Hydrotropic agents: a new definition

Examination of the Hydrotropic Effect of Sodium p -Toluenesulfonate on a Nonionic Surfactant (C 12 E 6 ) Solution

“…Originally this denomination was restricted to anions of organic salts like sodium benzoates and hydroxybenzoates, benzene-, toluene-, xylene-, or naphthalenesulfonates, salicylate, etc. However cationic molecules like p-aminobenzoic acid-hydrochloride and nonionics like pyrogallol, cathecol, and resorcinol also present hydrotropic properties (2). Hydrotropes are extensively used in the detergent industry to obtain clear liquid formulations that preserve their aspect during usage and storage.…”

Molecular Dynamics Simulations of Hydrotropic Solubilization and Self-Aggregation of Nicotinamide

“…1 A term first coined at the beginning of 20th century, 2 hydrotropy has been found to occur to a diverse collection of chemical structures. [3][4][5][6][7] The nature and mechanism of this phenomenon have raised great interests, and to that end a variety of experimental techniques have been invoked, which include UV/Vis and fluorescence spectrometry, 7,8 infrared spectrometry, 9 solvent variation, 8 conductance measurement, 10 light-scattering and vapor pressure osmometry, 11 nuclear magnetic resonance, 3,12 as well as thermal analysis and microscopy. 13,14 Some theoretical tools have also been attempted, such as molecular orbital calculations.…”

“…15,16 Solution properties, such as pH, viscosity, specific gravity, surface tension, refractive index, conductance, and diffusion rate, were thoroughly examined. 10,17 These studies led to proposals of several potential mechanisms, including complexation, ''salting-in,'' changes in the nature of the solvent, 2,8 and molecular aggregation. 17,18 Nevertheless, for most hydrotropic systems the solubilization mechanisms remain a topic of debate, 7 which is exemplified in the case of nicotinamide (NA) below.…”

Toward the Rationalization of Facilitated Hydrotropy: Investigation with the Ternary Dimethyl Isosorbide / Benzyl Alcohol / Water System

“…sulfate, sulfonate or carboxylate group. The mechanism of aggregation was assigned to a stacking of the hydrophobic part of the hydrotrope [2], i.e. the aromatic planar cycle.…”