ANNALES UNIVERSITATIS MARIAE CURIE-SKLODOWSKA LUBLIN – POLONIA VOL. LXIV, 13 SECTIO AA 2009 Clusterization of water at a surface of nanosilica A-380 ♣ A. Yu. Petin 1 , V. M. Gun'ko 1,* , A. V. Turov 2 , V. V. Turov 1 , R. Leboda 3 1 Institute of Surface Chemistry, 17 General Naumov Str., Kiev 03-164, Ukraine 2 Taras Shevchenko University, Kiev 01-030, Ukraine 3 Maria Curie-Sklodowska University, 20-031 Lublin, Poland Thermodynamic and structural characteristics of water (0.07–1 g per 1 g of silica) bound to nanosilica A-380 (S BET = 378 m 2 /g, primary particle diameter 7.2 nm) alone or on co-adsorption with chloroform alone or in the mixture with DMSO or acetonitrile were determined using 1 H NMR spectroscopy with layer-by-layer freezing-out of water at 200–273 K and NMR-cryoporometry. 1. INTRODUCTION One of important trends in surface science deals with features of chemical and physical processes in nano-confined space [1,2]. In such space adsorbed substances can lose homogeneity due to clusterization and strong dependence of the properties on clusters localization and solid surface characteristics. Structural heterogeneity of adsorbates can be especially great for strongly associated liquids such as water. The thickness of a boundary water layer disturbed by surface forces can reach ten or more molecular layers [3,4]. Water in nano- confined space especially with mosaic hydrophilic/hydrophobic walls has the hydrogen bond network largely different from that of bulk water. Clusters of hexagonal ice with four hydrogen bonds per a molecule can be considered as a structural model of liquid water [5,6]. However, thermal motions of molecules can destroy a portion of the hydrogen bonds, and certain water molecules can be ♣ This article is dedicated to Professor Roman Leboda on the occasion of his 65 th birthday * Author to whom the correspondence should be addressed Unauthentifiziert | Heruntergeladen 07.03.20 03:11 UTC