Viscosity studies of polyvinyl alcohol (PVA, Mw = 1,25,000) in solvent distilled water and aqueous solution of urea

2010 ◽  
Vol 7 (2) ◽  
pp. 443-448
Author(s):  
S. Panda ◽  
G. C. Mohanty ◽  
R.N. Samal ◽  
G. S. Roy
Keyword(s):  
Aqueous Solution ◽  
Polyvinyl Alcohol ◽  
Polymer Solution ◽  
Flow Time ◽  
Inherent Viscosity ◽  
Distilled Water ◽  
Reduced Viscosity ◽  
Aqueous Urea ◽  
C 30

Reduced viscosity (ηsp/C) and inherent viscosity ln (ηrel/C) of PVA (Mw = 1,25,000) has been calculated by measuring the flow time of polymer solution in solvents like distilled water and 4M Urea at six different tempratures 25° C, 30° C, 35° C, 40° C, 45° C, and 50° C. From exptrapolation of curve (/C) versus C and (ln /C) versus C, thermoviscosity parameters like Huggins’ Constrant (KHl), Kraemer's constant (KHll) and viscosity concentration co-efficient (a2) have been estimated. In aqueous solution (PVA in distilled water), Huggins' relation does not hold good. So a2 = .201[h]2.28 is used; but in aqueous Urea (PVA in 4M Urea), Huggins' relation holds good. Also η =KMα and value of a more for 4M Urea i.e aqueous Urea is better solvent for PVA than distilled water.

The Terminology of Intrinsic Viscosity and Related Functions

1946 ◽  
Vol 19 (4) ◽  
pp. 1092-1098
Author(s):  
L. H. Cragg
Keyword(s):  
Intrinsic Viscosity ◽  
Kinematic Viscosity ◽  
Relative Viscosity ◽  
Flow Time ◽  
Inherent Viscosity ◽  
Routine Practice ◽  
Concentration Coefficient ◽  
Specific Viscosity ◽  
Reduced Viscosity ◽  
Relative Flow

Abstract The confusion existing in the use of symbols and names for Kraemer's “intrinsic viscosity” and other functions related to it is illustrated and deplored. The reasonable plea is made that one name be adopted for each function and that it be used with no other meaning. To stimulate discussion and ultimate action, the following names are proposed: “specific viscosity” for ηsp; “reduced viscosity” for ηsp/c, “inherent viscosity” for (ln ηr)/c; and “intrinsic viscosity” for [η], whether determined as “limiting reduced viscosity” limc→0 (ηsp/c), or as “limiting inherent viscosity” limc→0 (ηr/c), or as “limiting viscosity concentration coefficient” limc→0 (dηr/dc). Often, especially in routine practice, it is the relative kinematic viscosity νr, that is determined ; unless this is shown to be numerically equal to the relative viscosity ηr, the symbols and names of the derived functions should be modified accordingly: thus, (ln νr)/c inherent kinematic viscosity, [ν] intrinsic kinematic viscosity. Frequently, also, kinetic energy corrections are neglected; under these circumstances the suggested usage is tr, relative flow time, tsp/c reduced flow time, [t] intrinsic flow time, etc.

Acute Mercury Poisoning After Polyvinyl Alcohol Preservative Ingestion

PEDIATRICS ◽  
1980 ◽  
Vol 66 (1) ◽  
pp. 132-134
Author(s):  
James Seidel
Keyword(s):  
Aqueous Solution ◽  
Acetic Acid ◽  
Polyvinyl Alcohol ◽  
Mercuric Chloride ◽  
Medical Center ◽  
Mercury Poisoning

Polyvinyl alcohol preservative (PVA) is used routinely in the laboratory for collection of specimens for examination for ova and parasites.1-4 PVA, presently used at Harbor-UCLA Medical Center, contains: 4.5% mercuric chloride, 5% polyvinyl alcohol, 30% denatured alcohol, 4.5% acetic acid, and 1.5% glycerin in an aqueous solution. The kit, as shown in the Figure, contains three bottles with 10-ml aliquots of PVA, wooden sticks for mixing the specimen, and written instructions for collection of the specimens. The bottles are clearly labeled as poison in English and Spanish, and specific verbal as well as written instructions are given to patients and their families when the ova and parasite kits are dispensed.

