A combination of operando Fourier transform infrared spectroscopy, operando electrochemical-impedance spectroscopy, and moisture-sorption measurements has been exploited to study the adsorption and conduction behavior of H2O and D2O on the technologically important ceramic oxides YSZ (8 mol % Y2O3), ZrO2, and Y2O3. Because the characterization of the chemisorbed and physisorbed water layers is imperative to a full understanding of (electro-)catalytically active doped oxide surfaces and their application in technology, the presented data provide the specific reactivity of these oxides toward water over a pressure-and-temperature parameter range extending up to, e.g., solid-oxide fuel cell (SOFC)-relevant conditions. The characteristic changes of the related infrared bands could directly be linked to the associated conductivity and moisture-sorption data. For YSZ, a sequential dissociative water ("ice-like" layer) and polymeric chained water ("liquid-like") water-adsorption model for isothermal and isobaric conditions over a pressure range of 10(-5) to 24 mbar and a temperature range from room temperature up to 1173 K could be experimentally verified. On pure monoclinic ZrO2, in contrast to highly hydroxylated YSZ and Y2O3, a high surface concentration of OH groups from water chemisorption is absent at any temperature and pressure. Thus, the ice-like and following molecular water layers exhibit no measurable protonic conduction. We show that the water layers, even under these rather extreme experimental conditions, play a key role in understanding the function of these materials. Furthermore, the reported data are supposed to provide an extended basis for the further investigation of close-to-real gas adsorption or catalyzed heterogeneous reactions.

No abstract

Moisture triggers the growth of existing form I nuclei but it exerts a weaker effect on nucleation, and the presence of residual ethanol greatly accelerates the transformation.

No abstract

No abstract

No abstract

Three regenerated cellulosic fiber types: lyocell, viscose, and modal were subjected to repetitive wetdry treatments. Simulated treatments showed reorganization of the internal fiber structure which could be determined by accessibility studies. The reduction in liquid water retention capacity was found to be greater for lyocell than that for modal and viscose, sorption of iodine, and water vapor reduced for all studied fibers. The wet-dry treatment did not have influence on chemical reactivity of cellulosic fibers characterized by complexation of iron under highly alkaline conditions. The effect of wet-dry treatment on the tenacity, elongation at break, abrasion resistance, and molecular weight distribution of fibers was also explored in this study. The reduced strength in treated specimens was not accompanied by changes in molecular weight distributions. Based on these results, the changes observed in wet-drytreated specimens were observed mainly owing to polymer reorganization in amorphous parts of the fibers. V C 2012Wiley Periodicals, Inc. J Appl Polym Sci 126: E396-E407, 2012

A comparative structural and spectroscopic study, combined with reactivity tests in (inverse) water-gas shift and methanol steam reforming reaction, has been performed on various Ga 2 O 3 polymorphs with special focus on δ-Ga 2 O 3 and ε-Ga 2 O 3 with the aim of highlighting the eventual intrinsic physico-chemical properties of the latter two. Using this comparative approach, the question whether δ-Ga 2 O 3 in fact is a nanocrystalline modification of ε-Ga 2 O 3 , a mixture of ε-Ga 2 O 3 and β-Ga 2 O 3 or a single polymorphic form could be answered: especially Raman spectroscopy measurements, alongside reactivity tests, indicate that δ-Ga 2 O 3 exhibits lots of properties of ε-Ga 2 O 3. In fact, particularly in Raman measurements it appears as a mixture of ε-Ga 2 O 3 and β-Ga 2 O 3. MCCM_Template_Vers 4