Professor Joshua Schrier from Haverford College (http://www.haverford.edu/chemistry/schrier/) will be presenting. His talk information is below.
Quantum Chemical Engineering: The feasibility of isotope separation using quantum tunneling effects in nanostructures.
Membrane-based
gas methods are potentially more energy efficient than adsorption and
cryogenic distillation for the separation of gases, and are being
adopted for a number of applications. Because classical membrane
permeance is inversely proportional to membrane thickness, the
theoretical maximum is reached for membranes that are only a single
molecular layer thick, leading to recent theoretical and experimental
work on two-dimensional polymers and nanometer-sized pores in graphene.
Besides the possible technological improvements, new types of transport
mechanisms occur with these two-dimensional membranes. In particular,
because of the thinness of these materials, quantum tunneling of atoms
and molecules can become an important contributor transport.
In this talk, I will discuss our ongoing computational efforts to
identify nanostructures which display atomic quantum tunneling
phenomena, with a specific application to helium isotope separation. I
will then describe our recent theoretical work on a temperature-driven
"though experiment" which enables us to distinguish between tunneling
and classical transport. In addition to practical simplicity, the
direction of the isotope concentration can provide a direct confirmation
of tunneling, and the effect is large enough to be measured using a
simple gas density balance. Finally, I will discuss our recent progress
on the use organometallic assemblies to create double-barrier potentials
that display resonant tunneling of the helium atoms.
Anna B. Shin
Laboratory Administrator | Aspuru-Guzik Research Group
Department of Chemistry and Chemical Biology | Harvard University
12 Oxford Street | Cambridge, MA 02138
617.496.9964 office | 617.694.9879 cell | 617.496.9411 fax
http://aspuru.chem.harvard.edu/