Monika Dhiman | Chitkara University (original) (raw)

Physics Research by Monika Dhiman

Research paper thumbnail of Estimation of Effective Debye Temperature of Polymeric Solutions at 303.15 K based on Quasi-Crystalline Model

Journal of Pure and Applied Ultrasonics, 44 (3-4). 64-73., 2022

Based on the quasi-crystalline model of liquids, the effective Debye temperature (θD) of six bina... more Based on the quasi-crystalline model of liquids, the effective Debye temperature (θD) of six binary polymeric solutions has been computed at 303.15 K, using ultrasound velocity and density data. The binary systems studied herein are polypropylene glycol (PPG) 400 + ethanol, PPG-400 + 1-propanol, and PPG-400 + 1-butanol, polyethylene glycol (PEG) 200 + methyl acrylate, PEG 200 + ethyl acrylate, and PEG-200 + n-butyl acrylate. To understand the anharmonic and quasi-crystalline behavior of these systems, several other parameters such as excess Debye temperature (θDE), diffusion constant (Di), Latent heat of melting (Hm), Debye frequency (vm), pseudo-Grüneisen parameter (Γ), Bayer's parameter (B/A) and Len-nard-Jones potential repulsive term exponent (n) have also been determined. Excess Debye temperature (θDE) values are fitted with the Redlich-Kister polynomial equation. From the knowledge of R-K coefficients physicochemical characteristics of the binary mixtures are analyzed and discussed in terms of molecular interactions leading to the existence of qua-si-crystalline structures in the systems under study. The effect of the variation of the alkyl chain of alkanols on the properties of PPG-400 + n-alkanol binary systems has been investi-gated. In addition, the effect of the alkyl chain variation of acrylates on the properties of PEG-200 + alkyl acrylate binary systems has also been studied. The analysis of the obtained results points out that the effective Debye temperature and other related parameters can be successfully estimated for these binary polymeric solutions using the quasi-crystalline model. The present investigation provides significant information about the existence of quasi-crystalline structures and the related structural changes occurring in these polymer solutions with the variation of the type and concentration of a solute.

Research paper thumbnail of Prediction of Refractive Indices and Molecular Radii of Binary Mixtures of Polyethylene Glycol (PEG-200,400) and Cyclic Ethers: Insight into Molecular Interactions

Karbala International Journal of Modern Science, Iraq. 8(4). 703-717. Nov., 2022

Using five refractive index mixing rules: Lorentz-Lorenz, Gladstone-Dale, Weiner, Heller, and Ara... more Using five refractive index mixing rules: Lorentz-Lorenz, Gladstone-Dale, Weiner, Heller, and Arago-Biot, refractive indices of six binary polymer mixtures have been determined at 303.15 K under atmospheric pressure. The binary mixtures investigated here are PEG-200 + 1,3-Dioxolane, PEG-200 + Oxolane, PEG-200 + Oxane, PEG-400 + 1,3-Dioxolane, PEG-400 + Oxolane, and PEG-400 + Oxane. A good agreement has been observed between the obtained results and respective literature data for all these mixtures. The relative merit of refractive index mixing rules is assessed. Deviation in refractive index and reduced free volume values are also calculated using the refractive index data taken from the literature. Furthermore, the molecular radius of these binary polymer mixtures is computed with the help of the refractive index and molar volume data. In addition, an ideal mixing method is also employed to calculate the molecular radius of these systems. The molecular radius of these binary mixtures is found to be additive concerning the mole fraction of the pure components. Finally, the results are discussed regarding the intermolecular interactions among the constituent molecules.

Papers by Monika Dhiman

Research paper thumbnail of Prediction of refractive indices and molecular radii of binary mixtures of Polyethylene glycol (PEG-200,400) and cyclic ethers: Insight into molecular interactions

Karbala International Journal of Modern Science

Prediction of refractive indices and molecular radii of binary mixtures of Prediction of refracti... more Prediction of refractive indices and molecular radii of binary mixtures of Prediction of refractive indices and molecular radii of binary mixtures of Polyethylene glycol (PEG-200,400) and cyclic ethers: Insight into molecular Polyethylene glycol (PEG-200,400) and cyclic ethers: Insight into molecular interactions interactions

