Aluminium fluorides surface studies

In the second part (Section 5.3), the strong potential of these techniques for the study of functionalized Al-based inorganic fluorides, synthesized for their possible application as catalysts (fluorinated alumina and zeolites, high surface area aluminium trifluorides and nanostructured aluminium fluoride hydrates and hydroxyfluorides), is shown. The compounds used as model for the assignment of the V and Al NMR lines in these materials are also presented. 

Transgranular stress corrosion cracks are known [7.49] from i) austenitic steels in acidic chloride solutions, ii) low-strength ferritic steels in acidic media, iii) ferritic steels in phosphate solutions, iv) carbon steel in water saturated with CO2 and CO, v) a-brass in ammonia solutions that do not cause surface films, vi) aluminium alloys in NaCl/K2Cr04 solutions and vii) magnesium alloys in diluted fluoride solutions. For further study of fracture surface appearance, see, e.g. Lees [7.49] and Scully [7.53]. 

In this chapter recent developments in the study of the acidity in metal fluorides have been surveyed. The relatively large specific surface areas encountered aid the study of acidic metal fluorides both by FTIR spectroscopy and by a reaction-specific radiotracer approach. Where the structure of the solid is known, the enhanced surface area and the application of both techniques enables a relatively detailed picture of the acidic properties to be obtained. This is the situation for the HTB-aluminium hydroxy fluoride, Figure 4.24. 

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