Current Physical Chemistry - Online First

Our research aims to uncover how solute-solvent and solute-solute interactions behave in aqueous solutions, exploring how temperature variations and concentration changes influence these interactions. This can provide deeper insights into the behavior of molecules in different environments, potentially leading to applications in fields such as drug delivery, chemical reactions, and material science.

In the aqueous ternary system, the physicochemical interactions between a medically powerful pharmacological molecule and two naturally occurring amino acids were explored. The investigations were performed in a dilute to infinite dilute medium to study the interactions between the solutes and solvent extensively.

The objective of this research is to systematically investigate the nature of solute-solvent and solute-solute interactions in aqueous solutions across a range of temperatures and concentrations. By doing so, we aim to elucidate the underlying principles governing these interactions, which could contribute to a deeper understanding of solution chemistry. This knowledge is intended to inform the development of more efficient and effective applications in various scientific and industrial fields, including drug formulation, catalysis, and material design.

To characterize and calculate the interactions in the ternary system, various models and formulas were considered and applied. Based on various parameters, including viscosity B-coefficient, apparent molar volume, and molar conductance from viscosity, density, and conductance studies, varying temperatures and concentrations were used to elucidate the molecular interactions. To elucidate the interactions between solute with co-solute and with solvent, the limiting apparent molar volumes and the experimental slopes, derived from the Masson equation, and the Viscosity constants A and B, obtained via the Jones-Doles equation, were examined. To illustrate the structure- breaking/making character of the solutes in the solution, Hepler’s method and dB/dT values were applied.

The results indicated that hydrophobic-hydrophobic interaction plays a significant role in the system.

These amino acid interaction models may explain the properties of a variety of physiologically active compounds, and the mechanism can be expanded to comprehend the nature of similar systems. Furthermore, the research could lead to advancements in areas such as pharmaceutical sciences, where controlling solute interactions is crucial for drug delivery systems, and in environmental chemistry, where understanding pollutant behavior in water is essential for remediation efforts.

Barium Titanate (BaTiO3) is a good candidate for a variety of applications due to its excellent dielectric, ferroelectric and piezoelectric properties.

Pure and doped Barium Titanate (BTO) nanoparticles have been synthesized by the sol-gel method. Barium hydroxide octahydrate (Ba (OH)2.8H2O) and titanium (IV) iso-propoxide (Ti {OCH[CH3]2}4) were used as starting materials. Apart from pure Barium Titanate nanoparticles, Fe-doped BaTiO3 nanoparticles of three different concentrations: 0.1, 0.2 and 0.3 in mol% were prepared and characterized using X-ray diffraction (XRD), UV visible spectroscopy, Fourier Transform Infrared Spectroscopy (FTIR).

From the X-ray diffraction pattern, the particle size was found to be varied in a range of 17-25nm. By using UV visible spectroscopy it was observed that the band gap energy of pure BaTiO3 NP is 3.2eV. As the pure BaTiO3 nanoparticles are doped with 0.1% Fe, the band gap reduces to 3.175eV. For BaTiO3 doped with 0.2% and 0.3% Fe, the band gap energy values are 2.709 and 2.652 respectively. FTIR spectra were used to analyze the vibrational modes of BaTiO3. From the result obtained from FTIR, we can see that the absorption spectrum ranges from 450cm^-1-4000cm^-1. The prominent peak of pure BaTiO3 is at 500cm^-1 which is due to the vibration of the Ti-O band in crystal lattice. For BaTiO3 doped with Fe2O3, the wave number of the absorption peak is shifted from 500cm^-1 in pure BaTiO3. The antibacterial studies were conducted on Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli.

Both pure and iron-doped Barium Titanate showed significant antibacterial properties, confirming the antibacterial property of Barium Titanate nanoparticles.

The interaction of dyes (crystal violet, malachite green, and congo red) with cationic (cetrimide) and anionic surfactants (sodium dodecyl sulfate) in the aqueous medium were studied via conductometric and UV-visible spectroscopy.

The critical micelle concentration (CMC) of both cetrimide and SDS upsurges in all the selected dyes on increasing the temperature. Thermodynamic parameters like change in Gibb’s free energy of micellization (), change in enthalpy of micellization () as well as change in entropy of micellization () were calculated by employing mass action model.

The values obtained are positive with and values being negative signified that the phenomenon of micellization is spontaneous as well as exothermic in nature. Moreover, the more negative in water as well as in the presence of dyes signify the presence of electrostatic forces of attraction between the oppositively charged dyes and surfactant moieties. UV-spectroscopy reveals that spectral changes occur because of the interaction of surfactants with dye molecules.

By analyzing shifts in absorption peaks, changes in intensity, and alterations in band shape, insights into the nature of surfactant-dye complexes and their potential applications in various industries can be assessed. This understanding can help in the design and optimization of products and processes involving surfactants and dyes.

Concrete's filler material gets strengthened over time by specific chemical reactions that harden it. Multi-walled carbon nanotubes (MWCNTs) are more frequently used as fillers than SWCNTs, owing to their lower cost of production and their superior reinforcement properties in cement composites.

Mechanical properties like compressive strength, splitting tensile strength, and modulus of elasticity are proportional to the water/cement ratio (w/c) and are considered critical criteria in the design of structural elements.

The aim of the present work was to prepare, characterize, and determine the effects that multi-walled carbon nanotubes (MWCNTs) can have on the mechanical strength of various matrix cementitious composites.

The results showed that the addition of multi-walled carbon nanotubes to the concrete greatly improved both its compressive strength and its splitting tensile strength.