Pyrrolidone Blend Research Articles

Innovative enhancements in polymer nanocomposites: Integrating ZnO nanorods into Hydroxypropyl methylcellulose/Polyvinyl pyrrolidone blend for advanced energy storage devices

Polymer nanocomposites are promising for various industrial and scientific applications due to their flexibility, diverse functionalities, and unique properties. In this study, zinc oxide nanorods (ZnO NRs) were incorporated into a blend of polymers (Hydroxypropyl methylcellulose - HPMC and Polyvinyl pyrrolidone - PVP) using a solution-casting technique, with concentrations varying from 2 % to 8 % by weight. Transmission electron microscopy (TEM) revealed that the ZnO NRs had an average diameter of 140 nm and a length of 3.22 μm. X-ray diffraction (XRD) analysis showed reduced crystallinity in the samples as the ZnO NR content increased. Fourier-transform infrared spectroscopy (FTIR) indicated changes in vibrational peaks due to interactions between functional groups in the blend and the nanorods. The addition of ZnO NRs significantly influenced the optical bandgap energies and UV/visible light absorption spectra of the samples. The bandgap of the nanocomposites significantly decreased upon ZnO NR incorporation, with direct and indirect bandgaps ranging from 5.19 to 4.70 eV and 4.74–3.66 eV, respectively. Electrical conductivity and dielectric characteristics were assessed across frequencies ranging from 0.1 to 10 MHz, revealing increasing AC conductivity, dielectric permittivity, and dielectric loss with higher ZnO NR content. Notably, at 10 Hz, the electrical conductivity increased from 3.5 × 10⁻12 S/m to 3.62 × 10⁻10 S/m upon loading with ZnO NR. The combination of adjustable optical bandgaps, frequency-dependent AC conductivity, and a wide range of tunable permittivity highlights the potential of these HPMC/PVP-ZnO NR nanocomposites for developing flexible optoelectronic and energy storage devices.

Influence of γ irradiation on the optical and colour characteristics of the polyvinyl alcohol/polyvinyl pyrrolidone blend film

With the aid of a solution casting technique, we created a blended film made of polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP). Gamma doses (5-40 kGy) were applied to samples of the synthetic PVA/PVP film. UV spectroscopy and the CIE colour alterations procedure were used to investigate the impact of the γ dose on the optical features of the synthesized film. The direct optical bandgap (Eg), affected by cross-linking, destroyed the crystalline structure and formed the amorphous regions, dropped from 2.53 to -2.08 eV with the increase in γ dose to 40 kGy. Thus, the PVA/PVP film's compact structure increases. The films displayed a transition which was directly allowed as the ϵ'' vs. hν plots revealed Eg approximately equal to the values derived from Tauc's equation. The colour variances, between the unaltered and irradiated films, were also identified. Significant colour differences could be seen in the pure PVA/PVP film.

Optical Transmission and Color Investigation of the Effect of Gamma Radiation on Polyvinyl Alcohol/Polyethylene Glycol/Polyvinyl Pyrrolidone Blend Films

In the current paper we prepared a blend film containing polyvinyl alcohol (PVA), polyethylene glycol (PEG) and polyvinyl pyrrolidone (PVP) using a solution casting technique. Samples from the prepared PVA/PEG/PVP film were irradiated with gamma radiation doses (10 − 80 kGy). The resultant effects of the gamma ray irradiation on the optical and color properties of the prepared films were investigated using UV-vis spectroscopy and the International Commission on Illumination (CIE) color changes technique. When the gamma dose was increased to 80 kGy, the direct optical band gap (Eg) decreased from 3.28 to 3.22 eV. We attribute this decrease to the dominance of crosslinking that damaged the ordered structure and thus increased the amorphous regions. Moreover, the values of Eg, obtained from ε″ vs. energy plots, were close to those values obtained using Tauc’s relation, indicating that the blend films exhibited a direct allowed transition. Finally, the color changes between the pristine and irradiated films were estimated. The pristine PVA/PEG/PVP blend film exhibited significant color differences.

