Study of the temperature effect on the acid-base properties of cellulose acrylate by inverse gas chromatography at infinite dilution

J Chromatogr A. 2018 Sep 21:1568:168-176. doi: 10.1016/j.chroma.2018.07.025. Epub 2018 Jul 17.

Abstract

Inverse gas chromatography (IGC) at infinite dilution was used to characterize the surface and interfacial properties of polymers, oxides or polymers adsorbed on oxides. In this paper, the dispersive component of the surface energy of CA was calculated following the molecular models of the surface areas of n-alkanes proving the presence of two linear zones with two different slopes in the temperature intervals and indicating a change in the structure of CA groups. The acid-base properties in the Lewis terms of cellulose acrylate were determined. One proved that the specific enthalpy and entropy of interaction of polar probes are functions of the temperature The application of Hamieh's model allows to the determination of the acid-base constants KA and KD and the amphoteric constant K of cellulose acrylate surface. It was proved that the constants KA, KD and K of cellulose acrylate strongly depend on the temperature. This study allowed us to determine the probability w of the specific adsorption of polar probes on the cellulose acrylate surface. This probability parameter also depends on the temperature.

Keywords: Adsorption; Amphoteric constant; Hamieh’s model; Lewis acid and base constants; Specific enthalpy; Surface energy.

MeSH terms

  • Acids / chemistry*
  • Acrylates / chemistry*
  • Adsorption
  • Alkalies / chemistry*
  • Cellulose / chemistry*
  • Chromatography, Gas / methods*
  • Kinetics
  • Models, Theoretical
  • Solvents
  • Surface Properties
  • Temperature*

Substances

  • Acids
  • Acrylates
  • Alkalies
  • Solvents
  • Cellulose