Effects Of Polyvinylpyrrolidone Concentration Research Articles

Effect of polyvinylpyrrolidone concentration on optical properties of CuCrO2 thin films

In this study, CuCrO2 thin films were fabricated by spin-coating technique on alkali-free glass substrates and a two-step annealing process. The copper-based delafossite CuCrO2 is a p-type transparent conductive oxide that exhibits a wide energy bandgap and excellent stability. To improve the transmittance of CuCrO2 thin films, polyvinylpyrrolidone (PVP) was used as a porogen for preparing thin films with high transmittance and high haze values. The highest transmittance of 73.75% was achieved with 0.5 g of PVP. The bandgaps of prepared CuCrO2 thin films were estimated at 2.82 eV to 3.11 eV. The prepared CuCrO2 thin films had a porous structure and high transmittance. The high potential transmittance of porous CuCrO2 thin films makes them applicable to photovoltaic systems, transistors and touch screens or displays in the future.

The Effect of PVP Concentration on Particle Size, Morphological and Optical Properties of Cassiterite Nanoparticles

Different concentrations of polyvinylpyrrolidone (PVP) have been successfully employed to prepare high purity tetragonal cassiterite nanoparticles, and control the growth of particle size. The effect of PVP on the structural, morphological, size, composition, and optical properties of the prepared cassiterite nanoparticles has been investigated. It has been found that various characteristics of tetragonal cassiterite nanoparticles could be optimized by simply changing the values of PVP. The pure tetragonal cassiterite nanoparticles have been produced at the optimum calcination temperature. The XRD and SEM results indicated the structural and morphological properties of the tetragonal cassiterite nanoparticles, respectively. The particles' size and their distribution have been displayed by TEM images. The composition phase and the surface composition of the prepared samples have been evaluated via FTIR and XPS, respectively. The optical properties of the prepared tetragonal cassiterite nanoparticles have been studied using UV-vis and PL spectroscopy. Outcomes cassiterite nanoparticles are useful for antibacterial activity and application of solar energy.

Effect of PVP concentration on prepared PEI membranes for potential use on water treatment: effect of additive on membranes prepared for water treatment

Abstract In this work, a series of polyetherimide (PEI) flat sheet membranes were produced with different concentrations of polyvinylpyrrolidone (PVP) addition via the phase inversion method. The effects of additions on membrane morphology and performance were investigated. Synthesized membrane had the properties of ultrafiltration membrane. Although PEI is not widely used for water treatment, in this study, the ferrous iron removal rate was investigated and good results were obtained. Through the membrane production experiments, the PEI content was 22 wt%. PVP was added as a pore-forming agent with concentrations of 2, 4 and 8 wt%. N-methyl-2-pyrrolidone (NMP) was used as solvent. Distilled water was used for the coagulation bath. After production, all membranes were characterized by using contact angle, permeability, porosity, and scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT/IR) analyses. With the increasing doses of PVP addition, the permeability of the PEI membranes produced in this study increased, while porosity results were changeable. The permeability was 23 L/m2h bar for the membrane with 2 wt% PVP content, while the permeability for the membrane with 8 wt% PVP content was 32 L/m2h bar. Contact angles increased with PVP addition to PEI membranes. With the increasing PVP concentration, the finger-like pores and the pores located in the sub-layer expanded.

Surfactant assisted self assembly of novel ultrathin Cu[Fe(CN)5NO] nanosheets for enhanced electrocatalytic oxygen evolution: Effect of nanosheet thickness

A morphology-controlled ion exchange route has been investigated for the preparation of Copper Nitroprusside (CNP) nanosheet. Polyvinylpyrrolidone (PVP) was used as capping agent. The effect of PVP concentration during synthesis was also studied which provides a local control over the morphology of CNP nanosheet to produce an ultrathin CNP nanosheet. Effect of PVP concentration in crystal growth and mechanism has been established. Cyclic voltammogram shows that oxygen evolution reaction (OER) onset potential for CNP nanosheet was found to be 1.45 V with a measured current density of 26 mA/cm2. Linear sweep Voltammetry test has also been conducted to analyze the electrocatalytic OER performance. Anodic slope of Tafel plot establishes higher OER performance of CNP nanosheet than commercial RuO2. CNP nanosheets was found to be cheap and efficient eletrocatalyst for water splitting reaction. Voltammetric current density has also been expressed as a function of average thickness of nanosheets.

