Polyvinylpyrrolidone Binder Research Articles

Ultrathin PVP/ZnMoO4@PE separator for high-safety sodium-ion batteries

In this work, an ultrathin (∼19 μm) PVP/ZnMoO4@PE separator is designed and achieved with much enhanced thermal performance for high-safety sodium-ion batteries (SIBs). The PVP/ZnMoO4@PE separator is prepared by coating the polyvinyl pyrrolidone (PVP)/ZnMoO4 ceramic slurry on one side of commercial polyethylene (PE) separator in an economically efficient way. It is found that the superior PVP binder would interact with ZnMoO4 nanoparticles and enhance the bonding strength of heat-resistant ZnMoO4 ceramic nanoparticles on the surface of PE substrate, which significantly improves the thermal performance of the optimized separator. The optimized PVP/ZnMoO4@PE separator shows high thermal stability with no shrinkage at 180 °C for 30 min. In addition, the PVP/ZnMoO4@PE separator shows improved wettability with electrolyte, larger porosity and better electrolyte storage capacity than bare PE separator, which are quite beneficial to ionic conductivity. Furthermore, the electrochemical results show that half-cell (hard carbon/sodium) assembled with the optimized PVP/ZnMoO4@PE separator shows better electrochemical performance that the half-cell assembled with commercial glass fiber separator (thickness of ∼ 455 μm), while bare PE separator does not work properly in SIBs. This study provides insight into the practical application of ultrathin and high-safety PVP/ZnMoO4@PE separator in commercial SIBs.

A novel Al2O3/polyvinyl pyrrolidone-coated polyethylene separator for high-safety lithium-ion batteries

In this study, a novel ceramic-polyethylene (PE) composite separator is designed and achieved by a very facile preparation strategy for high-safety lithium-ion batteries (LIBs). The optimized ceramic slurry composed of Al2O3 and polyvinyl pyrrolidone (PVP) is coated on one side of PE separator in an economically efficient way to form the novel Al2O3/PVP-PE separator. It is found that the superior PVP binder can improve the adherence of heat-resistant Al2O3 ceramic powders on the PE substrate, which significantly enhances the thermal stability of the optimized separator. The Al2O3/PVP-PE separator shows negligible shrinkage at a high temperature of 180 °C after 30 min thermal treatment. In addition, the prepared Al2O3/PVP-PE separator shows excellent wettability with electrolyte, large porosity and high liquid storage capacity, which are quite beneficial to the ionic conductivity and charge storage kinetics. Furthermore, LIBs (LiFePO4/graphite) assembled with the optimized Al2O3/PVP-PE separator shows superior electrochemical performance than LIBs assembled with bare PE separator. This study provides insight into the practical application and commercialization of novel Al2O3/PVP-PE separator for high-safety LIBs with improved electrochemical performance.

Formulasi Sediaan Tablet Ekstrak Daun Talas (Colocasia esculenta (L.) Schott.) Dengan Variasi Kadar Polivinil Pirolidon (PVP) Sebagai Bahan Pengikat

Taro leaves (Colocasia Esculenta (L.) Schott.) contain alkaloids, saponins, tannins, flavonoids and polyphenols. Utilization of taro leaves requires new innovations by developing ways of making tablets, which increase the convenience of use through more comfortable use and more stable storage compared to liquid pharmaceutical preparations or suspensions. The aim of this study was to determine the effect of the comparison of variations of Polyvinylpyrrolidone (PVP) binder on the physical properties of granules and tablets and to obtain the optimum formula. Tablets were made by wet granulation process with 1%, 3% and 5% PVP. Granules were tested for water content, flow time test, angle of repose and tapping. The resulting tablets were then tested for their physical properties. Research result; Weight uniformity with 5% PVP fulfills the physical requirement of 600 g. Size uniformity fulfills the physical requirements with a yield of 2.91 mm. Hardness with 3% PVP meets the physical requirements of 5.95 kg. Fragility meets the physical requirements of 1% PVP, namely 0.4%. The disintegration time with 1% PVP met the physical requirements, namely 7.88 minutes. The results stated that variations in the concentration of the PVP binder could be formulated into tablets and the tablet binder resistance was measured which met the requirements of the best tablet physical properties. Optimal formulation is achieved in formula III with binder containing 5% PVP.

