Crystalline Microporous Organosilicates with Reversed Functionalities of Organic and Inorganic Components for Room-Temperature Gas Sensing.

A deepened investigation on an innovative organic-inorganic hybrid material, referred to as ECS-14 (where ECS = Eni carbon silicates), revealed the possibility to use them as gas sensors. Indeed, among ECS phases, the crystalline state and the hexagonal microplateletlike morphology characteristic of ECS-14 seemed favorable properties to obtain continuous and uniform films. ECS-14 phase was used as functional material in screen-printable compositions and was thus deposited by drop coating for morphological, structural, thermal, and electrical characterizations.

Fabrication of Hybrid Organic-Inorganic Materials with Tunable Porosity for Catalytic Application.

Novel layered organic-inorganic materials functionalized with amino groups have been synthesized by using a two-dimensional zeolitic precursor, IPC-1P, prepared by a top-down approach from zeolite UTL. The formation of porous materials containing silsesquioxane linkers covalently bonded to zeolite layers in the interlayer space was confirmed by a variety of characterization techniques (N  sorption, XRD, TEM). The textural properties and catalytic behavior of functionalized hybrid materials synthesized by direct pillaring of IPC-1P or by grafting of (3-aminopropyl)silyl groups to the IPC-1P precursor preliminarily pillared with tetraethoxysilane (TEOS) were compared.

The role of boric acid in the synthesis of Eni Carbon Silicates.

The influence of H3BO3 on the crystallization of hybrid organic-inorganic aluminosilicates denoted as Eni Carbon Silicates (ECS's) was investigated. Syntheses were carried out at 100 °C under different experimental conditions, using bridged silsesquioxanes of general formula (EtO)3Si-R-Si(OEt)3 (R = -C6H4- (BTEB), -C10H6- (BTEN) and -C6H4-C6H4- (BTEBP)), in the presence of equimolar concentrations of NaAlO2 and H3BO3. The study, involving the synthesis of three different but structurally related phases (ECS-14 from BTEB, ECS-13 here described for the first time from BTEN, and ECS-5 from BTEBP), confirmed a catalytic role for H3BO3 which in general increased the crystallization rate and improved the product quality in terms of amount of crystallized phase (crystallinity), size of the crystallites and phase purity, while it was weakly incorporated in trace amounts in the framework of ECS's.

Hierarchical hybrid organic-inorganic materials with tunable textural properties obtained using zeolitic-layered precursor.

Novel layered zeolitic organic-inorganic materials have been synthesized using a two-dimensional zeolite precursor IPC-1P prepared by a top-down approach from zeolite UTL. The formation of porous materials containing organic linkers or polyhedral oligomeric siloxane covalently bonded to zeolite layers in the interlayer space was confirmed by a variety of characterization techniques (N2/Ar sorption analysis, XRD, (29)Si and (13)C NMR, TEM). The organic-inorganic porous hybrids obtained by intercalation with silsesquioxane posessed layered morphology and contained large crystalline domains.

A highly crystalline microporous hybrid organic-inorganic aluminosilicate resembling the AFI-type zeolite.

ECS-14, a crystalline microporous hybrid organic-inorganic aluminosilicate, has been synthesized by using 1,4-bis-(triethoxysilyl)-benzene (BTEB) as a source of silica. Its structure contains a system of linear channels with 12-membered ring openings, running along the [001] direction, resembling the pore architecture of the AFI framework type.

Size-dependent extinction coefficients of PbS quantum dots.

We report here on a detailed study on PbS colloidal quantum dots. A characterization via X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HRTEM) allowed us to reliably determine the diameter and the shape of the nanocrystals. These data, together with second-derivative analysis of the absorption spectra, allowed us to determine the size dependence of seven transitions in the absorption spectrum; some of these transitions were identified on the basis of their normalized confinement energy.