Inverse gas-liquid chromatography

Inoue, K. Fujii, R. Baba, Y. Kagemoto, A., "Heat Interaction Parameter of Polystyrene Solutions Determined by Inverse Gas-Liquid Chromatography," Makromol. Chem., 187, 923 (1986). 

Actually, we should separate inverse gas chromatography into inverse gas-liquid chromatography and inverse gas-solid chromatography. The obvious basis of such discrimination is the state of the column content being examined. Polymers and their mixtures, commercial stationary phases, surfactants represent liquids (at the measurement temperature) involving a mixed mechanism of the retention of the test solutes. Modified silicas are examples of solids that have been studied, and, in this case, adsorption effects predominate, while solution partition in graft chains seems to be negligible. These problems will be discussed in details by Papirer and Balard in another chapter of this book. 

Inverse gas-liquid chromatography (IGC) at infinite dilution, IGC at finite concentrations, and headspace gas chromatography (HSGC)... 

Enthalpy data from light scattering, osmometry, vapor pressure or vapor sorption measurements, and demixing experiments can be found in the literature. However, agreement between enthalpy changes measured by calorimetry and results determined from the temperature dependence of solvent activity data is often of limited quality. In this Handbook, data for AmHa°° determined by inverse gas-liquid chromatography (IGC) have been included. 

In 1969 Smidsrod and Guillet demonstrated that GLC could be used to determine the activity coefficient of a solute in a (molten) polymer at essentially zero solute concentration. This type of activity coefficient is known as an infinite-dilution activity coefficient. Smidsrod and Guillet also introduced the term inverse gas-liquid chromatography (IGC) because in IGC the liquid polymer in the stationary phase acts as a solvent for the very small amount of an inj ected solvent sample like the solute in this case. Methods and results of the application of IGC to polymers and polymer solutions have been reviewed continuously so that an extensive discussion is not required here. The equipment in principle does not differ very much from that used in analytical GLC. Figure 4.4.11 is a schematic of a simple IGC unit. 

In addition to the above methods, 82 of polymer can be determined from a threshold of sedimentation and by critical opalescence. In recent years the method of inverse gas-liquid chromatography has been used to evaluate 82 of polymers. One may also use some empirical ratios relating solubility parameters of polymers with some of their physical properties, such as, surface tension and glass transition temperature. ... 

A large number of theoretical assumptions and the scatter in particle sizes make the usefulness of the method doubtful. The Huggins parameter may also be estimated using data on sedimentation, light scattering, and from inversion gas-liquid chromatography. 

Partial molar enthalpies of mixing at infinite dilution of water and enthalpies of solution of water vapor in molten polymers from inverse gas-liquid chromatography (IGC) Polymer (B) polyester (hyperbranched) 2009DOM Characterization M /g.mor = 6500,M yg.mor = 9750, fatty acid modified, Boltom U3000, Perstorp Specialty Chemicals AB, Perstorp, Sweden ... 

Partial molar enthalpies of mixing at infinite dilution of solvents and enthalpies of solution of gasesA apors of solvents in molten polymers from inverse gas-liquid chromatography (IGC)... 

PARTIAL MOLAR ENTHALPIES OF MIXING AT INFINITE DILUTION OF SOLVENTS AND ENTHALPIES OF SOLUTION OF GASESA APORS OF SOLVENTS IN MOLTEN POLYMERS FROM INVERSE GAS-LIQUID CHROMATOGRAPHY (IGC)... 

A special problem are polymer solutions with concentrations higher than 90 wt% up to the limit of the region of Hemy s law. For this purpose, the inverse gas-liquid chromatography (IGC) is the most useful method. Measurements can be made at infinite dilution of the solvent for determining the activity coefficient at infinite dilution or Hemy s constant, but IGC can also be performed at finite solvent concentra-... 

GLC can be used to determine the activity coefficient of a solute in a (molten) polymer at essentially zero solute concentration. This type of activity coefficient is known as an infinite-dilution activity coefficient. Because the liquid polymer in the stationary phase acts as a solvent for the very small amount of an injected solute sample, this technique is often called inverse gas-liquid chromatography (IQC). 

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