PVP Concentration Research Articles

Effect of the Concentration of PVP Capping Agent on Silver Nanowires Synthesized via CuCl2⋅2H2O Mediated Polyol Route

Effect of the Concentration of PVP Capping Agent on Silver Nanowires Synthesized via CuCl2⋅2H2O Mediated Polyol Route

Formulation and Characteristics of Film Forming Hydrogel (FFH) of Yellow Root Extract (Arcangelisia Flava (L.) Merr.) As Wound Healing for Burns

The aim of this study was to determine the effect of different concentrations of yellow root extract (Arcangelisia Flava (L.) Merr.) and film-forming hydrogel (FFH) polymer on the physicochemical characteristics and stability of the preparation. The method for making FFH is carried out using varying concentrations (%) of 0,5 extract, 1, and 1,5, as well as variations in concentration (%) of PVP and PVA (2,8:15,2; 2,8:17,2; 2,8:19,2). F1 – F9 were evaluated for physicochemical characteristics, including organoleptic, pH, spreadability, adhesive power, drying time, viscosity, stickiness, and mechanical properties. Next, freeze-thaw stability and data analysis were carried out using the LSD test at a confidence level of 95%. This research indicates that the FFH formulation of yellow root extract has good characteristics in the F1 formula with an extract concentration of 0.5% and a concentration (%) of PVP and PVP polymer (2.8:15.2), which meets all physicochemical characteristic tests. The results of data analysis using SPSS showed that the extract concentration and polymer concentration had a significant effect (0.05<0.05) on the characteristics and stability of the Yellow Root Extract Film Forming Hydrogel (FFH) preparation.

Synthesis of uniform-sized spherical monodisperse K2Ba[Ni(NO2)6] via polymer-assisted anti-solvent crystallization method for the enhanced catalytic pyrolysis of HNIW

Nitro complexes (NCs) have been selected as combustion catalysts for propellants due to their synergistic behavior. However, NCs prepared by traditional methods suffer from poor dispersion and irregular shape, which limit their catalytic potential. Hence, a polymer-assisted anti-solvent crystallization (PAASC) strategy was developed to fabricate potassium barium hexanitronickelate (K2Ba[Ni(NO2)6], PBHNN) crystals. In this method, emulsion particles created by mixing the solvent with the poor solvent serve as spherical templates. The particle size and monodispersity of PBHNN are controlled by PVP content. With 0.042 mol/L PVP, PBHNN were monodisperse with a particle size of 1.05±0.03 μm, which showed the best catalytic behavior for increasing the exothermic amount of hexanitrohexaazaisowurtzitane (HNIW) by 100.6 %. The high catalytic performance is due to the large specific surface area and improved contact efficiency. The in-situ TG-FTIR-MS test revealed that the procedure of PBHNN enhanced the pyrolysis of HNIW. The N-NO2 bonds of HNIW are weakened by the strong attraction of metal oxides to electrons, which accelerates the formation of NO2. Consequently, increased NO2 promotes subsequent oxidation reactions and improves the pyrolysis efficiency of individual HNIW. Therefore, the PAASC method is crucial for the fabrication of spherical monodisperse NCs with uniform particle size and high catalytic activity.

Characterization of Taro (Colocasia esculenta) stolon polysaccharide and evaluation of its potential as a tablet binder in the formulation of matrix tablet

This investigation focuses on the extraction, characterization, and evaluation of taro (Colocasia esculenta) stolon polysaccharide (TSP) as a tablet binding agent, which is obtained from edible taro stolon. TSP was subjected to phytochemical screening and characterized by FTIR, DSC, TGA, DTA, XRD, particle size, polydispersity index, zeta potential, rheological behavior, and SEM. The tablets prepared with varying concentrations of TSP (2.5 %, 5 %, 7.5 %, and 10 % w/w) and diclofenac sodium (DS) were evaluated and compared with the same concentrations of gum acacia and PVP K-30. The presence of carbohydrates was confirmed by Molisch's test. The FTIR spectra established the compatibility of the drug with excipients. The SEM images revealed asymmetric and elongated particles of TSP powder. The hydration kinetics study showed matrix hydration and water penetration velocity within the range of 0.602–0.753 g/g and 0.112–0.189 cm/g.h, respectively. The tablets showed drug release of >75 % at 45 min. The release-exponent value above 0.89 indicated a super case II drug transport combining matrix erosion and diffusion. Optimum tablet hardness and very low friability, even at 2.5 % binder concentration, suggested the potential application of the novel TSP as a tablet binder in the formulation of the tablets.

