scholarly journals An Interaction of Anionic- and Cationic-Rich Mixed Surfactants in Aqueous Medium through Physicochemical Properties at Three Different Temperatures

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
K. M. Sachin ◽  
Sameer A. Karpe ◽  
Man Singh ◽  
Ajaya Bhattarai
Keyword(s):  
Physicochemical Properties ◽  
Hydrodynamic Radius ◽  
Sodium Dodecyl ◽  
Relative Viscosity ◽  
Solvent Interaction ◽  
Mixed Micellization ◽  
Surface Excess Concentration ◽  
Excess Concentration ◽  
Different Temperatures ◽  
Aqueous Binary Mixtures

The mixed micellization of aqueous binary mixtures of DTAB-rich and SDS-rich surfactants, comprising sodium dodecyl sulfate (SDS) and dodecyltrimethylammonium bromide (DTAB) is studied in aqueous solution by using the physicochemical properties (PCPs) at three different temperatures (T = 293.15, 298.15, and 303.15 K) and P=0.1  MPa. The DTAB concentration is varied from 0.0001 to 0.03 M/mol·L−1 in the ∼0.01 M/mol·L−1 SDS solution, while the concentration of SDS is varied from 0.001 to 0.015 M/mol·L−1 in the ∼0.005 M/mol·L−1 DTAB. The stable formulations have been obtained by employing the DTAB-rich and SDS-rich surfactants solutions in 3 : 1 ratio. Therefore, different phases and aggregated states formed in the ternary combinations of DTAB/SDS/H2O have been identified and described. The calculated PCPs have been utilized for determining the nature of the solute-solvent interaction (SLS0I). With increasing surfactants concentration, the polarisation of the solution also increases along with an increase in relative viscosity (ηr), viscous relaxation time (τ), and surface excess concentration (Γmax). However, the surface area of the molecule (Amin), hydrodynamic volume (Vh), and hydrodynamic radius (Rh) decrease along with an increase in surfactants concentration.

scholarly journals Studies on the Solute Solvent Interaction of Nimesulide in Aqueous Solutions of Hydrotropic Agents at Different Temperatures

2010 ◽  
Vol 7 (s1) ◽  
pp. S223-S230 ◽  
Author(s):  
Chandravir S. Solanki ◽  
Sushree Tripathy ◽  
Minaketan Tripathy ◽  
Upendra N. Dash
Keyword(s):  
Aqueous Solutions ◽  
Sodium Salicylate ◽  
Relative Viscosity ◽  
Partial Molar Volumes ◽  
Transition Theory ◽  
Solvent Interaction ◽  
Solvent Water ◽  
Different Temperatures ◽  
Density Values ◽  
Solute Solvent Interaction

The present study deals with experiments so as to highlight the solute (drug nimesulide) - solvent(water) interactions and related modifications in case of the presence of hydrotropic agents at different temperatures T(=298.15 to 313.15)K. Density and viscosity values of nimesulide have been determined in water in (0.1, 0.2, 0.4, 0.6, 0.8, 1 and 2) mol dm-3aqueous solutions of hydrotropic agents (sodium benzoate, sodium salicylate, sodium bromide and nicotinamide) at temperatures 298.15, 303.15, 308.15 and 313.15 K where as the solubility was studied at 308.15 K. From the density values, the limiting partial molar volumes and expansibilities have been calculated. The experimental viscosity values have been analyzed in terms of jones-dole equation and on the basis of transition theory for relative viscosity.

Comparison of physicochemical properties of edible vegetable oils commercially available in Bahir Dar, Ethiopia

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Physicochemical Properties ◽  
Vegetable Oils ◽  
Relative Viscosity ◽  
Acid Value ◽  
Smoke Point ◽  
Refractive Indices ◽  
Bahir Dar ◽  
Icp Oes ◽  
Saponification Value ◽  
Oil Sunflower

The physicochemical properties of six imported and one locally produced edible vegetable oils (soybean oil, sunflower oil, sunlit oil, hayat oil, avena oil, USA vegetable oil and Niger oil) purchased from Bahir Dar city, Ethiopia, were examined for their compositional quality. All the oil samples were characterized for specific gravity, moisture content, color, relative viscosity, refractive indices, ash content, peroxide value, saponification value, smoke point, acid value, free fatty acid value and trace metals contents using established methods. The result clearly indicates that some of the oil samples exhibited unacceptable value when compared with physicochemical parameters recommended by the Codex Alimentations Commission of FAO/WHO and the specification of Ethiopian standards. The contents of nickel (Ni), copper (Cu) and iron (Fe) in seven samples were determined using ICP-OES and their concentrations were found in the range of 1.8-20.4, 45.8-82.2 and 136.04-445.0 mg/kg, respectively.