Research paper thumbnail of Effective Debye Temperature and Quasi-Crystalline Behavior of Water at Elevated Pressure and in the Temperature Range: 353.15 K to 473.15 K

ECS transactions, Apr 24, 2022

Based on Quasi-crystalline model for liquids, Debye temperature for water has been estimated in t... more Based on Quasi-crystalline model for liquids, Debye temperature for water has been estimated in the high pressure region (0.25 GPa-3.5 GPa) and temperature range; T= 353.15 K-T=473.15 K. The obtained results infer that Debye temperature changes to a greater extent as the pressure increases from 0.25 G Pa-3.5 G Pa, whereas no significant increase is observed with increase in temperature from 353.15 K-473.15 K. The reasonable values of θ D (~180 K-423 K) are the strong evidence of existence of effective Debye temperature and quasi-crystalline state in water at elevated pressure. Present study also indicate that molecular motion of water is more sensitive to increase in pressure rather than increase in temperature.

Research paper thumbnail of Molecular interactions study in polymer blends of chitosan(Ch)/polyvinyl pyrrolidone(PVP) in a buffer solution, within 303.15 K-323.15 K

AIP Conference Proceedings

Ultrasonic investigations of molecular interactions of polymer blends of chitosan (Ch)/ polyvinyl... more Ultrasonic investigations of molecular interactions of polymer blends of chitosan (Ch)/ polyvinyl pyrrolidone (PVP), in a buffer solution (0.1 M acetic acid + 0.2 M sodium acetate) have been reported within the temperature range 303.15 K-323.15 K. Several acoustic parameters such as acoustic impedance, isothermal compressibility, adiabatic compressibility, internal pressure have been determined. Various thermo-dynamical parameters viz; pseudo-Gruneisen parameter and surface tension have been evaluated. Some thermo-elastic parameters such as bulk modulus, shear modulus and Young's modulus are also computed. The non-ideal behaviour of the blend, in the buffer solution has been explained in terms of its composition and temperature variation of acoustical and thermo-dynamical parameters. The reliability model for polymer blends of chitosan (Ch)/ polyvinyl pyrrolidone (PVP) has also been proposed.

Research paper thumbnail of Estimation of ultrasonic velocity and viscosity of polymer solutions of HTPB + chlorobenzene at different temperatures

AIP Conference Proceedings

Ultrasonic velocity and viscosity in binary polymer solutions of hydroxyl terminated poly butadie... more Ultrasonic velocity and viscosity in binary polymer solutions of hydroxyl terminated poly butadiene (HTPB) and chlorobenzene are estimated using four theoretical models for ultrasonic velocity; Schaaff's collision factor theory, ideal mixing rule, Nomoto's relation, Vandeal-Vangeel relation and impedance dependence relation and five mixing rules for viscosity; Bingham's relation, Arrhenius relation, Kendall Munroe relation, Hind-Ubbelohde relation, Frankel relation at different compositions and temperatures ranging from 303 K-318 K. The relative merits of the various mixing rules have been reported in terms of percentage deviation of theoretically estimated value from the experimental value as available in literature.

Research paper thumbnail of Estimation of effective Debye Temperature of Water over Extended Pressure Range; 0.25 GPa -3.5 GPa

SPAST Abstracts, Nov 6, 2021

Research paper thumbnail of Thermo-viscous investigations of molecular interactions for the binary mixtures of polyethylene glycol-400 and polyethylene glycol-600 with dimethyl sulfoxide and water at different temperatures

Journal of Molecular Liquids, 2021

Abstract Thermo-viscous investigations of molecular interactions for the binary mixtures of polye... more Abstract Thermo-viscous investigations of molecular interactions for the binary mixtures of polyethylene glycol-400 + dimethyl sulfoxide and polyethylene glycol-600 + water has been done within the temperature range 298.15 K to 308.15 K. Several thermo-dynamical parameters such as Moelwyn-Hughes parameter, Beyer's non-linear parameter, Lattice Gruneisen parameter, Sharma's constant, Excess Gibbs free energy of activation, and Gruenberg-Nissan interaction parameter have been determined. The validity of five mixing rules for viscosities viz; Bingham's relation, Arrhenius relation, Kendall Munroe relation, Hind-Ubbelohde relation, and Frankel relation is checked for the systems under study. The obtained results are compared with pertinent experimental values. The variations of thermo-dynamical parameters and the deviations in excess viscosity values are explained in terms of the polymer-solvent interactions. Excess Gibbs free energy of activation values are fitted with the Redlich-Kister polynomial equation. A quantitative analysis of the molecular interactions prevalent in these binary systems is described in terms of nature, type and strength of interactions, anharmonicity and structural changes.

