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Damper is frequently used to suppress panel vibration and related vehicle interior noise. Unlike an unconstrained damper, a method to find material properties of a constrained damper is more complicated. This study presents a verified method for obtaining material properties of a constrained asymmetrical damper. The most important material parameters of this constrained damper are shear modulus, shear factor, and of course damping loss factor. The paper provides newly corrected equations to give proper numerical values of these parameters. The difference of natural frequencies between the test and the simulation using the estimated values is about 2 %, which shows that the estimation method is correctly presented. Important characteristics such as shear motion and wavelength of a composite beam constrained by a damper are also investigated. Finally, vibration response of a vehicle roof with a constrained damper is measured and is compared to the simulation. It is noticed that the correlation is much improved, comparing with the simulation based on old material properties.

As part of efforts to fabricate FeMnAlC lightweight steels suitable for high-temperature applications, the influence of Nb addition on the microstructure and tensile deformation behaviors has been investigated. Electron backscattered diffraction analysis showed that Fe–20Mn–8Al–1.0C base steel consisted of a full austenite matrix after solution treatment, and the addition of 0.1 wt pct Nb resulted in grain refinement from 56 to 23 μm without significant changes in the microstructure. After aging treatment at 550 °C for 1 hour, significant hardening occurred (base steel: 257 → 392 HV, Nb-added steel: 273 → 359 HV) by the precipitation of nanosized κ-carbides with sizes of 2 to 6 nm. A higher strain-hardening rate at 400 °C by Nb addition was clearly brought about by the mutual interaction of dislocations with κ-carbides (through both shearing and Orowan bypassing mechanisms). The nanoindentation results and the calculation of the strength increment indicated that Nb addition led to a smaller hardening by κ-carbide precipitation. In terms of the microstructural evolution by thermal exposure time (100 to 5000 hours at 400 °C), it was first found that the intensive slip band impingement at grain boundaries occurred in these lightweight steels, but Nb addition effectively inhibited the significant reduction in ductility by suppressing the formation of slip bands. The effect of Nb addition is discussed in terms of the collaborative effects of grain refinement, κ-carbide precipitation, and microstructural stability.

There is a great demand for a dispersion evaluation method that can be applied even when a nano-sized filler is incorporated, that can evaluate a three-dimensional (3D) quantitative dispersion of a composite material, and that is not expensive and time consuming. Here, we proposed light-intensity dispersion index (LDI) to quantitatively evaluate the dispersion based on the light scattering distribution on divided optical microscopy (OM) images. Difference in the light-intensity is determined by the dispersion and agglomeration of the filler in the polymer matrix; therefore, the smaller the distribution and the number of peaks of light-intensity, the more uniform the dispersion. The reliability of the developed LDI was improved by introducing an agglomeration size weighting factor. Furthermore, the validity of the LDI was also verified in comparison with the experimental results. In conclusion, we have successfully developed a method for the 3D quantitative dispersion evaluation of nanocomposites with minimal cost and time consumption.

There is a growing demand for the development of a melt process-based nanocomposite manufacturing process capable of minimizing the incorporation of expensive carbon nanotubes (CNTs) by inducing a uniform dispersion of multi-walled CNTs (MWNTs). In this study, we proposed a nanocomposite manufacturing process that includes both physical particle mixing using high-speed rotation and anionic polymerization of e-caprolactam (CL) to induce a uniform dispersion of MWNTs. MWNTs were uniformly dispersed by powder mixing and then wrapped with polyamide 6 polymers by in-situ polymerization of CL. The synergistic effect of the two sub-processes resulted in an enhanced dispersion of MWNTs and prevented aggregation of the MWNTs. The composites fabricated by the proposed process exhibited electrical conductivities of 4.49 × 10−5 S/m and 1.45 × 10 S/m at 1 wt% and 3 wt% MWNTs, respectively, indicating that by applying the proposed process it is possible to incorporate a smaller amount of MWNT to achieve electrical conductivities applicable for electrostatic discharge (ESD) (>1 X 10−5 S/m) and electromagnetic interference shielding effectiveness (EMI SE) (>10 S/m) applications. An ESD chip tray and EMI SE mobile phone case were fabricated using the prepared composite, and it was verified that the ESD and EMI SE performances can be realized.