Micronization of ciprofloxacin by the Supercritical Antisolvent (SAS) Technique

Ciprofloxacin is a broad-spectrum antibiotic that is proposed for pulmonary administration. In this work micronization of ciprofloxacin was performed by the Supercritical Antisolvent Technique (SAS) using ciprofloxacin base (CIP) in ethanol/acetic acid and ciprofloxacin hydrochloride salt (CIP·HCl) in methanol at 40–60 ºC and 100–150 bar. Yields ranged from 40 % to 90 %. CIP precipitated incorporating acetate whilst CIP·HCl precipitated as the AH1 anhydrous form. CIP and CIP·HCl particles exhibited an acicular morphology (0.2–0.9 μm wide × 1–4 μm long). Micronization adding lactose, PVP K-10 and K-30 modified the precipitate morphology. CIP·HCl:lactose and CIP·HCl:PVP K-30 at a 4:1 drug:excipient mass ratio precipitated like flakes. CIP·HCl:PVP K-10 precipitated as submicron globular particles suitable for oral formulation. Increasing the PVP content, the morphology changed to sheets and flakes, which could be used for pulmonary administration. The antibacterial activity of the samples for Staphylococcus epidermidis was confirmed.

Synergistic Effects of Radical Distributions of Soluble and Insoluble Polymers within Electrospun Nanofibers for an Extending Release of Ferulic Acid.

Polymeric composites for manipulating the sustained release of an encapsulated active ingredient are highly sought after for many practical applications; particularly, water-insoluble polymers and core-shell structures are frequently explored to manipulate the release behaviors of drug molecules over an extended time period. In this study, electrospun core-shell nanostructures were utilized to develop a brand-new strategy to tailor the spatial distributions of both an insoluble polymer (ethylcellulose, EC) and soluble polymer (polyvinylpyrrolidone, PVP) within the nanofibers, thereby manipulating the extended-release behaviors of the loaded active ingredient, ferulic acid (FA). Scanning electron microscopy and transmission electron microscopy assessments revealed that all the prepared nanofibers had a linear morphology without beads or spindles, and those from the coaxial processes had an obvious core-shell structure. X-ray diffraction and attenuated total reflectance Fourier transform infrared spectroscopic tests confirmed that FA had fine compatibility with EC and PVP, and presented in all the nanofibers in an amorphous state. In vitro dissolution tests indicated that the radical distributions of EC (decreasing from shell to core) and PVP (increasing from shell to core) were able to play their important role in manipulating the release behaviors of FA elaborately. On one hand, the core-shell nanofibers F3 had the advantages of homogeneous composite nanofibers F1 with a higher content of EC prepared from the shell solutions to inhibit the initial burst release and provide a longer time period of sustained release. On the other hand, F3 had the advantages of nanofibers F2 with a higher content of PVP prepared from the core solutions to inhibit the negative tailing-off release. The key element was the water permeation rates, controlled by the ratios of soluble and insoluble polymers. The new strategy based on core-shell structure paves a way for developing a wide variety of polymeric composites with heterogeneous distributions for realizing the desired functional performances.

Injectable chitosan-polyvinylpyrrolidone composite thermosensitive hydrogels with sustained submucosal lifting for endoscopic submucosal dissection

To develop a submucosal injection material with sustained submucosal lifting for endoscopic submucosal dissection (ESD), this study designed and prepared a novel composite thermosensitive hydrogel system with high pH chitosan-polyvinylpyrrolidone-β-glycerophosphate (HpHCS-PVP-GP). HpHCS improved the injectability of the hydrogels and retained the rapid gelation ability at low concentrations. The modification of PVP significantly improved the stability of low-temperature hydrogel precursor solutions and the integrity of hydrogels formed at 37 °C through hydrogen bonds between PVP and HpHCS. A mathematical model was established using response surface methodology (RSM) to evaluate the synergistic effect of HpHCS, GP, and PVP concentrations on gelation time. This RSM model and submucosal lifting evaluation using in vitro pig esophageal models were used to determine the optimal formula of HpHCS-PVP-GP hydrogels. Although the higher PVP concentration (5 % (w/v)) prolonged gelation time, it improved hydrogel mechanical strength, resulting in better submucosal lifting performance. The experiments of Bama mini pigs showed that the heights of the cushions elevated by the HpHCS-5%PVP-GP hydrogel remained about 80 % 1 h after injection. Repeated injections were avoided, and the hydrogel had no cytotoxicity after electric cutting. Therefore, the HpHCS-PVP-GP thermosensitive hydrogel might be a promising submucosal injection material for ESD.