scholarly journals Physicochemical characterisation of kafirins extracted from sorghum grain and dried distillers grain with solubles related to their biomaterial functionality

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Umar Shah ◽  
Deepak Dwivedi ◽  
Mark Hackett ◽  
Hani Al-Salami ◽  
Ranjeet P. Utikar ◽  
...  
Keyword(s):  
Secondary Structure ◽  
Physicochemical Properties ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Chemical Properties ◽  
X Ray ◽  
Distillers Grain ◽  
Sorghum Grain ◽  
Dried Distillers Grain ◽  
Polypeptide Profile

AbstractKafirin, the hydrophobic prolamin storage protein in sorghum grain is enriched when the grain is used for bioethanol production to give dried distillers grain with solubles (DGGS) as a by-product. There is great interest in DDGS kafirin as a new source for biomaterials. There is however a lack of fundamental understanding of how the physicochemical properties of DDGS kafirin having been exposed to the high temperature conditions during ethanol production, compare to kafirin made directly from the grain. An understanding of these properties is required to catalyse the utilisation of DDGS kafirin for biomaterial applications. The aim of this study was to extract kafirin directly from sorghum grain and from DDGS derived from the same grain and, then perform a comparative investigation of the physicochemical properties of these kafirins in terms of: polypeptide profile by sodium-dodecyl sulphate polyacrylamide gel electrophoresis; secondary structure by Fourier transform infra-red spectroscopy and x-ray diffraction, self-assembly behaviour by small-angle x-ray scattering, surface morphology by scanning electron microscopy and surface chemical properties by energy dispersive x-ray spectroscopy. DDGS kafirin was found to have very similar polypeptide profile as grain kafirin but contained altered secondary structure with increased levels of β-sheets. The structure morphology showed surface fractals and surface elemental composition suggesting enhanced reactivity with possibility to endow interfacial wettability. These properties of DDGS kafirin may provide it with unique functionality and thus open up opportunities for it to be used as a novel food grade biomaterial.

scholarly journals Changes of Physicochemical Properties of Starch Syrups Recommended for Winter Feeding of Honeybees during Storage

Agriculture ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 374
Author(s):  
Teresa Szczęsna ◽  
Ewa Waś ◽  
Piotr Semkiw ◽  
Piotr Skubida ◽  
Katarzyna Jaśkiewicz ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Physicochemical Properties ◽  
Physicochemical Parameters ◽  
Storage Temperature ◽  
Storage Conditions ◽  
Different Temperatures ◽  
And Storage ◽  
Bee Colonies ◽  
Temperature Time ◽  
Winter Feeding

The aim of this study was to determine the influence of storage temperature and time on physicochemical parameters of starch syrups recommended for the winter feeding of bee colonies. The studies included commercially available three starch syrups and an inverted saccharose syrup that were stored at different temperatures: ca. 20 °C, 10–14 °C, and ca. 4 °C. Physicochemical parameters of fresh syrups (immediately after purchase) and syrups after 3, 6, 9, 12, 15, 18, 21, and 24 months of storage at the abovementioned temperatures were measured. It was observed that the rate of unfavorable changes in chemical composition of starch syrups and the inverted saccharose syrup, mainly the changes in the 5-hydroxymethylfurfural (HMF) content, depended on the type of a syrup and storage conditions (temperature, time). Properties of tested starch syrups intended for winter feeding of bees stored at ca. 20 °C maintained unchanged for up to 6 months, whereas the same syrups stored at lower temperatures (10–14 °C) maintained unchanged physicochemical parameters for about 12 months. In higher temperatures, the HMF content increased. To date, the influence of this compound on bees has not been thoroughly investigated.

scholarly journals The Investigation of Effects of Temperature and Nanoparticles Volume Fraction on the Viscosity of Copper Oxide-ethylene Glycol Nanofluids

