scholarly journals Effect of Solvents on the Ultrasonic Velocity and Acoustic Parameters of Polyvinylidene Fluoride Solutions

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
S. S. Kulkarni ◽  
U. V. Khadke

Ultrasonic studies provide a wealth of information in understanding the molecular behavior and intermolecular interaction of polymer solvent mixtures. Attempts were made to measure ultrasonic velocity, density, and viscosity for the mixture of polyvinylidene fluoride (PVDF) in acetone and dimethylformamide (DMF) of various stoichiometric ratios at 300 K using crystal controlled ultrasonic interferometer (Mittal make), pyknometer (specific gravity bottle), and Ostwald viscometer, respectively. The acoustic parameters adiabatic compressibility (β), intermolecular free path length (Lf), acoustic impedance (Z), relative association (RA), ultrasonic attenuation (α/f2), and relaxation time (τ) have been estimated using experimental data with well-known techniques. The variation of these acoustic parameters is explained in terms of solute-solvent molecular interaction in a polymer solution.

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
S. S. Kulkarni ◽  
U. V. Khadke

The modification of polyvinylidene fluoride (PVDF) polymer properties with irradiation is of interest as it possesses unique piezo-, pyro-, and ferroelectric properties. In this paper, we report the results of acoustic parameters of irradiated PVDF mixed with dimethylacetamide (DMAC) solution with low energy γ-source (Cs-137). The polymer solution covered with mica film assures only γ-ray passage and the duration was increased from 18 to 50 hours to achieve the higher dose rate. The dose rate was estimated using the strength of the radioactive source and the duration of the exposure. The ultrasonic velocity (v), density (ρ), and viscosity (η) of 0.2 wt% and 0.5 wt% PVDF dissolved in pure DMAC solution, irradiated with different dose rate were measured using ultrasonic interferometer (Mittal make), Pyknometer, and Oswald’s viscometer, respectively. It is observed that the values of v, ρ, and η change with dose rate. The acoustic parameters such as adiabatic compressibility (β), intermolecular free path length (Lf), acoustic impedance (Z), relative association (RA), ultrasonic attenuation (α/f2), and relaxation time (τ) are calculated using the experimental data. These results are interpreted in terms of the solute-solvent interaction in a polymer solution and scissoring chain damage.


2013 ◽  
Vol 33 (9) ◽  
pp. 851-856 ◽  
Author(s):  
Baljinder Kaur ◽  
Kailash C. Juglan

Abstract Density, viscosity and ultrasonic velocity of polyvinyl acetate with acetic acid have been measured at a temperature of 299K for different concentrations. Density and viscosity have been measured for a binary liquid mixture with a specific gravity bottle and a viscometer. Ultrasonic velocity has been measured using a single crystal interferometer at a frequency of 2 MHz. Ultrasonic velocities for the binary mixture at 1 MHz and 2 MHz was compared by taking some values from the literature. The sound velocity (V), density (ρ) and viscosity (η) were used to calculate the parameters such as adiabatic compressibility (β), acoustic impedance (Z), intermolecular free length (Lf), ultrasonic attenuation (α/f2) and relaxation time (τ). The variations of experimentally obtained parameters indicate the presence of molecular interaction between the molecules of the mixture. The ultrasonic velocity increased with an increase in concentration. Solute-solvent interaction is further confirmed by viscosity values, which increased with increasing concentration suggesting more association between solute and solvent molecules. The linear variations in Rao’s constant and Wada’s constant suggest the absence of complex formation.


Author(s):  
Mrunal M. Mahajan ◽  
Pravin B. Raghuwanshi

<div><p><em>The present work deals with the study of acoustic parameters like ultrasonic velocity (V), </em><em>adiabatic compressibility (β<sub>s</sub>), apparent molar volume (</em><em>f</em><em><sub>v</sub></em><em>) and intermolecular free length (L<sub>f</sub>) by ultrasonic </em><em>interferometric measurements</em><em> which reflects structural interaction of water molecules and organic solvent molecules with substituted Schiff bases. The study of N–(2-hydroxybenzylidene)-3-substituted pyridine -2- amine Schiff bases were carried in different percentage of 1,4-dioxane-water medium, at 293, 297 and 300 K. The densities and velocities thus obtained were used to evaluate acoustic parameters for all the ligands.</em></p></div>


Author(s):  
Baljeet Singh Patial

Ultrasonic velocity, viscosity and density studies on solution of tetrapentylammonium bromide (Pen4NBr) in N,N-dimethylformamide, ethylmethylketone (EMK) and DMF-EMK solvent mixtures containing 0, 20, 40, 60, 80 and 100 mol % of DMF at 298, 308 and 318K have been reported. From the velocity, viscosity and density data values, various parameters namely, the adiabatic compressibility (β), Intermolecular free length (Lf), specific acoustic impedance (Z), free volume (Vf), internal pressure (πi) and relaxation time (τ) have been calculated. All these parameters have been discussed separately to throw light on the solute-solvent and solvent-solvent interactions.


