Hydrothermal synthesis of framed titanosilicates with a structure of ivanyukite mineral

The phase formation in the Na2O-TiO2-SiO2-H2SO4-H2O system during hydrothermal has been studied. The obtained data were used for the producing of a new type of sorbents with a frame structure similar to the mineral ivanyukite. Excess amounts of silicon and sodium in relation to titanium (III) and titanium (IV) as well as pH up to 12 provide “supersaturating” of the salt mass and affect the rate of precipitation, phase composition, structure and surface properties. The framework arrangement of SiO4 tetrahedron and TiO6 octahedron create channels where Na+ and water molecules are located. The structure of ivanyukite along with mesoporosity provides its high ion-exchange properties.

Quantitative Ultrafast Spectroscopy and Microscopy of Traditional and Soft Condensed Matter

We demonstrate and analyze a series of experiments in traditional and soft condensed matter using coherent optical spectroscopy and microscopy with ultrafast time resolution. We show the capabilities of resolving both real and imaginary parts of the third-order nonlinearity in the vicinity of Raman resonances from a medium probed within microscopic volumes with an equivalent spectral resolution of better than 0.1 cm−1. We can differentiate between vibrations of various types within unit cells of crystals, as well as perform targeted probes of areas within biological tissue. Vibrations within the TiO6 octahedron and the ones for the Ti-O-P intergroup were studied in potassium titanyl phosphate crystal to reveal a multiline structure within targeted phonon modes with closely spaced vibrations having distinctly different damping rates (~0.5 ps−1 versus ~1.1 ps−1). We also detected a 1.7–2.6 ps−1 decay of C-C stretching vibrations in fat tissue and compared that with the corresponding vibration in oil.