Guaiacol and its mixtures: New data and predictive models. Part 2: Gibbs energy of solvation

Abstract

Guaiacol is a model molecule for lignocellulosic biomass processing, and thus understanding its interactions with solvents is an important step when developing units for processing lignocellulosic biomass. In this work, activity coefficient measurements of different solvents (acetonitrile, ethanol, tetrahydrofuran) in guaiacol have been performed at different concentrations and temperatures. These measurements have been used to estimate the infinite dilution activity coefficients and the Gibbs energy of solvation of guaiacol in the different solvents, and of each solvent in guaiacol. These estimated values were compared to those obtained with different predictive models: UNIFAC DMD, Monte Carlo Molecular Simulation, COSMO-SAC and GC-PPC-SAFT. The predictions are in very good agreement with the Gibbs energies of solvation derived from experimental data. Some conclusions are also drawn regarding the inter and intramolecular hydrogen bonding in guaiacol and about its affinity with different solvents on the basis of the inter and intra molecular interactions taking place.

Interaction mechanism of collagen peptides with four phenolic compounds in the ethanol-water solution

“…As shown in the molecular structure, the phenolic hydroxyl of 4-EP was located at the para of the substituent group, and no substituent group was found for phenol. Meanwhile, the phenolic hydroxyls of guaiacol and 4-EG were located at the ortho of the substituent group, and intramolecular hydrogen bonds may be formed [37], resulting in signal reduction and the broadening of the hydrogen of phenolic hydroxyl. Therefore, 4-EP and phenol could easily to form hydrogen bonds with CPs.…”