Interference of potassium chloride and diammonium hydrogen phosphate on volumetric, viscometric and spectroscopic properties of aqueous nicotinamide†

Abstract

Understanding how vitamins and fertilizers interact in aquatic environments is crucial for managing water quality, protecting aquatic life, and promoting sustainable agricultural practices. The molecular interactions between nicotinamide (NA) and two fertilizers, potassium chloride (KCl) and diammonium hydrogen phosphate (DAP), were examined by density (ρ) and viscosity (η) measurements in order to investigate and analyze the solvation behavior that occurs in the ternary solutions (NA + KCl/DAP + water). All of these investigations were conducted at temperatures ranging from 293.15 to 313.15 K and experimental pressures P = 101 kPa. The volumetric characteristics such as apparent molar volume (V_ϕ), partial molar volume (V⁰_ϕ) and partial molar expansibility (E⁰_ϕ) were analyzed. The Jones–Dole equation was used to link experimentally observed viscosity values with solution molarity, yielding viscosity coefficients A_F and B_J, temperature derivatives of E⁰_ϕ (∂E⁰_ϕ/∂T)_P and B_J (∂B_J/∂T) have been used to determine the structure-building/breaking properties of the solute. The free energy of activation for viscous flow per mole of solvent (Δμ^0#₁) and per mole of solute (Δμ^0#₂), as well as the entropy and enthalpy of activation per mole of solvent (ΔS^0#₂ and ΔH^0#₂ respectively) were also evaluated. The results show that ion–ion and ion–hydrophilic interactions are dominant in the systems under investigation. The novelty of studying vitamins and fertilizers in aquatic environments lies in the potential to uncover new interactions and mechanisms, leading to more effective environmental management strategies, innovative agricultural practices, and improved understanding of aquatic ecosystem dynamics.