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The electrospinning process was used to manufacture nanofiber mats of polymeric materials that have low thickness and improved sound absorption characteristics. The processed nanofiber composites consisted of a number of formulated combinations of polymeric materials, i.e., Polyvinyl Alcohol (PVA), Polystyrene (PS), and Polyvinyl Chloride (PVC). These materials were further modified by addition of fillers like Carbon nanotubes (CNTs), Graphene (GN), Wollastonite (WS) and Fiberglass (FG) for the purpose of betterment of their soundproofing characteristics. This paper focuses on an experimental study for evaluating the sound absorption coefficient of these composites by implementing the standard test method of sound absorption using an impedance tube. The effects of back cavity, air gaps, layering and graded thickness of different combination of the produced nanofiber mats were also investigated in this study. The experimental results revealed that these nanofiber mats demonstrate good sound absorption potential in low and medium frequency ranges (Up to 2000Hz). These cost-effective nanofiber mats have the potential of being used as sound barriers, to reduce noise transmission and keep it contained and/or as sound-dampening and sound-deadening materials in applications where space and volume savings are critical, especially in the electronic and aerospace industries. [ABSTRACT FROM AUTHOR]

This paper concerns the numerical simulation of electrified jets with application to the electrospinning process for the fabrication of fibers with controllable size, diameter, and cross section shape. Most numerical models used to simulate electrospinning rely on the Upper Convected Maxwell model (UCM) which is fit to model polymer melts. However, in most electrospinning processes the fluid is a polymer solution with a Newtonian solvent that evaporates after the fiber is deposited on the collector. In this work we propose to describe the fluid rheology using Giesekus model, which predicts the properties of polymer solutions more accurately, and show the impact of the rheological model on the prediction of the fiber radius and size. [ABSTRACT FROM AUTHOR]

Hyaluronic acid (HA) is rightfully considered as a promising and advanced polymer for development and producing a variety of applications in medicine, biotechnology and tissue engineering. One such trend is electrospun fiber materials obtained from HA solutions. However, HA has absolutely highly resistance to volatile organic solvents (such solvents are strongly encouraged for utilizing in case of electrospinning), that make the obtaining of polymer fibers difficult. Despite this, some authors could elaborate nanofibers based on HA from the aqueous-organic solutions, for instance, dimethyl formamid (DMF)/water solvent mixtures, but in the context of biomaterials utilizing DMF is prohibited. In addition, several studies describe fiber materials obtained from HA and carrier polymers such as polyvinyl alcohol (PVA) or polyethylene oxide (PEO). Having said that, utilizing such polymers notably decreases biomedical worth of native HA. This study describes the primary results of obtaining polymer structures via electrospinning from the HA solutions based on water and dimethyl sulfoxide/water systems without modifying polymers. Moreover, in this paper, the impact assessment of technological parameters on electrospinnability of spinning solutions was carried out. This finding is expected to broad the application of the electrospinning micro- and nanofibers from biopolymers for the development of modern materials. [ABSTRACT FROM AUTHOR]

Tungsten trioxide (WO3) nanoplates were grown employing a low cost acid treatment method. Firstly, the tungsten oxide hydrate (WO3⋅H2O) nanoplates were grown on silicon wafer and glass slide substrate at different HNO3 temperature from 60 to 90°C. The as prepared were the tungsten oxide hydrate (WO3⋅H2O), then transformed into monoclinic WO3nanoplate after annealed at 400 °C at air ambient for 2 hour. The aim of this study was determined the optimum HNO3 temperature in grown WO3nanoplates. The structure and morphology of WO3nanoplate were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The optical property was determined by UV-Vis spectrophotometer. The result indicated that morphologies was strongly related to the grown temperature and will discuss in this paper. The relationship between morphologies and optical reflection will be discussed. [ABSTRACT FROM AUTHOR]