Research paper thumbnail of Thermo-acoustic investigations of molecular interactions in CuO nano particles contained aqueous solutions of some glycols

AIP Conference Proceedings, 2020

This paper presents an extensive numerical work on the thermo acoustical properties of CuO nano-p... more This paper presents an extensive numerical work on the thermo acoustical properties of CuO nano-particles contained aqueous solutions of ethylene-, propylene- and hexylene-glycols. Several thermo-acoustical parameters such as Moelwyn-Hughes parameter, reduced volume, reduced compressibility, Sharma’s constants, Huggins parameter, isobaric, isochoric, and isothermal acoustical parameters, fractional free volume, repulsive exponent etc, have been evaluated using the data available in the literature. The variation of these parameters has also been investigated within the temperature range 303.15K-313.15K. Using four different approaches, a comparative study of non-linearity parameter, B/A, has also been done. The present analysis provides a deep insight into the nature, type and strength of particle-particle and particle-fluid interactions prevalent in the systems under study.

Research paper thumbnail of Study of excess acoustical and thermo-dynamical parameters of binary solutions of polypropylene glycol-400 and n-alkanols at 303 K

3RD INTERNATIONAL CONFERENCE ON CONDENSED MATTER AND APPLIED PHYSICS (ICC-2019), 2020

The study of the acoustical and thermodynamic properties of binary mixtures helps to obtain infor... more The study of the acoustical and thermodynamic properties of binary mixtures helps to obtain information on various molecular features of the mixtures. As polypropylene glycol (PPG) is an industrially important polymer and the alcohols are excellent solvents for many polymers, this fact has tingled our interest to study the molecular interactions in the solutions of PPG and alcohols. In the present investigation, using ultrasonic velocity and density data, taken from literature, several excess parameters e.g. excess ultrasonic velocity (UE), excess acoustic impedance (ZE), excess isentropic compressibility (KsE), excess intermolecular free length (LFE), excess internal pressure (πiE) and excess free volume (VFE) for binary solutions of polypropylene glycol-400 with ethanol, 1-propanol and 1-butanol have been determined at 303 K. The behavior of polymeric solutions is discussed in terms of molecular interactions among different molecules. The negative values of KsE, LFE, and VFE over the entire range of mole fraction indicate the presence of strong associative interactions and suggest the possibility of hydrogen bonding between the different molecules, clathrate formation and likelihood of complex formation in the systems under study. The effect of the increasing size of the alkyl group of alkanols, on the intermolecular interactions has also been discussed.

Research paper thumbnail of Frequency Dependence Studies of Acoustical and Thermo-Dynamical Parameters of The Binary Mixtures of Isopropyl Sulphide And Acetic Acid

Romanian Journal of Acoustics and Vibration, Dec 30, 2020

Using thermal expansivity and ultrasonic velocity data for the binary mixtures of isopropyl sulph... more Using thermal expansivity and ultrasonic velocity data for the binary mixtures of isopropyl sulphide and acetic acid, at room temperature, a number of acoustical and thermo-dynamical parameters such as Moelwyn-Hughes parameter (C1), reduced volume (Ṽ), fractional free volume (f), repulsive exponent (n), Sharma's constants (S 0), isobaric (b), isochoric (c), isothermal Gruneisen parameters (T), Bayer's non-linear parameter (B/A), Lattice Gruneisen parameters (), cohesive energy density (i) and interaction parameter () has been evaluated. The frequency dependence of these parameters has been investigated at various concentrations of the binary mixture under study, within the frequency range 1-7 MHz. The variations of these parameters with change in the composition of the mixture and variation of frequency of the ultrasonic waves, propagating in the medium, have been used to explain the molecular interactions, anharmonicity and structural information about the systems under study. The obtained results indicate a decrease in intramolecular modes of vibration and anharmonicity in liquid mixture at higher frequency. These also suggest that binary mixture of isopropyl sulphide and acetic acid becomes less associative and hence weak interaction forces dominate at higher frequency.

