Date of Award

12-2013

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Chemistry

First Advisor

John Ford, Ph.D.

Second Advisor

Keith Kyler, Ph.D.

Third Advisor

Lawrence Kupchella, Ph.D.

Abstract

Inverse gas chromatography (IGC) was used to study the surface energy characteristics of commercial microcrystalline cellulose (MCC), Avicel PH-101. The IGC measurements were performed under dry conditions and under humid conditions at different column temperatures (30 to 45°C), at infinite dilution. The parameters determined were the column hold-up time, the enthalpy and entropy of adsorption for non-polar probes (n-alkanes), the dispersive component of surface energy of the MCC. The influence of humidity on these parameters was demonstrated. The dispersive component of surface energy decreased slightly as a function of relative humidity (from 50 mJ/m2 at 0% RH to 44 mJ/m2 at 42% RH) which would be expected from swelling of the moist MCC. The higher values of the dispersive component of surface energy of cellulose, under dry conditions, were contributed by strong probe-cellulose dispersive force interactions. Thus, the hydrophobicity of the MCC surface was clearly indicated.

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