A concept of Differential-Integral (DI) method applied in polymer processing and molding was proposed, which included melt DI injection molding, DI nano-composites extrusion molding and melt differential electrospinning principle and equipment. Taking the melt differential electrospinning for example to introduce the innovation research progress, two methods preparing polymer ultrafine fiber have been developed: solution electro-spinning and melt electrospinning, between which solution electro-spinning is much simpler to realize in lab. More than 100 institutions have endeavored to conduct research on it and more than 30 thousand papers have been published. However, its industrialization was restricted to some extend because of the existence of toxic solvent during spinning process and poor mechanical strength of resultant fibers caused by small pores on fiber surface. Solvent-free melt electrospinning is environmentally friendly and highly productive. However, problems such as the high melt viscosity, thick fiber diameter and complex equipment makes it relatively under researched compared with solution electrospinning. With the purpose of solving the shortage of traditional electro-spinning equipment with needles or capillaries, a melt differential electrospinning method without needles or capillaries was firstly proposed. Nearly 50 related patents have been applied since 2005, and systematic method innovations and experimental studies have also been conducted. The prepared fiber by this method had exhibited small diameter and smooth surface. The average fiber diameter can reach 200-800 nm, and the single nozzle can yield two orders of magnitude more than the capillaries. Based on the above principle, complete commercial techniques and equipment have been developed to produce ultra-fine non-woven fabrics for the applications in air filtration, oil spill recovery and water treatment, etc. [ABSTRACT FROM AUTHOR]

This paper is focused on the formulation and characterization of membranes that can act as biomedical devices with a mesh sample structure to reduce local inflammation and improve the tissue regeneration. These systems were realized homogenously dispersing lamellar Hydrotalcite loaded with Diclofenac Sodium (HTLc-DIK) in a polymeric matrix of Poly-caprolactone (PCL). Membranes were obtained through the electrospinning technique that has shown many advantages with respect to other techniques. Experiments carried out on the manufactured samples highlight the no- toxicity of the samples and very good interactions between cells and device. [ABSTRACT FROM AUTHOR]

The production of lignin fibers has been studied in order to replace the need for petroleum based precursors for carbon fiber production. In addition to its positive environmental effects, it also benefits the economics of the industries which cannot take advantage of carbon fiber properties because of their high price. A large amount of lignin is annually produced as the byproduct of paper and growing cellulosic ethanol industry. Therefore, finding high value applications for this low cost, highly available material is getting more attention. Lignin is a biopolymer making about 15 - 30% of the plant cell walls and has a high carbon yield upon carbonization. However, its processing is challenging due to its low molecular weight and also variations based on its origin and the method of separation from cellulose. In this study, alkali solutions of organosolv lignin with less than 1 wt/v% of poly (ethylene oxide) and two types of lignin (hardwood and softwood) were electrospun followed by carbonization. Different heating programs for carbonization were tested. The carbonized fibers had a smooth surface with an average diameter of less than 5 µm and the diameter could be controlled by the carbonization process and lignin type. Scanning electron microscopy (SEM) was used to study morphology of the fibers before and after carbonization. Thermal conductivity of a sample with amorphous carbon was 2.31 W/m.K. The electrospun lignin carbon fibers potentially have a large range of application such as in energy storage devices and water or gas purification systems. [ABSTRACT FROM AUTHOR]

This paper details the impact of protonic doping via humidity exposure on the response mechanism of electrospun polyaniline based NO2 sensors. Sensing test results reveal that water vapor absorbed into the electrospun mat and adsorbed on LEB-PANI can perform as a primary charge carrier for polyaniline. [ABSTRACT FROM AUTHOR]

Dye sensitized solar cells (DSSCs) is a promising photovoltaic technology that still needs further improvement in manufacturing processes for mass production. This paper studies direct deposition method to enhance the manufacturing steps of semiconductor layer on conductive substrate. Electro spun Zinc Oxide (ZnO) nanofiber are directly coated on transparent conductive oxide (FTO) glass by electrospinning machine. The variation of electrospinning distances from 4, 6 and 8 cm were applied on this work to examine its effects on ZnO nanofiber morphology. The results showed that at 8 cm electrospinning distance produced small, regular and unbroken ZnO nanofiber structure. Furthermore, it also produced the highest solar cell’s performance under irradiation of AM 1.5 simulated sunlight (1000 mW/cm2) than the other electrospinning distances. [ABSTRACT FROM AUTHOR]

A nanofiber-based of dye-sensitized solar cell (DSSC) attracts high interest for researchers due to its high efficiency, low cost, and mass production availability. This paper investigated the electrospinning machine to fabricate ZnO nanofiber and will be used as photoanode of DSSC. Direct deposition method was applied on electrospinning machine to directly capture the liquid jet electrospun of ZnO solution on transparent conductive oxide (TCO) glass. The stream velocity variation of 4, 6 and 8 μl/min were conducted to investigate its effects on ZnO nanofiber morphology. The results showed that at the stream velocity of 4 μl/min produced small average droplet size, and uniform morphology with a diameter of 138.20 nm. Furthermore, it also obtained the highest electrical efficiency of DSSC due to high of dye absorbance and electron excitation. [ABSTRACT FROM AUTHOR]

