scholarly journals Experimental measurements and modeling of solvent activity and surface tension of binary mixtures of polyvinylpyrrolidone in water and ethanol

2017 ◽  
Vol 82 (4) ◽  
pp. 427-435
Author(s):  
Majid Taghizadeh ◽  
Saber Amiri
Keyword(s):  
Surface Tension ◽  
Vinyl Pyrrolidone ◽  
Polymer Mixtures ◽  
Temperature Range ◽  
Molecular Weights ◽  
Activity Measurements ◽  
Mass Fractions ◽  
Eyring Model ◽  
Poly Vinyl Pyrrolidone ◽  
Solvent Activity

In this paper, the density (?), viscosity (?) and surface tension (?) of solutions of poly(vinyl pyrrolidone) (PVP) with molecular weights of 25000 (K25) and 40000 g mol-1 (K40) in water and ethanol were measured in the temperature range 20?65?C and at various mass fractions of polymer (0.1, 0.2, 0.3 and 0.45). The solvent activity measurements were performed at 45 and 55?C. Thereafter, two thermodynamic models for predicting the solvent activity and surface tension of binary polymer mixtures (PVP in water and ethanol) were proposed. The Flory?Huggins theory and Eyring model were employed to calculate the surface tension of the solution and the solvent activity, respectively. Additionally, the proposed activity model was dependent on the density and viscosity of the solution. Afterwards, the ability of these models at various temperatures and mass fractions were investigated by comparing the results with the experimental data. The results confirmed that, in the investigated temperature range, these models have good accuracy.

scholarly journals Testing the Performance of Various Polymeric Antiscalants for Mitigation of Sb-Rich Precipitates Mimicking Stibnite-Based Geothermal Deposits

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Celal Çiftçi ◽  
Emre Karaburun ◽  
Serhat Tonkul ◽  
Alper Baba ◽  
Mustafa M. Demir ◽  
...  
Keyword(s):  
Power Plants ◽  
Vinyl Pyrrolidone ◽  
Poly Vinyl Alcohol ◽  
Poly Ethylene Glycol ◽  
Molecular Weights ◽  
Geothermal Fields ◽  
The World ◽  
Testing Potential ◽  
Poly Ethylene ◽  
Poly Vinyl Pyrrolidone

Scaling is frequently observed in geothermal fields and reduces the energy harvesting of power plants. Recently, Sb-rich deposits have developed in many fields around the world. Various polymeric macromolecules have been used as antiscalants to mitigate the formation of scale. Testing potential commercial antiscalants in field conditions is a tedious and costly process. The artificial synthesis of geothermal deposits in the lab is a more practical and economical way to test the performance of antiscalants. This study obtained a Sb-rich deposit by refluxing SbCl3 and Na2S·3H2O in 18 h. The product was found to be a mixture of Sb2O3 and Sb2S3. We examined the performance of antiscalants such as poly(ethylene glycol), poly(vinyl pyrrolidone), Gelatin, and poly(vinyl alcohol) of various molecular weights at 5 to 100 ppm. The formation of Sb2S3 is suppressed in the presence of the polymeric antiscalants. The dosage was found to be critical for the solubilization of Sb-rich deposits. Gelatin of 5 ppm showed the highest performance under the conditions employed in this study. While low dosages improve the concentration of [Sb3+], high dosages are required to increase the solubility of [S2-]. Moreover, the amount of deposit is reduced by 12.4% compared to the reference (in the absence of any polymeric molecules). Thus, comparatively, Gelatin shows the most promising performance among the molecules employed.

Modification of Bisphenol A Dicyanate Ester Resin with Poly Vinyl Pyrrolidone (K30)

2011 ◽  
Vol 217-218 ◽  
pp. 1497-1503
Author(s):  
Jie Liang Wang ◽  
Ai Juan Gu ◽  
Guo Zheng Liang
Keyword(s):  
Bisphenol A ◽  
Gelation Time ◽  
Vinyl Pyrrolidone ◽  
Infrared Spectrometry ◽  
Scanning Calorimetry ◽  
Sem Images ◽  
Mass Fractions ◽  
Low Mass ◽  
Poly Vinyl Pyrrolidone ◽  
Pvp K30

