing nonlinear partial differential models. The proposed method may be applied for searching exact travelling wave solutions of other nonlinear fractional partial differential equations that appear in engineering and physics fields. Furthermore, the obtained soliton solutions are depicted in some 3D graphs to observe the behaviour of these solutions.

Piezoelectric principle is one of the popular choices when it comes to mechanical energy recovery and conversion of energy into electrical energy which can be either stored or used straightaway. In general, ceramic-based piezoelectric materials like Lead Zirconate Titanate (PZT) had been the popular choice for piezoelectric devices even though they are brittle in nature and found to be toxic in long uses. At the same time, organic-based Polyvinylidene Fluoride (PVDF) and similar polymeric materials have been used in different applications with an offer of flexibility, lightweight and biocompatibility. One major factor dragging down the usage of organic materials in piezoelectric applications is their poor piezoelectric responses. In this work, authors are reporting the enhanced piezoelectric properties of nanofibers of PVDF in composite with copper nanoparticles and Multiwalled Carbon Nanotubes (MWCNTs). Fourier Transformation Infrared (FTIR) analysis has been carried out for nanofibers and was able to prove the higher beta phase conversion of PVDF in composite nanofibers when compared with pristine nanofibers. Composite nanofibers were later fabricated into a piezoelectric device with two electrodes and have shown a peak voltage of 6.78 V upon a drop test. As a proof of concept, the mentioned piezoelectric device was integrated into a shoe-based prototype where it has shown 18–20V energy harvesting upon walking at leisurely pace.

Nanofibers based on the polymer mixture that was associated with poly(vinyl alcohol) (PVA) and poly(acrylamide) (PAAm) (50/50 wt.%) doped with different ratios of silver nanoparticles (Ag NPs) were successfully synthesized using electrospun method, which was performed at room temperature (RT) and high voltage (12 kV). The products were studied using techniques including scanning electron microscopy (SEM), atomic force microscopy (AFM), Fourier transform infrared (FTIR), X-ray diffraction (XRD) and ultraviolet–visible absorption spectroscopy. SEM results show uniform structures and a smooth surface without particles visible on the surface of the nanofibers. Also, SEM images show that the average diameter of polymer blend nanofibers is 157.40 nm and decreases with the increasing concentration of Ag NPs. The small capacity of the carbonyl group to operate as a powerful electron donor for interacting with ${\mathrm{\text{Ag}}}^{+}$ cation is shown by the fact that the FTIR signal strength decreases with increasing dopant concentration, indicating an increase in the basicity of the major functional groups. The X-ray diffraction pattern results confirm the amorphous nature (nano-crystalline) of the PVA–PAAm. The XRD results show that the crystallite size increases with the increase of the concentration of Ag and the peaks of weak intensity at a concentration of 6% agree with Ag in the cubic structure. Indirect allowed and forbidden transition optical energy gap values decreased with increasing Ag NPs content. The effect of doping on the other parameters (absorption coefficients, refraction index and extinction coefficient) of different blend behavior was investigated in detail which qualifies them for solar cell applications.

This study is an attempt to optimize the electrospinning process to produce minimum Nylon 6,6 nanofibers by using Taguchi statistical technique. Nylon 6,6 solutions were prepared in a mixture of formic acid (FA) and Dichloromethane (DCM). Design of experiment by using Taguchi statistical technique was applied to determine the most important processing parameters influence on average fiber diameter of Nylon 6,6 nanofiber produced by electrospinning process. The effects of solvent/nylon and FA/DCM ratio on average fiber diameter were investigated. Optimal electrospinning conditions were determined by using the signal-to-noise (S/N) ratio that was calculated from the electrospun Nylon 6,6 nanofibers diameters according to “the-smaller-the-better” approach. The optimum Nylon 6,6 concentration (NY%) and FA/DCM ratio were determined. The morphology of electrospun nanofibers is significantly altered by FA/DCM solvent ratio as well as Nylon 6,6 concentration. The smallest diameter and the narrowest diameter distribution of Nylon 6,6 nanofibers ($166\pm 33$nm) were obtained for 10 wt% Nylon 6,6 solution in 80 wt% FA and 20 wt% DCM. An increase of 118%, 280% and 26% in tensile strength, modulus of elasticity and elongation at break over as-cast was obtained, respectively. Glass transition temperature of Nylon 6,6 nanofibers were determined by using differential scanning calorimeter (DSC). Analysis of variance ANOVA shows that NY% is the most influential parameter.

