Molecular Weight Of Polyvinylpyrrolidone Research Articles

The structural and figure of merit photodetector of PVP-doped with lanthanum

This study describes the fabrication and characterization of PVP and PVP/La thin films from a mixture of high molecular weight polyvinylpyrrolidone (PVP) and (1, 2, and 3)% lanthanum chloride using an electrospinning process on glass and silicon. It includes an N- type (Si) (111) substrate at room temperature. Field Emission Scanning Electron Microscopy (FESEM) analysis reveals fibers with an average diameter in the range of 125-250 nm. The mean fiber diameter decreases with increasing concentration (La). The optical energy gap was determined from the analysis of the transmission spectrum in the UV-visible region. The optical gap (Eg) gradually decreases from 4 eV to 3.64 eV for undoped PVP films due to the increase in La ion content at 3%, which determines the feasibility of using these obtained fibers in the manufacturing process. PVP/La nanofibers as detectors.

Fabrication, characterization, and performance of poly (aryl ether nitrile) flat sheet ultrafiltration membranes with polyvinyl pyrrolidone as additives

Abstract Poly(aryl ether nitrile) (PEN) was used to fabricate ultrafiltration membrane via immersion precipitation phase inversion method. The effects of polyvinyl pyrrolidone (PVP) of different molecular weights and concentrations on the structure and performance of PEN membranes were investigated. The membranes were observed by scanning electron microscope, atomic force microscope, equilibrium water content (EWC), porosity (ε), and so on. The membranes were subjected to ultrafiltration characterizations such as pure water flux (PWF), compaction factor (CF), hydraulic permeability (P m), and bovine serum albumin (BSA) rejection rate. The hydrophilicity was characterized by infrared spectroscopy and contact angle tests. Results showed that molecular weight of PVP had significant effect on PEN membrane formation, which the membrane prepared by PVP-k30 exhibited excellent comprehensive performance. Meanwhile, the concentration of PVP-k30 could effectively control the select-permeability of PEN membrane. With PVP-k30 concentration increased from 7 to 13 wt%, the prepared PEN membranes got higher EWC, ε, CF, and P m. The PWF increased from 146.5 to 249.1 L m−2 h−1 bar−1, while the overall rejection of BSA remained above 90%. Further increasing the addition amount to 16 wt%, the membrane performance began to decline. Finally, the addition of PVP-k30 could effectively improve the hydrophilicity of prepared PEN membrane surface.

ZIF-8 enriched electrospun ethyl cellulose/polyvinylpyrrolidone scaffolds: The key role of polyvinylpyrrolidone molecular weight

A set of zeolitic imidazolate framework-8 (ZIF-8) incorporated ethyl cellulose/polyvinylpyrrolidone scaffolds was prepared by electrospinning method. The impact of polyvinylpyrrolidone molecular weight on characteristics of prepared scaffolds was investigated. The ethyl cellulose/polyvinylpyrrolidone scaffold made of polyvinylpyrrolidone 17,000 showed the narrowest nanofibers (mean diameter = 140 nm), the highest percentages of porosity (62%) and swelling (>130%), the most hydrophilic surface (water contact angle = 74°), the fastest rate of degradation, and the best elongation at break (6.3%) among the samples. Furthermore, the higher capability of this scaffold for cell proliferation was revealed through MTT test (125% after 5 days of culture), Live/Dead assay, and FESEM images of cell attachment. This scaffold also represented the highest released amount of ZIF-8-induced Zn2+ ions (20 ppm after 84 h) leading to its greatest antibacterial activity. These findings indicated that the ZIF-8 incorporated ethyl cellulose/polyvinylpyrrolidone scaffold can be used in future skin tissue-engineered constructs.

Chronic Kidney Disease from Polyvinylpyrrolidone Deposition in Persons with Intravenous Drug Use.

