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Structure-Function-Property Relationships in Conjugated Polyelectrolytes (CPEs) Thuc-Quyen Nguyen, University of CA, Santa Barbara, DMR 0547639.
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Structure-Function-Property Relationships in Conjugated Polyelectrolytes (CPEs) Thuc-Quyen Nguyen, University of CA, Santa Barbara, DMR 0547639 • The aim of this project is to understand structure-function-property relationships in CPEs. Our goal is to optimize the materials function and properties by a systematic study that incorporates new materials design, a range of processing options and characterization techniques. • The electronic properties of CPEs with poly(fluorene-co-phenylene) backbones and different counterions and charges are investigatedusing absorption and ultraviolet photoelectron spectroscopy (UPS). The optical energy band gap of CPEs (~2.9 eV) depends mainly on their conjugated backbone and is insensitive to the charges or counterions. UPS measurements reveal that electron injection from Au to polymers with cationic groups is more efficient (i.e., low felectron) than for the neutral and anionic counterparts. The vacuum levels () of CPEs were also shifted toward higher or lower binding energy, relative to that of Au depending on the charge and counterion presence, and provide insight into the general alignment of dipoles at the metal/organic interface. PFN-Br PFN+Br- PFN+BIm4- PFNSO3-Na+ (Top) Chemical structures of CPEs. (Bottom) Summary of results from UPS measurements. Φ is charge injection barrier (Unit = eV).
Education and Outreach Activities Thuc-Quyen Nguyen, University of CA, Santa Barbara, DMR 0547639 • The PI helped organizing the Advanced Materials Science and Nanotechnology Conference in Vietnam (September 15-20, 2008) • The PI participated in “Science Night” at local middle schools. She introduced various types of materials and their applications to young students, parents, and teachers (top picture: Kellogg School, Santa Barbara). • The PI is a guest speaker and a member of the planning board for the Women in Science and Engineering (WiSE) at UCSB. WiSE promotes equal opportunity for women and girls in science and engineering and supports their scientific and career advancement. • The PI helped organize the Science and Technology Mathematics Engineering Science Achievement Day. This annual event at UCSB is designed to increase student diversity, to encourage students to go to college and to consider careers in science and engineering. She and her group developed and gave workshops at this year event (bottom picture, from left to right: Mark Dante, the PI, Andres Garcia, and Bright Walker ).