Model Analysis of Cellobiose Solubility in Organic Solvents and Water

• Main Author: Heng, Joseph O.
• Other Authors: Michael T. Timko, Advisor
• Format: Others
• Published: Digital WPI 2020
• Subjects: cellobiose; solubility; Hansen solubility parameters; Linear free energy relationship; UNIFAC; A-UNIFAC
• Online Access: https://digitalcommons.wpi.edu/etd-theses/1352; https://digitalcommons.wpi.edu/cgi/viewcontent.cgi?article=2373&context=etd-theses

The solubility of cellobiose in 18 organic liquids and water was measured at 20°C. Hydrogen bond acceptors were the most effective solvents. Three models were analyzed to evaluate their accuracy and to understand factors that affect cellobiose solubility: Hansen solubility parameters (HSP), linear free energy relationship (LFER), and UNIQUAC functional-group activity coefficients (UNIFAC). The HSP of cellobiose were determined and the model was able to distinguish between most good and poor solvents, however, proved to be occasionally unreliable due to a false negative. The LFER model produced an empirical equation involving contributions from solvent molar refraction, polarizability, acidity, basicity, and molar volume, which predicted cellobiose solubilities to within ±2 log units. LFER indicated that good solvents were highly polarizable and had low molar volume, which was consistent with the good solvents found for cellobiose. A modified version of UNIFAC that includes an association term (A-UNIFAC) predicted the solubility of cellobiose in water and alcohols to within ±0.6 log units, indicating that A-UNIFAC can be used to predict the solubility of cellobiose and other carbohydrates provided additional data to extend the model to solvents other than water and alcohols.