Positive voltage electrospinning (PVES) has been mainly used for forming fibrous polymer scaffolds for different applications including tissue engineering. There is virtually no report on negative voltage electrospinning (NVES) of tissue engineering scaffolds. In this study, NVES of four biopolymers, namely, gelatin, chitosan, poly(lactic-co-glycolic acid) (PLGA), and polybutylene terephthalate (PBT), to form nanofibrous membranes was systematically investigated. For comparisons, PVES of these polymers was also conducted. It was found that chitosan fibers could not be produced using NVES. Under NVES or PVES, the fiber diameter of electrospun scaffolds generally increased with increasing needle inner diameter and polymer solution concentration but decreased with increasing working distance for all four polymers. Neither NVES nor PVES altered the chemical structure of gelatin, PLGA, and PBT. PVES and NVES resulted in fibrous membranes bearing positive charges and negative charges, respectively. PLGA and PBT fibrous membranes retained around 30% and 50%, respectively, of the initial charge one week after electrospinning. Charges on gelatin and chitosan fibrous membranes were almost completely dissipated within 60 min of electrospinning. For all four polymers, under either PVES or NVES, the retained charges on fibrous membranes increased with increasing applied electrospinning voltage. This study explored a new approach for forming fibrous scaffolds by using NVES and has opened a new area for developing negatively charged fibrous scaffolds for tissue engineering applications.

ZnO:Co thin films were synthesized by the chemical spray pyrolysis (CSP) on glass substrates. Then, investigated the impact of Co doping concentration on its physical properties. XRD analyses show that all films have a polycrystalline structure of hexagonal ZnO. The crystallite size increased from 18nm to 25nm with Co doping concentrations. Furthermore, the unit cell volume increased from 47.485Å to 47.831Å, and the Zn–O bond length expanded from 1.97588Å to 1.98071Å. SEM observations reveal the formation of fiber-like nanostructures in the Co-doped thin films. The diameter of nanofibers increased with Co doping concentration from 260nm to 700nm. The optical characteristics were studied by the UV-Visible spectrophotometer and manifest the optical transparency vary with Co doping. In addition, the band gap decreases from 3.27eV to 2.73eV with increasing Co doping concentrations. The conductivity varied from 3.35S$\cdot$m${}^{-1}$ to 19.88S$\cdot$m${}^{-1}$ with Co doping concentrations. Empirical models were proposed to evaluate the correlated variables with excellent accuracy with the experimental data. The best result was accomplished in ZnO:Co1% films, where good transparency and high conductivity were achieved.

Fabrication of Nanogenerators (NGs) using Electrospun polyvinylidene fluoride (PVDF) nanofibers for sensing and energy harvesting applications is a trending research due to its flexibility, biocompatibility, low-cost, etc. Different electrode materials, polymer composites had been proposed to increase the energy output. However, the contact area between the electrode material and nanofiber mat which helps to conduct more piezoelectric charges to the electrode surface are still unexplored especially at nanoscale level. In this paper, authors have proposed the use of low-cost carbon conductive paint to increase the contact area between the electrode and nanofiber mat. The electrode material is coated with conductive paint and the NG was fabricated with that electrode to compare the performances with conventional NG. Piezoelectric performance of the proposed NG has increased substantially as it generates an open circuit voltage ${(V}_{\mathrm{\text{oc}}}$) of 4.5V and short circuit current $(I_{\mathrm{\text{sc}}}$) of 25nA, whereas the conventional NG can only produce 1.6 $(V_{\mathrm{\text{oc}}}$) and 1.5nA $(I_{\mathrm{\text{sc}}}$). A drop test experiment was conducted, and the device consistency was verified experimentally.