Persons with intravenous drug use have a higher risk of developing CKD compared with the general population. In Norway, deposits of polyvinylpyrrolidone have been observed in kidney biopsies taken from persons with opioid addiction and intravenous drug use since 2009. Polyvinylpyrrolidone is an excipient commonly used in pharmaceuticals, and the polyvinylpyrrolidone deposits observed in these patients were caused by intravenous injection of a specific oral methadone syrup containing very high molecular weight polyvinylpyrrolidone. Here, we present the clinicopathologic findings from 28 patients with CKD associated with polyvinylpyrrolidone deposition in the kidney. The 28 patients and their kidney biopsies were included when polyvinylpyrrolidone deposition was recognized, either retrospectively or at the time of diagnostic evaluation. Biopsies were taken between 2009 and 2016. We collected laboratory parameters and clinical data from digital patient charts. For each kidney biopsy, the glomerular volume, extent of polyvinylpyrrolidone deposition, and tubulointerstitial area with tubular atrophy were assessed quantitatively. All patients (mean age: 37 years) had CKD (mean eGFR: 33 ml/min per 1.73 m2) and normal urine protein or non-nephrotic-range proteinuria. Biopsies showed moderate to severe tubular atrophy (mean extent: 65%) and interstitial infiltrates of vacuolated macrophages containing polyvinylpyrrolidone (mean share of biopsy area: 1.5%). Underperfused and ischemic glomeruli were common findings. In 22 samples, ultrastructural investigation revealed polyvinylpyrrolidone-containing vacuoles in the mesangial or endothelial cells of glomeruli. At the last follow-up, most patients had stable or improved eGFR. Two patients had developed kidney failure and underwent hemodialysis. Intravenous injection of a specific oral methadone syrup caused polyvinylpyrrolidone deposition in the kidney in persons with opioid addiction and intravenous drug use. Kidney biopsy findings suggested an association between polyvinylpyrrolidone deposition and tubular atrophy.

Technical note: Temperature and concentration dependence of water diffusion in polyvinylpyrrolidone solutions.

ObjectiveThe goal of this work is to provide temperature and concentration calibration of water diffusivity in polyvinylpyrrolidone (PVP) solutions used in phantoms to assess system bias and linearity in apparent diffusion coefficient (ADC) measurements.MethodADC measurements were performed for 40 kDa (K40) PVP of six concentrations (0%, 10%, 20%, 30%, 40%, and 50% by weight) at three temperatures (19.5°C, 22.5°C, and 26.4°C), with internal phantom temperature monitored by optical thermometer (±0.2°C). To achieve ADC measurement and fit accuracy of better than 0.5%, three orthogonal diffusion gradients were calibrated using known water diffusivity at 0°C and system gradient nonlinearity maps. Noise‐floor fit bias was also controlled by limiting the maximum b‐value used for ADC calculation of each sample. The ADC temperature dependence was modeled by Arrhenius functions of each PVP concentration. The concentration dependence was modeled by quadratic function for ADC normalized by the theoretical water diffusion values. Calibration coefficients were obtained from linear regression model fits.ResultsMeasured phantom ADC values increased with temperature and decreasing PVP concentration, [PVP]. The derived Arrhenius model parameters for [PVP] between 0% and 50%, are reported and can be used for K40 ADC temperature calibration with absolute ADC error within ±0.016 μm2/ms. Arrhenius model fit parameters normalized to water value scaled with [PVP] between 10% and 40%, and proportional change in activation energy increased faster than collision frequency. ADC normalization by water diffusivity, D W, from the Speedy–Angell relation accounted for the bulk of temperature dependence (±0.035 μm2/ms) and yielded quadratic calibration for ADCPVP/D W = (12.5 ± 0.7) ·10−5·[PVP]2 − (23.2 ± 0.3)·10−3·[PVP]+1, nearly independent of PVP molecular weight and temperature.ConclusionThe study provides ground‐truth ADC values for K40 PVP solutions commonly used in diffusion phantoms for scanning at ambient room temperature. The described procedures and the reported calibration can be used for quality control and standardization of measured ADC values of PVP at different concentrations and temperatures.