Techniques for optimizing the dispersion of carbon nanotubes in composites by applying small amounts of additives in a simple manner are recognized as one of the most important core technologies in nanocomposite engineering. In this study, we reported the feasibility of phenyl glycidyl ether (PGE) as an effective noncovalent functionalization agent and suggested a facile and low-temperature process that applied high-speed rotation based on a planetary centrifugal mixer to improve the dispersion of multiwalled carbon nanotube (MWCNT) in the polyamide 6 (PA6) composite. PGE molecules were introduced on MWCNTs based on the π-π* interaction, resulting in enhanced MWCNT dispersion by preventing of the aggregation between the MWCNTs due to the van der Waals force. The tensile strength of the PA6 composite fiber filled with 1 wt% MWCNTs was improved up to 31.8% by the PGE treatment, indicating that PGE molecules were an effective noncovalent functionalization agent.

Synthetic natural gas (SNG) from syngas is considered a promising substitute for fossil fuels because of its environmental advantages; however, its heating value is below the standard heating value (especially in South Korea and Japan). In this study, bimetallic Co-Fe catalysts were developed for the production of C2-C4 hydrocarbons for usage as mixing gases to improve the heating value of SNG. The effect of the process conditions on the catalytic behavior was investigated. Catalyst 5Co-15Fe/γ-Al2O3 showed the best results with 91.2% CO conversion, 28.2% C2-C4 selectivity, and 0.98 paraffin ratio at H2/CO = 3.0 and 300 °C.

Bilayered cell sheets were fabricated with coaxial hydro-nanofibrils for three-dimensional (3D) cultivation in a biomimetic environment. Polycaprolactone (PCL) was electrospun and hydrolyzed to release fragmented nanofibrils (NF) in an alkaline condition. Methacrylated gelatin (GelMA) was adsorbed and phototethered on the surface of the fibrils to prepare coaxial NF composed of hydrophilic shells and hydrophobic cores. GelMA layers on the NF were characterized by X-ray photoemission spectroscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. The GelMA showed higher decoration level on NF compared to that on native gelatin. GelMA-decorated NF significantly enhanced cell proliferation rate and phenotypic expression of human dermal fibroblasts when spontaneous formation of cell sheets was observed for 7 days. HaCaT cells were layered on top of the fibroblast sheets and further cultivated in air-water interfaces to prepare bilayered skin sheets. After 21 days of incubation, the top layers of the bilayered sheets showed higher expression of pan-keratin, and the dermal cells showed higher proliferation in the GelMA-decorated NF.

Sulfide-based lithium superionic conducting solid electrolytes for all-solid-state lithium batteries have received much attention due to their high safety, ionic conductivity, and compatibility. However, high-temperature treatment over a long time is needed to achieve high ionic conductivity. In this work, we have prepared the dual-halide-based Li7P2S8X type lithium superionic conductors by dry ball mill process and the high ionic conducting phase was achieved by low temperature (200℃) heat-treatment process. High ionic conducting halogen-halogen composition was arrived at through a series of optimization processes. Among the compositions tested, the Li7P2S8Br0.25I0.75 solid electrolyte exhibited a high ionic conductivity value of 6.16 mS cm−1, at room temperature. The ionic radius of the halogen element played an important role in the formation of the high ionic conducting phase. Further, the ionic conductivity of Li7P2S8I0.75Br0.25 solid electrolyte was improved by metal doping at P-site. The Sn-doped Li7P2S8I0.75Br0.25 solid electrolyte exhibited a high ionic conductivity value of 7.78 mS cm−1, at room temperature. The addition of large-sized Sn atoms extended the crystal lattice parameters and increased the Li-ions transport path. The partial substitution of Sn atoms at P-site was confirmed by NMR and Laser Raman analysis. The electrochemical stability of the prepared solid electrolyte was studied by cyclic voltammetry and DC charge-discharge analysis. The addition of a metal atom to the Li7P2S8Br0.25I0.75 solid electrolyte decreased the side reaction with the Li metals. Thus, low-temperature treated metal-doped Li7P2S8Br0.25I0.75 solid electrolytes are highly favourable for the fabrication of high-performance all-solid-state batteries. The fabricated all-solid-state battery using Sn doped Li7P2S8Br0.25I0.75 solid electrolyte exhibited the high specific capacity value of 170 mAh g−1 (0.1C), at room temperature.

