
%0 Journal Article
%A Mizukami, Masashi 
%A Kurihara, Kazue 
%T Hydrogen-Bonded Macrocluster Formation of 1-Propanol and 2-Propanol on Silica Surfaces
%J Australian Journal of Chemistry
%D 2003/09/12
%V 56
%N 10
%P 1071-1080
%K 
%R https://doi.org/10.1071/CH03127
%U https://www.publish.csiro.au/paper/CH03127 
%X We have investigated the adsorption of 1- and 2-propanol on silica surfaces from their mixtures with cyclohexane using a combination of colloidal probe atomic force microscopy, adsorption excess isotherms, and FTIR spectroscopy in the ATR mode. The adsorption isotherm indicated that a similar amount of each alcohol was adsorbed on the silica surfaces. FTIR spectra revealed that 1-propanol adsorbed on the surface employing hydrogen-bonding between the surface silanol groups and the hydroxyl groups of 1-propanol as well as between the hydroxyl groups of 1-propanol in the form of a linear zig-zag structure. This structure is similar to the linear hydrogen-bonded structure of ethanol, which we have found on silica and called a &#8216;surface molecular macrocluster&#8217; (M. Mizukami, M. Moteki, K. Kurihara, J. Am. Chem. Soc. 2002, 124, 12 889). The contact of adsorbed layers of 1-propanol on the opposed silica surfaces brought about the long-range attraction extending to 69 &#177; 9 nm at 0.1 mol-% 1-propanol. 2-Propanol was also adsorbed on the surface by the hydrogen-bonding, however, in the form of a cyclic structure. No long-range attraction was observed in the 2-propanol/cyclohexane binary liquids at 0.1&#8211;6.0 mol-%. The absence of a long-range attraction can be explained by the cyclic aggregation structure of 2-propanol on the surface. 