Modulating nanostructures with polyvinylpyrrolidone: Design and development of a porous, biocompatible, and pH-Stable core-shell magnetic microrobot for demonstrating drug absorption from wastewater

Increased antineoplastic drug concentrations in wastewater stem from ineffective treatment plants and increased usage. Although microrobots are promising for pollutant removal, they face hurdles in developing a superstructure with superior adsorption capabilities, biocompatibility, porosity, and pH stability. This study focused on adjusting the PVP concentration from 0.05 to 0.375 mM during synthesis to create a favorable CMOC structure for drug absorption. Lower PVP concentrations (0.05 mM) yielded a three-dimensional nanoflower structure of CaMoO4 and CuS nanostructures, whereas five-fold concentrations (0.25 mM) produced a porous structure with a dense CuS core encased in a transparent CaMoO4 shell. The magnetically movable and pH-stable COF@CMOC microrobot, achieved by attaching CMOC to cobalt ferrite (CoF) NPs, captured doxorubicin efficiently, with up to 57 % efficiency at 200 ng/mL concentration for 30 min, facilitated by electrostatic interaction, hydrogen bonding, and pore filling of DOX. The results demonstrated that DOX removal through magnetic motion showed superior performance, with an estimated improvement of 57% compared to stirring conditions (17 %). A prototype PDMS microchannel system was developed to study drug absorption and microrobot recovery. The CaMoO4 shell of the microrobots exhibited remarkable robustness, ensuring long-lasting functionality in harsh wastewater environments and improving biocompatibility while safeguarding the CuS core from degradation. Therefore, microrobots are a promising eco-friendly solution for drug extraction. These microrobots show promise for the selective removal of doxorubicin from contaminated wastewater.

Skin Penetration of Corn Silk (Zea mays L.) Transdermal Patch on Wistar Mice Skin Using Franz Diffusion Cell

Background: Corn silk (Zea mays L.) contains many active compounds, especially the flavonoid quercetin which has pharmacological activity as an antihyperlipidemic agent by reducing cholesterol and triglyceride levels in the body. Antihyperlipidemic treatment by oral route, such as statin drugs, has the disadvantage of experiencing a first-pass effect in the liver, which reduces the bioavailability of the drug. In addition to avoiding the first-pass effect, transdermal patches can improve patient compliance because they are easy to use. Objective: This study aims to optimize the transdermal patch formula of corn silk extract and test the penetration of the optimum formula by in vitro. Method: Optimization of the formula using the Regular Two-Level Factorial Design method on Design Expert®. This study used 2 factors, namely HPMC with a concentration of 3%-4% and PVP with a concentration of 1%-2%. The optimum formula obtained was subjected to in vitro penetration test using Franz diffusion cell. Results: Based on the results of factorial design analysis, the optimum formula of transdermal patches is at HPMC and PVP concentrations of 3.49% and 1% with moisture content, moisture uptake, percentage of elongation, and folding endurance respectively of 7.79%, 4.19%, 13.26% and 470.58 fold. The optimum formula of corn silk extract transdermal patch preparation also had an optimum percent cumulative amount of penetrated flavonoids of 96.06% and flux of 6.17 µg/cm2.hour at 3 hours. Conclusion: Transdermal patch dosage of corn silk extract with HPMC and PVP concentrations of 3.49% and 1% proved to have good characteristics and penetration rate.