To induce uniform dispersion and excellent interfacial properties, we adopted a strategy of combining both polyamide 6 (PA6) grafting for multi-walled carbon nanotubes (MWCNTs) and reactive extrusion of PA6 matrix, based on anionic ring-opening polymerization of &epsilon, caprolactam (CL). Compared to &ndash, COOH and &ndash, NCO treatments of MWCNTs, enhanced MWCNT dispersion and tensile properties of the composites were achieved using the applied strategy, and the tensile strength and modulus of the PA6-grafted MWCNT-filled PA6 composites were 5.3% and 20.5% higher than those of the purified MWCNT-filled PA6 composites, respectively. In addition, they were almost similar to the theoretical ones calculated by the modified Mori&ndash, Tanaka method (MTM) assuming a perfect interface, indicating that the tensile properties of MWCNT-filled PA6 composites can be optimized by PA6 grafting and reactive extrusion based on the anionic ring-opening polymerization of CL due to uniform MWCNT dispersion and excellent interfacial property.

Numerous studies have been reported on thermal interface materials based on synergistic hybrid effects, however, most of them contain only fragmentary experimental results and the related model has been rarely proposed to explain the effects exactly. Herein, the thermal conductivities of the composites were systematically evaluated according to various filler contents and ratios. It was found that the fraction of the secondary filler inducing the maximum synergistic effect decreased as the total filler content increased. In addition, when the fraction was higher than the optimum fraction, the anti-synergistic effect occurred. At the optimum fraction, effective phonon transfer was induced due to the improved filler network formation of graphene nanoplatelet (GNP)-carbon nanotube (CNT), thereby achieving high thermal conductivity of 7.69 W/m·K at fGNP = 27.69 vol% and fCNT = 0.57 vol%. Moreover, the Kim-Jang-Lee (KJL) model for the synergistic effect was proposed by introducing filler-ratio variables into the critical percolation equation reported previously, and the KJL model for the anti-synergistic effect was proposed based on the rule of mixture of composites filled with the optimal connected filler network and filled with the excessive secondary filler.

The nanoscopic characteristics of the multi-walled carbon nanotubes (MWCNTs) used in composites are crucial for attempting to understand and design nanocomposites of a novel class. We investigate the correlations between the nanofiller properties and effective electrical properties of MWCNT-embedded polycarbonate composites by theoretical and experimental approaches. A probabilistic computational model is proposed to predict the influence of MWCNT morphology on the electrical behaviors of MWCNTs-embedded polymer composites. A parameter optimization method in accordance with a genetic algorithm is then applied to the model, resulting that the ideal sets of model constant for the simulation are computationally estimated. For the experimental validation purpose, a comparison between the present theoretical and experimental results is made to assess the capability of the proposed methods. In overall, good agreement between the predictions and experimental results can be observed and the electrical performance of the composites can be improved as the MWCNT length increases.

Polypropylene-grafted-maleic anhydride (PP-g-MAH) is known as an excellent interface modifier that can improve the interface between carbon fiber (CF) and PP. In this study, the effect of PP-g-MAH content on the physical properties of PP composites containing long-fiber CFs was investigated. It was confirmed that PP-g-MAH acted as an interface modifier between the interface between CF and PP, and when an appropriate amount of 10 wt% was incorporated, the tensile strength, tensile modulus, Izod impact strength, and heat deflection temperature were improved by 110%, 50%, 86.7% and 12.7%, respectively. On the other hand, the blending effect of PP-g-MAH, which is a low molecular weight, was greater than the compatibilizing effect when the PP-g-MAH content was mixed above the appropriate content, thereby reducing the physical properties. Therefore, the content of PP-g-MAH as the interface modifier must be designed to be the optimum content considering the CF content to be mixed in order to optimize the physical properties of the composite material.