Thermal shrinkage of electrospun PVP nanofibers

ABSTRACTThis paper outlines the shrinkage of electrospun polyvinylpyrrolidone (PVP) fiber mats during thermal treatment. The thermal behavior and phase changes within the fibers were investigated by DSC and TGA/DTA. Five precursors with different PVP loading in ethanol were electrospun. The mats shrinkage as function of temperature was measured in the RT–200 °C range. Shrinkage rate drastically increased above the polymer glass transition point, Tg (150–180 °C), due to increase in polymer chain mobility. Mats shrinkage at 200 °C as function of PVP concentration showed a minimum at ∼10%wt. Below 10% PVP the mats morphology is non‐uniform, consisting of beads and fibers. Above 10% PVP, only flat and uniform fibers were observed. This paper outlines the dominant mechanism governing the mats shrinkage during heating. In addition, the effect of PVP concentration on the expansion of fibers diameter was investigated and found to be consistent with the linear shrinkage observing a minimum at ∼10% PVP. The effect of applied voltage on mat shrinkage was investigated, and showed a minimum at 12 kV. Understanding the interplay between fibers morphology and thermal shrinkage allows precursor composition and system optimization needed for minimizing shrinkage negative effects on the structure and properties of electrospun fiber mats. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 248–254

Effect of PVP concentration on microstructure and physical properties of electrospun SnO2 nanofibers

ABSTRACTThe various exceptional crystalline morphologies of tin oxide (SnO2) nanofibers were fabricated using conventional electrospinning and calcination process. Polyvinylpyrrolidone (PVP) was used as polymer template and tin (IV) chloride (SnCl4·5H2O) was chosen as starting material for electrospun SnO2 nanofibers. The concentration of PVP was varied from 6%w/w to 12%w/w while the concentration of SnCl4·5H2O was kept constantly. The diameter of the as-spun SnO2 nanofiber was ranging from 154 to 464 nm. After calcination at 600°C for 3 h, the crystal structure can be identified to the tetragonal structure of SnO2 with various morphologies. The EDX analysis confirmed the existence of major elements and formation of SnO2 from starting precursor. SEM results revealed that low PVP concentration led to the formation of porous SnO2 nanofibers comprising long chain of SnO2 nanobeads. When the PVP concentration was reached to 12%w/w, the arrangement of crystalline of SnO2 became the cluster of SnO2 plates.

Fabrication and Characterization of Hexagonal SrMnO3Nanofibers by Electrospinning

SrMnO 3 /Polyvinylpyrrolidone (PVP) composite nanofibers have been prepared successfully by electrospinning from Cerous(II) nitrate and Manganese(II) acetate tetrahydrate, after the heat treatment at 800 °C for 3 h, the hexagonal SrMnO 3 nanofibers was obtained. The effect of PVP concentration was investigated. The size and morphology, phase information, thermal properties of nanofibers were characterized by SEM, EDX, XRD, TGA, FT-IR, respectively.

A hierarchical porous carbon membrane from polyacrylonitrile/polyvinylpyrrolidone blending membranes: Preparation, characterization and electrochemical capacitive performance

Novel hierarchical porous carbon membranes were fabricated through a simple carbonization procedure of well-defined blending polymer membrane precursors containing the source of carbon polyacrylonitrile (PAN) and an additive of polyvinylpyrrolidone (PVP), which was prepared using phase inversion method. The as-fabricated materials were further used as the active electrode materials for supercapacitors. The effects of PVP concentration in the casting solution on structure feature and electrochemical capacitive performance of the as-prepared carbon membranes were also studied in detail. As the electrode material for supercapacitor, a high specific capacitance of 278.0 F/g could be attained at a current of 5 mA/cm2 and about 92.90% capacity retention could be maintained after 2000 charge/discharge cycles in 2 mol/L KOH solution with a PVP concentration of 0.3 wt% in the casting solution. The facile hierarchical pore structure preparation method and the good electrochemical capacitive performance make the prepared carbon membrane particularly promising for use in supercapacitor.