Due to their special combination of characteristics, graphene oxide-polyvinyl alcohol (GO-PVA) nanofibrous composites have attracted a lot of attention and are attractive candidates for a variety of applications. The creation, characteristics, and analysis of GO-PVA nanofibrous composites are the main topics of this study. Electrospinning, a flexible method that enables the creation of nanofibers with high aspect ratios, is used in the fabrication process. The resulting nanofibrous composites have improved mechanical strength, electrical conductivity, and thermal stability by adding graphene oxide to the polyvinyl alcohol matrix. To obtain the desired qualities, fabrication factors including solution concentration, electrospinning parameters, and post-treatment techniques are optimized. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) are used in the morphological characterization of GO-PVA nanofibrous composites during analysis. [ABSTRACT FROM AUTHOR]

Low-dimensional nanoparticles of copper oxide (CuO) have attracted great attention because it is an important p-type semiconductor with stable narrow band gap energy (1.2 eV) [1]. It also has good photoconductive and photochemical properties, suitable for application such as gas sensors [2], solar cell [3] and catalysts [4]. Therefore, many methods have been developed to prepare CuO with various morphologies via template based sol-gel route [5], microwave-assisted synthesis [6], alcohothermal method [7], electrospinning method [8] and ultrasonic irradiation [9]. We chose the ultrasonic irradiation technique because it produces products with good homogeneity and optical properties. Karimi et al. carried out a novel sonochemistry route from copper acetate and sodium hydroxide in the presence of polyethylene glycol, polypropylene glycol and polyvinyl alcohol to control the dispersion and stabilization of CuO nanoparticles in the solution and look at the effects of mechanical and optical properties of the produced [10]. Similarly, in this study we controlled the growth of nuclei by employing the absorption of the triethanolamine (TEA) and ethylenediamine (EDA) onto the surface of the nanoparticles under ultrasonic irradiation conditions. TEA is an interesting ligand which is both a tertiary amine and a triol with a lone pair of electrons on the nitrogen atom [11]. It is widely used in cosmetology as a pH regulator and belongs to the group of tripodal ligands [12]. Meanwhile, EDA is a colorless liquid organic compound with an ammonia-like odor basic amine. It is attractive because these compounds are employed as intermediates for various fine chemicals [13]. We used EDA as a reducing and capping agent at the same time in this reaction. In this paper, we report the synthesis, structural characterization and optical properties of nanospheres CuO with the optimum ratio of TEA to EDA. [ABSTRACT FROM AUTHOR]

This study aims to perform functional group analysis on PVA/Alginate/Red Binahong fiber. Fabrication of PVA/Alginate/Red Binahong (Anredera cordifolia (Ten.) Steenis) using an electrospinning method by adding a mixture of PVA/Alginate with a ratio of 80:20 with a volume variation of red binahong leaf extract 2.5 mL, 3, 75 mL, and 5 mL in each PVA/Alginate mixture. The internal electrospinning parameters used are 25 kV voltage, 10 cm nozzle-to-collector distance, an hour synthesis time, flowrate 140 rpm. The functions of O-H stretching and bending, C-H stretching and bending, C-O stretching, and C=O group were found in PVA/Alginate fiber and PVA/Alginate/Red Binahong fiber, however, the C=C functional group in fibers with added of red binahong extract indicates of flavonoid compounds which contained in it. The volume variation in the red binahong extract did not affect the functional group. These variations in volume affect the amount of transmittance in each functional group. [ABSTRACT FROM AUTHOR]

In recent times, nanofibers have attracted the attention of researchers due to their pronounced micro and nano structural characteristics that enable the development of advanced materials that have sophisticated applications. The production of nanofibers by the electrospinning process is influenced both by the electrostatic forces and the viscoelastic behavior of the polymer. Process parameters, like solution feed rate, applied voltage, nozzle-collector distance and spinning environment and material properties, like solution concentration, viscosity, surface tension, conductivity and solvent vapor pressure, influence the structure and properties of electrospun nanofibers. Significant work has been done to characterize the properties of PALF nanofibers as a function of process and material parameters. [ABSTRACT FROM AUTHOR]

