Study of Intermolecular Interactions of CTAB with Amino Acids at Different Temperatures: A Multi Technique Approach

2019 ◽  
Vol 233 (2) ◽  
pp. 167-182 ◽  
Author(s):  
Anwar Ali ◽  
Nizamul Haque Ansari ◽  
Ummer Farooq ◽  
Shadma Tasneem ◽  
Firdosa Nabi

Abstract The densities, ρ, viscosities, η and specific conductivities κ, of (0.0002, 0.0004, 0.0006 and 0.0008 m) CTAB in 0.1 m aqueous valine, leucine and isoleucine were measured at different temperatures. The measured data were used to calculate various useful thermodynamic parameters. A complete characterization of any mixture can be performed by means of these thermodynamic properties. The apparent molar volume, ϕv, partial molar volume, $\phi _v^0$ and partial molar isobaric expansibilities, $\phi _E^0,$ were calculated using density data. The viscosity data were analyzed using Jones–Dole equation to obtain viscosity coefficients, A- and B-, free energy of activation per mole of solvent, Δμ1°∗, and solute, Δμ2°∗, enthalpy, ΔH∗ and entropy, ΔS∗ of activation of viscous flow. Measuring the changes in these properties has been found to be an excellent qualitative and quantitative way to obtain information regarding the molecular structure and intermolecular interactions occurring in these mixtures. Various structure-making/breaking ability of solute (cetyltrimethylammonium bromide) in presence of aqueous amino acid solutions were discussed. In addition, fluorescence study using pyrene as a photophysical probe has been carried out, the results of which support the conclusions obtained from other techniques.

2009 ◽  
Vol 64 (11) ◽  
pp. 758-764 ◽  
Author(s):  
Anwar Ali ◽  
Rajan Patel ◽  
Shahjahan Khan ◽  
Vidiksha Bhushan

The densities (ρ), viscosities (η), and refractive indices (nD) of (0.01, 0.05, 0.10, 0.15, and 0.20 m) amino acid, glycine, and peptides, diglycine and triglycine in 0.01 m aqueous tartrazine solution were determined at 288.15, 293.15, 298.15, 303.15, 308.15, and 313.15 K. The density data were utilized to evaluate apparent molar volumes (φv) which, in turn, were used to determine partial molar volumes (φv ◦) using Masson’s equation. The transfer volumes were also calculated. The viscosity data were analyzed using the Jones-Dole equation to determine the viscosity coefficients and the activation parameters. The activation parameters of viscous flow were obtained to throw light on the mechanism of viscous flow. The molar refraction was calculated using the refractive index data. The results were interpreted in the light of ion-ion, ion-nonpolar, and nonpolar-nonpolar interactions and the effect of increasing hydrophobicity as we move from glycine to triglycine on these interactions in presence of the dye tartrazine was also investigated.


2020 ◽  
Vol 10 (01) ◽  
pp. 170-174 ◽  
Author(s):  
Sundus H. Merza ◽  
Nagham H. Abood ◽  
Ahamed M. Abbas

The interactions of drug amoxicillin with maltose or galactose solutions with a variation of temperature have been discussed by taking in the volumetric and viscometric procedures. Physical properties [densities (ρ) and viscosities (η)] of amoxicillin (AMOX) aqueous solutions and aqueous solutions of two type saccharides (maltose and galactose 0.05m) have been measured at T = (298.15, 303.15 and 308.15) K under atmospheric pressure. The apparent molar volume (ϕv cm3mole-1) has been evaluated from density data and fitted to a Redlich-Mayer equation. The empirical parameters of the Mayer-Redlich equation and apparent molar volume at infinite dilution Ø°v were explicated in terms of interactions from type solute-solvent and solute–solute interactions. Transfer molar volume ΔtraØ°v for AMOX from water to aqueous maltose and galactose solutions were calculated to comprehend different interactions in the ternary solutions. Limiting apparent molar expansibility (Ø°E) and Hepler’s coefficient was also calculated to indicate the structure making ability of AMOX in the ternary solutions. Jones–Dole coefficient B and A have been calculated from viscosity data by employing the Jones–Dole equation. The free energy of activation of viscous flow per mole of the solute (Δμ°2*) and solvent (Δμ°1*) have been explained on the basis of the Eyring and Feakins equation.