Triethylammonium thiocyanate ionic liquid electrolyte-based supercapacitor fabricated using coconut shell-derived electronically conducting activated charcoal electrode material

Organic solvents are commonly used as commercial electrolytes in supercapacitors, but they have several drawbacks, such as high volatility, toxicity, and environmental issues. To overcome these problems, ionic liquids are used though their high costs hamper commercial applications. In this study, a novel and low-cost ionic liquid based on triethylammonium cation and thiocyanate anion were synthesized and used as the electrolyte in a low-cost supercapacitor fabricated using electronically conducting activated carbon derived from cleaned coconut shells as electrode material. The temperature dependence of electrolyte conductivity was investigated, in the frequency range of 1 Hz-500 kHz, using AC impedance analysis, in the temperature range from 30 °C - 90 °C in ten-degree increments and found to be in the range of 4.5 to 14.4 mS cm−1. The ion transport kinetics behaves according to the Vogel-Tammann-Fulcher (VTF) model with an activation energy (Ea) and the pre-exponential factor (AσT) of 0.0158 eV and 114.9 S m−1 K1/2, respectively. The activated carbon material developed has a high porosity and high electronic conductivity. The electrode fabrication methodology was optimized by varying the polyvinylpyrrolidone (PVP) binder amount with respect to the mass of activated carbon on a titanium sheet as a function of heat treatment temperature. The supercapacitor that gives the highest specific capacitance is based on the electrode constructed using 5 % w/w PVP in 0.50 g of activated carbon deposited on a titanium sheet by heat treating at 200 °C for 20 min. At the scan rate of 5 mV s−1, two-electrode CV studies revealed a specific capacitance of 36.8 F g−1 for the optimized supercapacitor assembly. The electrolyte triethylammonium thiocyanate (TAT) demonstrated good electrochemical stability and a large operating voltage window of 1.8 V and high stability, with 94.4 % capacity retention after 1000 cycles. The AC impedance studies also gave comparable results. Prime novelty statementThe manuscript describes a method to prepare a novel and low-cost ionic liquid material triethylammoniumthiocyanate starting from triethylamine and ammonium thiocyanate, and its application as the ionic liquid electrolyte in a low-cost supercapacitor. The electrode material used in the supercapacitor was fabricated using electronically conducting activated carbon derived from cleaned coconut shells, which were deposited firmly adhering to titanium sheets using polyvinylpyrrolidone binder under optimized heat treatment conditions. As such, both the ionic liquid electrolyte and the activated carbon electrode material are novel and attractive materials for the commercial production of low-cost supercapacitors.

A Simple Method for Fabricating Ink Chamber of Inkjet Printheads.

The process of fabricating chambers is becoming more important for inkjet printheads. However, there are some problems with the majority of present fabrication methods, such as nozzle structural deformation, blocked chambers, and collapsed chambers. In this paper, we propose a new process for preparing printhead chips by bonding tantalum nitride thin-film heaters and SU-8 chamber film using UV curing optical adhesive. This process simplifies the preparation process of printhead chips and overcomes the limitations of the traditional adhesive bonding process. Firstly, a chamber film was prepared by the molding lithography process based on a PDMS mold. The chamber film was then bonded with the membrane heater by the adhesive bonding process based on film transfer to form a thermal bubble printhead chip. Finally, the chip was integrated with other components to form a thermal inkjet printhead. The results show that the overflow width of bonding interface of 3.10 μm and bonding strength of 3.3 MPa were achieved. In addition, the printhead could stably eject polyvinyl pyrrolidone binder droplets, which are expected to be used for binder-jetting printing of powder such as ceramics, metals, and sand molds. These results might provide new clues to better understand the adhesive bonding process based on film transfer and the new applications of inkjet printheads.

The critical role of polymeric binders on AgO cathodes in high rate batteries

Electrochemical performance of AgO cathodes containing six different binders at high rate discharge are investigated in detail. Polytetrafluoroethylene, Polyvinylalcohol, polyvinylidene fluoride, polyacrylonitrile, carboxymethyl cellulose (CMC) and polyvinylpyrrolidone (PVP) are used as binders for the AgO cathodes. Electrochemical performances of prepared AgO cathodes are investigated by a galvanostatic discharge test, cyclic voltammetry and electrochemical impedance spectroscopy and the field emission scanning electron microscopy (FESEM). The galvanostatic discharge tests show that the capacity of AgO cathodes based on PVP and CMC binders (380 mAh g−1 and 360 mAh g−1, respectively) are much higher than that other prepared cathodes. The FESEM images of AgO cathodes show that, the CMC cathode have poor physical strength, while PVP binder could maintain integrity of cathodes during discharge test. Also, a superior reduction peak current (−0.89 A) and minimum ohmic polarization confirm that the AgO cathode based on PVP has the highest electrochemical activity.

