Electrosurface Properties Of Quarts Fibres
ELECTROSURFACE PROPERTIES OF QUARTS FIBRES
V. G. Lutsenko
Institute of general and inorganic chemistry of National Academy of Sciences of Ukraine Kiev, Ukraine
The properties of fibrous heat-shielding materials are largely determined at the first stage of its production - dispergation of fibers in water solutions. Therefore this research is dedicated to examination of physicochemical processes on the interfacial border quartz fiber - water solutions.
Object of investigation - quartz fibers of the various manufacturers (Russia, France) with specific surface area from 2,5 up to 11m2 g-1 and length-to-diameter ratio more than 10000.
Methods of research - potentiometric acid-base titration, mass titration, microelectrophoresis, adsorption methylic red of a solution in benzol, Augw-electron microscopy, thermogravimetry, optical and electron microscopy.
Quarts fibers are nonporous. Content of impurities of alkali elements is less then 10-5 %. Surface layer of fibers contains an impurity of carbon (from 0,1 up to 0,8 mass %), and its content is in inverse proportion to the content of volumetric OH groups. The point of a zero charge (PZC) both surfaces of fibers, and inner volume of a fibers (pulverized fibers) is at pH 6,5-6,8. At long-lived contact (30-120 days) of fibers with water solutions NaCl there is a PZC bias to parameter domain pH ~ 2-3. Forced insertion into original fibers of impurities of Na+ (~10-2–10-3%) results in change PZC from pH 6,6 up to pH 1,8-2.
The isoelectric point of the investigated fibers sustained in water solutions more than 60 days, is at pH 2-3. The character of change of ζ-potential go with the data on silicon dioxide in literature.
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