The potential of polymethyl methacrylate (PMMA) nanofiber prepared by the electrospinning technique for the methyl orange (MO) adsorption from aqueous solution was investigated. In this study, the adsorption experiments were carried out to investigate the effect of temperatures in a batch system. From experiment it can be seen that the MO adsorption using PMMA nanofiber increased with increasing temperature. The kinetic data of MO were analyzed by pseudo-first-order and pseudo-second-order kinetic models. It was found that the amount of MO adsorbed increase with increasing temperature. Kinetics parameters data indicated that the MO adsorption onto PMMA nanofiber was found to follow both pseudo first and second-order rate equations. [ABSTRACT FROM AUTHOR]

This paper describes the features of new membranes that can act as local biomedical devices owing to their peculiar shape in the form of mesh structure. These materials are designed to provide significant effects to reduce local inflammations and improve the tissue regeneration. Lamellar Hydrotalcite loaded with Diclofenac Sodium (HTLc-DIK) was homogenously dispersed inside a polymeric matrix of Poly-caprolactone (PCL) to manufacture membranes by electrospinning technique. The experimental procedure and the criteria employed have shown to be extremely effective at increasing potentiality and related applications. The employed technique has proved to be very useful to manufacture polymeric fibers with diameters in the range of nano-micro scale. In this work a dedicated collector based on a proprietary technology of IME Technologies and Eindhoven University of Technology (TU/e) was used. It allowed to obtain devices with a macro shape of a 3D-mesh. Atomic Force Microscopy (AFM) highlights a very interesting texture of the electrospun fibers. They show a lamellar morphology that is only slightly modified by the inclusion of the interclay embedded in the devices to control the drug release phenomena. [ABSTRACT FROM AUTHOR]

In this paper we formulated and characterized biomedical devices for bone tissue regeneration. These systems were realized homogenously dispersing lamellar Hydrotalcite loaded with Diclofenac Sodium in a polymeric matrix of PCL (Poly-caprolactone). These biomedical devices were obtained through the electrospinning technique that has shown many advantages with respect to others techniques, in particular very interesting micro-fiber loaded with HDik were obtained. Drug delivery results were analyzed considering a mathematical modeling to evaluate the diffusivity coefficients. [ABSTRACT FROM AUTHOR]

Potassium ion (K+) is important in regulating normal cell function in the human body, specifically the heartbeat and the muscle function. Thus, it is important to be able to monitor potassium ion concentrations in human fluids. This paper describes a novel concept for a potassium ion biosensor that accurately, rapidly, and efficiently monitors the presence and records the concentration of potassium ions with high specificity, not only in serum and urine, but also in the sweat or even eye fluid. This specific biosensor design utilizes a nanomanufacturing technique, i.e. electrospinning, to produce advanced nano-bio-composites that specifically trace even minute quantities of potassium ions through the use of selective bio-receptors (ionophores) attached to high surface area nanofibers. Electroactive polymers are then employed as transducers to produce an electronic (rather than ionic) output that changes instantly with the change in K+ concentration. Such biosensors may be manufactured in a skin patch configuration. [ABSTRACT FROM AUTHOR]

Electrospinning is the most common and most widely used method of making nanofiber. The simple process of electrospinning is widely used for nanofibers manufacturing with various polymeric materials. In this research, an electrospinning device has been made using a flyback as a high voltage power supply, and synthesis of nanofiber by using electrospinning from polymer materials: polyvinyl alcohol (PVA) has been carried out. Optimization of nanofibers synthesis was performed by investigating the effect of the input voltage on the morphology of nanofibers. Increasing the input voltage can affect the morphology of the PVA fiber formed. This increase is thought to be caused by the speed of the electric field at the output voltage of the electrospinning which can affect the flow rate of the PVA coating on the substrate. In addition, the applied output voltage electric field can affect the surface morphology of PVA nanofibers due to its relationship with viscosity conditions. [ABSTRACT FROM AUTHOR]

