Ceramic membranes spectroscopy

A new type of ceramic membrane electrode that is selective for F" ions has been prepared by sintering LaFg, EuFj, and CaFz at above 1200 °C in an atmosphere of Hf The approximate determination of the F" ion concentration in polluted waters can be made by means of a F ion electrode in the presence of citrate ion however, for an accurate determination a photometric method was applied after separation of F by distillation. The probable composition of the La " -alizarin complexone (H4A)-F complex is said to be La(LaA)4F2. ° Alizarin fluorine blue 5-sulphonate is more soluble in water than the unsulphonated reagent the ternary La -F -complexone absorbs at 583 nm. The application of neutron activation analysis to the determination of fluorine has has been reviewed briefly by Verot and Jaumier. X-Ray photoelectron spectroscopy (p.e.s.) has been used to identify and to provide a quantitative estimate of CF3, CF2, and CF groups on the surface of fluorinated diamond. Proton and deuteron radiolysis of... 

Microstructure of commercial alumina ceramic used as a support in this work is shown in Fig. 1. According to XRD, atomic emission spectroscopy and SEM data this membrane consists of a coarse a- A1203 - tube coated with finer layer of a- A1203 - tube (thickness of 40-60 pm). Traces of B, Ca and Si are detected by atomic emission spectroscopy. Pore sizes in the barrier layer of these tubes vary in the rather wide range from 0.05 to 0.5 micron, mean pore diameter being 0.2... 

Solid-state NMR is used in the analysis of ceramics (they are neither soluble nor meltable), biological cell membranes, wood, cellulose and other plant materials, bone, and even gemstones (any volunteers for solution NMR spectroscopy of... 

To understand the importance of nanostructures in microsieving membranes, the basic structure of nanophased ceramics must be briefly described. Because the particles are extremely small, one to a few tens of nanometers, an important fraction of the atoms is found in or very near the interface between grains, as reported in Table 2 [32]. Figure 11 is a schematic representation of a nanophase material. One can see that individual grains in the 5 nm range induce a biphasic material with an interfacial phase between the grains and a residual nanoporosity, evidenced by positron lifetime spectroscopy [33]. Transmission electron microscopy is also a well-adapted technique for nanoscale structure characterization, as illustrated later. 

Figure 5. Time evolution at 75 °C of the amducUvny of a UPFc/EC/DMCyPAN + 6 w/o AkOs composite gel electrolyte membrane and of an analogous, ceramic-fiee membrane. Data obtained by impedance spectroscopy.

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