Advanced Sample Preparation Techniques for Surface Spectroscopy Analysis of Organic: Inorganic Hybrid Silica Particles

Silica due to its large inorganic amorphous wall and hydrophilic surface properties renders its suitability for designing different varieties of organic–inorganic silica-based materials. Characterization of such hybrid silica-based materials is one of the fascinating as well as challenging topics to be covered. Surface analysis of these hybrid materials can be done utilizing various techniques, out of which X-ray photoelectron spectroscopy (XPS), 29Si Solid-state Nuclear magnetic resonance (NMR) spectroscopy, and Fourier-transform infrared spectroscopy (FTIR) is the most ideal ones. Thus, before analyzing these silica materials, it requires a massive study on its sample preparation for appropriate characterization of the organic molecules present in the inorganic network. Hence, this chapter will give a brief elucidation of the sample preparation techniques for analyzing the hybrid materials utilizing the above instrumentation techniques.

Lanthanide ion-doped silica nanohelices: helical inorganic network acts as chiral source for metal ions

We demonstrate that lanthanide ions doped in nanometrical silica helices with chirally arranged siloxane network without any organic mediates show induced chiroptical properties such as circular dichroism and circularly polarized...

Improved Magnetization Transfers among Quadrupolar Nuclei in Two-Dimensional Homonuclear Correlation NMR Experiments Applied to Inorganic Network Structures

We demonstrate that supercycles of previously introduced two-fold symmetry dipolar recoupling schemes may be utilized successfully in homonuclear correlation nuclear magnetic resonance (NMR) spectroscopy for probing proximities among half-integer spin quadrupolar nuclei in network materials undergoing magic-angle-spinning (MAS). These (SR2 2 1 ) M , (SR2 4 1 ) M , and (SR2 8 1 )M recoupling sequences with M = 3 and M = 4 offer comparably efficient magnetization transfers in single-quantum–single-quantum (1Q–1Q) correlation NMR experiments under moderately fast MAS conditions, as demonstrated at 14.1 T and 24 kHz MAS in the contexts of 11 B NMR on a Na 2 O–CaO–B 2 O 3 –SiO 2 glass and 27 Al NMR on the open framework aluminophosphate AlPO-CJ19 [(NH 4 ) 2 Al 4 (PO 4 ) 4 HPO 4 · H 2 O]. Numerically simulated magnetization transfers in spin–3/2 pairs revealed a progressively enhanced tolerance to resonance offsets and rf-amplitude errors of the recoupling pulses along the series (SR2 2 1 ) M < (SR2 4 1 ) M < (SR2 8 1 )M for increasing differences in chemical shifts between the two nuclei. Nonetheless, for scenarios of a relatively minor chemical-shift dispersions ( ≲ 3 kHz), the (SR2 2 1 )M supercycles perform best both experimentally and in simulations.

Obtención de materiales híbridos homogéneos de tipo Orgánico/Inorgánico

Tridimensional polymers are mutually incompatible and a solution is the formation of interpenetrating polymer networks (IPN’s). In order to obtain optically transparent plaques, the polyurethane (PU), polymethylmetacrylate (PMMA) and sílica (SiO2) were syntetized and we obtained the best conditions of reaction for each material. We sintetized the binary networks and the ternary ones with different percentage from sílica were obtained, incorporating to the system 10% in weight of sílica, carrying out a curing in situ in mass. The interest of this work lies in the association of an inorganic network (SiO2) to two organic networks PU and PMMA. In order to reduce the phase separation that occurs in the PU, PMMA and SiO2 system, coupling agents of organic/inorganic nature were introduced. Optically transparent plaques were obtained using trimethoxysilyl propyl methacrylate and isocyanatopropyl triethoxy silane. The materials were characterized by Fourier Transformed Infrared Spectroscopy, verifying the presence of representative functional groups in each of the samples. The purpose of incorporating these materials to a single network is the improvement of the mechanical, optical and thermal properties of the organic polymers.

Exfoliation of a two-dimensional cationic inorganic network as a new paradigm for high-capacity CrVI-anion capture

This work represents the selective capture of the aqueous CrVI-anions in record capacityviathein situexfoliation of a rare cationic copper hydroxide material.