The paper reviews the structure formation of fibrous materials based on poly-3-hydroxybutyrate depending on parameters of electrospinning and characteristics of polymer solution. Fiber structure was studied by DSC, ESR and SEM. The molecular weight affects the diameter and uniformity of the fiber. An electromechanical impact leads to an orientation of crystalline structure in the fiber. The design of an artificial bioresorbable implant based on nano- and microfibers of poly-3-hydroxybutrate is created. Dynamics of growth of mesenchymal stem cells on poly-3-hydroxybutrate scaffolds is studied. Successful field tests of implants of the Achilles tendon in Wistar rats are conducted. [ABSTRACT FROM AUTHOR]

Delamination is a major mode of failure in laminated composites. This paper addresses development of advanced delamination resistant composites using interlaminar SiO2 nanofibers. The SiO2 nanofibers were manufactured using Tetra Ethyl Orthosilicate (TEOS) sol gel. The sol gel viscosity of 100–200 cps Voltage of 18kV and distance between spinneret and grounded collector plate of 80 mm were found to be suitable for maximizing production of electrospun fibers. It was observed that typical electrospun fibers were of 300 nm diameter after they were sintered at 600 degrees C. These SiO2 nanofibers produced using electrospinning were then integrated into fiber glass Epon 862 resin matrix composites. During mechanical characterization of these three phase (fiber glass+Epon 862+SiO2 nanofibers) composites, extensive experimentation was carried out as per the ASTM D 5528 standard to study the influence of electrospun SiO2 nanofibers on the Mode I fracture toughness of fiber glass composites. Other characterization studies were related to determining the effect of SiO2 nanofibers on short beam shear strength, flexure properties, and tensile properties of three phase composites. [ABSTRACT FROM PUBLISHER]

The article presents a study which investigates the potential use of new synthetic biodegradable polyester amide drug-eluting fibrous membranes in skin wound treatment. The study fabricates the polyester amide fibrous membranes through electrospinning method in chloroform. It employs gallium nitrate as the incorporated therapeutic agent within electrospun PEA fibrous membranes.

The electrospinning is a manufacturing technique that allows non-woven to create a variety of polymeric matrices. The chemical structure, mechanics, stability, functionality and other properties can be modified to match applications in coatings for vascular stents used for correction of aneurysms. The SMPU are high-performance elastomers, due to its combination of elasticity, thermal and mechanical properties, so that may be useful for coating vascular stents. In this paper we developed a team of electropinning for coating stents, the team allowed to control the process variables on various polymers. [ABSTRACT FROM PUBLISHER]

There is a growing interest in development of textiles with electrical conductivity due to the variety of applications including electromagnetic interference shielding, electrostatic dissipating, antistatic applications, microwave reduction, gas sensors, biomechanical sensors. Polypyrrole is one of the most promising conductive polymers due to its high electrical conductivity and good chemical stability, however it has some drawbacks such as poor processability. In this paper, production of nanofibers of Polyurethane by using polypyrrole was studied. Films and nanofibers of PU-PPy were successfully prepared for the purpose of combining the properties of polyurethane with polypyrrole. The effects of polypyrrole content on thermal, mechanical, dielectric and morphological properties of the composites were investigated by using Dynamic Mechanical Analyzer (DMA), Dielectric Spectrometer, UV - Vis spectrophotometer and the Scanning Electron Microscope (SEM). [ABSTRACT FROM AUTHOR]

Electrospinning is a unique technique able to prepare the fiers having diameters in the ranges from nano- to a few micrometers. In this paper, PVP/AlCl3 organic-inorganic hybrid fibers were prepared by using sol - gel processing and electrospinning technique using polyvinyl pyrrolidone(PVP), aluminum trichlkride anhydrors (AlCl3), ethanol and distilled water as materials. The hybrid fibers were then calcined in air at 1100 °C for 5 h to obtain alumina (Al2O3) fibers. The fibers were characterized by means of SEM, FT-IR and XRD, respectively, and it was found that the resulted alumina fibers have diameters in the range of 100 to 800 nm, and they are highly crystalline in α phase. [ABSTRACT FROM AUTHOR]

Electrospinning is a straightforward, cheap and unique method to produce novel fibers with diameter in the range of 100 nm and even less. Those nanofibers have a wide variety of applications such as: filters, membranes, composite reinforcement, drug delivery, protective barriers, sensors, wound dressings and tissue-engineered scaffolds where their unique properties contribute to product functionality. However, this process is characterized by a chaotic oscillation of the electrospinning jet which leads to the formation of beads an uneven nanofiber. This research work envisages the development of an apparatus to control the deposition of electrospun nanofibers through the use of a series of charged metal rings and the addition of a secondary power source, which enables a greater control over the polymer jet stream. [ABSTRACT FROM AUTHOR]