Adsorption of Chromium (VI) from Aqueous Solution by Agricultural Waste Derived Activated Carbon

2013 ◽  
Vol 726-731 ◽  
pp. 2100-2106 ◽  
Author(s):  
Hua Zhang ◽  
Xue Hong Zhang ◽  
Yi Nian Zhu ◽  
Shou Rui Yuan
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Agricultural Waste ◽  
Order Kinetic ◽  
Chromium Vi ◽  
Initial Ph ◽  
Order Kinetic Model ◽  
Grapefruit Peel ◽  
Pseudo Second Order ◽  
C 30

Activated carbon prepared from grapefruit peel, an agricultural solid waste by-product, has been used for the adsorption of Cr(VI) from aqueous solution. The effects of adsorbent dosage, pH and temperature on adsorption of Cr(VI) were investigated. The maximum adsorption yield was obtained at the initial pH of 3. The dynamical data fit very well with the pseudo-second-order kinetic model and the calculated adsorption capacities (23.98, 24.33 and 24.81 mg/g) were in good agreement with experiment results at 20°C, 30°C and 40 °C for the 100 mg/L Cr(VI) solution. The Freundlich model (R2 values were 0.9198-0.9871) fitted adsorption data better than the Langmuir model. The calculated parameters confirmed the favorable adsorption of Cr(VI) on the activated carbon prepared from grapefruit peel.

scholarly journals Clarification of superficial waters of the magdalena river using seeds of Tamarindus indica as bio-coagulants

Respuestas ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 170-176
Author(s):  
Saúl David Buelvas-Caro ◽  
Yelitza del Rosario Aguas-Mendoza ◽  
Rafael Enrique Olivero-Verbel
Keyword(s):  
Aqueous Solution ◽  
Surface Water ◽  
Industrial Waste ◽  
Aluminum Sulfate ◽  
Saline Solution ◽  
Distilled Water ◽  
Tamarindus Indica ◽  
Efficient Alternative ◽  
High Turbidity ◽  
Magdalena River

Biocoagulants have emerged as an environmentally friendly and efficient alternative to surface water clarification, allowing the use of agro-industrial waste as a bioavailable source for the treatment of high turbidity water. The objective of this research was to compare the efficiency in the surface water coagulation process of the Magdalena river using aluminum sulfate and tamarind seeds (Tamarindus indica) dissolved in aqueous solution and saline solution. The clarification process was carried out by testing jar, for this was performed an extraction of the hot and cold tamarind coagulant which were evaluated in conjunction with an inorganic coagulant in different mother dilutions (distilled water and saline) at concentrations of 35 and 40 mg/L and at a stirring speed of 100 and 200 rpm. The parameters of pH, electrical conductivity (S/cm), turbidity (NTU) and color (UPC) were measured during the clarification process. The results show a 97.2% reduction in inorganic treatment (SAL) compared to initial turbidity and a decrease in natural cold extracted (STF) and hot (STC) treatments of 58.2% and 39.1% respectively, when diluted in aqueous solution. While diluting in saline solution there was a greater removal of turbidity when applying aluminum sulfate, followed by STF and STC treatment, with removal values of 99%, 75% and 53% respectively. The highest coagulating activity occurred when applying a dose of 40mg/L and when diluting treatments in NaCl with maximum reported values for SAL, STF and STC treatment of 93%, 85% and 59%. Tamarind seeds proved to be an efficient coagulant for water clarification

scholarly journals Enhancement of Liver Toxicity on Diabetes Mellitus by a Universal Chemical Pollutant (Acrylonitrile) in Rats

2019 ◽  
Vol 26 (2) ◽  
pp. 9-17
Author(s):  
Sameer E. Alharthi
Keyword(s):  
Oxidative Stress ◽  
Diabetes Mellitus ◽  
Aqueous Solution ◽  
Liver Toxicity ◽  
Elevated Serum ◽  
Diabetic Rat ◽  
Control Group ◽  
Distilled Water ◽  
Serum Aminotransferase ◽  
Cyp2e1 Activity

The present study was designed to investigate potential liver damage due to acrylonitrile in Streptozotocin induced diabetes in rats. Twenty-four rats were divided into 4 treatment groups. Nondiabetic control rat receiving distilled water, non-diabetic rat receiving acrylonitrile aqueous solution (10 mg/kg/day), diabetic control rat receiving distilled water and diabetic rat receiving acrylonitrile aqueous solution. All groups received the treatment for 4 weeks. The animals were assessed for hepatoxicity markers in serum, oxidative stress markers, CYP2E1 activity and cyanide formation in tissues. Acrylonitrile significantly elevated serum aminotransferase, alanine aminotransferase, total bilirubin levels, triglycerides and total cholesterol in diabetic groups as compared to normal control group. Antioxidant markers like glutathione showed significant decline while a significant increase in malondialdehyde, superoxide dismutase and catalase in diabetic rats treated with acrylonitrile. CYP2E1 activity was observed in acrylonitrile – exposed nondiabetic and diabetic groups as compared to control. Cyanide formation was raised in both the nondiabetic and diabetic groups as compared to control group. Acrylonitriles can produce acute hepatic injury, induction of diabetes mellitus type II, and accomplish the CYP2E1 enzyme which sequentially leads to generation of oxidative stress and its metabolic product–cyanide that may potentiate the oxidative stress posing more deleterious effect.

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