Influence of organics on the structure of water adsorbed on activated carbons.
The influence of organics on the structure of water adsorbed on activated carbons was studied using adsorption of nitrogen, benzene, and water, and by (1)H NMR spectroscopy with freezing out of bulk water with the presence of benzene-d(6) or chloroform-d. It was found that interactions of water with the activated carbon surface depend on both structural characteristics (contributions of micro- and mesopores, pore size distributions) of adsorbents and chemical properties (changed by oxidation or reduction) of the adsorbents. Moreover, the interfacial behavior of water is affected by water-insoluble organics such as benzene and chloroform. Changes in the Gibbs free energy of water adsorbed on carbons exposed to air, water, chloroform-d, or benzene-d(6) are related to textural properties of adsorbents and the degree of their oxidation. Since chloroform-d and benzene-d(6) are strongly adsorbed on activated carbons and immiscible with water they replace a significant portion of adsorbed water in micropores, on the walls of mesopores, and in the transport pores of carbons causing changes in the Gibbs free energy and other characteristics of water.
Turov
V V
VV
Institute of Surface Chemistry, 17 General Naumov Street, Kiev 03164, Ukraine.
Gun'ko
V M
VM
Leboda
R
R
Bandosz
T J
TJ
Skubiszewska-Zieba
J
J
Palijczuk
D
D
Tomaszewski
W
W
Zietek
S
S