Effect of Polyvinylpyrrolidone on Separation Performance of Cellulose Acetate-Polysulfone Blend Membranes

Blend membranes comprising cellulose acetate and polysulfone (CA/PSf) were prepared through a solution casting method using a different concentration of polyvinylpyrrolidone (PVP) as the pore former. Fourier transform infrared spectroscopy (ATR-FTIR) was used to investigate structural properties of membranes. Membranes morphology and its thermal properties were characterized by scanning electron microscope (SEM) and thermogravimetric analysis (TGA). The strength of membranes was studied by mechanical stability. The effect of PVP concentration on separation performance of the prepared membranes was studied. The separation performance of prepared membranes was tested by using an aqueous solution of cadmium metal complexed with humic acid. The results showed that an increase in the PVP concentration in the cast film from 0 to 3 wt% increased the thermal stability, water content (%), pure water flux, and solute rejection. SEM results showed that the pore size decreased but the number of pores increased on an increase in the PVP concentration.

Effects of PVP Concentration on the Formation of Size and Shape of Gold (Au) Nanoparticles for Mercury Adsorption

Mercury is a natural occurring element and present in various concentrations in natural gas. Mercury is not only hazardous to human health and the environment but could also attack equipment components resulting in mechanical failure and gas leakage. This sudy describes the preparation of various sizes and shapes of Au nanoparticles for mercury adsorption by using a microwave (MW)-polyol method in the presence of different polyvinylpyrrolidone (PVP) concentrations (1.9, 3.8 and 5.7 mM) as a polymer surfactant. Mixtures of spherical, triangular, hexagonal, octahedral, decahedral and icosahedral particles were obtained using this rapid method. Sizes and shapes was found strongly depend on the concentrations of PVP. Large spherical particles were the major product of PVP concentrations (1.9 and 3.8 mM), whereas small spherical particles were preferentially produced at the highest PVP concentration (5.7 mM). It should be noted that the polygonal particles also increases with increasing PVP concentrations. The amount of mercury adsorbed using 10 ppm mercury solution is the highest (7.2%) for PVP concentration of 5.7 mM. It is concluded that PVP concentrations affects the formation of sizes and shapes of Au nanoparticles thus affects the mercury adsorption. The present result provides new information about mercury adsorption on Au nanoparticles.

Cellulose acetate (CA)/polyvinylpyrrolidone (PVP) blend asymmetric membranes: Preparation, morphology and performance

Abstract Cellulose acetate (CA) membranes are widely used for reverse osmosis (RO) and ultrafiltration (UF) applications. In this study, asymmetric CA membranes were synthesized using phase inversion method. CA with molecular weight of 52,000, polyvinylpyrrolidone (PVP) with molecular weight of 15,000 and 1-methyl-2-pyrrolidone (NMP) were used as polymer, additive and solvent, respectively. The effects of PVP concentration (at 0, 3 and 6 wt.%) and coagulation bath temperature (CBT at 0, 25 and 50 °C) on morphology, contact angle and permeability of the prepared membranes were studied and discussed. It was found out that the effects of PVP concentration and CBT depend on their values.

Detecting system for intracranial murmur

A morphology-controlled ion exchange route has been investigated for the preparation of Copper Nitroprusside (CNP) nanosheet. Polyvinylpyrrolidone (PVP) was used as capping agent. The effect of PVP concentration during synthesis was also studied which provides a local control over the morphology of CNP nanosheet to produce an ultrathin CNP nanosheet. Effect of PVP concentration in crystal growth and mechanism has been established. Cyclic voltammogram shows that oxygen evolution reaction (OER) onset potential for CNP nanosheet was found to be 1.45 V with a measured current density of 26 mA/cm2. Linear sweep Voltammetry test has also been conducted to analyze the electrocatalytic OER performance. Anodic slope of Tafel plot establishes higher OER performance of CNP nanosheet than commercial RuO2. CNP nanosheets was found to be cheap and efficient eletrocatalyst for water splitting reaction. Voltammetric current density has also been expressed as a function of average thickness of nanosheets.