Abstract
The behavior of interfacial liquids adsorbed alone or co-adsorbed as miscible or immiscible pairs or triples strongly differs from that for bulk liquids because of several effects, and the main of them is the confined space effect. In the confined space of pores the mobility of molecules decreases, the activity of solvents is reduced, and the freezing temperature decreases. This can lead to the separation of bulk-miscible liquids into weakly miscible or immiscible structures in pores. The pore size distributions and the chemistry of pore walls affect the interfacial behavior of adsorbates because these factors can enhance differentiation of co-adsorbed liquids. These effects were analyzed upon co-adsorption of water and a set of organic solvents, acids, and polymers onto a variety of adsorbents including chars, activated carbons, fumed oxides, silica gels, and porous polymers using low-temperature 1H NMR spectroscopy, differential scanning calorimetry, thermally stimulated depolarization current, thermogravimetry, adsorption, infrared and Raman spectroscopies, SEM, TEM, and quantum chemical methods.
Keywords: Activated carbons, freezing point depression, fumed oxides, interfacial water, lowtemperature 1H NMR spectroscopy, pore size distribution, silica gels, thermally stimulated depolarization current, water/organics co-adsorption.
Graphical Abstract