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58 A. M. KŁONKOWSKI

ABSTRACT

The most basie difference between crystalline and non-crystalłine solids is that a long rangę order (LORO) in the distribution of atoms (ions) or molecules exists only in crystalline materials [1]. This is indicated by diffraction pattems: the ideał crystal (the first extreme case) shows reflectants whose location and intensity obey three Laue conditions. The second extreme case is an ideally random structure. Scattering of radiation is impossible in the case of an ideally homogenous medium. Any real substance, including non-crystalłine materials, is inhomogenous regardless of its form or scalę. Thus glasses can be thought of as assemblies of microcrystals (i.e. microcrystallites or paracrystals). Strain in-troduced due to lattice mismatch at grain boundaries, the presence of a disor-dered interfacial or matrix region, and defects such as dislocations, or stacking faults can be assumed to give rise to departures from periodicity at distances smaller than the average grain size [10]. In this sense glasses are interesting in the supramolecular science because they are intermediate objects in the way from random to organized matter [5].

The object of this article are such amorphous materials as inorganic oxide glasses with structural groups Y0₄, where Y = Si, P, and organically modified silicate gels. Among the studied glasses are ones of the type: R₂0-Si0₂ and R₂0-Ał₂0₃-Si0₂, where R represents alkali atom (Li to Cs) 123, 25, 27], as well as M(II)0-P₂0₅, where M(II) is an alkaline earth atom (Mg to Ba) (28, 29, 32, 33]. Undoped glasses and those doped with copper(II) ions were investigated. These metal ions have played the role of probes.

Ali the vitreous systems are classified according to their theoretical optical basicity zl_cal proposed by Duffy and Ingram [34]. Thanks to this method one can methodically observe and sensibly interpret changcs of real measures of basicity as molar refractivity of oxide ions R₀ (see Figs 9 and lOa), the so-callcd Imagawa’s basicity (Fig. lOb) and other physical and Chemical propertics of oxide glasses (Fig. 11). The studied glasses are also classified according to their bond naturę (Fig. 6), taking into account their proximity to the onset ot metal-lization [4], Attention is also focused on the mixed alkali effect [22, 24].

A fuli understanding of the properties of colloids calls upon a wide rangę of physical and Chemical ideas, while the multitude of colloidal systems presen-ted to us in naturę, and familiar in modern society, exhibits a daunting comp-lexity. On the experimental side there is an ever-increasing emphasis on the application of modern physical techniques to colloidal problems. Oolloid science is thus a truły interdisciplinary subject [3].

In the case of the xerogels there are described Cu(II) complexes existing on surface and in interior of the materiał [59 63]. Morcover, silica xerogels with immobilized supramolecular ligands show intcnsive luminescence (Fig. 17) which is effectively ąuenched by Cu(II) ions [64].