PVP-assisted preparation of high-performance LiMn0.6Fe0.4PO4/C cathode materials

LiMnXFe1-XPO4 (X = 0.6) has excellent energy density and thermal stability, combining the excellent multiplicity performance of LiFePO4 and the high operating voltage of LiMnPO4. However, lower electronic conductivity and lithium ion diffusion rate are the main problems faced. We successfully synthesized LiMn0.6Fe0.4PO4 with uniform particles by a solvothermal method using surfactant PVP as an anti-agglomeration agent. At the same time, we found that the concentration of PVP in the reaction mixture plays a crucial role in the controllable structure and morphology of LiMn0.6Fe0.4PO4, thus accelerating the de-embedding of lithium ions reached 145.2 mAh g−1 under 1 C test. Therefore, the high-performance LiMn0.6Fe0.4PO4/C nanomaterials synthesized by the solvothermal method are significant for developing and applying lithium-ion batteries.

Heterointerface engineering of hollow CoP/CeO2 p-n heterojunction for efficient electrocatalytic oxygen evolution

Heterointerface engineering is a promising strategy to realize electronic redistribution and enhance oxygen evolution reaction (OER) activity. However, preparing and designing heterojunction with appropriate band structures and outstanding performance remains a challenge. Herein, a novel hollow CoP/CeO2 heterojunction (h-CoP/CeO2) is constructed by electrospinning and a selective phosphorization process. Hollow structure can create more active sites and promote the intimate contact between catalysts and electrolyte to facilitate the mass and charge transfer. Mott-Schottky plots demonstrate p-n heterojunction is formed between p-CoP and n-CeO2, which induces a strong intrinsic field and redistribution of charges. Attributed to its hollow structure and p-n heterojunction, the optimal h-CoP/CeO2 prepared with appropriate PVP content and [Co/Ce] ratio exhibits remarkable alkaline OER activity (overpotential = 198 mV at 10 mA cm−2, Tafel slope = 83 mV dec−1). This result is better than or comparable to previous reports. Besides, h-CoP/CeO2 acing as a co-catalyst can improve the photoelectrochemical (PEC) performance of TiO2 nanorods, which not only increases the photocurrent density, but also reduces the onset potential (negatively shifted 58 mV for TiO2/CoP-CeO2). This study provided a new insight for constructing hollow heterojunction with uniform distribution of each component to enhance OER and PEC performance.

PVP assisted sol-electrospraying, unlike sol electrospinning, yields highly pure rhombohedral zinc titanate particles that reduce 4-nitrophenol under visible light

This work demonstrates for the first time that switching from sol-electrospinning to sol-electrospraying using PVP as a carrier polymer leads to enhanced purity of rhombohedral zinc titanate (Rh-ZTO) after calcination. Unlike in sol-electrospinning, the purity systematically increases and crystallite size decreases as PVP concentration is increased in sol-electrospraying. 100% pure Rh-ZTO powders were prepared with PVP fraction of 31.25 wt%. After careful characterization by XRD, rheology, zeta potential measurements, and SEM, we conclude that the interaction of multipole moments of the incipient sol-clusters with the electrostatic field influences the purity. We propose that in electrospinning the sol clusters spatially separate to yield multiple crystalline phases whereas in electrospraying they intermix due to polymeric cages in droplets and yield a single crystalline phase. The highest purity samples were found to enhance photo-reduction of 4-nitrophenol in presence of visible light, with rate constant increasing from 0.000415 to 0.00104 min−1. This could result from complex formed between oxygen vacancy and the shallow donor states of Ti3+ as confirmed by DRS, XPS, and PL.

Experimental study on the preparation of monodisperse nano-silver by hydrothermal synthesis

As a new material with wide application prospect, nano-silver is getting high attention. Hydrothermal synthesis has the advantages of green, easy operation and low cost, and is a promising technology for the preparation of nano-silver. In this paper, the effects of reaction time, reaction temperature, precursor concentration, PVP concentration and modifier addition on the particle size distribution and surface morphology of nano-silver during the subcritical hydrothermal reaction were optimized by comparing the supercritical and subcritical hydrothermal methods. Then, the important role and reaction mechanism of PVP as a modifier and the formation mechanism of spherical nano-silver particles were analyzed. The experimental results showed that the average particle size of 23.68 nm can be obtained by using NaHCO3 and PVP as reducing and dispersing agents, the reaction time is 5 h, the reaction temperature is 180 °C, and the concentrations of AgNO3 and PVP are 0.1 M and 0.3 M, respectively, to obtain the more uniformly dispersed silver nanoparticles. The results provide an important reference for future research on the preparation of conductive pastes.