Electrical Conductivity Properties of Solid Polymer Electrolytes PEO-PVP-NaIO4 Filled with TiO2 Nanoparticles

Frequency-dependent conductivity and conduction relaxation in nanocomposite solid polymer electrolyte films consisting of poly(ethylene oxide) and polyvinyl pyrrolidone blend as host matrix, NaIO4 as ions dopant, and titanium dioxide (TiO2) nanoparticles of average size 10 nm, were studied. The films were characterized using measurements of complex electrical impedance spectra in the frequency range from 1 Hz to 1 MHz, at room temperature. The concentration of the salt NaIO4 was 10 wt%, the TiO2 percentage varied from 1 wt% to 5 wt%. The frequency spectra of both alternating-current (AC) conductivity and electric modulus were analyzed in order to elucidate the effect of TiO2 nanoparticles on the electrical transport properties of the examined electrolyte thin films with a thickness of 150 μm.

Nanosecond laser ablation assisted the enhancement of antibacterial activity of copper oxide nano particles embedded though Polyethylene Oxide/Polyvinyl pyrrolidone blend matrix

Via one-step Laser Ablation process, different contributions of copper oxide nanoparticles (CuONPs) were scattered through Polyethylene Oxide (PEO)/Polyvinyl pyrrolidone (PVP) blend matrix. The obtained films were characterized via XRD and FTIR. Their micro-structural features and morphological behaviors were investigated using TEM and FESEM. The CuONPs were formed in a spherical shapes with dimensions around 50 nm in case of processing time 5.0 min, while their size was deteriorated at t = 25.0 min to be around 30 nm upon TEM micrographs. In addition, surface roughness average was enhanced from 26.0 nm at no contribution of CuONPs reaching to 37.0 nm at the highest content. The composite films displayed antibacterial activity against E. coli and S. aureus upon CuONPs contribution. The antibacterial activity jumped from no effect at no contribution of CuONPs to be around 89 ± 4% and 82 ± 3% against E. coli and S. aureus respectively at their highest contribution. Therefore, it could be seen that these films were carried out using facile method and displayed a great effectiveness through biological environment which could encourage more investigations for these compositions to be suggested for wound healing applications.

Pulsed laser ablation route assisted copper oxide nanoparticles doped in Polyethylene Oxide/Polyvinyl pyrrolidone blend for enhancement the electrical conductivity

Polyethylene Oxide/Polyvinyl pyrrolidone blend was doped by Copper Oxide Nanoparticles (CuONPs) prepared by laser ablation process. Synthesized Copper oxide nanoparticles were prepared by ablating pure copper plate immersed in DDW by nanosecond Nd:YAG laser in different times. PEO/PVP/CuONPs nanocomposites have been synthesized via casting technique. Effect of CuONPs doping on enhancing PEO/PVP have been obtained. The influence of various times of laser ablation on the properties of the synthesized nanocomposite films was analyzed via several techniques. SEM and XRD proved the interaction between PEO/PVP blend and CuONPs. The presence of the distinctive absorption peak at UV–Vis range at 277 nm was due to copper oxide surface plasmon resonance (SPR). The direct and indirect optical band gap values illustrate a decrease following doping of copper oxide inside PEO/PVP matrix. Dielectric constant and dielectric loss activity gradually diminished as the frequency rises. AC conductivity were increased as laser time increased.

Structural and Electrical Properties of Ammonium Thiocyanate Doped Poly Ethylene Oxide / Poly Vinyl Pyrrolidone Blend Polymer Electrolytes

Blend polymer electrolytes based on PEO:PVP with various wt% of NH4SCN are prepared by simple solution casting method. The prepared polymer electrolytes are characterized using several techniques. The XRD studies confirm the amorphous and crystalline behavior of prepared BPEs. Functional groups present in the systems are confirmed by Fourier Transform Infrared spectroscopy (FTIR) studies. The electrical properties are analyzed by ac impedance technique. The maximum ionic conductivity is obtained for 20wt% of ammonium thiocyanate doped system and it is 1.81×10-5 S/cm-1 . The dielectric properties of polymer films are also studied and discussed.