With the recent demand for miniaturization and integration of electronic devices, there has been a growing interest in device malfunction due to high temperature. In this study, a experimental and theoretical study on the composites with improved thermal conductivity by dispersing multi-walled carbon nanotubes (MWCNTs) in the thermoplastic resin was carried out. A micromechanical model was derived based on the ensemble volume-averaging method and the modified Eshelby’s tensor reflecting the interface properties. The effects of the waviness, interface, and orientation of fillers on the thermal conductivity of composites were numerically analyzed. A computational intelligence-based particle swarm optimization (PSO) algorithm was adopted to the proposed model for optimizing the model constants. The thermal conductivity of the polymerized cyclic butylene terephthalate (pCBT)/MWCNT composites was experimentally measured according to the content of MWCNT. Finally, the experimentally measured data were utilized in the PSO to improve the predictive capability of the proposed model.

In order to develop a nanocomposite film based on multi-walled carbon nanotubes (MWCNTs) as an electromagnetic wave shielding material, we propose a solvent-free melting process for fabricating highly dispersed MWCNT-filled polymer composite films with high electrical conductivity and electromagnetic interference (EMI)-shielding properties. By observing aggregates (particles larger than 0.7 μm) using X-ray micro-computed tomography (micro-CT), the uniform dispersion of the MWCNT fillers in the composite films was confirmed. Furthermore, the electrical conductivity and EMI shielding effectiveness (SE) values calculated using percolation and Simon's equations, respectively, were confirmed to agree with experimental data, indicating excellent MWCNT dispersion. The fabricated composites exhibited excellent electrical conductivity, EMI SE, and EMI specific SE (SSE) values of 4.33 S/cm, 30 dB, and of 24.8 dBcm3g−1, respectively, and the EMI SSE value was as good as metal levels. The proposed solvent-free process can be contributed to the commercialization of EMI SE composite films based on MWCNTs.

There is growing interest in carbon fibre fabric reinforced polymer (CFRP) composites based on a thermoplastic matrix, which is easy to rapidly produce, repair or recycle. To expand the applications of thermoplastic CFRP composites, we propose a process for fabricating conductive CFRP composites with improved electrical and thermal conductivities using an in-situ polymerizable and thermoplastic cyclic butylene terephthalate oligomer matrix, which can induce good impregnation of carbon fibres and a high dispersion of nanocarbon fillers. Under optimal processing conditions, the surface resistivity below the order of 10+10 Ω/sq, which can enable electrostatic powder painting application for automotive outer panels, can be induced with a low nanofiller content of 1 wt%. Furthermore, CFRP composites containing 20 wt% graphene nanoplatelets (GNPs) were found to exhibit an excellent thermal conductivity of 13.7 W/m·K. Incorporating multi-walled carbon nanotubes into CFRP composites is more advantageous for improving electrical conductivity, whereas incorporating GNPs is more beneficial for enhancing thermal conductivity. It is possible to fabricate the developed thermoplastic CFRP composites within 2 min. The proposed composites have sufficient potential for use in automotive outer panels, engine blocks and other mechanical components that require conductive characteristics.

The anisotropic development of thermal conductivity in polymer composites was evaluated by measuring the isotropic, in-plane and through-plane thermal conductivities of composites containing length-adjusted short and long multi-walled CNTs (MWCNTs). The thermal conductivities of the composites were relatively low irrespective of the MWCNT length due to their high contact resistance and high interfacial resistance to polymer resins, considering the high thermal conductivity of MWCNTs. The isotropic and in-plane thermal conductivities of long-MWCNT-based composites were higher than those of short-MWCNT-based ones and the trend can accurately be calculated using the modified Mori-Tanaka theory. The in-plane thermal conductivity of composites with 2 wt% long MWCNTs was increased to 1.27 W/m·K. The length of MWCNTs in polymer composites is an important physical factor in determining the anisotropic thermal conductivity and must be considered for theoretical simulations. The thermal conductivity of MWCNT polymer composites can be effectively controlled in the processing direction by adjusting the length of the MWCNT filler.