The Beneficial Role of Low PVP Concentration on Sperm Apoptotic Gene Expression, Embryo Morphokinetics Status, and Clinical ICSI Outcomes

The Beneficial Role of Low PVP Concentration on Sperm Apoptotic Gene Expression, Embryo Morphokinetics Status, and Clinical ICSI Outcomes

PENGEMBANGAN SEDIAAN TABLET ESTROGENIK DARI EKSTRAK RUMPUT KEBAR (Biophytum petersianum) MENGGUNAKAN VARIASI KONSENTRASI PENGIKAT PVP K-30

Kebar grass (Biophytum petersianum Klotzsch) contains steroid, saponins, flavonoids, alkaloids, and triterpenoids. The use of Kebar grass extract can increase the development of follicles because it contains saponins which are the basic ingredients for the synthesis of steroid hormones and can improve the performance of reproductive system. This study aims to determine the quality the tablets made from Kebar grass extract with varying concentrations of PVP K-30 binder. Tablets were made in 3 formulas with varying concentrations of PVP K-30 as a binder, namely 2% (F1), 3% (F2), and 4% (F3). Methods of making tablets by wet granulation. Tablet quality testing includes organoleptic, weight uniformity, thickness, diameter, hardness, friability, and disintegration time. The flavonoid quercetin was used as a marker for tablet analysis. The results showed that the tablets were round in shape, white-gray in color, had a slightly bitter taste and had a characteristic aromatic odor. The average value of tablet weight uniformity is 290.06 – 306.45 mg (KV <5%), tablet diameter is 0.91 -0.92 cm, thickness is 0.41 – 0.48 cm, hardness is 4.06 – 7.95 kp, friability 0.17 – 0.21% and tablet disintegration time < 15 minutes. The results of the statistical analysis showed that the differences in the concentration of PVP K-30 did not affect the hardness and friability of the tablets (p> 0.05). The level of the flavonoid quercetin in the tablet is 0.17 – 0.21%. The conclusion that Kebar grass extract tablets can be made using PVP K-30 at a concentration of 2-4% as a binder and the quality of the tablets is not significantly different.

Enhancing Ag2MoO4 catalytic activity: An investigation on synthesis, characterization, and application in catalytic ozonation reactions

Silver molybdate (Ag2MoO4) has promising results in photocatalysis and Fenton-like reactions, but its use in catalytic ozonation and the role of its different crystalline phases remain poorly understood. The understudied metastable α-phase remains a challenge in terms of production, characterization, and catalytic properties, due to its tendency to convert to the stable β-phase. This study investigates the optimized synthesis of the α-phase using a face-centered central composite experimental design by varying PVP concentration and pH. Results revealed that significant effects of synthesis conditions on α-phase formation and optical-textural properties. Increasing pH negatively affects textural properties and crystalline phases distribution, while the interaction between PVP concentration and pH proportionally improves optical properties. The statistical analyses predicted a maximum α-phase formation of 71 % (PVP: 2.9 mmol L−1 and pH: 4.9) externally from the parameters range applied. Silver molybdate produced under pH > 4.5 showed catalytic activity to remove trimethoprim in aqueous suspensions. Moreover, particle morphology strongly influenced on the catalytic activity, with well-structured particles achieving up to 76 % removal of trimethoprim. Higher crystallinity had a greater impact on catalysts activity. Thus, strict control during α-Ag2MoO4 synthesis is crucial, emphasizing the dependence of catalytic activity on synthesis conditions.

Relationship between the Polymer Blend Using Chitosan, Polyethylene Glycol, Polyvinyl Alcohol, Polyvinylpyrrolidone, and Antimicrobial Activities against Staphylococcus aureus.

