Мајкл Правица

24. маја 2018.

У оквиру семинара Центра за фотонику, у петак, 25. маја 2018. у 12 часова у читаоници библиотеке „Др Драган Поповић“, професор Мајкл Правица (Универзитет Неваде, Лас Вегас) ће одржати предавање

Harnessing hard x-rays to drive novel science


Though x-ray related damage has been considered a nuisance since x-rays were first discovered, we use them to initiate decomposition and synthetic reaction chemistry at extreme (high pressure, variable temperature) or isolated conditions by harnessing their highly ionizing, highly penetrating, and highly focused properties. This talk will focus on three areas where we have made progress in developing useful hard x-ray photochemistry:

1. Possible formation of HgF4 by irradiation of a mixture of XeF2 and HgF2 at high pressure to produce molecular fluorine in situ in a diamond anvil cell via XeF2 + hυ → Xe + F2 and then reacting the mobile F2 to form HgF4 via HgF2 + F2→ HgF4 at pressures in the 25 GPa up to 40 GPa pressure range. This appears to confirm predictions of “inner shell chemistry” at extreme conditions made by Miao.

2. By irradiation of strontium oxalate, we have produced a novel compound: stable doped polymeric-CO that traps CO2 at ambient conditions for over one year via:
SrC2O4 + hυ → SrCO3 + CO
n(CO) → poly-CO
We plan on synthesizing a family of doped polymers using this method (patent granted).

3. By irradiating lightly pressurized Cs2(C2O4) ∙ H2O, we have created a novel structure of cesium superoxide (CsO2).
These methods may offer hope to synthesize novel compounds with novel structures (and thus with potentially useful and targeted properties).