Fe-36Ni alloy nanopowder was prepared via electrical explosion of wire in DI water. The nanopowder was reduced in hydrogen at 500 degrees C for 30 min. Spark plasma sintering at 800 and 1000 degrees C for 10 min was used to obtain bulk samples from the hydrogen-reduced nanopowder. The sintered samples were annealed at 500 degrees C for 2 h. X-ray diffraction was used to analyze the phases of the nanopowder and sintered samples. The results showed that the sintered samples were formed in gamma-(Fe-Ni) solid solution. The particles sizes and morphologies of the as-synthesized and hydrogen-reduced nanoparticles were observed via transmission electron microscopy. The morphologies of the as-synthesized nanoparticles had spherical core-shell structures. Core was gamma-(Fe-Ni) and the shell was FeO. The nanoparticles of the as-synthesized and hydrogen reduced samples were found to be nearly spherical in shape, with average diameters of 32 and 70 nm, respectively. The hysteresis loops of the as-synthesized nanopowder, hydrogen reduced nanopowder, and sintered samples revealed ferromagnetic characteristics.

Gold colloids were prepared by electrical explosion of wire in various media: cold water (0 degrees C), room temperature water (25 degrees C), hot water (80 degrees C), 0.01 M polysorbate surfactant 20 (TW 20) solution, mixture of 0.01 M TW 20 and 0.01 M ascorbic acid. The size distribution of nanoparticles measured by transmission electron microscope was found to shift to a smaller size with a decrease of temperature and a presence of TW 20 surfactant. The multiple light scattering results showed that medium temperature and ambient medium of explosion process is much influence on the stability of colloid. The gold colloid prepared in cold water is unstable in comparison with one prepared in warm and hot water. The best stability of gold colloid obtained with explosion medium of TW 20 and ascorbic acid solution.

We prepared electrospun polymer nanofibers by the electrospinning method and investigated about their applications to dye-sensitized solar cells (DSSCs). Electrospun poly(vinylidenefluoride–co-hexafluoropropylene) (PVDF–HFP) and PVDF–HFP/polystyrene (PS) blend nanofibers were prepared and examined the uptake, the ionic conductivity, and the porosity by impedance measurement and Scanning Electron Microscope (SEM). The best results of Voc, Jsc, FF, and efficiency of the DSSC devices using the electrospun PVDF–HFP/PS(3:1) blend nanofibers were 0.76 V, 11.8 mA/cm2, 0.66, and 5.75% under AM 1.5.

This study was carried out to optimize dyeing conditions of unripe Citrus Unshiu extract on silk fabric and to evaluate antimicrobial activity of the dyed fabric for its potential use as a functional natural dye. Unripe fruits of Citrus Unshiu in Jeju Island, Korea, extracted in 80 % Ethanol solution to final solid dye powder were dyed on silk fabric under a variety of conditions such as dye bath concentrations, temperature, and dyeing duration together with mordanting. Dyeing fastness properties to washing, rubbing, perspiration, and light were tested and the antimicrobial activities of the dyed fabric against Staphylococcus aureus and Klebsiella pneumoniae were investigated quantitatively. As results, the fabric showed the maximum dye uptake (K/S) under the conditions of 80 °C for temperature, 30 min for duration, and 600 % (o.w.f.) for dye concentration. Both pre- and post-mordanting seemed not to be effective on increasing K/S values of the dyed silk fabrics under the optimum dyeing conditions. Fastness ratings to washing, rubbing, and perspiration were all very good (4–5 grades) for both 300 and 600 % dyed silk fabrics. Excellent antimicrobial activities over 99 % reduction rate against two both bacteria were exhibited for all of dyed fabrics undergone more than 300 % of dye concentration. From these results, it was concluded that the dye concentration of 300 % of unripe Citrus Unshiu could be employed to produce antimicrobial silk fabric. Furthermore, to get more saturated shades on the fabric by the citrus, higher dye concentration such as 600 % was available as well.