Fabrication of multilayer Graphene-coated Copper nanoparticles for application as a thermal interface material

A process to fabricate a thermal interface material (TIM) was developed to coat graphene, which is chemically stable and thermally conductive, on the surface of copper nanoparticles (CNPs) to prevent their oxidation while promoting heat dissipation. The CNPs were synthesized using the polyol method to convert polyvinylpyrrolidone (PVP) into multilayer graphene (MLG) via chemical vapor deposition (CVD). For optimization, CVD temperature, the amount of additional PVP solution, and PVP molecular weight (MW) in polyol process were varied. The results showed that thermal properties degraded with increasing residual PVP, and an increasing ID/IG ratio confirmed improved MLG quality. The optimal MLG coating conditions were found to be a CVD temperature of 880℃, 50 wt% additional PVP solution and using K30 PVP in polyol process (MW: 45,000). These conditions provided the highest thermal conductivity of 19.66 W/m∙K. Thermogravimetric analysis established that oxidation began at 150℃, which is higher than the upper temperature limit of electronic components. Therefore, MLG-coated CNPs would be suitable as TIM.

Synthesis of silver nanorings through a glycerol-base polyol method

Silver nanoring, a new nanomaterial with special morphology, exhibits attractive potential in optoelectronics applications. In this work, a glycerol-base modified polyol method is investigated. Using this method, silver nanorings with perfect geometry and ring diameter range from 6.54 to 30.67ss μm, wire diameter of 66.7-115.5 nm were synthesized by replacing EG with glycerol and adjusting the molecular weight and concentration of polyvinylpyrrolidone (PVP). The growth mechanism and factors that affect the morphology were studied in detail. The formation of silver nanorings showed high dependence on the viscosity of solution, wire diameter of AgNWs and the molecular weight of PVP.

Revisiting the preparation of cylindrical polystyrene particles by magnetic stirring

The cylindrical shape is one of the most common shapes in geometry. The preparation of cylindrical polystyrene (PS) particles by magnetic stirring has been previously reported (Angew. Chem. Int. Ed.2018, 57, 9936–9940) via two steps: spherical PS particles were synthesized by dispersion polymerization of styrene with polyvinylpyrrolidone (PVP) as the stabilizer, followed by stirring the spherical PS particles in a water medium in the presence of PVP. However, the effects of various parameters on the deformation were not fully investigated. Herein we report full details of the preparation of cylindrical PS particles by stirring at room temperature. The influence of PVP molecular weight in the polymerization process, and various stirring parameters such as the molecular weight of PVP for stirring, concentration of PVP for stirring, stirring time, stirring rate, size of stirrer and amount of the mixture for stirring on the morphology of the resulting particles was investigated systematically. Moreover, a larger glass vial and correspondingly a larger magnetic stirrer were used in this work, which could produce cylindrical polymer particles at a five-fold larger scale. However, the production of cylindrical polymer particles at a even (fifty-fold) larger scale was less successful and might lead to a substantial part of peanut-shaped particles. This work is expected to be useful for improved understanding of the formation of these cylindrical polymer particles.

Transport of silver nanoparticles coated with polyvinylpyrrolidone of various molecular sizes in porous media: Interplay of polymeric coatings and chemically heterogeneous surfaces

Silver nanoparticles (AgNPs) are usually capped with stabilizing agents to protect their activities and improve stability. Polyvinylpyrrolidone (PVP) is one of the most used capping agents of AgNPs, and may affect the transport of AgNPs in porous media. The transport and retention of AgNPs capped with PVPs of different molecular weights (PVP10-AgNP, PVP40-AgNP and PVP360-AgNP) in uncoated, and humic acid (HA)-, kaolinite (KL)- and ferrihydrite (FH)-coated sand porous media were investigated. Among the three AgNPs, PVP360-AgNP exhibited the highest mobility and eluted from all types of porous media. This is because PVPs of higher molecular weight provided stronger steric effect and electrostatic repulsive forces among PVP-AgNPs, inducing stronger blocking and shadow effects. The transport of the PVP-AgNPs increased in the HA-Sand columns, while decreased in the KL- and FH-Sand columns, especially for PVP10-AgNP and PVP40-AgNP. The simulation results using one-site kinetic model indicated that HA-Sand reduced the maximum retention capacity (Smax), while KL- and FH-Sand increased the Smax as well as the first-order attachment rate coefficients (katt), particularly at high ionic strength. The results shed light on the interplay of the capping agents of AgNPs and the surface heterogeneity on the transport of AgNPs in porous media.

