Analysis and structural characterization of pigments and materials used in Nicolae Grigorescu heritage paintings

The combination of various mobile, non-invasive techniques (IR reflectography technique, optical microscopy, XRF, Raman and NIR spectroscopies) and lab-based devices (FTIR and XPS spectroscopies, SEM-EDX microscopy) lead to the first exhaustive investigation of pigments and materials used by the famous Romanian painter Nicolae Grigorescu in three cultural heritage paintings. The study of a large number of spots and samples allowed a rigorous analysis and a far-reaching insight into his work.

Functional silsesquioxane-based hierarchical assemblies for antibacterial/antifungal coatings

This paper reports the first study on functional silsesquioxane-based hierarchical assemblies containing an ordered distribution of silver nanoparticles with a large number of {111} facets, obtained through sol–gel reaction, intended for antibacterial/antifungal coatings.

PVA-based hybrid composites with luminescent properties for drug delivery

The aim of this study was to synthesize and characterize new poly(vinyl alcohol)s (PVAs) hybrid composites with or without a basic drug content, e.g., 2-[4-(2-methylpropyl)phenyl]propanoic acid (ibuprofen), obtained at different pH values. Through sol-gel approach of chloropropyltriethoxysilane with a PVA precursor containing a fluorescent dye (lissamine rhodamine-B sulfonyl chloride), new hybrid materials with porous structures were obtained. Due to encapsulation in a porous network, the influence of rhodamine H-dimers on fluorescence quenching was negligible and the presence of free dye was exploited as a mechanism for anchoring the ibuprofen molecules through hydrogen bonding onto pore surfaces.

Silsesquioxane-based Hybrid Nanocomposite with Self-assembling Properties for Porous Limestones Conservation

The study was concerned with the synthesis and characterization of a silsesquioxane-based hybrid nanocomposite with self-assembling properties intended for monumental porous limestone conservation. Radical polymerization of 3-(trimethoxysilyl)propyl methacrylate in the presence of a primary amine surfactant yielded a new type of hybrid nanocomposite, in which silica was dispersed as domains with typical sizes in the nanometer range. The self-assembling properties of the synthesized composite have been ascribed to the supramolecular assembling abilities of the surfactant, as well as to the combination of linear, ladder, and cage-like fragments of silsesquioxane type. This new sol—gel approach, in which the surfactant makes the pore size of the network more coarse and uniform, avoids cracking while drying inside the stone and thus provides an effective alternative for porous limestone conservation.