Nanofibers produced by electrospinning show an interlaced and highly porous structure with a large surface-to-volume ratio. Such property makes the nanofibers useful in several applications such as healthcare, biotechnology, environmental engineering, defense & security, and energy storage. In this study polycaprolactone nanofibers have been tested as a mock-up separator in a lithium metal battery to evaluate the ion transport properties of ultrafine electrospun materials and assess the potential of this fabrication technology for lithium batteries. The membranes were soaked with an electrolyte solution and characterized by electrochemical impedance spectroscopy, finding that the porous structure of the polycaprolactone nanofiber membrane favors a complete and rapid uptake of the electrolyte. Furthermore, the large surface area of the nanofibrous network enhances ion conductivity, improving the power response of the polymer battery as compared with other polymer batteries. The electrochemical performance of a full battery was obtained on a prototype battery assembled by sandwiching the electrolyte-soaked nanofibrous membrane between a lithium anode and a LiFePO4 based cathode. The results showed that the battery can be discharged at high power with a good capacity retention. Despite intrinsic limitation of the polycaprolactone per se, the good performance of these membranes as separator certainly indicates that electrospinning is a relevant candidate method to develop and produce separators for high power batteries. [ABSTRACT FROM AUTHOR]

One of the most important characteristics investigated during the obtaining of polymer nanofibers is the mean fiber diameter, which depends on the technological parameters of the electrospinning process. Polyvinyl chloride (PVC) nanofibres were obtained on the NANON-01A, Japan. The following technological parameters were used to obtain nanofibers: voltage is in the range 15 to 30 kV, a solution feed rate is in the range of 0.3 to 1.0 mL/h, a distance between the collector and the tip of the syringe is in range 7.5 to 15 cm. During the work, the 15% solution of PVC in the mixture of solvents tetrahydrofuran: dimethylformamide (1:1 by volume) was used. The morphology of the polymer fibers was determined by micrographs obtained using an Olympus STM6 optical microscope. Images were processed in the ImageJ program. The mean diameter of the polymer fibers and their size distribution were determined from the photographs, depending on the feed rate of the solution and the applied voltage and the distance between the needle and the collector. It is shown that the feed rate of PVC solution, the applied voltage, the distance between the needle and the collector affects the mean diameter of electroformed nanofibers. Increasing the applied voltage from 15 kV to 30 kV leads to decrease in the diameter of the nanofibers from 350 nm to 270 nm. An increase in the feed rate of PVC solutions leads to an increase in the diameter of the obtained nanofibers from 320 nm to 450 nm with an increase in the feed rate of the solution from 0.3 to 1 mL/h. No change in the diameter of nanofibers was observed when changes the distance between the collector and the tip of the syringe. [ABSTRACT FROM AUTHOR]

Nylon 6,6 nanofibrous mats containing different amounts of graphene nanoplatelets (GNPs) (500-150,000 ppm) as nano-reinforcement were produced via electrospinning technique and characterized with a particular attention to their mechanical properties. The production method of these materials was improved with the aim to reach a very good dispersion of the nano-reinforcement and the formation of nano-reinforced nanofibers (Nano² materials) with no defects. Among the others, the study demonstrated the importance of the choice of an appropriate solvent system (trifluoroacetic acid/acetone 1:1 v/v) and of a suitable sonication process. The obtained electrospun nanofibrous mats were characterized by Scanning Electron Microscopy (SEM) and by tensile tests with a particular attention to the effect of the amount of nano-reinforcement on their mechanical properties. All nanofibrous mats do not show defects neither macroscopically nor at the nano level, even at high GNPs content. Tensile tests revealed that significant improvements in both modulus and maximum load are achieved when nanofibers contain up to 1,000 ppm of GNPs, without affecting the tenacity of the material. [ABSTRACT FROM AUTHOR]