Sensitized green emission of terbium with dibenzoylmethane and 1, 10 phenanthroline in polyvinyl alcohol and polyvinyl pyrrolidone blends

Tb doped polyvinyl alcohol: polyvinyl pyrrolidone blends with dibenzoylmethane (DBM) and 1, 10 Phenanthroline (Phen) have been prepared by solution cast technique. Bond formation amongst the ligands and Tb3+ ions in the doped polymer has been confirmed employing Fourier Transform Infrared (FTIR) techniques. Optical properties of the Tb3+ ions have been investigated using UV–Vis absorption, excitation and fluorescence studies excited by different radiations. Addition of dimethylbenzoate and 1, 10 Phenanthroline to the polymer blend increases the luminescence from Tb3+ ions along with energy transfer from the polymer blend itself. Luminescence decay curve analysis affirms the non-radiative energy transfer from DBM and Phen to Tb3+ ions, which is identified as the reason behind this enhancement. The fluorescence decay time of PVA-PVP host decreases from 6.02ns to 2.31ns showing an evidence of energy transfer from the host blend to the complexed Tb ions. Similarly the lifetime of DBM and Phen and both in the blend reduces in the complexed system showing the feasibility of energy transfer from these excited DBM and Phen to Tb3+ and is proposed as the cause of the above observations. These entire phenomena have been explained by the energy level diagram.

Polyvinyl alcohol and polyvinyl alcohol/ polyvinyl pyrrolidone biomedical foams crosslinked by gamma irradiation

Foams for biomedical applications were made from polyvinyl alcohol, polyvinyl alcohol / polyvinyl pyrrolidone blend and their nanocomposites with nanoclay by clean processes. Air was entrapped into the aqueous polymer solutions during vigorous mixing and then the solutions were freeze-dried. The foams structure was stabilized by crosslinking via gamma irradiation without using any harmful chemicals. The hydrophilic biocompatible foams possessed interconnected open cell structure with remarkable capacity to absorb and retain water. The foams in wet state were soft and flexible. Desirable pore structure and higher water absorption was obtained at a solution concentration of 5 wt% for both polyvinyl alcohol and polyvinyl alcohol / polyvinyl pyrrolidone foams and also for the nanocomposite foams. The polyvinyl alcohol / polyvinyl pyrrolidone foams at a composition of 80/20 had a uniform porous structure. Addition of 20 wt% polyvinyl pyrrolidone increased the size and interconnectivity of the cell structure and rendered more flexible foams than the neat polyvinyl alcohol. Also the nanoclay, in the nanocomposite foams, elevated pore population through generation of more air bubbles during aqueous polymer solution mixing.

Controlling the porosity of a polyethersulfone membrane surface with an XeCl laser

Pure and polyvinyl pyrrolidone blend polyethersulfone (PES) membranes were irradiated by an XeCl laser with various numbers of pulses at different fluences to investigate the changes in the surface morphology and the porosity. The results show that the membrane pore size and distribution on the surface can be modified following irradiation dependent on the laser fluence, the number of pulses and the membrane composition. These changes are very attractive for improving the membrane surface in filtration processes and biological applications.

Polyvinyl alcohol-polyvinyl pyrrolidone thin films provide local short-term release of anti-inflammatory agents post spinal cord injury

Spinal cord injury (SCI) triggers a large inflammatory response that results in exacerbated tissue damage. Locally delivering anti-inflammatory drugs could mitigate this secondary wave of degeneration. The mitogen-activated protein kinase family members p38 and c-Jun N-terminal kinase (JNK) play important roles in the inflammatory response and cell death. We propose that the use of polymer thin films, made of polyvinyl alcohol and polyvinyl pyrrolidone blends (PVA-PVP), can be used to provide local release of inhibitors to p38 and JNK post-SCI. Release studies performed in vitro confirmed the inhibitors could be released from the film for up to 7 days. The thin film was also tested for its surgical feasibility using a cervical contusion model of SCI in adult female rats. Films with or without the inhibitors were placed subdurally over the injury site immediately following SCI. Animals were sacrificed 5 days post-SCI and spinal cord tissue above and below the injury site was harvested. Additionally, films were removed for analysis. Scanning electron microscopy confirmed the anti-fouling properties of the PVA-PVP film. Tissue histology confirmed that the films themselves did not generate a large immune response, but they did compress the tissue slightly at its placement above the injury site. Finally, quantitative Western blot analysis determined the films loaded with p38 and JNK inhibitors delivered bioactive agents to the injury site and resulted in a significantly decreased amount of pro-cell death proteins. These data indicate that PVA-PVP films can be used to effectively deliver drugs to a SCI site.

