scholarly journals Analysis of electrical measurements oncadmium chloridedoped PVA-PVP blend

2017 ◽  
Vol 16 (1) ◽  
pp. 45-65 ◽  
Author(s):  
Basavarajeshwari M Baraker ◽  
Blaise Lobo
Keyword(s):  
Charge Carriers ◽  
Vinyl Pyrrolidone ◽  
Poly Vinyl Alcohol ◽  
Electrical Measurements ◽  
Temperature Dependent ◽  
Mobility Of Charge Carriers ◽  
Solution Casting Method ◽  
Poly Vinyl Pyrrolidone ◽  
Electrical Data

Films of Poly(vinyl alcohol) (PVA) - Poly(vinyl pyrrolidone) (PVP) blend, doped withcadmium chloride (CdCl2) from 0.5 wt% up to 40 wt% andprepared by solution casting method,were studied using temperature dependent direct current (DC)electrical measurements. The DC electrical data were analyzed using Variable Range Hopping (VRH) modelin the temperature range varying from 303K up to 318K. The Mott parameters are determined. The study of time evolution of current passing through the sample, when a constant voltage is applied across it reveals that ions are the majority charge carriers, but the role of electrons in charge transport cannot be neglected. The activation energy (Ea) for mobility of charge carriers has been calculated from VRHand Arrhenius models.

Role of pumice particles in the thermal, electrical and mechanical properties of poly(vinyl alcohol)/poly(vinyl pyrrolidone) composites

2016 ◽  
Vol 126 (2) ◽  
pp. 511-519 ◽  
Author(s):  
Manammel Thankappan Ramesan ◽  
Ankita George ◽  
Panniyamvelli Jayakrishnan ◽  
Gopalannair Kalaprasad
Keyword(s):  
Mechanical Properties ◽  
Vinyl Alcohol ◽  
Vinyl Pyrrolidone ◽  
Poly Vinyl Alcohol ◽  
Poly Vinyl Pyrrolidone

Enhanced Thermo-Mechanical Properties of Poly(vinyl alcohol)/Poly(vinyl pyrrolidone) Polymer Blended with Nanographene

2020 ◽  
Vol 16 ◽  
Author(s):  
Seenaa Hussein ◽  
Alaa Abd-Elnaiem ◽  
Nadia Ali
Keyword(s):  
Thermal Stability ◽  
Vinyl Alcohol ◽  
Nanocomposite Films ◽  
Vinyl Pyrrolidone ◽  
Poly Vinyl Alcohol ◽  
Good Thermal Stability ◽  
Blend Morphology ◽  
Poly Vinyl Pyrrolidone ◽  
Blend Polymer

Background: The addition of nanofillers to polymers for enhanced performance is delivering more interesting applications for aerospace, aeronautic industries, and other numerous nano-technical applications. Objective: The aim was therefore to examine the role of graphene nanopowder on the thermal stability and conductivity of the poly(vinyl alcohol)/poly(vinyl pyrrolidone) (PVA/PVP) polymer nanocomposites. Methods: In this work, graphene nanofillers were incorporated into the PVA/PVP polymer blended by solution mixing for the preparation of nanocomposite films. Results: Results showed that; increasing graphene ratio improved thermal conductivity up to 330%, moreover enhancing hardness shore A up to 16.3% compared to pure PVA/PVP blend polymer. TGA analysis confirmed that the PVA/PVP and graphene network showed good thermal stability. Conclusion: From the present findings, it is proved that PVA/PVP blends have profound effects on thermal stability that cannot be attained by using individual counterparts. The property of the nanocomposite depends on the host blend, morphology, and interfacial characteristics.

scholarly journals PREPARATION AND CHARACTERIZATION OF POLY (VINYL ALCOHOL)–POLY (VINYL PYRROLIDONE) MUCOADHESIVE BUCCAL PATCHES FOR DELIVERY OF LIDOCAINE HCL

2018 ◽  
Vol 10 (1) ◽  
pp. 115 ◽  
Author(s):  
Napaphak Jaipakdee ◽  
Thaned Pongjanyakul ◽  
Ekapol Limpongsa
Keyword(s):  
Vinyl Alcohol ◽  
Vinyl Pyrrolidone ◽  
Poly Vinyl Alcohol ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Casting Technique ◽  
In Vitro Permeation ◽  
Lidocaine Hcl ◽  
Poly Vinyl Pyrrolidone

Objective: The objectives of this study were to prepare and characterize a buccal mucoadhesive patch using poly (vinyl alcohol) (PVA), poly (vinyl pyrrolidone) (PVP) as a mucoadhesive matrix, Eudragit S100 as a backing layer, and lidocaine HCl as a model drug.Methods: Lidocaine HCl buccal patches were prepared using double casting technique. Molecular interactions in the polymer matrices were studied using attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR), differential scanning calorimetry (DSC) and X-ray diffractometry. Mechanical and mucoadhesive properties were measured using texture analyzer. In vitro permeation of lidocaine HCl from the patch was conducted using Franz diffusion cell.Results: Both of the free and lidocaine HCl patches were smooth and transparent, with good flexibility and strength. ATR-FTIR, DSC and X-ray diffractometry studies confirmed the interaction of PVA and PVP. Mechanical properties of matrices containing 60% PVP were significantly lower than those containing 20% PVP (*P<0.05). Mucoadhesive properties had a tendency to decrease with the concentration of PVP in the patch. The patch containing 60% PVP had significantly lower muco-adhesiveness than those containing 20% PVP (*P<0.05). In vitro permeation revealed that the pattern of lidocaine HCl permeation started with an initial fast permeation, followed by a slower permeation rate. The initial permeation fluxes follow the zero-order model of which rate was not affected by the PVP concentrations in the PVA/PVP matrix.Conclusion: Mucoadhesive buccal patches fabricated with PVA/PVP were successfully prepared. Incorporation of PVP in PVA/PVP matrix affected the strength of polymeric matrix and mucoadhesive property of patches.

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.

Characterization of polymeric biocomposite based on poly(vinyl alcohol) and poly(vinyl pyrrolidone)

2006 ◽  
Vol 27 (2) ◽  
pp. 147-152 ◽  
Author(s):  
Vladimír Sedlařík ◽  
Nabanita Saha ◽  
Ivo Kuřitka ◽  
Petr Sáha
Keyword(s):  
Vinyl Alcohol ◽  
Vinyl Pyrrolidone ◽  
Poly Vinyl Alcohol ◽  
Poly Vinyl Pyrrolidone

Characterization of associating hydrogels of poly(vinyl alcohol) and poly(vinyl pyrrolidone)

2009 ◽  
Vol 112 (1) ◽  
pp. 541-549 ◽  
Author(s):  
X. Liu ◽  
G. Fussell ◽  
M. Marcolongo ◽  
A. M. Lowman
Keyword(s):  
Vinyl Alcohol ◽  
Vinyl Pyrrolidone ◽  
Poly Vinyl Alcohol ◽  
Poly Vinyl Pyrrolidone
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