Research paper thumbnail of Estimation of Effective Debye Temperature of Polymeric Solutions at 303.15 K based on Quasi-Crystalline Model

Journal of Pure and Applied Ultrasonics, 44 (3-4). 64-73., 2022

Based on the quasi-crystalline model of liquids, the effective Debye temperature (θD) of six bina... more Based on the quasi-crystalline model of liquids, the effective Debye temperature (θD) of six binary polymeric solutions has been computed at 303.15 K, using ultrasound velocity and density data. The binary systems studied herein are polypropylene glycol (PPG) 400 + ethanol, PPG-400 + 1-propanol, and PPG-400 + 1-butanol, polyethylene glycol (PEG) 200 + methyl acrylate, PEG 200 + ethyl acrylate, and PEG-200 + n-butyl acrylate. To understand the anharmonic and quasi-crystalline behavior of these systems, several other parameters such as excess Debye temperature (θDE), diffusion constant (Di), Latent heat of melting (Hm), Debye frequency (vm), pseudo-Grüneisen parameter (Γ), Bayer's parameter (B/A) and Len-nard-Jones potential repulsive term exponent (n) have also been determined. Excess Debye temperature (θDE) values are fitted with the Redlich-Kister polynomial equation. From the knowledge of R-K coefficients physicochemical characteristics of the binary mixtures are analyzed and discussed in terms of molecular interactions leading to the existence of qua-si-crystalline structures in the systems under study. The effect of the variation of the alkyl chain of alkanols on the properties of PPG-400 + n-alkanol binary systems has been investi-gated. In addition, the effect of the alkyl chain variation of acrylates on the properties of PEG-200 + alkyl acrylate binary systems has also been studied. The analysis of the obtained results points out that the effective Debye temperature and other related parameters can be successfully estimated for these binary polymeric solutions using the quasi-crystalline model. The present investigation provides significant information about the existence of quasi-crystalline structures and the related structural changes occurring in these polymer solutions with the variation of the type and concentration of a solute.

Research paper thumbnail of Prediction of Refractive Indices and Molecular Radii of Binary Mixtures of Polyethylene Glycol (PEG-200,400) and Cyclic Ethers: Insight into Molecular Interactions

Karbala International Journal of Modern Science, Iraq. 8(4). 703-717. Nov., 2022

Using five refractive index mixing rules: Lorentz-Lorenz, Gladstone-Dale, Weiner, Heller, and Ara... more Using five refractive index mixing rules: Lorentz-Lorenz, Gladstone-Dale, Weiner, Heller, and Arago-Biot, refractive indices of six binary polymer mixtures have been determined at 303.15 K under atmospheric pressure. The binary mixtures investigated here are PEG-200 + 1,3-Dioxolane, PEG-200 + Oxolane, PEG-200 + Oxane, PEG-400 + 1,3-Dioxolane, PEG-400 + Oxolane, and PEG-400 + Oxane. A good agreement has been observed between the obtained results and respective literature data for all these mixtures. The relative merit of refractive index mixing rules is assessed. Deviation in refractive index and reduced free volume values are also calculated using the refractive index data taken from the literature. Furthermore, the molecular radius of these binary polymer mixtures is computed with the help of the refractive index and molar volume data. In addition, an ideal mixing method is also employed to calculate the molecular radius of these systems. The molecular radius of these binary mixtures is found to be additive concerning the mole fraction of the pure components. Finally, the results are discussed regarding the intermolecular interactions among the constituent molecules.

Research paper thumbnail of Prediction of refractive indices and molecular radii of binary mixtures of Polyethylene glycol (PEG-200,400) and cyclic ethers: Insight into molecular interactions

Karbala International Journal of Modern Science

Prediction of refractive indices and molecular radii of binary mixtures of Prediction of refracti... more Prediction of refractive indices and molecular radii of binary mixtures of Prediction of refractive indices and molecular radii of binary mixtures of Polyethylene glycol (PEG-200,400) and cyclic ethers: Insight into molecular Polyethylene glycol (PEG-200,400) and cyclic ethers: Insight into molecular interactions interactions

Research paper thumbnail of Effective Debye Temperature and Quasi-Crystalline Behavior of Water at Elevated Pressure and in the Temperature Range: 353.15 K to 473.15 K