2017 ◽  
Author(s):  
Mohammad Hemmat Esfe
Keyword(s):  
Ethylene Glycol ◽  
Copper Oxide ◽  
Volume Fraction ◽  
Relative Viscosity ◽  
Experimental Results ◽  
Different Temperatures ◽  
Nanoparticles Volume Fraction ◽  
Effects Of Temperature ◽  
Nanofluid Viscosity ◽  
Experimental Values

In the present article, the effects of temperature and nanoparticles volume fraction on the viscosity of copper oxide-ethylene glycol nanofluid have been investigated experimentally. The experiments have been conducted in volume fractions of 0 to 1.5 % and temperatures from 27.5 to 50 °C. The shear stress computed by experimental values of viscosity and shear rate for volume fraction of 1% and in different temperatures show that this nanofluid has Newtonian behaviour. The experimental results reveal that in a given volume fraction when temperature increases, viscosity decreases, but relative viscosity varies. Also, in a specific temperature, nanofluid viscosity and relative viscosity increase when volume fraction increases. The maximum amount of increase in relative viscosity is 82.46% that occurs in volume fraction of 1.5% and temperature of 50 °C. Some models of computing nanofluid viscosity have been suggested. The greatest difference between the results obtained from these models and experimental results was down of 4 percent that shows that there is a very good agreement between experimental results and the results obtained from these models.

Mobility of DR1 Molecules Embedded in Nanostructured PMMA Films

2009 ◽  
Vol 5 ◽  
pp. 135-142
Author(s):  
Jorge A. García-Macedo ◽  
A. Franco ◽  
Guadalupe Valverde-Aguilar ◽  
M.A. Ríos-Enríquez
Keyword(s):  
Second Harmonic ◽  
Sodium Dodecyl ◽  
Orientation Distribution ◽  
Decay Rates ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Poling Field ◽  
Different Temperatures ◽  
Cetyl Trimethyl Ammonium ◽  
Kinetics Of

The kinetics of the orientation of Disperse Red 1 (DR1) molecules embedded in nanostructured Polymethylmetacrylate (PMMA) films was studied under the effect of an intense constant electric poling field. The changes in the orientation distribution of the DR1 molecules were followed by Second Harmonic Generation (SHG) measurements. The SHG signal was recorded as function of time at three different temperatures. We focused on both, the signal increases under the presence of the poling field and the signal decays without the poling field. The studied PMMA films were nanostructured by the incorporation of ionic surfactants as the Sodium Dodecyl Sulfate (SDS) and the Cetyl Trimethyl Ammonium Bromide (CTAB) during their preparation. The kinds of nanostructures obtained in the films were determined by means of X-ray diffraction (XRD) measurements. Substantial differences in signal intensity and in growth and decay rates between amorphous and nanostructured films were found.

scholarly journals Torrefaction of Almond and Walnut Byproducts

2021 ◽  
Vol 9 ◽  
Author(s):  
Zach McCaffrey ◽  
Lennard Torres ◽  
Bor-Sen Chiou ◽  
Saulo Rocha Ferreira ◽  
Luiz Eduardo Silva ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Moisture Absorption ◽  
Calorific Value ◽  
Dynamic Vapor Sorption ◽  
Energy Applications ◽  
Thermochemical Process ◽  
Heat Treated ◽  
The Us ◽  
Torrefied Biomass ◽  
Different Temperatures

While the US nut industry is growing, markets for nut by-products, particularly nutshells and tree prunings, have not kept pace. Torrefaction is a thermochemical process used to improve physicochemical properties of biomass for energy and other applications. The goal of the paper was to characterize the effects of a range of torrefaction conditions on the properties of nut by-product feedstock. The process consists of thermal treatment of biomass at a temperature between 200 and 300°C in the absence of oxygen, where final material properties of the torrefied biomass depend on the temperature, heating rate, and residence time. In general, torrefied biomass exhibits higher hydrophobicity and calorific value with reduced moisture absorption compared to untreated biomass, making it an ideal fuel source for energy applications compared to raw biomass. In this study, almond shells of soft, semi-soft, and hardshell varieties, as well as walnut shells and almond wood, were torrefied at two different temperatures (230 and 290°C) and three different residence times (20, 40, and 60 min) in order to characterize the physicochemical properties. The thermal behavior of raw and heat-treated biomass was investigated by TGA analysis, elemental analysis, pH, helium pycnometry, FTIR spectroscopy, and dynamic vapor sorption analysis.

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