Poly vinyl pyrrolidone (PVP(K30)) / Bisphenol A Dicyanate ester (BADCy) blends were fabricated to increase the toughness of BADCy by blending processing in this paper. Curing parameters were determined by gelation time curves and differential scanning calorimetry (DSC) of the systems. Fourier transform infrared spectrometry (FTIR) and DSC data were employed to show the curing behavior and kinetics of the systems. Mechanical properties of the cured resin had been improved rapidly with the increasing of PVP(K30) at low mass fraction, but would decrease when mass fractions of PVP(K30) were higher than 15%. Scanning electron micrograph (SEM) was applied to show the microstructures of the cured matrixes. Based on the thermogravimetric analysis (TGA) curves, water absorption curves, SEM images and dielectric properties of the blends, it can be concluded that the addition of PVP(K30) can improve the toughness of BADCy greatly with little loss of other properties.

Investigation of Poly(vinyl pyrrolidone) in methanol by dynamic light scattering and viscosity techniques

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Adel Aschi ◽  
Mohamed Mondher Jebari ◽  
Abdelhafidh Gharbi
Keyword(s):  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Molecular Mass ◽  
Vinyl Pyrrolidone ◽  
Least Squares Regression ◽  
Particle Structure ◽  
Crossover Point ◽  
Molecular Weights ◽  
Poly Vinyl Pyrrolidone ◽  
Methanol System

AbstractThe behavior of poly(vinyl pyrrolidone) (PVP) in methanol was examined using several independent methods. The hydrodynamic radius (Rh) of individual samples, over a range of molecular weights (10,000-360,000), was determined using dynamic light scattering (DLS) measurements. Dynamic Light Scattering (DLS) techniques directly probe such dynamics by monitoring and analyzing the pattern of fluctuations of the light scattered from polymer molecules. Some viscosity measurements were also performed to complete the DLS measurements and to provide more information on the particle structure. The results obtained with PVP-methanol system showed that plotting the variation of intrinsic viscosity versus the logarithm of the molecular mass of this polymer, we observe one crossover point. This crossover point appears when we reach the Θ-solvent behavior and delimit two molecular mass regions. The second order least-squares regression was used as an approach and was in excellent agreement with viscometric experimental results.

New amphiphilic copolymers derived from hydrophobically modified vinyl saccharides

1995 ◽  
Vol 73 (11) ◽  
pp. 1941-1947 ◽  
Author(s):  
Joachim Klein ◽  
Markwart Kunz ◽  
Lutz Guderjahn
Keyword(s):  
Aqueous Solution ◽  
Surface Tension ◽  
Glycidyl Ether ◽  
Vinyl Pyrrolidone ◽  
Hydrophobic Association ◽  
Amphiphilic Copolymers ◽  
Molecular Weights ◽  
Hydrophobically Modified ◽  
Allyl Glycidyl Ether

The synthesis and characterization of new amphiphilic copolymers derived from copolymerization of hydrophobically modified so-called vinyl saccharides with 1-vinyl-2-pyrrolidone are described. The vinyl saccharides were prepared in a two-step synthesis. In the first step hydrophobically modified saccharide derivatives were synthesized without protecting procedures by direct reductive amination of the reducing keto-disaccharide isomaltulose (Palatinose®) with n-dodecylamine. In the second step the resulting N-dodecylaminopolyols were coupled with allyl glycidyl ether to give polymerizable amphiphilic vinyl saccharides. The copolymerizations with 1-vinyl-2-pyrrolidone were performed as free radical aqueous solution polymerizations. The characterization of the copolymers was carried out by measuring the viscosity and light scattering in water as well as in trichloromethane, in addition to surface tension measurements and solubilization studies. The solution properties of the copolymers in water and trichloromethane differ remarkably. While the values for the intrinsic viscosities in both solvents are comparable, the weight-average molecular weights in water are much higher than those in trichloromethane, indicating the formation of aggregates in aqueous solution. The vinyl pyrrolidone copolymers are also very surface active, lowering the surface tension of water to as low as 30 mN/m. The combination of measurements of surface tensions and solubilization studies indicates that their hydrophobic association behaviour is formally comparable to those of low molecular weight surfactants. Keywords: vinyl saccharides, isomaltulose, hydrophobic association, amphiphilic polymers.

