Clathrates with mixed guests

MIXED GUEST CLATHRATES AND PLANETARY DYNAMICS : CONTINUOUS vs

Thermodynamic stability of hydrogen clathrates.

The stability of the recently characterized type II hydrogen clathrate [Mao, W. L., Mao, H.-K., Goncharov, A. F., Struzhkin, V. V., Guo, Q., et al. (2002) Science 297, 2247-2249] with respect to hydrogen occupancy is examined with a statistical mechanical model in conjunction with first-principles quantum chemistry calculations. It is found that the stability of the clathrate is mainly caused b...

Rattling ‘‘guest’’ impurities in Si and Ge clathrate semiconductors

In addition to their ground state, diamond structure, Si, Ge and Sn can form crystalline solids called clathrates. As in the diamond structure, in the clathrates, the Group IV atoms are tetrahedrally coordinated and sp covalently bonded to their neighbors. However, the clathrates contain pentagonal atomic rings and have open-framework lattices containing 20-, 24and 28-atom ‘‘cages’’. There are ...

Unwelcome Guests: Exotic Forest Pests

Exotic forest pests cost China and the United States billions of dollars each year. Current regulatory systems worldwide are overwhelmed with the increasing volume of international trade. Trade in nursery stock, wood products, pallets and dunnage have proven the most common means of transport for exotic forest pests. Despite our best efforts, pests such as chestnut blight, gypsy moth, Dutch elm...

Methane storage in tea clathrates.

Methane can be stored in tea clathrates, that is kinetics of methane clathrate formation can be significantly accelerated (90% saturation uptake in 20 min) by ingredients (polyphenols and saponins) in tea infusions with a volumetric capacity of up to 172 v/v.