Colligative properties Complexes

Other physical methods often used include measurements of polarimetry, infrared (see Infrared Spectroscopy) and Raman (see Raman Spectroscopy) spectroscopy, conductivity, and colligative properties such as depression of the freezing point, solubility, and reaction kinetics. These topics and the extensive work carried out on mixed and polynuclear complexes is discussed in many of the books to which reference has aheady been made. ... 

This section presents an introductory view of colligative properties, considering only the simple case of a solution in which the solute is nonvolatile (i.e., has a negligible vapor pressure at the solution temperature) and the dissolved solute neither dissociates (which rules out ionizing acids, bases, and salts) nor reacts with the solvent. Discussions of more complex systems can be found in most physical chemistry texts. 

The description of the polymer-surfactant interaction outlined above is based on the conception that the complex formation is a cooperative process of surfactant ions and reflects the general experimental finding, viz., the existence of a critical surfactant concentration for interaction. It also suggests a decrease of Cgp with increasing polymer concentration, which was experimentally found by many authors, as well as the appearance of two breakpoints in the different colligative properties vs. surfactant concentration curves. 

Unless the nature and number of the liaisons in the initial and final states are known with certainty, the reliability of the x-Parameter (based on Eq. 7 and relationships derived therefrom) suffers accordingly, even with the most accurate thermodynamic methods for measuring colligative physical properties of polymer-liquid systems. It would be well, therefore, to develop methods for defining the mode of complexation at the initial and final states on a molecular basis. Elucidation of the molecular nature of these complexations at gel-saturation (or in true solution) is an end-objective of the work described in Sect. 3 of this review. 

A review of dielectric, spectroscopic, thermodynamic, colligative and conductivity properties of complexes of carboxylic acids with pyridines and pyridine A -oxides in non-aqueous solution was reported <94H(37)627). 

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