ECS transactions, Apr 24, 2022

Based on Quasi-crystalline model for liquids, Debye temperature for water has been estimated in t... more Based on Quasi-crystalline model for liquids, Debye temperature for water has been estimated in the high pressure region (0.25 GPa-3.5 GPa) and temperature range; T= 353.15 K-T=473.15 K. The obtained results infer that Debye temperature changes to a greater extent as the pressure increases from 0.25 G Pa-3.5 G Pa, whereas no significant increase is observed with increase in temperature from 353.15 K-473.15 K. The reasonable values of θ D (~180 K-423 K) are the strong evidence of existence of effective Debye temperature and quasi-crystalline state in water at elevated pressure. Present study also indicate that molecular motion of water is more sensitive to increase in pressure rather than increase in temperature.

Research paper thumbnail of Molecular interactions study in polymer blends of chitosan(Ch)/polyvinyl pyrrolidone(PVP) in a buffer solution, within 303.15 K-323.15 K

AIP Conference Proceedings

Ultrasonic investigations of molecular interactions of polymer blends of chitosan (Ch)/ polyvinyl... more Ultrasonic investigations of molecular interactions of polymer blends of chitosan (Ch)/ polyvinyl pyrrolidone (PVP), in a buffer solution (0.1 M acetic acid + 0.2 M sodium acetate) have been reported within the temperature range 303.15 K-323.15 K. Several acoustic parameters such as acoustic impedance, isothermal compressibility, adiabatic compressibility, internal pressure have been determined. Various thermo-dynamical parameters viz; pseudo-Gruneisen parameter and surface tension have been evaluated. Some thermo-elastic parameters such as bulk modulus, shear modulus and Young's modulus are also computed. The non-ideal behaviour of the blend, in the buffer solution has been explained in terms of its composition and temperature variation of acoustical and thermo-dynamical parameters. The reliability model for polymer blends of chitosan (Ch)/ polyvinyl pyrrolidone (PVP) has also been proposed.

Research paper thumbnail of Estimation of ultrasonic velocity and viscosity of polymer solutions of HTPB + chlorobenzene at different temperatures

AIP Conference Proceedings

Ultrasonic velocity and viscosity in binary polymer solutions of hydroxyl terminated poly butadie... more Ultrasonic velocity and viscosity in binary polymer solutions of hydroxyl terminated poly butadiene (HTPB) and chlorobenzene are estimated using four theoretical models for ultrasonic velocity; Schaaff's collision factor theory, ideal mixing rule, Nomoto's relation, Vandeal-Vangeel relation and impedance dependence relation and five mixing rules for viscosity; Bingham's relation, Arrhenius relation, Kendall Munroe relation, Hind-Ubbelohde relation, Frankel relation at different compositions and temperatures ranging from 303 K-318 K. The relative merits of the various mixing rules have been reported in terms of percentage deviation of theoretically estimated value from the experimental value as available in literature.

Research paper thumbnail of Estimation of effective Debye Temperature of Water over Extended Pressure Range; 0.25 GPa -3.5 GPa

SPAST Abstracts, Nov 6, 2021

Research paper thumbnail of Thermo-viscous investigations of molecular interactions for the binary mixtures of polyethylene glycol-400 and polyethylene glycol-600 with dimethyl sulfoxide and water at different temperatures

Journal of Molecular Liquids, 2021

Abstract Thermo-viscous investigations of molecular interactions for the binary mixtures of polye... more Abstract Thermo-viscous investigations of molecular interactions for the binary mixtures of polyethylene glycol-400 + dimethyl sulfoxide and polyethylene glycol-600 + water has been done within the temperature range 298.15 K to 308.15 K. Several thermo-dynamical parameters such as Moelwyn-Hughes parameter, Beyer's non-linear parameter, Lattice Gruneisen parameter, Sharma's constant, Excess Gibbs free energy of activation, and Gruenberg-Nissan interaction parameter have been determined. The validity of five mixing rules for viscosities viz; Bingham's relation, Arrhenius relation, Kendall Munroe relation, Hind-Ubbelohde relation, and Frankel relation is checked for the systems under study. The obtained results are compared with pertinent experimental values. The variations of thermo-dynamical parameters and the deviations in excess viscosity values are explained in terms of the polymer-solvent interactions. Excess Gibbs free energy of activation values are fitted with the Redlich-Kister polynomial equation. A quantitative analysis of the molecular interactions prevalent in these binary systems is described in terms of nature, type and strength of interactions, anharmonicity and structural changes.