2016 ◽  
Vol 4 (2) ◽  
pp. 15 ◽  
Author(s):  
M Vigneswari ◽  
S. S Saravanakumar ◽  
V. N Suresh ◽  
S Sankarrajan

Ultrasonic velocity, density, viscosity have been measured experimentally in the binary and ternary mixtures of Poly Vinyl Alcohol (PVA), water and borax with various concentration at 301.32 K. As the acoustical parameters like adiabatic compressibility, intermolecular free length, relaxation time, acoustic impedance, surface tension, Rao’s and Wada’s constant, ultrasonic attenuation and free volume would be more useful to predict and confirm the molecular interaction, these have been determined by using ultrasonic velocity, density and viscosity of the prepared solution. It has been identified that the molecular interactions in binary mixture were stronger than that of in ternary mixtures. And also there is a strong solute – solvent interaction occurring in both binary and ternary solutions. This may be due to the greater possibility of hydrogen bonding between PVA and Water molecules. When the borax is added, the molecular interaction is getting weaker due to greater affinity of borate ion towards the hydrogen in hydroxyl group of PVA.


2011 ◽  
Vol 181-182 ◽  
pp. 43-46
Author(s):  
D. Madhavi Latha ◽  
V.G.K.M. Pisipati ◽  
M. Ramakrishna Nanachara Rao ◽  
P.V. Datta Prasad

Ultrasonic velocity measurements are carried out on fournOmcompounds viz., N-(p-n-methoxy and ethoxy benzylidene)-p-n-dodecyl and tetradecyl anilines, 1O.12, 1O.14, 2O.12 and 2O.14. The first three compounds exhibit mono variant nematic phase while the last compound exhibits nematic and smectic-A phases with variable thermal ranges. The temperature dependence of sound velocity, U shows minima at the isotropic-nematic and nematic-smectic-A transitions. In conjunction with the density data of these compounds, the thermo acoustic parameters such as adiabatic compressibility (βad), the molar sound velocity (Rao’s number) (Rn), molar compressibility (W), molecular free length (Lf) and available volume (Va) are estimated. In addition the intermolecular free length (Lf) is estimated in three different ways employing density and ultrasonic velocity data. The results are compared with the data available in literature of other compounds.


2021 ◽  
Vol 2 (1) ◽  
pp. 012-027
Author(s):  
M. Sathish ◽  
K. Venkataramanan ◽  
R. Padmanaban ◽  
Helan Ruth ◽  
K. Vadivel ◽  
...  

In this work, acoustic, thermal, and optical properties were tested on the different concentrations of the Disodium Tartrate solutions. First, the viscosity studies were analyzed for the Disodium tartrate in the concentration range from 2% to 20% with different temperatures 303K, 308K, 313K, and 318K. It was noted that the relative viscosity and the activation energy of the prepared compound increase with increases in concentration and decreases with temperature increases. The properties like density and ultrasonic velocity are varied when increases the concentration of the aqueous solutions of Disodium Tartrate. In this study, the values of adiabatic compressibility show an inverse behavior when compared with ultrasonic velocity due to the interaction between solute and solvent molecules. Also observed that the inter-molecular free length is maximum for a lower percentage. The free volume for the compound is maximum at 2% and a minimum of 20%, since it reduces when the internal pressure increases. It was revealed that the classical absorption coefficient and relaxation time for Disodium Tartrate is minimum for lower percentage and minimum for a higher percentage. The interactions between the solute and solvent are confirmed through the property like specific Acoustical impedance. It was noted that the increase in internal pressure increases the concentration of the compound. The ion-solvent interaction was discussed by the relative association study, thus the values of relative association increases with an increase in concentration. The Rao’s and Wada’s constant increases linearly in aqueous solutions of Disodium Tartrate for the entire system.


2020 ◽  
Author(s):  
Gang Wang ◽  
Jinzhou Li ◽  
Huaixing Li ◽  
Zhiyuan Liu ◽  
Yanpei Guo ◽  
...  

Abstract In order to examine the effect of briquettes with different crack structures on ultrasonic characteristics under different wetting conditions, a series of ultrasonic testing are carried out on briquettes at different wetting heights and the ultrasonic characteristics in these coal samples are explored. The results show that ultrasonic amplitude is positively correlated with the emission voltage, whereas ultrasonic frequency is negatively correlated with the emission voltage. Changes in both are closely related to the particle size and density. The ultrasonic velocity is positively correlated with the wetting degree. Sample mass has the greatest effect on the ultrasonic velocity, followed by particle size, and pressure has the smallest effect. At dry stage, ultrasonic velocity in gas coal is less than that in bituminous coal. The opposite is true in the fully wet state. The influence of crack thickness on ultrasonic velocity gradually increases with the wetting degree increasing. At dry stage, the velocity gradually increases with the crack dip increasing, while as the wetting height increasing, magnitude of velocity increase gradually decreases with the dip increasing. The ultrasonic attenuation in the briquettes reduces with the emission voltage enhancing. The attenuation decreases with sample particle size, crack thickness and crack size decreasing and with sample mass, pressure and crack dip increasing. The ultrasonic attenuation shows a trend of increase before decrease with the wetting height increasing. The attenuation of ultrasonic wave increases with wave velocity increasing for intact samples and shows a trend of increase before decrease for cracked samples.


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