We prepared poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanofibers by the electrospinning method and applied to the polymer matrix in polymer electrolytes for dye-sensitized solar cells (DSSCs). The uptake, ionic conductivity, and porosity of the electrospun PVDF-HFP nanofiber films showed 653±50%, 4.53±1.3×10−3 S/cm, and 70±2.3%, respectively, regardless of the diameter and morphology of nanofibers. In addition, several DSSC devices using the electrospun PVDF-HFP nanofiber films as the polymer matrix were prepared to investigate the photovoltaic effect of iodine (I2) concentrations on DSSC devices. With an increase of I2 concentration in electrolyte solutions, the ionic conductivity increased, while the photocurrent density of DSSC devices decreased.

Dye-sensitized solar cells (DSSCs) were prepared with a poly(ethylene glycol) (PEG) electrolyte using various metallophthalocyanines (MPcs) as an additive. The DSSC device using MPcs has higher power conversion efficiency than that without MPcs, due to decrease of electron transfer distance by the interface adsorption between TiO2 film and PEG electrolyte. The best result on power conversion efficiency was 4.18% in DSSC device using InOHPc. The open-circuit voltage (Voc) was 0.70 V, the short-circuit current density (Jsc) was 10.20 mA/cm2, and the Fill Factor (FF) was 0.58. The addition of MPcs as an additive is useful to improve the performances of DSSC devices such as Voc, Jsc, and power conversion efficiency.

Multi-layered TiO2 nanostructured films were fabricated to improve the light harvest efficiency of the dye-adsorbed TiO2 electrode in dye-sensitized solar cells (DSSCs) by light scattering. Three different structures of TiO2 electrodes, with layers consisting of TiO2 pastes with average diameters of 9, 20, and 300 nm, respectively, were fabricated and their photovoltaic effects on the DSSC devices were investigated. By utilizing the multi-layered TiO2 electrode constructed using the three different TiO2 pastes, the overall power conversion efficiency of the DSSC devices in the PEG-based electrolyte was increased to 5.24% under irradiation of 100 mW/cm2 at AM 1.5.

The dye-sensitized solar cell devices using PEDOT:PSS films as counter electrodes have the lower production cost and more simple fabrication process than devices using Pt counter electrode. To enhance the power conversion efficiency of devices, we fabricated DSSC devices using thermal treated poly(3,4-ethylenedioxythiophene)/poly(styrenesulfonate) (PEDOT:PSS) as counter electrodes. The power conversion efficiency of DSSC device using a counter electrode based PEDOT:PSS film treated at 45°C for 720 min achieved a value of 3.22%.

Thin films of having structure were fabricated using self-seed layer method by R.F. Magnetron sputter. Self-seed layers were deposited at room temperature and , which had 30 nm thickness. To investigate crystallization of self-seed layer we characterized by XRD after various heat treatment. And we characterized the crystallinity and electrical properties of SBT on self-seed layer after various heat treatment.

Symmetrically and unsymmerically substituted bis-dithiobenzil nickel complexes containing four substituted and unsubstituted methoxy groups were synthesized from a benzoin compound using phosphorous pentasulfide under the conventional thermal and microwave processing. The efficiency of microwave synthesis over the conventional thermal synthesis was illustrated by the yield of bisdithiobenzil nickel complex dyes. The samples were characterized by the means of elemental analyzer, 1HNMR, IR spectroscopy, Uv-vis spectroscopy and DSC.

