Abstract: Protecting marble, stone, tiles, cement, and similar materials utilized in the building industry from the action of atmospheric agents and pollutants, which comprises applying a perfluoropolyether having perfluoroalkyl end groups onto the surface of the article, said perfluoropolyether being in the form of an aqueous microemulsion.

Abstract: An electrochemical process, in which a gaseous matter is reduced at the cathode and in which microemulsions of the water-in-oil (w/o) type are utilized as catholytes, the microemulsions having ionic electric transfer and matter interphase transfer capacities, and in which the oil phase consists of a perfluoropolyether having perfluoroalkyl end groups or functional end groups of the hydrophilic type, or of perfluorocarbons, the microemulsions being obtained by the use of perfluorinated surfactants, in particular those having a perfluoroalkylpolyether structure and/or by the use of an alcohol as a co-surfactant.

Abstract: Protecting marble, stone, tiles, cement, and analogous materials utilized in the building industry, from the action of atmospheric agents and pollutants, by applying onto the surface thereof a microemulsion of perfluoropolyethers, optionally provided at one end or at both ends or in the chain with functional groups capable of acting as anchoring agents to the substrate.

Abstract: An electrochemical process, in which a gaseous matter is reduced at the cathode and in which microemulsions of the oil-in-water (o/w) type are utilized as catholytes, the microemulsions having ionic electric transfer and matter interphase transfer capacities, and in which the oil phase consists of a perfluoropolyether having perfluoroalkyl end groups or functional end groups of the hydrophilic type, or of perfluorocarbons, the microemulsions being obtained by the use of perfluorinated surfactants, in particular those having a perfluoroalkylpolyether structure and/or by the use of an alcohol as a co-surfactant.

Abstract: Microemulsions based on perfluoropolyethers, comprising:an aqueous medium,a perfluoropolyether having a mean molecular weight from 400 to 10,000, and perfluoroalkyl end groups;a fluorinated surfactant, and optionally also a short-chain hydrogenated alcohol or a fluoroalkanol, or a water-soluble salt, said microemulsions being permanently stable in a certain temperature range, in which they are preparable by simple mixing of the components.

Abstract: Protecting marble, stone, tiles, cement and analogous materials, utilized in the building industry, from the action of atmospheric agents and pollutants, by applying to the surface of the material an emulsion of perfluoropolyethers, optionally having at one end or at both ends or in the chain functional groups capable of acting as anchoring agents to the substrate.

Abstract: A process for polymerizing or copolymerizing fluorinated monomers, in an aqueous dispersion, by using radicalic-type starters and fluorinated surfactants, characterized in that it is operated in the presence of a perfluoropolyether having neutral end groups and prepared in the form of an aqueous microemulsion, in order to increase the polymerization rate, to increase the process reproducibility and to minimize the consumption of said perfluoropolyether.

Abstract: Process for the production of a composite material based on a polymer matrix comprising homogeneously dispersed therein an organic and/or inorganic filler, said process consisting in mixing together the aqueous dispersions of the single components, in which the dispersed particles of the dispersion have a surface charge of the same sign and a "zeta potential" between 10 and 100mV (in absolute value) and wherein the ratio (in absolute value) between the "zeta potentials" of the particles of each dispersion is between 0.2 and 5.

Abstract: New catalysts for photo-assisted (i.e. promoted by light) oxidation-reduction (redox) reactions are disclosed. These catalysts consist of colloidal particles of a semiconductor, containing on their surface a reduction catalyst and an oxidation catalyst. In a first class of catalysts, the semiconductor has a difference of energy between valence band and conduction band such as to allow the hole-electron separation by absorption of visible light. This semiconductor is selected, in the case of the photo-decomposition of water, from the group consisting of TiO.sub.2 doped with Mn, Cr, or Cr and Nb; CdS doped with In or Ga; SrTiO.sub.3 doped with Cr or Mn; gallium phosphide; and cadmium sulphoselenide. In the case of the other photo-decomposition reactions, the semiconductor is selected from the group consisting of the above-mentioned compounds and CdS.

Abstract: The present invention concerns a catalyst for the photodecomposition of water. Said catalyst consists of particles of TiO.sub.2 doped with Nb, said particles containing RuO.sub.2 on their surface. This catalyst may be used, for instance, in combination with ruthenium trisbipyridyl, methylviologen and colloidal platinum.

Abstract: Titanium dioxide, in the form of discrete, solid substantially spherical particles of a substantially uniform shape and size, is obtained by providing an aerosol comprising discrete liquid particles of a hydrolyzable titanium compound, contacting the aerosol with water vapor in dynamic flow to hydrolyze the liquid titanium (IV) compound to titanium dioxide, and recovering the desired product.