Microscopy, diffraction and spectroscopy of surfactant monolayer films

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The goals of this*research program in surfactant films are: (1) to investigate molecular-level structure-function*relationships in monolayer films comprised of a new type of anionic gemini*surfactant; (2) to investigate electronic energy transfer dynamics in multifluorophoric*photopolymer films using single-molecule fluorescence spectroscopy; and*(3) to develop cutting-edge spectroscopy tools for molecular-level characterization*of monolayers at the air-water interface. The program will generate fundamental*knowledge that will inform applied aspects of our group's research, including work*on crop protection and edible oil encapsulation, as well as provide high-caliber*training of HQP in areas of economic importance to Canada.*** Over the program's duration,*we will investigate: (1) Fundamental structure-function relationships in monolayer*films comprised of a newly-discovered class of anionic gemini surfactants. The key issue of interest is how the molecular structure of surfactants affects fundamental monolayer properties including lateral packing*density, ion-binding capacity, mechanical stability and shear rheology. Studies will involve thermodynamic,*microscopic and diffraction-based structural characterization of monolayers supported*by chemical synthesis to prepare custom surfactants as required. (2) Molecular-level*factors that regulate electronic energy transfer efficiency in coupled, luminescent*molecules in thin films. The systems of*interest are fluorescent polydiacetylene films prepared from polymerizable*surfactants. We will measure energy*transfer efficiency in these films and correlate alignment of individual*fluorophores in the photopolymers with energy transfer dynamics. Measurements*will use single-molecule fluorescence anisotropy imaging in combination with traditional fluorescence*measurements supported by quantum chemical calculations. (3) New*spectroscopic tools for measuring molecular-level structure of films at the*air-water interface, including polarization modulated infrared reflection absorption*spectroscopy and sum frequency generation vibrational spectroscopy. The former will make use of unique,*high-intensity synchrotron radiation to enable unprecedented temporal resolution,*and the latter will build on our expertise with pico- and femtosecond laser instrumentation. This program will advance fundamental research*in materials science, inform applied surfactant research and provide*world-class training of HQP in areas of national importance.