Optical Oxygen Sensor Patch Printed with Polystyrene Microparticles-based Ink on Flexible Substrate.

Optical oxygen sensors based on photoluminescence quenching have gained increasing attention as a superior method for continuous monitoring of oxygen in a growing number of applications. A simple and low-cost fabrication technique was developed to produce sensor arrays capable of two-dimensional oxygen tension measurement. Sensor patches were printed on polyvinylidene chloride film using an oxygen-sensitive ink cocktail, prepared by immobilizing Pt(II) mesotetra(pentafluorophenyl)porphine (PtTFPP) in monodispersed polystyrene microparticles. The dispersion media of the ink cocktail, high molecular weight polyvinyl pyrrolidone suspended in 50% ethanol (v/v in water), allowed adhesion promotion and compatibility with most common polymeric substrates. Ink phosphorescence intensity was found to vary primarily with fluorophore concentration and to a lesser extent with polystyrene particle size. The sensor performance was investigated as a function of oxygen concentrations employing two different techniques: a multi-frequency phase fluorometer and smart phone-based image acquisition. The printed sensor patch showed fast and repetitive response over 0-21% oxygen concentrations with high linearity (with R2 >0.99) in a Stern-Volmer plot, and sensitivity of I0/I21 >1.55. The optical sensor response on a surface was investigated further using two-dimensional images which were captured and analyzed under different oxygen environment. Printed sensor patch along with imaging read-out technique make an ideal platform for early detection of surface wounds associated with tissue oxygen.

Выбор спейсера на первом этапе лечения поздней глубокой перипротезной инфекции тазобедренного сустава

Abstract. Introduction Periprosthetic infection in hip arthroplasty is a social and economic problem. Its main reason is multidrug resistance of microorganisms. Purpose To evaluate the effectiveness of the first stage in two-stage revision arthroplasty for the treatment of deep periprosthetic infection of the hip joint by improving the constructive and antibacterial features of spacers. Materials and methods The treatment results of 127 patients with late deep periprosthetic hip joint infection who underwent two-stage revision arthroplasty in the period from 2015 to 2019 were analyzed. In the first group, 42 patients were fitted with a two-component (total) spacer based on the developed antimicrobial composition of bone cement with gentamicin, antiseptics and polymer (patent RU 191236). In the second group, a two-component spacer (patent RU 174697) based on conventional bone cement with gentamicin was implanted in 43 patients; the third group of 42 patients had a preformed spacer. Results A bactericidal and antiadhesive, nontoxic composition based on bone cement with gentamicin with antiseptics poviargol, dioxidine and high molecular weight polyvinylpyrrolidone with a prolonged action for 348 days against gentamicin-resistant staphylococci has been developed. All patients underwent the first stage of hip arthroplasty with removal of the implant and installation of a spacer. Recurrence of periprosthetic infection was observed in 1 (2.3 %) patient of the first group, in 5 (11.6 %) in the second and in 6 (14.2 %) patients of the third group. Non-infectious complications such as spacer dislocation and instability were observed in 12 cases, one case (2.3 %) in the first, 2 (4.6 %) in the second and 9 (21.4 %) in the third group. The average time from the first stage of treatment to the second stage of re-implantation was 7.5 months (range, 4–13 months). Discussion According to the literature, the introduction of new antibiotics into the bone cement with gentamicin does not increase the antimicrobial action of the spacer, especially against antibiotic-resistant isolates, and the use of a preformed spacer contributes to an increase in the number of non-infectious complications. Antiseptics with different mechanisms of action are able to act on antibiotic-resistant bacteria, and the polymer can prolong this effect. Conclusions Creation of two-component spacers based on bone cement with gentamicin using antiseptics with different mechanisms of action and polymer promotes long-term bactericidal action of the spacer, which leads to effective sanation of the joint area, reducing non-infectious complications.

