Studies of the Sublimation Mechanism of Solids

New Eras in Molten Salt Corrosion Research

“…Experimental studies of vaporization and decomposition have largely been confined to solids (51,57), but recently there have been some thermodynamic studies of molten sulfates (9,11,33,35). Kinetic studies have largely been limited to alkali halides (10) and a study of Na2S04 is in progress (18).…”

Surface coordination chemistry of platinum studied by thin-layer electrodes. Adsorption, orientation, and mode of binding of aromatic and quinonoid compounds

“…For example, earlier studies of benzene adsorption at well-defined Pt single crystals in ultrahigh vacuum (UHV) employed sample pressures near 10"6 torr, at which only t;6(7r)-bonded intermediates are to be expected. 3 The partial pressure corresponding to concentrations at which flat-to-vertical orientational transitions were observed for species adsorbed from aqueous solutions is about 20 torr.21 Prolonged and/or comparatively higher sample dosages were reported to induce reorientation of benzene adsorbed on Pt(l 11) and Pt(100).4 In the present article, surface chemical reactivities of selected diphenolic and quinonoid compounds2 are described. Five reactions have been investigated with respect to mode of attachment, temperature, and electrode potential: (i) reversible electrochemical reactivity of the adsorbed state compared with that of the free state; (ii) electrocatalytic oxidation of compounds exhibiting multiple orientational states; (iii) electrocatalytic hydrogenation of hydroquinone and S-attached thiophenol derivatives; (iv) exchange reactions between nonidentical aromatic adsorbates; (v) substitution reactions between aromatics and halides.…”

Evolved gas analysis during sintering of barium titanate

“…Evolved gas analysis (EGA) from inorganic compounds heated to high temperature has been performed by a number of techniques over the last 50 years. 1-5 Under conditions corresponding to chemical equilibrium, the gases emanating from a Knudsen cell at high temperature can be either trapped for subsequent analysis or monitored directly by a mass spectrometer (MS). Under non-equilibrium conditions such as those possibly prevailing during sintering, a carrier gas may be used to transport the evolved species from the furnace environment to a characterisation tool, such as a MS, gas chromatograph (GC) or infrared detector (IR), for subsequent analysis.…”