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Three-components suspension, based on a mixture of titania (TiO2)-silica (SiO2)-functionalized graphene oxide (GO) is prepared and used for surface consolidation of historical andesite stone and mortar. For comparison, monoand bi-component suspensions are also involved in this study. In order to increase the attachment capacity of GO to substrate with silicon, GO functionalized with (3-aminopropyl) triethoxysilane (GO-APTES) was involved. Unmodified and modified by painting with prepared suspensions andesite and mortar samples were investigated by microscopy (Optic and SEM-EDX), XRD, FT-IR and Raman spectra before and after 6 months of exposure to ambient conditions. After investigation, even the amount of used consolidant suspension was low, the stability of the modified samples was found that remains constant and in a long time it is possibly to reach even a higher stability level. This approach provides the idea that the prepared suspension could be an interesting option to be involved in stone and mortar consolidation-restoration field. [ABSTRACT FROM AUTHOR]

Carbon aerogel (CA) and xerogel (CX) were proposed as new carbon adsorbent materials for Cu and Cd ions from contaminated water (synthetic water samples). These materials were prepared by a sol-gel process that involves a polycondensation of resorcinol and formaldehyde in Na2CO3 catalysis, followed by a drying step, either in supercritical conditions of CO2 to aerogel obtaining or in normal conditions to xerogel obtaining, and a pyrolytic step. Nitrogen adsorption, AFM, SEM, TEM and XRD were used for morpho-structural adsorbent investigation. Cu and Cd ions adsorption experiments were carried out in batch conditions under magnetic stirring. Adsorbent quantity and grain size influence over the adsorption efficiency were considered. Adsorption results expressed as adsorption capacities showed that prepared CA is a better adsorbent than CX. Adsorption capacities up to 14.2 mg g-1 and 8.5 mg g-1 were obtained for Cd2+ and Cu2+ adsorption on CA, respectively.

Electrostatic painting is the fastest and most efficient technology through industrial paints due to its impact on the environment, and also for its very easy application on different surfaces. The first and most important stage of the electrostatic painting is to clean the surface to be painted by removing the dirt, lubricants, oils, metal oxides or welding residues. In order to increase the efficiency of carbon steel surface cleaning, the influence of alkali and surfactant concentrations, temperature and stirring was investigated. To produce a uniform surface required for the electrostatic painting, some degreased samples were subjected to pickling operation using aqueous HCl solution. [ABSTRACT FROM AUTHOR]

The influence of Au nanoparticles dimension on the photocatalytic performances of the TiO2 aerogels-Au composites was evaluated. Structural and morphological peculiarities of the TiO2 aerogel, unloaded and loaded with 5 and 22 nm Au nanoparticles, were studied by transmission electron microscopy technique, X-ray diffraction and N2-sorption measurements. UV-Vis diffuse reflectance measurements were performed to determine the band gap energies. The photocatalytic activity was evaluated by monitoring the salicylic acid photodegradation. It was found that the Au nanoparticles promote the anatase phase crystallization and produce the decrease of the specific surface area and band gap energy values. The porous composite with the smallest Au nanoparticles dimension exhibits the best photocatalytic performances. [ABSTRACT FROM AUTHOR]