Comparative and optimization studies of PE and PVP binder with different graphene electrodes for the reduction of hardness

An investigation was carried out in this work to assess the potential of graphene as an Electrode in the removal of hardness. The synthesis of graphene was obtained from pencil graphite by using the modified hummers method. Three sets of experimental studies were carried out to achieve the aim of this work. The first set of studies was carried out to assess the potential of Graphene Oxide (GO), Reduced Graphene Oxide (rGO), and graphene as an electrode material to reduce the concentration of hardness. The second set of studies was carried out to investigate the efficiency of different proportions of Poly Ethylene (PE) and Polyvinyl Pyrrolidone (PVP) binders to reduce the concentration of hardness. The last set of experimental studies was carried out to identify the parameters like Contact time, pH and initial concentration of hardness affecting the performance of the selected electrode material with the selected proportions of binder. The Graphene was found to have high removal efficiency of hardness due to its high specific surface area rather than GO and rGO. The PVP binder has high removal efficiency than PE binder. The maximum reduction of 87.75% hardness may be obtained when the contact time is kept as 30 min, pH in neutral condition and the electrolyte concentration as 400 mg/L.

Characterization of silica gel-based composites for adsorption cooling applications

Abstract In this study, adsorption characteristics of water vapor onto several silica gel-based composites have been investigated experimentally. Adsorbent samples under investigation are silica gel powder (SGP), 98wt% SGP with 2wt% Polyvinylpyrrolidone (PVP) binder, 93wt% SGP, 2wt% PVP binder with 5wt% EG500 and 93wt% SGP, 2wt% PVP binder with 5wt% EG100. The three composite samples have been named as (S1-PVP), (S2-EG500) and (S3-EG100), respectively. Porous properties and thermal conductivity of S2-EG500 and S3-EG100 have been measured and compared with that of SGP. Experimental results showed that S2-EG500 has higher effect on enhancing the thermal conductivity of the composites where its thermal conductivity reached about 2.8 times that of SGP whilst thermal conductivity of S3-EGP100 is found to be about 2.3 times that of SGP. Adsorption isotherms of composite samples/water pairs have been measured gravimetrically at 30, 50 and 70 °C. The Toth and Dubinin-Astakhov (D-A) equations have been used to fit adsorption uptake measurements, Toth equation shows a better fitting. Isosteric heat of adsorption of the studied pairs have been extracted from the experimental measurements using Clausius-Clapeyron equation. The Linear Driving Force (LDF) model is found to be able to present adsorption kinetics of the studied pairs through a good agreement with the experimental data.

Facile and eco-friendly synthesis of water-soluble Cu2-xSe nanoparticles for photovoltaic applications

Water-soluble Cu2-xSe (x = 0.2) nanoparticles (NPs) were synthesized by an eco-friendly modified chemical co-precipitation method at 70 °C within a short reaction time of 15 min using ascorbic acid. Cu2-xSe NPs showed pseudo-spherical and hexagonal shapes with sizes in the range of 20–50 nm. XRD analysis showed cubic structure to Cu2-xSe NPs. Thin films of Cu2−xSe were deposited by drop-casting the synthesized Cu2-xSe NPs solution using polyvinylpyrrolidone binder and their physical properties were investigated. The annealed Cu2-xSe NPs thin film showed a direct optical band gap of 1.82 eV and an indirect band gap of 1.69 eV. Hall Effect measurements of the annealed films showed p-type conductivity with a carrier concentration of 3.18 × 1019cm−3, resistivity of 1.31 × 10−1 Ω-cm, and hole mobility of 1.5 cm2/V-s. In order to investigate the potential of Cu2-xSe NPs as an absorber, solar cells with a device configuration of soda-lime glass (SLG)/Mo/Cu2-xSe NPs/CdS/i-ZnO/Al:ZnO/Ni/Ag were fabricated and tested, which showed a power conversion efficiency (PCE) of 0.095%. Even though the Cu2-xSeNPs solar cell showed low PCE, the use of environmentally benign reducer like ascorbic acid offers the benefit of eco-friendliness and compatibility of water-soluble Cu2-xSe NPs synthesis, and its ultimate use in solar cell as well as other applications.

