Mary Jane Shultz Tufts University, Award

1
Mary Jane Shultz Tufts University, Award
CHE9816380
UV
Reversible wetting unveiled. TiO2 coated glass
exhibits an intriguing phenomenon it is
hydrophobic until treated with UV light, then it
is hydrophilic. This reversible wetting is the
basis for antifogging and self-cleaning windows.
There has been a paucity of experimental evidence
to support proposed mechanisms to account for
reversible wetting. A combined nonlinear optical
and molecular probe technique has provided the
answer. Prior to UV irradiation, the TiO2 coated
window supports a thin aliphatic hydrocarbon
layer that blocks reactive adsorption sites on
the surface.1,2 Irradiation removes the
hydrocarbon.
Before UV hydrocarbon film poisons reactive
sites. After UV Water wets the surface
1) Wang, Chuan-yi Groenzin, Henning Shultz,
Mary Jane, "Surface Characterization of Nanoscale
TiO2 Film by Sum Frequency Generation Using
Methanol as a Molecular Probe" J. Phys.Chem. B
2004, 108, 265-272. 2) Wang, Chuan-yi Groenzin,
Henning Shultz, Mary Jane, "Molecular Species on
Nano-Particle Anatase TiO2 Film Detected by Sum
Frequency Generation Trace Hydrocarbons and
Hydroxyl Groups" Langmuir 2003, 19, 7330-7334.