ZnO@CeO₂ core–shell hetero-structural nanofibers (NFs) were synthesized by a coaxial electrospinning method and the materials characterization results proved that the core–shell hetero-structure was formed. Furthermore, the sensing properties test indicated that the ZnO@CeO₂ NFs exhibited higher response values and enhanced selectivity to acetone in low concentration range (0.2–10ppm) compared with ZnO and CeO₂ NFs, which showed the potential value in the field of diabetes diagnose. It is suggested that the enhanced sensitivity to acetone is attributed to the synergistic effect of one-dimensional (1D) structure and the formation of ZnO and CeO₂ hetero-structure.

One-dimensional (1D) CuO/In₂O₃ heterostructured nanofibers with the diameter of about 300 nm were successfully prepared through combining a facile single-capillary electrospinning with sintering process, and investigated by thermogravimetric and differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM) techniques, etc. The photocatalytic activities were examined by degrading methylene blue (MB) under 500W xenon lamp, halogen lamp and mercury lamp irradiation, respectively. The heterostructured nanofibers exhibited a higher photocatalytic activity than P25-TiO₂ under 500W xenon lamp irradiation due to the enhanced absorption for visible light and the efficient electron–hole separation and transportation. The single CuO microfibers and In₂O₃ nanofibers were also prepared as the control groups by the same method.

The properties of nanomaterials usually depend on their microstructures, the same material of different microstructures could be used for various applications. However, most devices could only synthesize a single microstructure, so it is meaningful that the different microstructures were synthesized by one method. In our study, electrospinning was applied to fabricate ZnO nanofibers and nanoparticles. In this approach, Zn(Ac)/PVP composite fibers of different component ratio were synthesized by electrospinning method which was subsequently calcined and formed ZnO nanofibers and nanoparticles. The microstructure, chemical composition and gas sensing were investigated with scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy and WS-60A gas sensing measurement system. The synthesis mechanisms of ZnO nanofibers and nanoparticles were discussed in detail.

Zinc oxide (ZnO) nanofibers and nanopetals were successfully deposited onto mesoporous silicon (meso-PSi), silicon, and glass substrates using zinc acetate via Spray Pyrolysis method. Electrochemical etching of the P-type (100) silicon wafer was used to prepare the mesoporous silicon layer. The effects of nozzle diameter and substrate type on the morphological, structural, and optical properties were investigated using XRD, SEM, EDX techniques, FT-IR, and UV-Vis spectrometry. Scanning Electron Microscopy (SEM) confirms the meso-PSi morphology with a diameter varying from 20nm to 45nm and illustrates the prepared ZnO nanostructures. EDX results show that the ratio of Zn:O is found to be similar to 1:1 for the 3-mm diameter when the oxygen is much higher than the Zn element in the 18-mm diameter. XRD measurements indicated that all films show a hexagonal Wurtzite structure with a variation of crystallographic properties and orientation according to the prepared morphology. The mean value of the crystallite size is 14.27nm for the 3-mm diameter and 19.01 nm for the 18-mm diameter. The variation in the morphological characteristics of the deposited ZnO leads to a variation in the optical properties of the sprayed ZnO thin films. The layers bandgap energy (Eg) was estimated to be 3.28 and 3.26eV for the ZnO layers prepared by 18-mm and 3-mm nozzle diameters, respectively. This study is also helpful for subsequent studies on the tailoring of morphology and ZnO growth control on PSi substrates.

We present here the simple procedure for synthesizing elongated fibers like porphyrin aggregates. Usually whenever the aggregation in dye molecules takes place the emission always tends to quench. In this work we explore and discuss the unusual enhanced emission property of these aggregates. The nanofibers of porphyrin were characterized with the help of atomic force microscopy and UV-vis spectroscopy whereas photoluminescence spectroscopy was used to check their emission property.