scholarly journals Influence of water-soluble nonionic polymers adsorption on colloidal properties of nanosilica dispersions

2019 ◽  
Vol 7 (1) ◽  
pp. 57-73
Author(s):  
Olena V. Goncharuk ◽  
Maria L. Malysheva ◽  
Konrad Terpilowski ◽  
Salvador Pérez Huertas ◽  
Volodymyr M. Gun’ko
Keyword(s):  
Water Soluble ◽  
Vinyl Pyrrolidone ◽  
Poly Vinyl Alcohol ◽  
Aggregative Stability ◽  
Polymer Content ◽  
Molecular Weights ◽  
Adsorbed Polymer ◽  
Influence Of Water ◽  
Silica Dispersion ◽  
Poly Vinyl Pyrrolidone

The relationships between the adsorption of poly(vinyl alcohol) (PVA), poly(ethylene oxide) (PEO), and poly(vinyl pyrrolidone) (PVP) of various molecular weights onto nanosilica and the stability and rheological properties of the aqueous dispersions were analyzed. The adsorption isotherms for the polymers correspond to the Langmuir-type isotherms. The adsorption maximum slightly increases with increasing molecular weight of the polymers. The sedimentation and aggregative stability of the silica dispersion decreased at a low amount of an adsorbed polymer (less than a monolayer). At this polymer content, a significant increase in the viscosity of dispersions is observed due to the formation of polymeric bridges between silica nanoparticles from neighboring aggregates of them. If the amount of adsorbed polymer exceeds the monolayer then the stabilizing effect is observed due to the steric factor preventing the bridge formation and the viscosity of dispersion decreases slightly compared with systems with a low polymer content.

scholarly journals ALD coating of centrifugally spun polymeric fibers and postannealing: case study for nanotubular TiO2 photocatalyst

2021 ◽  
Author(s):  
Martina Rihova ◽  
Oksana Yurkevich ◽  
Martin Motola ◽  
Ludek Hromadko ◽  
Zdeněk Spotz ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Vinyl Pyrrolidone ◽  
Tio2 Photocatalyst ◽  
Polymeric Fibers ◽  
Layer Deposition ◽  
Centrifugal Spinning ◽  
Poly Vinyl Pyrrolidone

This work describes the synthesis of highly photocatalytically active TiO2 tubes (TiTBs) by combining centrifugal spinning and atomic layer deposition (ALD). Poly(vinyl pyrrolidone) (PVP) fibers were first produced by centrifugal...

scholarly journals Potential Implantable Nanofibrous Biomaterials Combined with Stem Cells for Subchondral Bone Regeneration

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3087
Author(s):  
Rana Smaida ◽  
Luc Pijnenburg ◽  
Silvia Irusta ◽  
Erico Himawan ◽  
Gracia Mendoza ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Regeneration ◽  
Subchondral Bone ◽  
Therapeutic Potential ◽  
Sodium Hyaluronate ◽  
Vinyl Pyrrolidone ◽  
Regenerative Ability ◽  
Poly Vinyl Pyrrolidone

The treatment of osteochondral defects remains a challenge. Four scaffolds were produced using Food and Drug Administration (FDA)-approved polymers to investigate their therapeutic potential for the regeneration of the osteochondral unit. Polycaprolactone (PCL) and poly(vinyl-pyrrolidone) (PVP) scaffolds were made by electrohydrodynamic techniques. Hydroxyapatite (HAp) and/or sodium hyaluronate (HA) can be then loaded to PCL nanofibers and/or PVP particles. The purpose of adding hydroxyapatite and sodium hyaluronate into PCL/PVP scaffolds is to increase the regenerative ability for subchondral bone and joint cartilage, respectively. Human bone marrow-derived mesenchymal stem cells (hBM-MSCs) were seeded on these biomaterials. The biocompatibility of these biomaterials in vitro and in vivo, as well as their potential to support MSC differentiation under specific chondrogenic or osteogenic conditions, were evaluated. We show here that hBM-MSCs could proliferate and differentiate both in vitro and in vivo on these biomaterials. In addition, the PCL-HAp could effectively increase the mineralization and induce the differentiation of MSCs into osteoblasts in an osteogenic condition. These results indicate that PCL-HAp biomaterials combined with MSCs could be a beneficial candidate for subchondral bone regeneration.

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