The influence of chemical and thermal modifications of ordered mesoporous carbon on the melting processes of water confined in pores

In this work, the mesoporous carbon (MC) of the ordered structure was synthesized using silica (SBA-15) as a template and glucose as a carbon precursor. The received MC was subjected to wet oxidation in nitric acid and thermal treatment at 150, 400, 600 and 800 degrees C to differ its hydrophobic/hydrophilic character. The obtained unmodified (MC), oxidized (MC-OX) and thermally modified oxidized carbon (MC-OX-150, MC-OX-400, MC-OX600 and MC-OX-800) were investigated by various techniques: transmission electron microscopy (TEM), scanning electron microscopy (SEM), and low-temperature nitrogen adsorption to characterize material porosity, Xray photoelectron spectroscopy (XPS) and suspension potentiometric titration (SPT) to provide the statement of quality and quantity of groups presented onto the surface and the surface charge, and dielectric spectroscopy (DS) and differential scanning calorimetry (DSC) to register the changes in the water melting processes in carbon pores. The DS and DSC studies revealed the correlation between the water melting temperature inside the pores of MCs and their chemical characteristics, which were determined mainly by surface functional groups and only slightly by textural properties.