Issue 10 Volume 41 May 16, 2003

important role in the production of ultraviolet, visible, and infrared radiation signatures at high altitudes. A detailed
understanding of the pertinent chemical reactions that produce the electronically excited species, and of the competing
quenching reactions that remove the internal energy in radiation-less processes is needed to accurately calculate short
wavelength plume spectral signatures and absolute radiances and their temporal/spatial evolution in the high atmosphere. To
facilitate these efforts, we are currently carrying out laboratory investigations to elucidate the reaction mechanism(s) in the
oxidation of CH, CH2, C2H, and C2O with O-atoms and O2. Sufficient exothermicity in CH, CH2, and C2H reactions (except
C2H + O) is available to produce CO in one or more of the triplet states (a, a’, and d). Even more reaction enthalpy is available
in C2O reaction(s) to produce higher excited states of CO (e, A, I, and D). Other excited species such as CH(A(exp 2) Delta)
in C2H plus O or O2, and OH(A(exp 2)Sigma+) in CH + O2 reactions are also possible. CO-uv chemiluminescence has
previously been identified in C2H + O2 reaction and both CO-uv and CO-vuv in the C2O + O reaction. However, no
information is available on the product branching ratios of the excited CO states responsible for the emission. Estimates of
the branching ratio of CH(A(exp 2)Delta) formation in the reactions of C2H with O and O2 can be found in the literature. To
our knowledge, triplet CO formation in CH and CH2 reactions has not yet been positively identified. Fast discharge-flow tube
and pulsed-laser photolysis methods have been employed in this work to study the reaction kinetics and chemiluminescence
in these and C2O reactions. The experimental approach and results of these studies will be presented.
DTIC
Excitation; Photolysis; Oxygen; Carbon Monoxide; Chemiluminescence; Ketenes
20030034682 Engineering Research and Consulting, Inc., Edwards AFB, CA, USA
Polyhedral Oligomeric Silsesquioxanes Surfactants
Viers, Brent D.; Esker, Alan; Farmer, Katie; Jan. 2001; 3 pp.; In English
Contract(s)/Grant(s): Proj-2303
Report No.(s): AD-A410399; AFRL-PR-ED-TP-2001-029; No Copyright; Avail: CASI; A01, Hardcopy
There has been recent interest in using polyhedral oligomeric silsesquioxanes (POSS) as the smallest particles of silica
for reinforcement of polymers. These materials are monodisperse, have tailored functionality (including a hydrophobic
coating) and should thus act as model nanoparticulate filler. Feher et al have shown that sol-gel condensation into cage
compounds can yield two thermodynamically stable main isolates: a fully condensed R8T8 cube and an incompletely
condensed R7T4D3(OH)3 trisilanol. (T refers to a SiO3/2 and D is a SiO2/2 moiety in a silicate framework) There are large
differences in the solubility of POSS in common organic solvents based on the substitution of the cages. For example, a fully
condensed iBu8T8 cube is more soluble than a similar cyclohexyl Cy8T8 cube which in turn is more soluble than a
cyclopentyl Cp8T8 substituted cube. Furthermore the breaking of symmetry in the incompletely condensed cubes could also
be expected to enhance solubility/compatibility. The dispersion of POSS will likely determine how well the material can act
as a ‘nanofiller.’ Farmer et. al. have recently performed molecular dynamics simulations which suggest that POSS molecules
have no tendency for aggregation in a polymeric matrix if they are originally well dispersed.
DTIC
Polymers; Surfactants; Cyclohexane; Clathrates; Nanoparticles
20030034683 Air Force Research Lab., Edwards AFB, CA, USA
Hybrid Inorganic-Organic Performance Fluids Based on Polyhedral Oligomeric Silsesquioxanes (POSS)
Blanski, Rusty; Leland, Justin; Viers, Brent; Phillips, Shawn; Dec 2001; 3 pp.; In English
Contract(s)/Grant(s): Proj-1011
Report No.(s): AD-A410400; AFRL-PR-ED-AB-2001-243; No Copyright; Avail: CASI; A01, Hardcopy
Performance fluids that operate at high temperature can be useful for many applications including highly efficient
automobile engines and jet turbines. One challenging aspect to this project is to increase the use temperature of the
performance fluid while maintaining low temperature pourability. One possible solution to this hurdle is to combine the high
temperature stability of a silsesquioxane framework with the lubricity of hydrocarbons. Data will be presented on a wide
variety of POSS alkyls were synthesized to test the various POSS frameworks for temperature stability and pourability at
lower temperatures. Thermal and viscosity data will also be discussed.
DTIC
Polyhedrons; Oligomers
43