Electrospinning technique was used for the preparation of "conductive polymer films" from PVA / with (0, 1, 2, 3, 4 and 5) wt. % Cu nanoparticles. "Morphology" test of synthesis films via "SEM", the average diameters of fibers mensuration was (85 nm) for (PVA/5 wt. % Cu NPs film). Increasing (Cu NPs) concentration Leads to promoting the (DC)" electrical conductivity" of nanofibers films from the value(3.7 x 10-7 S.cm-1) for pure (PVA) film to (1.23x10-2 S.cm-1) for 5wt.% Cu NPs, it also leads to promote (AC) "electrical conductivity" from the value (1.17 x 10-6 S. cm-1) for pure PVA film to (3.42 S.cm-1) for 5wt. % (Cu NPs). The "activation energy" and (S) factor decreased with increasing the (Cu NPs) concentration. The mechanical properties of PVA film enhanced with adding of (Cu NPs) by enhanced the modules of elasticity from (12.87MPa) for pure (PVA) to (13.90, 22.38, 35.50, 54.90, 120.6) (MPa) for PVA/(1, 2, 3, 4 and 5) wt. % (Cu) films respectively. [ABSTRACT FROM AUTHOR]

Electrospun scaffolds based on hydrophobic and biodegradable polymers exhibit good mechanical properties but are not suitable for cell attachment. In contrast, scaffolds with natural polymers show inherent tendency for cell attachment, but they are mechanically brittle. Thus core-shell nanostructured scaffolds are expected to be the best candidate. In the present work, attempts have been made to design and fabricate nonwoven mat based on nanofibers with core-shell structure comprising thermoplastic urethane elastomer (TPU) and gelatin as core and shell, respectively. For this purpose, electrospun process was employed with a core-shell type needle, and two polymers were processed in the form of solution in several solvent. We've tried to use many solvents such as: DMF, DMAC, DCM, THF, HFIP and their mixture for TPU and TFA, TFE, AA, FA, DMF, HFIP and their mixture for Gt, but just HFIP as a solvent for two solutions, lead to produce core-shell structure. Effects of solution and processing parameters upon the developed nanofibers and corresponding mat micro morphology were investigated. Scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) evidenced the formation of the gelatin layer on the TPU fibers as the core. The bulk mechanical properties of the obtained mat was evaluated and correlated with the diameter and orientation of the core-shell nanofibers. The surface of the prepared mat exhibited a good hydrophilic behavior with excellent surface softness in the presence of an aqueous media, indicating the potential for the preparation of scaffolds with desired bulk mechanical strength as well as biocompatibility for mussel and tendon regeneration. [ABSTRACT FROM AUTHOR]

In the treatment of many infectious diseases and cancer, transdermal systems based on solid polymer matrices or gels containing functional substances with antiseptic (antibacterial) properties are often used. One of the most promising types of matrices with antiseptic properties are the ones of nano- and microfiber-bonded cloth obtained by electrospinning based on biopolymer poly(3-hydroxybutyrate). The present work investigates the effects of iron (III) complex with tetraphenylporphyrin and the influence on the geometry, crystalline order and molecular dynamics in the intercrystalline (amorphous phase) of ultrathin PHB fibers. [ABSTRACT FROM AUTHOR]

The low production rate of electrospinning process may limit the industrial use of single needle system. Multiple needles can be used to improve the throughput. But the jets bend outward because adjacent electric fields interfere with one another. In this paper, the electric field was analyzed by electromagnetic analysis software. The influence of needle distance on electric field interference and jets. bending was investigated. The results indicate that the incline of electric field direction near the needles is the major factor of jet's incline. [ABSTRACT FROM AUTHOR]

A novel electrospun polymer electrolyte membrane (PEM) based on Sulfonated Poly (ether ether ketone) were prepared and characterized. The poly (ether ether ketone) PEEK was sulfonated using concentrated sulfuric acid at room temperature for 60 hours reaction time. The degree sulfonation (DS) of the SPEEK are 58% was determined by H¹ NMR using area under the peak of the hydrogen shielding at aromatic ring of the SPEEK. Then, the functional group of the SPEEK was determined using Fourier transfer infrared (FTIR) showed O-H vibration at 3433 cm-1 of the sulfonated group (SO2-OH). The effect of the solvent and polymer concentration toward the electrospinning process was investigated which, the DMAc has electrospun ability compared to the DMSO. While, at 20 wt.% of the polymer concentration able to form a fine and uniform nanofiber, this was confirmed by FESEM that shown electrospun fiber mat SPEEK surface at nano scale diameter. [ABSTRACT FROM AUTHOR]