Study on the antioxidant cosmetic preparation from Spirulinaplatensis and gold nanoparticles

Oxidation can generate free radicals which damage important molecules including lipids, proteins, and nucleic acid, and causes premature aging. The oxidation of skin cells manifests as wrinkles, freckles and many other serious symptoms. To develop natural products with high antioxidant ability for skin care, we developed mixtures of Spirulina platensis biomass, gold nanoparticles (AuNP: 10 nm) and vitamin C at different ratios. The antioxidant activity of the mixtures was measured by ABTS (2,2′-azino-bis (3- ethylbenzothiazoline-6-sulfonic acid) diammonium salt) assay. The mixture of S. platensis (1000 ppm), AuNP (10 ppm), and vitamin C (10 ppm) showed excellent antioxidant activity with 95 % efficiency after 30 minutes and 100 % efficiency after 120 minutes under the reaction conditions. The combination of the mixture and the polyvinylpyrrolidone (PVP) binder was sterilized by gamma Co-60 radiation. The sterilization dose of 16 kGy was selected due to theabsence of aerobic microorganisms in the antioxidant cosmetic preparation. Thus, the cosmetic preparation in paste form containing three main components of S. platensis, gold nanoparticles, and vitamin C combinated with PVP binder has a potential applications in the field of cosmetics, especially for facial skin rejuvenation.

PVP a binder for the manufacture of ultrathin ITO/polymer nanocomposite films with improved electrical conductivity

This paper presents the manufacture of ultrathin (<1 µm) transparent conductive indium tin oxide (ITO) films based on nanoparticulate ITO slurries by the profile rod technique using the binder polyvinyl pyrrolidone (PVP) as an organic additive. The influence of the slurry composition on the film thickness and the specific electrical resistance as well as the transmission of the dried films is evaluated. The organic solvent ethanol and different types of the PVP binder were tested for slurry preparation and layer performance. ITO green films with low specific electrical resistance of 3 Ω cm, 87 % inline transmission, and layer thicknesses of only 250 nm could be manufactured. Furthermore, the influence of heat treatments up to 400 °C on the electrical properties of the ITO films was evaluated.

Model Membrane-Free Li-S Batteries for Enhanced Performance and Cycle Life.

The success of the rechargeable Li-S cell is limited in part by the dissolution of lithium-polysulfide in the electrolyte. Remarkably, it is found that removal of the conventional membrane separator in a Li-S cell improves sulfur utilization and cycling performance, whether the sulfur is initially contained in the cathode or electrolyte. An optimized cell design yields discharge capacities as high as 980 mA h g-1 after 100 cycles.

Li2S cathode modified with polyvinylpyrrolidone and mechanical milling with carbon

Polyvinylpyrrolidone (PVP) is used with polyethylene oxide (PEO) as a mixed binder for mechanically milled Li2S. PVP demonstrates its advantage in terms of increasing the capacity of Li2S, but boosts the potential barrier at the beginning of the first charge. It is also revealed that PVP retards the charge-transfer kinetics of Li2S. In Li2S-C prepared by mechanical milling, carbon compensates for the electrochemical insulation of the PVP binder and improves the cycle stability. As a result, the Li2S-C-PVP electrode with 60 wt% Li2S content displays a low potential barrier at the onset of charge and a stable capacity of about 460 mAh g−1 at 0.1 C.

Application of Water-Based Alumina Tapes Prepared Using PVP Binder for All-Ceramic Dental Crowns

Aqueous alumina tapes were prepared by a doctor blade using polyvinyl pyrrolidone (PVP) as a binder and gelatin and polyvinyl alcohol (PVA) as additional binders to improve drying rate and mechanical properties of the tapes containing PVP. As binder was prepared by mixing 89.5 wt% of PVP, 10 wt% of PVA, and 0.5 wt% of gelatin, tape properties were optimized showing complete drying in 3h, tensile strength of 1 MPa, and high flexibility. Marginal gap of all-ceramic dental crowns prepared using the tapes was about 56 µm indicating the tape cast alumina dental crowns are clinically applicable.