Evaluation of polyvinylpyrrolidone as draw solute for desalination forward osmosis systems

Abstract In this study, polyvinylpyrrolidone (PVP) was evaluated as a potential draw solute for desalination forward osmosis (FO) systems. The effect of various draw solute and draw solution parameters on the efficiency of FO operation was investigated, including PVP molecular weight, PVP concentration in solution, and the salinity of feed solution. Experiment results showed that at draw solution initial concentration of 200 g/L and feed solution initial salinity up to 15 g/L, the PVP-based draw solution can offer water flux up to 14.23 LMH in FO mode with raw material cost only at 0.61 USD/m3. PVP K17 was proven to be an effective draw solute for FO systems, providing good water flux and low reverse draw solute flux; while also being relatively non-toxic, non-corrosive, cheap and widely available compared to other types of novel draw solutes.

Interactions in solvent–polycaprolactone–cellulose nanocrystals–polyvinyl pyrrolidone system: Experiment and molecular dynamics simulation

In this paper, physical adsorption of polyvinylpyrrolidone (PVP) was used as the method of surface modification of cellulose nanocrystals (CNCs). The work also considers the PVP molecular weight effect on dispersion of the surface-modified CNC in dichloromethane (DCM). The authors analyze the physicochemical properties of the composite with polycaprolactone (PCL) - CNC/PVP/PCL - prepared from a solution of PVP-modified CNCs in DCM, and conduct a molecular dynamics simulation of the interactions between the system (CNC, PVP, PCL) components in vacuum and in a solvent medium (water, DCM). According to the simulation results, the CNC/PVP/PCL composite has the following structure: PCL macromolecules have practically no direct contacts with the CNC surface but are located between the PVP macromolecules that, in their turn, are predominantly located near the CNC particle surface.

A Comparative Study on the Role of Polyvinylpyrrolidone Molecular Weight on the Functionalization of Various Carbon Nanotubes and Their Composites.

Polyvinylidene fluoride (PVDF) nanocomposites filled with polyvinylpyrrolidone (PVP) wrapped carbon nanotubes were prepared via a solution casting technique. The effect of the molecular weight (polymer chain length) of the PVP on the ability to wrap different nanotube structures and its impact towards nanotube dispersibility in the polymer matrix was explored. The study was conducted with PVP of four different molecular weights and nanotubes of three different structures. The composites that exhibit an effective nanotube dispersion lead to a nanotube network that facilitates improved thermal, electrical, and mechanical properties. It was observed that nanotubes of different structures exhibit stable dispersions in the polymer matrix though PVP functionalization of different molecular weights, but the key is achieving an effective nanotube dispersion at low PVP concentrations. This is observed in MWNT and AP-SWNT based composites with PVP of low molecular weight, leading to a thermal conductivity enhancement of 147% and 53%, respectively, while for P3-SWNT based composites, PVP of high molecular weight yields an enhancement of 25% in thermal conductivity compared to the non-functionalized CNT-PVDF composite.

The Effect of the Molecular Weight of Polyvinylpyrrolidone and the Model Drug on Laser-Induced In Situ Amorphization.

Laser radiation has been shown to be a promising approach for in situ amorphization, i.e., drug amorphization inside the final dosage form. Upon exposure to laser radiation, elevated temperatures in the compacts are obtained. At temperatures above the glass transition temperature (Tg) of the polymer, the drug dissolves into the mobile polymer. Hence, the dissolution kinetics are dependent on the viscosity of the polymer, indirectly determined by the molecular weight (Mw) of the polymer, the solubility of the drug in the polymer, the particle size of the drug and the molecular size of the drug. Using compacts containing 30 wt% of the drug celecoxib (CCX), 69.25 wt% of three different Mw of polyvinylpyrrolidone (PVP: PVP12, PVP17 or PVP25), 0.25 wt% plasmonic nanoaggregates (PNs) and 0.5 wt% lubricant, the effect of the polymer Mw on the dissolution kinetics upon exposure to laser radiation was investigated. Furthermore, the effect of the model drug on the dissolution kinetics was investigated using compacts containing 30 wt% of three different drugs (CCX, indomethacin (IND) and naproxen (NAP)), 69.25 wt% PVP12, 0.25 wt% PN and 0.5 wt% lubricant. In perfect correlation to the Noyes–Whitney equation, this study showed that the use of PVP with the lowest viscosity, i.e., the lowest Mw (here PVP12), led to the fastest rate of amorphization compared to PVP17 and PVP25. Furthermore, NAP showed the fastest rate of amorphization, followed by IND and CCX in PVP12 due to its high solubility and small molecular size.