Research paper thumbnail of Thermo-acoustic investigations of molecular interactions in CuO nano particles contained aqueous solutions of some glycols

AIP Conference Proceedings, 2020

This paper presents an extensive numerical work on the thermo acoustical properties of CuO nano-p... more This paper presents an extensive numerical work on the thermo acoustical properties of CuO nano-particles contained aqueous solutions of ethylene-, propylene- and hexylene-glycols. Several thermo-acoustical parameters such as Moelwyn-Hughes parameter, reduced volume, reduced compressibility, Sharma’s constants, Huggins parameter, isobaric, isochoric, and isothermal acoustical parameters, fractional free volume, repulsive exponent etc, have been evaluated using the data available in the literature. The variation of these parameters has also been investigated within the temperature range 303.15K-313.15K. Using four different approaches, a comparative study of non-linearity parameter, B/A, has also been done. The present analysis provides a deep insight into the nature, type and strength of particle-particle and particle-fluid interactions prevalent in the systems under study.

Research paper thumbnail of Study of excess acoustical and thermo-dynamical parameters of binary solutions of polypropylene glycol-400 and n-alkanols at 303 K

3RD INTERNATIONAL CONFERENCE ON CONDENSED MATTER AND APPLIED PHYSICS (ICC-2019), 2020

The study of the acoustical and thermodynamic properties of binary mixtures helps to obtain infor... more The study of the acoustical and thermodynamic properties of binary mixtures helps to obtain information on various molecular features of the mixtures. As polypropylene glycol (PPG) is an industrially important polymer and the alcohols are excellent solvents for many polymers, this fact has tingled our interest to study the molecular interactions in the solutions of PPG and alcohols. In the present investigation, using ultrasonic velocity and density data, taken from literature, several excess parameters e.g. excess ultrasonic velocity (UE), excess acoustic impedance (ZE), excess isentropic compressibility (KsE), excess intermolecular free length (LFE), excess internal pressure (πiE) and excess free volume (VFE) for binary solutions of polypropylene glycol-400 with ethanol, 1-propanol and 1-butanol have been determined at 303 K. The behavior of polymeric solutions is discussed in terms of molecular interactions among different molecules. The negative values of KsE, LFE, and VFE over the entire range of mole fraction indicate the presence of strong associative interactions and suggest the possibility of hydrogen bonding between the different molecules, clathrate formation and likelihood of complex formation in the systems under study. The effect of the increasing size of the alkyl group of alkanols, on the intermolecular interactions has also been discussed.

Research paper thumbnail of Frequency Dependence Studies of Acoustical and Thermo-Dynamical Parameters of The Binary Mixtures of Isopropyl Sulphide And Acetic Acid

Romanian Journal of Acoustics and Vibration, Dec 30, 2020

Using thermal expansivity and ultrasonic velocity data for the binary mixtures of isopropyl sulph... more Using thermal expansivity and ultrasonic velocity data for the binary mixtures of isopropyl sulphide and acetic acid, at room temperature, a number of acoustical and thermo-dynamical parameters such as Moelwyn-Hughes parameter (C1), reduced volume (Ṽ), fractional free volume (f), repulsive exponent (n), Sharma's constants (S 0), isobaric (b), isochoric (c), isothermal Gruneisen parameters (T), Bayer's non-linear parameter (B/A), Lattice Gruneisen parameters (), cohesive energy density (i) and interaction parameter () has been evaluated. The frequency dependence of these parameters has been investigated at various concentrations of the binary mixture under study, within the frequency range 1-7 MHz. The variations of these parameters with change in the composition of the mixture and variation of frequency of the ultrasonic waves, propagating in the medium, have been used to explain the molecular interactions, anharmonicity and structural information about the systems under study. The obtained results indicate a decrease in intramolecular modes of vibration and anharmonicity in liquid mixture at higher frequency. These also suggest that binary mixture of isopropyl sulphide and acetic acid becomes less associative and hence weak interaction forces dominate at higher frequency.