Trimethylsilyl derivatives for the study of silicate structures. Part 4. The conversion of hemimorphite into willemite

Distribution of protons and cations in sodium H-Y zeolites

“…The occupancies of protonic sites in highly decationated zeolite Y are in good agreement with the speculative conclusions of Olson and Dempsey5 and of Mortier and others. 6 We can conclude that the extension of the T-O; bond in zeolites, due to the attachment of a proton, has been confirmed experimentally. Encouraged with the consistency of the experimental data, we have tried to support it by some theoretical considerations.12,13 As it has been pointed out by Gibbs and others,14 the main properties of the structure are determined by the geometry of the system.…”

Thermal and chemical methods for producing zinc silicate (willemite): A review

“…Merkulov and Khristoforov [28] obtained products having the same XRD patterns as the Taylor's result [27] by calcinating at 700e750 C with the Si/Zn molar ratio of 1.1. Götz and Masson reported that the transformation of orthorhombic b-phase into a-phase commenced at 835 C as an exothermic reaction according to thermal analysis methods [39]. Leverenz et al reported that yellow-emitting b-phase and green-emitting a-phase were reversible by quenching at 1600 C and re-heating at around 950 C [40,41].…”

Trimethylsilylation of commonly occurring primary and secondary minerals in soils

“…The trimethylsilylation procedure is based on the fact that silicic acids will react with a monofunctional organosilicon compound to give a stable organosilyl derivative of the acid. Lentz (1964Lentz ( , 1966 showed that it was possible to detect trimethylsilyl derivatives of low-molecular-weight silicate anions (Si044-, Si2076-, Si,0g6-, Si,O,,Band Si,O,,8-) using gas chromatography and the method was developed further by Gotz andMasson (1970, 1971). It involves the simultaneous acid leaching of the silicate sample and trimethylsilyl end-blocking of the silicate anions produced.…”

“…Wu et al (1970) used high-resolution mass spectrometry directly to determine the molecular weight and hence the degree of polymerization of the TMS derivatives revealed by chromatography. According to Gotz andMasson (1970, 1971), the following reactions occur in the trimethylsilylation of silicates. Water partially hydrolyses the trimethylsilyl chloride to trimethylsilanol, which is not degraded under these conditions.…”

“…The trimethylsilanol reacts similarly with silicic acids of increasing degree of polymerization to yield homologous trimethylsilylated derivatives. The method has been used to study the constitution of various crystalline and highly disordered minerals (Cradwick et al, 1972;Wieker, 1972, 1974;Lachowski snd Glasser, 1973;Gotz and Masson, 1978). The preparation of organic derivatives of phyllosilicates by trimethylsilylation has been the concern of several authors.…”