Three alumina preparations, doped with ca. 3% CaO and corresponding to the y-, 6,Oand a-Al,O, phases, respectively, have been studied by XRD, TEM and FTIR spectroscopy. Owing to the presence of Ca, no bulk phase stabilization/destabilization effects were observed, but the particle morphology of the y-and a-phases was modified (though to a different extent), and in the a-phase the segregation of bulk Ca aluminate(s) was noted.The IF? spectra of the three materials, and the spectra of the adsorption of some probe molecules (pyridine, CO, CO, ) indicated that, starting from the lowest calcination temperatures, Ca tends to accumulate at the surface of the alumina phase(s). In doing so, it modifies the surface hydrated layer, the basicity of the surface, and the strength and nature of the surface Lewis acidity.It was postulated that, long before the segregation of separate Ca aluminate phases, there is the gradual formation of a (two-dimensional) surface layer of Ca aluminate, whose formation occurs primarily, but not exclusively, at the expense of the surface cationic centres in which Al possesses tetrahedral coordination.

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SynopsisAcrylamide and some of its derivatives were polymerized onto the surface of Fe plates by causing a slight corrosion of Fe to Fez+ in the presence of perdioxy compounds. In water within a suitable pH range, the acrylamide monomers are likely to store a t the metal-solution interface and to ahsorb on the iron surface. Thus, the polymerization takes place in situ, leading to the formation of uniform film coatings; the presence in the solution of a radical inhibitor imparts considerable stability to the hulk of the system. The dependence of the polymerization kinetics on several variables such as pH, monomer concentration, and peroxide concentration has been determined, and some characteristics of the resulting coatings were investigated.

Methanesulfonanilide and benzenesulfonanilide, salified by a suitable amine were electrolyzed with Cu sheets as anodes in water/organic solvent medium. Coherent insulating coatings on the Cu sheets were thus obtained, which on the basis of various analytical tests resulted to have an oligomeric structure. One electron oxidation of the anilide anions and carbonium-nitrogen coupling of the intermediate free radicals are suggested as the main steps of anilides oligomerization.