In this work, we fabricated nanorods by applying an electric potential on poly (ethylene oxide) (PEO) and polyaniline (PANI) as a polymeric solution by electrospinning method. Testing was conducted on the samples by field emission scanning Electron microscope (FE-SEM), X-ray diffraction (XRD) and Photoluminescence. And the results showed the emergence of nanorods in the sample within glass substrate. Diameters of nanorods have ranged between(52.78-122.40)nm And a length of between (1.15 - 1.32)µm. The emergence of so the results are for the first time, never before was the fabrication of nanorods for polymers using the same method used in this research. [ABSTRACT FROM AUTHOR]

Parallel oriented polyvinyl alcohol (PVA) nanofibers has been successfully prepared by using modified electrospinning method. This method uses two pairs of copper (Cu) electrodes which are set apart at a certain distance and applied voltage of 15 kV. The concentrations of PVA were varied from 11%, 13%, 15%, 17%, and 19%. The width of gap collector were varied from 5 mm, 10 mm, 15 mm, and 20 mm. The diameter of nanofibers increase as increasing concentration of PVA. As the width of gap collector increase, first diameter of nanofibers decrease and reach a minimum value at 355 ± 7nm in 15 mm of gap, then the diameters increase again. We also calculated the alignment parameter (S) for given aligned nanofiber. The result showed that alignment parameters (S) were on values around 0,9-1. [ABSTRACT FROM AUTHOR]

This research work focuses on process characteristics of polymer solutions, such as viscosity and electrical conductivity, as well as the parameters of electrospinning using poly-3-hydroxybutyrate modified by titanium dioxide nanoparticles, which have been optimized. Both physical-mechanical characteristics and photooxidation stability of materials have been improved. The structure of materials has been examined by means of X-ray diffraction, differential scanning calorimetry (DSC), IR-spectroscopy, and physical-mechanical testing. The fibrous materials obtained can find a wide application in medicine and filtration techniques as scaffolds for cell growth, filters for body fluids and gas-air media, and sorbents. [ABSTRACT FROM AUTHOR]

Nanotechnology is one of the key technologies of the 21st century. The exploitation of ''new'' effects that arise from materials structured on the nano-scale has also been proposed successfully for flame retardancy of polymers since the end of the 90s. Of all of the approaches these include, at this time the use of nanocomposites offers the best potential for industrial application, also some other ideas are sketched, such as using electrospun nanofibers mats or layer-by-layer deposits as protection coatings, as well as sub-micrometer multilayer coatings as effective IR-mirrors. The general phenomena, inducing a flow limit in the pyrolysing melt and changing the fire residue, are identified in nanocomposites. Key experiments are performed such as quasi online investigation of the protection layer formation to understand what is going on in detail. The flame retardancy mechanisms are discussed and their impact on fire behaviour quantified. With the latter, the presentation pushes forward the state of the art. For instance, the heat shielding is experimentally quantified for a layered silicate epoxy resin nanocomposite proving that it is the only import mechanism controlling the reduction in peak heat release rate in the investigated system for different irradiations. The flame retardancy performance is assessed comprehensively illuminating not only the strengths but also the weak points of the concepts. Guidelines for materials development are deduced and discussed. Apart from inorganic fillers (layered silicate, boehmite, etc.) not only carbon nanoobjects such as multiwall carbon nanotubes, multilayer graphene and graphene are investigated, but also nanoparticles that are more reactive and harbor the potential for more beneficial interactions with the polymer matrix. [ABSTRACT FROM AUTHOR]

Nanofibers of vanadium pentoxide (V2O5) were synthesized by electrospinning a polymeric solution containing vanadium ion and with subsequent sintering. Conventionally, electrospun TNFs were produced by using a co-axial spinneret; however, TNFs in the present study were obtained by manipulating the concentration ratio of the precursor solution, distance, humidity and flow rate during electrospinning using a single spinneret and sintering with time and temperature change. On the basis of this hypothesis, nanofibers could be altered from elongated 1-D nanofibers to nanowires, nanotubes, spheres and flakes respectively. The surface morphology, structure, roughness and the crystal structure were analyzed using Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), and X-ray diffraction (XRD). The current work has demonstrated a case study for energy storage where V2O5 nanotubes when tested shows the capacitance of 190 Fg-1 in 2M KCl electrolyte indicating an example for the energy storage which may be applicable for other electrochemical devices such as Li-ion batteries, fuel cells, hydrogen storage etc. [ABSTRACT FROM AUTHOR]