2011 ◽  
Vol 66 (5) ◽  
pp. 345-352
Author(s):  
Anwar Ali ◽  
Firdoos Ahmad Itoo ◽  
Nizamul Haque Ansari

The density ρ, and viscosity η of 0.00, 0.05, 0.10, 0.15, and 0.20 mol kg−1 glycine (Gly), dlalanine (Ala), dl-serine (Ser), and dl-valine (Val) have been measured in 0.002 mol kg−1 aqueous sodium dodecyl sulphate (SDS) at 298.15, 303.15, 308.15, and 313.15 K. These data have been used to calculate the apparent molar volume φv, infinite dilution apparent molar volume φv°, and the standard partial molar volumes of transfer φv° (tr), of the amino acids from water to the aqueous SDS solutions. Falkenhagen coefficient A, Jones-Dole coefficient B, free energies of activation per mole of solvent (aqueous SDS) Δμ1°*, and per mole solute (amino acids) Δμ2°*, also enthalpy ΔH* and entropy ΔS* of activation of viscous flow were evaluated using viscosity data. The molar refraction RD was calculated by using experimental values of the refractive index nD of the systems. The results have been interpreted in terms of ion-ion, ion-polar and hydrophobic-hydrophobic group interactions. The volume of the transfer data suggest that ion-ion intertactions are predominant.


2019 ◽  
Vol 31 (11) ◽  
pp. 2557-2566
Author(s):  
Shashi Kant Sharma ◽  
Poonam ◽  
Nisha Sharma

To investigate the behaviour of doxycycline hyclate in water, aqueous glycine and aqueous L-alanine solutions, the viscometric and conductometric studies have been conducted at different temperatures. Viscosity data has been used to derive the Jones-Dole viscosity B-coefficient, temperature derivative of B-coefficient (dB/dT), viscosity B-coefficient of transfer (ΔtrB), free energy of activation of viscous flow per mole of solvent (Δμ1 o*) and solute (Δμ2o*) respectively, activation entropy (ΔS2o*) and activation enthalpy (ΔH2o*). Conductance data has been used to compute Walden product (Λm oηo) and temperature coefficient of Walden product (dΛmoηo/dT) for doxycycline hyclate in water, and in aqueous glycine and aqueous L-alanine solution. The positive values of B-coefficient, ΔtrB indicate the prevailing of hydrophilic-ionic interactions in the systems under examination. The negative values of dB/dT and positive values of temperature coefficient of Walden product infer structure maker tendency of doxycycline hyclate in water, and in aqueous glycine and aqueous L-alanine solution. Transfer energy parameters indicate the breaking of intermolecular bonds in transition state which means that formation of activated complex is unfavourable


1992 ◽  
Vol 70 (10) ◽  
pp. 2645-2649 ◽  
Author(s):  
Paul Wiseman ◽  
Murray Heggie ◽  
Ramamurthy Palepu

Viscosities and densities of binary mixtures containing 2-(2-butoxyethoxy)ethanol with aniline and N-alkyl-substituted anilines have been determined at five different temperatures over the complete concentration range. Excess volumes, viscosities, and excess molar free energy of activation of flow were calculated and the departure from ideal behavior is explained on the basis of specific interactions between the components in these mixtures. McAllister's approach correlates the viscosity data with a significantly high degree of accuracy for all these systems.


1976 ◽  
Vol 31 (8) ◽  
pp. 967-973 ◽  
Author(s):  
J. J. van Loef

Abstract A single component hard sphere description molten halides and nitrates, applied to self-diffusion and viscosity data, has led to a hard sphere size which for a given cation depends linearly upon the anionic radius. This correlation has been used to predict viscosity coefficients of fused alkali fluorides and to estimate the effective size of the NO3- -anion in molten nitrates. The Stokes-Einstein relationship between η and D̅ is satisfied, where D̅= (D+ +D-)/2, and this relationship in combination with the observed linear dependence of T½/η] and D̅/T½ on the molar volume can in principle be used as a criterion for data selection.


1982 ◽  
Vol 10 (1) ◽  
pp. 37-54 ◽  
Author(s):  
M. Kumar ◽  
C. W. Bert

Abstract Unidirectional cord-rubber specimens in the form of tensile coupons and sandwich beams were used. Using specimens with the cords oriented at 0°, 45°, and 90° to the loading direction and appropriate data reduction, we were able to obtain complete characterization for the in-plane stress-strain response of single-ply, unidirectional cord-rubber composites. All strains were measured by means of liquid mercury strain gages, for which the nonlinear strain response characteristic was obtained by calibration. Stress-strain data were obtained for the cases of both cord tension and cord compression. Materials investigated were aramid-rubber, polyester-rubber, and steel-rubber.


Author(s):  
G. Meneghesso ◽  
E. Zanoni ◽  
P. Colombo ◽  
M. Brambilla ◽  
R. Annunziata ◽  
...  

Abstract In this work, we present new results concerning electrostatic discharge (ESD) robustness of 0.6 μm CMOS structures. Devices have been tested according to both HBM and socketed CDM (sCDM) ESD test procedures. Test structures have been submitted to a complete characterization consisting in: 1) measurement of the tum-on time of the protection structures submitted to pulses with very fast rise times; 2) ESD stress test with the HBM and sCDM models; 3) failure analysis based on emission microscopy (EMMI) and Scanning Electron Microscopy (SEM).


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