Preparation and characterization of asymmetric hollow fiber polyvinyl chloride (PVC) membrane for forward osmosis application

• Asymmetric nanofiltration PVC hollow fiber membranes were fabricated via dry-wet spinning technique. • Delayed demixing was achieved by addition of high molecular weigh PVP. • Volatile solvent evaporation resulted in dense selective layer. • The effect of fabrication parameters were investigated in order to introduce best-suited membrane. • The effect of DS concentration and temperature were studied by means of Flux and SRSF. PVC hollow fiber (HF) membrane for forward osmosis (FO) application as a potential candidate for water desalination was fabricated by altering the spinning conditions. High molecular weight polyvinylpyrrolidone (PVP) was used as a blending additive to control the phase inversion process by increasing viscosity leading to delayed demixing as observed on the ternary phase diagram and confirmed by the simulation results, and forming dense barrier layer structure by providing chain entanglements with the PVC matrix. PVP/PVC ratio of 5/100 was proved to offer suited membrane morphology and selective layer. Different air gap distances and bore fluid flow rates were investigated to achieve proper fabrication parameters. The prepared membranes presented high flux and salt rejection in nanofiltration (NF) and FO tests. The best-suited membrane demonstrated the structural parameter of 389 µm with a narrow pore size distribution and a molecular weight cut-off of 490 Da. In different draw solution (DS) concentrations, it was observed that the membranes perform well in all conditions. Considering the PVC-PVP chain entanglements and mobility and the possibility of PVP being washed away, the membranes’ performance at different temperatures indicated that 25–45 °C would be the safe operating range for the fabricated membranes with stable values of 31.0–33.4 LMH and 0.17–0.18 (FO mode) and 33.0–33.4 LMH and 0.23–0.24 (PRO mode) for water flux and specific reverse salt flux.

Synthesis of AgNWs Using High Molecular Weight PVP As a Capping Agent and Their Application in Conductive Thin Films

High molecular weight polyvinylpyrrolidone (PVP) and seeding conditions are considered to have important roles in the synthesis of AgNWs. In this work, we report a versatile synthesis of AgNWs in a salt-free environment and under Ar inert atmosphere using high molecular weight PVP and seeding step during the synthetic process. The high molecular weight PVP was found to efficiently promote the preparation of AgNWs via supporting the proper growth control of AgNWs on {111} facets and selective growth on {100} facets. The seeding step facilitates the formation of seeds such as multiple twinned nanoparticles (MTPs) and single crystal seeds, which promoted the feasible formation of AgNWs. The shape and size of the synthesized AgNWs were characterized by SEM and TEM. The crystalline nature of the synthesized AgNWs was characterized by HRTEM, SAED and XRD, and their LSPR peaks were confirmed by UV-Vis spectroscopy. The conductive properties of the synthesized AgNWs were determined by preparing their thin conductive film on a PET substrate. The prepared AgNWs thin films exhibited good sheet resistance.