The findings from Pareto charts, main effect plots, and interaction plots demonstrate the importance of polymer concentration. Increasing concentration improves the inhibition percentage and decreases the MIC50. However, the primary factor that influences these changes is chitosan (CS). Additionally, the interaction between CS and PVP, along with other polymers, plays a crucial role in achieving better antimicrobial effects. These results enhance our understanding of the antimicrobial properties of the studied polymers and offer valuable insights for developing effective antimicrobial formulations. The MIC50 value of M1-M16 was at a polymer percentage of 12.5%. At 12.5% polymer percentage, with the limits of [PVA], [PEG], and [PVP] being 0.002-0.004 g/mL and [CS] being 0.001-0.002 g/mL, using the 2-level full factorial method, the inhibition percentage is equal to 174.1 - 27,812 PVA - 18,561 PVP - 25,960 PEG - 38,752 CS + 9,263,047 PVA*PVP + 10,430,763 PVA*PEG + 15,397,157 PVA*CS + 7,088,313 PVP*PEG + 7,841,221 PVP*CS + 14,228,046 PEG*CS - 3,367,292,860 PVA*PVP*PEG - 5,671,998,721 PVA*PVP*CS - 6,619,041,275 PVA*PEG*CS - 3,917,095,529 PVP*PEG*CS + 2,273,661,969,470 PVA*PVP*PEG*CS. Theoretically, the most economical concentrations of PVA, PVP, PEG, and CS are 0.002, 0.002, 0.002, and 0.001 mg/mL at a concentration of 12.5% to reach an inhibition percentage of 99.162%, which coincides with the MBC value.

Electrospinning of PVP-based multilayered graphene oxide/BiFeO3/SrFe12O19 composite nanofibers

Four composite nanofibers with specific concentrations of PVP and BiFeO3, GO, and SrFe12O19 reinforcements were synthesized separately, which were named G, S, B, GBS: G (PVP + GO), S (PVP + SrFe12O19), B (PVP + BiFeO3), and GBS (PVP + GO + BiFeO3 + SrFe12O19). The structural, magnetic, and dielectric properties of the composite successfully prepared by the electrospinning method were investigated to absorb electromagnetic waves in the frequency range of 8–12.5 GHz. Negative values observed in imaginary parts of permeability and permittivity in a large frequency range can be explained by new structures called left-handed. The maximum amount of reflection loss in the X-Band range around the frequency of 11.66 GHz for G, S, B, and GBS samples are obtained at −36.8, −37.66, −39.3, and −39.5 dB, respectively, which shows relatively good potential in military applications.

Synthesis of castor oil/poly (N-vinyl-2-pyrrolidone)/ammonium persulfate hybrids emulsion as textile softeners

Two castor oil / poly (N-vinyl-2-pyrrolidone) / ammonium persulfate (CAO/PVP/APS) hybrids were synthesized via reaction of castor oil with PVP of molecular weights 40000 and 1300000 Dalton in presence of APS as an initiator. The optimum reaction conditions are: PVP/CAO weight ratio, 15%; PVP concentration, 60%; APS conc., 4% (based on weight of CAO); reaction temperature, 80 °C; reaction time, 60 min. The synthesized CAO/PVP/APS hybrids were characterized via FTIR analysis whereas their emulsions particle sizes were determined using TEM analysis. Incorporation of either of the aforementioned hybrids emulsions in the easy care finishing formulations of cotton fabric results in promoting of fabric softness, tensile strength, flexibility, and antibacterial activities of treated fabric along with reducing fabric wettabiliy and resiliency. Inclusion of Ag-NPs in the aforementioned finishing bath significantly improves extent of the antibacterial activities of treated fabric. The treated fabric morphology was examined using SEM as well as EDX analysis.

Polyvinylpyridine–carbon dots composite-based novel humidity sensor

This work describes the rational design of thin films based on PVP-modified carbon dots for potential resistive humidity sensing application, prepared via spin coating on ITO substrates. The modified carbon dots were manufactured from graphite waste and modified with PVP to test the synergetic effect of the two materials. The surface hydrophilicity, morphology, and sensing properties were studied. AFM has been performed to investigate the prepared films’ texture and distribution over the surface. Overall, the hydrophilicity of the prepared films increases with concentration, leading to enhanced water vapor absorption on the surface of the sensing film. As a result, the sensor’s sensitivity is improved with the increasing concentration of PVP–CDs. The electrical response of the PVP–CDs composite film sensor shows a higher sensitivity level above 80% RH sensor with an irregular response; however, the concentration of 0.5 wt%, higher sensitivity, and linear change in impedance response was noted compared to other concentrations.