The catalyst-free synthesis of silicon carbide (SiC) nanowires was carried out from polyvinyl alcohol (PVA)/silica electrospun nanofibers at high temperature. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), and thermogravimetery analysis (TGA) were employed to study morphology and formation of SiC nanowires. Based on the TGA analysis, the carbon yield was increased when inert gas flow rate and heating rate decreased and polymeric nanofibers has been stabilized. The XRD and TEM results showed that the produced nanowires were crystalline β-SiC and rather homogeneous in thickness with an average diameter around 50 to 70 nm and a length of more than 10 μm. Finally, a possible growth mechanism of β-SiC nanowire based on a vapor–solid (VS) mechanism was proposed.

Electrospinning is a well-established technique for creating submicron polymer fibers to create distinctive functional nanostructures. Electrospinning parameters including solution concentration, tip-to-collector distance and applied voltage are adjusted to produce nonwovens with variable fiber diameter distributions. This research on the response surface methodology (RSM) is being used to model the diameter of a polyamide-6,6 (PA-6,6) nanofiber mat. The experiments were designed using central composite design (CCD) and RSM, which evaluated the interactions between the operating variables (polymer concentration, applied positive voltage, needle tip to collector distance and spinning angle) on the diameter of the PA-6,6 nanofiber. The average nanofiber diameter increased as the concentration of the PA-6,6 polymer solution increased. The model’s strong regression coefficient ($R^2=0.98$) reveals that it did a desirable of predicting the diameter of PA-6,6 fibers. The experimental findings and predicted fiber diameters were in good agreement. The results demonstrate that the optimization of electrospinning process to produce the smallest nanofibers and narrowest diameter distribution ($183\pm \mathrm{\text{nm}}$) combined effects of 10% polymer concentration, 21kV applied positive voltage, 18cm needle tip to collector distance and ${60}^{\circ }$ spinning angle are substantial interacting effects that have an impact on the surface response nanofibers. The results of the research and several mathematical models will offer useful guidelines for choosing parameter settings for electrospinning PA-6,6 to achieve the required fiber diameter. By saving time, effort and money more effectively, this research will expand the field of investigation for the quality of electrospun nanofibers.

A combination of the remarkably simple technique of electrospinning, developed to fabricate polymer nanofibers, and sol–gel processing has been utilized to produce fine zinc oxide nanofibers with an average diameter of 70 nm. A non-toxic precursor solution of polyvinyl alcohol and zinc acetate was electrospun and the resulting fibers were then calcined at a relatively low temperature to produce ZnO nanofibers. Simultaneous thermal analyses were used to study the formation of ZnO nanofibers from the precursor material. X-ray diffraction was employed to analyze the phases and different microscopy techniques, such as scanning electron microscopy, transmission electron microscopy and atomic force microscopy were used to study the morphology and size of the fibers. Fourier transform infrared spectroscopy was employed to investigate the composition of the precursor and ZnO fibers. The specific surface area of the electrospun nanofibers was determined using the Brunauer–Emmett–Teller method and optical properties were measured by UV-Vis and PL spectroscopy. The very high specific surface area of the ZnO fibers makes them potential candidates for nanodevice applications in gas sensing, dye-sensitized solar cells, and UV/blue emission devices.

The NC/CL-20 composite fibers were successfully prepared using electrospinning method. The composite fibers have potential application in propellant, pyrotechnics and explosives by modifying the mass ratio of CL-20 in the composite fibers. The weight percentage of NC in the precursor solution was from 8% to 24%, and a mixture of acetone and N, N-dimethyl formamide was used as the solvent. In order to get uniform and smooth fibers with CL-20 homogeneously dispersed, the maximum content of CL-20 should be less than 75% in the fibers. The diameter of the fibers was from nanoscale to several micrometers. Thermal decomposition properties of the composite fibers were also characterized by DSC.