The effects of polyvinylpyrrolidone molecular weight on defect-free filling of through-glass vias (TGVs)

Through-glass vias (TGVs) have been extensively researched due to the unique properties of glass, including low dielectric constant, high transparency, high mechanical, thermal and chemical resistance, and low cost. The TGVs are typically filled with Cu by electrodeposition to make electrical connections in high-performance electronics with 3D integration. The Cu electrodeposition process employed to fill the through-holes is similar to the one used for printed circuit boards (PCBs), and defect-free Cu can be achieved with a butterfly filling mechanism. This study introduces the defect-free Cu filling of TGVs using polyvinylpyrrolidone (PVP) as a leveler. The effects of PVP molecular weight on the formation of suppression layers on the Cu surface was examined by electrochemical analyses. It was found that the smaller PVP (10,000g/mol) was beneficial, forming a more compact suppression layer. In contrast, the layer of larger PVPs (360,000g/mol) contained a large number of defects where the accelerator could adsorb, resulting in conformal electrodeposition. As a result, the PVP with a molecular weight of 10,000g/mol led to defect-free butterfly filling at TGVs with increasing the filling performance by 20% compared to the larger PVP.

High cut-off membrane: evaluation of pore collapse and the synergistic effect of low and high molecular weight polyvinylpyrrolidone

High cut-off (HCO) membranes are the new class of membranes using in several applications like blood purification systems. In the current study, efforts were based upon achieving the HCO membrane with defined properties. Membrane pore collapse is the most challenging problem recognized as an undesirable phenomenon occurring in the drying stage of membrane preparation. Herein, this phenomenon was investigated in detail. The results verified that further of liquid surface tension, other parameters including viscosity, boiling point, polarity, and solubility parameters can be effective on the formation or prevention of this phenomenon. After preventing the pore collapse phenomenon, the simultaneous effect of low and high molecular weights polyvinylpyrrolidone (PVP) to achieve the HCO membrane was evaluated. PVP-K90 is used as a hydrophilizing agent and PVP-K17 is a low molecular weight polymer utilized as a pore-former additive. The synergistic effects of both grades of PVP, provide appropriate membrane features. Contact angle analysis indicated that by incorporation of PVP-K90 in casting solution, membrane hydrophilicity was increased tangibly. With the addition of more content of PVP-K90 higher than 3 wt%, pure water permeability (PWP) of the membrane was decreased. With adding PVP-K17 till 5 wt%, membrane PWP was enhanced significantly which confirmed the pore-former property of this additive. Moreover, mean pore diameter of membranes was increased and subsequently MWCO was enhanced to a higher value with the addition of this pore-former additive. MTT analysis endorsed the biocompatibility of membranes.

Effect of Temperature and Additives on the Interaction of Ciprofloxacin Hydrochloride Drug with Polyvinylpyrrolidone and Bovine Serum Albumin: Spectroscopic and Molecular Docking Study.

The fluoroquinolone antibiotic drug namely ciprofloxacin hydrochloride (CFH) is widely prescribed for the treatment of different bacterial infections. The interaction of CFH with a synthetic polymer, polyvinyl pyrrolidone (PVP), and biopolymer, bovine serum albumin (BSA) was studied by UVvisible and fluorescence spectroscopic methods at different temperatures. The binding constant (K b ) for the CFH-PVP complex was determined from the Benesi-Hildebrand plot. PVP of different molecular weights (MW) (such as 24,000, 40,000, 360,000, and 700,000 g. mole-1) were used for the interaction between CFH and PVP. The gradual increase in K b value and the complexation reaction was found to be much enhanced with the augmentation of the MW of PVP. The values of K b were also found to be increased with increasing temperatures as well as with the increase of electrolyte/acetic acid concentration. The Gibbs free energy of binding (∆G 0) values of the interaction process was negative which indicates the complex formation is thermodynamically spontaneous. The positive values of enthalpy (∆H 0) and entropy (∆S 0) of binding connote that the binding force for CFH-PVP complexation is hydrophobic in nature and the complexation is entropy controlled. The negative intrinsic enthalpy (∆H *,0) values indicate the high stability of CFH-PVP complexes. Molecular docking calculation discloses the existence of similar binding forces between CFH and PVP obtained by the analysis of experimental data from UV-visible spectroscopic method. The binding constant between CFH and BSA (K b ), quenching constant (K sv ), the number of binding sites (n), and the quenching rate constant (K q ) for the CFH-BSA system were also calculated. The values of K sv , K q , and n for the CFH-BSA system are lower in 0.05 mol L-1 urea solution and higher in PVP solutions compared to those of aqueous medium.