Dye-sensitized solar cells (DSSCs) using organic liquid electrolytes have received significant attention because of their low production cost, simple structure and high power conversion efficiency [1-5]. Recently, the power conversion efficiencies of DSSCs using Ruthenium complex dyes, liquid electrolytes, and Pt counter electrode have reached 10.4 % (100 mW/cm2, AM 1.5) by Gratzel group [6]. However, the important drawback of DSSCs using liquid electrolyte is the less long-term stability due to the volatility of the electrolyte contained organic solvent. In the viewpoint for commercialize, durability is a crucial component. Then, gel electrolytes are being investigated to substitute the liquid electrolytes [7-10]. One way to make a gel electrolyte is to add organic or inorganic (or both) materials. In the past decades, many studies have been carried out on this kind of gel electrolyte, and great progress has been achieved [11-12]. The advantages of them include; limited internal shorting, leakage of electrolytes and non-combustible reaction products at the electrode surface existing in the gel polymer electrolytes [13-14]. However, because of their complicated preparing technology and poor mechanical strength, they cannot be used in commercial production [15-16]. To overcome this problem, the polymer membrane is soaked in an electrolyte solution that has been examined [17-19]. To prepare the polymer membrane for polymer electrolyte, a number of processing techniques such as drawing [20], template synthesis [21-22], phase separation [23], electrospinning [24], etc. have been used. Among of these, the electrospinning technology is a simple and low-cost method for making ultra-thin diameter fibers. This technique, invented in 1934, makes use of an electrical field that is applied across a polymer solution and a collector, to force a polymer solution jet out from a small hole [25]. When the diameters of polymer fiber materials are shrunk of micrometers to submicrons or nanometers, several amazing characteristics appear such as a very large surface area to volume ratio, flexibility in surface functionalities, and superior mechanical performance compared to any other known forms of this material [26]. In recent years, the electrospinning method has gained greater attention. A vastly greater number of synthetic and natural polymer solutions were prepared with electrospun fibers, such as poly(ethylene oxide) (PEO) in distilled water [27], polyurethane in N,N-dimethylformamide (DMF) [28], poly(e-caprolactone) (PCL) in acetone [29], PVDF in acetone/ N,N-dimethylacetamide (DMAc) (7:3 by weight) [30], and regenerated cellulose in 2:1(w/w) acetone/DMAc [31].

The dye-sensitized solar cell (DSSC) devices using polymer electrolytes based on electrospun poly(vinylidene fluoride-hexafluoro propylene) (PVDF-HFP) nanofibers were fabricated and investigated the photovoltaic performances. The electrospun PVDF-HFP nanofibers were prepared by various parameters such as; polymer concentrations, applied voltages, and tip to collector distances (TCD) by the electrospinning method. The open circuit voltage (VOC), short circuit current (JSC), fill factor (FF), and overall power conversion efficiency (η) of DSSC devices using electrospun PVDF-HFP nanofibers were 0.7180–0.7420 V, 9.7200–10.8837 mA/cm2, 0.5610–0.6250, and 4.1700–5.0186%, respectively. When 15 wt% of polymer concentration, 14 kV of applied voltage, and 14 cm of TCD is applied to fabricate the PVDF-HFP nanofiber, the electrospun PVDF-HFP nanofiber should be the regular diameter of a nanofiber, the power conversion efficiency of the DSSC device reached 5.0186% as the best result.

In this study, we fabricated the electrospun poly(vinylidene fluoride-hexafluoro propylene) (PVDF-HFP) /LiClO 4 nanofibers by electrospinning method and applied as polymer membrane on the Dye-Sensitized Solar Cells. We have prepared the DSSC devices, using Ruthenium dye as a photosensitizer, sandwiched with TiO 2 -deposited and Pt-coated electrode as two electrodes. To compare with the effect of LiClO 4 in PVDF-HFP nanofibers on photovoltaic performance, we prepared electrospun PVDF-HFP nanofibers without LiClO 4 . Photovoltaic characteristics were measured by using Solar Simulator with a black mask under AM 1.5. The V oc of the DSSC device was 0.773 V, the J sc was 9.77 mA/cm2, and the overall power conversion efficiency achieved up to 4.19 %. The photovoltaic performances of the DSSC device using electrospun PVDF-HFP nanofibers without LiClO 4 were lower than that of device using electrospun PVDF-HFP/LiClO 4 nanofibers. To investigate the photovoltaic effect of different LiClO 4 concentrations in electrolyte solutions, the electrospun PVDF-HFP nanofibers without LiClO 4 were soaked into the electrolyte solution with different LiClO 4 concentrations. An increase of concentration of LiClO 4 in electrolyte solution results in a decrease of photocurrent and efficiency due to the desorption of dyes by LiClO 4 .