Synergistic inhibition effect of polyethylene glycol–polyvinyl pyrrolidone blends for mild steel corrosion in sulphuric acid medium

AbstractThe corrosion inhibition of mild steel in sulphuric acid solution in the presence of polyethylene glycol (PEG), polyvinyl pyrrolidone (PVP), and their blends was investigated using weight loss and hydrogen evolution techniques at temperature range of 30–60°C. It was found that inhibition efficiency (η%) increases with increase in concentration of the homopolymers and decreases with increase in temperature. Inhibition efficiency was found to be synergistically enhanced on blending the two polymers with highest inhibition efficiency obtained for (PEG : PVP) blending ratio of 1 : 3. The experimental data obtained fitted well into Temkin adsorption isotherm model. Physical adsorption mechanism is proposed from the trend of inhibition efficiency with temperature. The proposed mechanism is also corroborated by kinetic and thermodynamic parameters obtained. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Dielectric and interaction behavior of chitosan/polyvinyl alcohol and chitosan/polyvinyl pyrrolidone blends with some antimicrobial activities

The blends of chitosan, polyvinyl alcohol and chitosan polyvinyl pyrrolidone in dilute acetic acid were found to be compatible by viscosity measurements. The dielectric behavior of the investigated blends were studied using frequency response analyzer covering a frequency range from 10 2 to 10 6 Hz and in a wide range of temperature. The permittivity ε′ was found to decrease by increasing the frequency showing an anomalous dispersion. The dielectric loss ε″ data on the frequency domain were found to be broad indicating that more than one relaxation mechanism is present. The data for the whole investigated systems were fitted using Fröhlich and/or Havriliak–Negami functions in addition to the conductivity term. The function detected below T g could be ascribed to an orientation movement related to the side chain. A second function in the lower frequency range could be ascribed as a Maxwell Wagner effect which arises from the interfacial polarization caused by the multi-constituents of the investigated systems. The biological activity of such investigated systems was tested against a representative number of pathogenic organisms by determining the minimum inhibitory concentration (MIC). The activity was found to increase by increasing the amount of CS in the blend.

Polysulfone and polyvinyl pyrrolidone blend membranes with reverse phase morphology as controlled release systems: experimental and theoretical studies

Blend membranes of poly(bis phenol–A-ether sulfone) (PSF) and poly( n-vinyl pyrrolidone) (PVP) in ratios (90:10 to 10:90; with increments of 10) were prepared via solution casting technique. The membranes were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that the blend is immiscible having the major phase of the blend homogeneously dispersed in the continuum of the minor phase indicating the presence of “reverse phase morphology” (RPM) by SEM analysis of the dissolution treated membranes. The interaction parameter χ PVP/PSF was calculated and the ternary phase diagram with tentative spinodal along with the super-imposed experimental cloud points has been illustrated. The symmetric spherical geometry of the dispersed phase was explained theoretically with the help of the Flory Huggins Theory. The performance of these membranes as rate controlling membranes in controlled release applications was studied by coating them on paracetamol tablets and the effect of the ratio of PVP in the blend membrane on the rate of drug release was monitored. Models of mass transfer employing Fickian principles at constant temperature and pressure were elucidated to support the experimental findings. The predicted models were found to be in excellent agreement with the experimental release profiles.

The compatibility study of polycarbonate-polyvinyl pyrrolidone blend using high-resolution solid-state nuclear magnetic resonance

The combining nuclear magnetic resonance techniques in the solid state permit the evaluation of the polymeric systems homogeneity. In the polycarbonate-poly(vinyl pyrrolidone) (PVP) blends, the response of proton spin-lattice relaxation time in the rotating frame was the determinant to obtain information on the transition when the quantity of PVP is close to 40% by weight and a better organization of amorphous phase was detected. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 449–453, 1998