Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Publication
Articles 1 - 2 of 2
Full-Text Articles in Chemical Engineering
Structure, Stability, And Electronic Interactions Of Polyoxometalates On Functionalized Graphene Sheets, Jean-Philippe Tessonnier, Stephanie Goubert-Renaudin, Shaun Alia, Yushan Yan, Mark A. Barteau
Structure, Stability, And Electronic Interactions Of Polyoxometalates On Functionalized Graphene Sheets, Jean-Philippe Tessonnier, Stephanie Goubert-Renaudin, Shaun Alia, Yushan Yan, Mark A. Barteau
Jean-Philippe Tessonnier
Polyoxometalates (H3PMo12O40, H 3PW12O40, H4PMo11VO 40) supported on oxygen- and alkyl-functionalized graphene sheets were investigated. Discrete molecular species were directly observed by electron microscopy at loadings below 20 wt.%. The interaction between the polyoxometalates and the graphene surface was found to significantly impact their vibrational spectra and a linear correlation between the frequency of the M-Oc-M vibration and the dispersion was evidenced by FTIR. While bulk-like electronic properties were observed for small aggregates (2-5 nm), UV-vis spectroscopy and cyclic voltammetry revealed changes in the electronic structure of isolated molecular species as a result of their interaction with graphene. Because of …
Ordered Network Phases In Linear Poly(Isoprene-B-Styrene-B-Ethylene Oxide) Triblock Copolymers, Thomas H. Epps Iii, Eric W. Cochran, Travis S. Bailey, Ryan S. Waletzko, Cordell M. Hardy, Frank S. Bates
Ordered Network Phases In Linear Poly(Isoprene-B-Styrene-B-Ethylene Oxide) Triblock Copolymers, Thomas H. Epps Iii, Eric W. Cochran, Travis S. Bailey, Ryan S. Waletzko, Cordell M. Hardy, Frank S. Bates
Eric W. Cochran
The equilibrium phase behavior of 43 linear poly(isoprene-b-styrene-b- ethylene oxide) (ISO) triblock copolymer melts, with molecular weights that place these materials near the order-disorder transition, is reported. Ordered phase morphologies were characterized using small-angle X-ray scattering, transmission electron microscopy, dynamic mechanical spectroscopy, and static birefringence measurements. Interpretation of these results was aided by a modeling technique that facilitates resolution of reciprocal and real-space experimental data, leading to definitive three-dimensional morphological structures. Three distinct multiply continuous network morphologies are identified across a range of compositions between 0.1 ≤ f o ≤ 0.3, situated between two-domain and three-domain lamellae, where f o …