7 research outputs found
Probe Location within Interfacial Layer of CTAB Reverse Micelle System
To understand the chemistry of the interfacial region of reverse micelles (RM), we studied RM system made with the cationic surfactant cetyltrimethylammonium bromide (CTAB), alkanol cosurfactants dissolved in cyclohexane with water core. Spectroscopic methods, specifically UV-Vis absorption of Coumarin 343 (C343) as a probe molecule, were used to determine basic properties of RM systems. However, the probe location was difficult to determine because the spectrum (absorbance), when dissolved in RM solution, didnât match the spectra in any of the pure components. Our data suggests that the interfacial layer of RM cannot be thought of behaving only the characteristic of single one of the components; rather, it behaves as a mixture of multiple components with unique characteristics. The interfacial layer appears to have roughly three distinct regions. By combining two components at a time, our data shows that C343 is most likely to reside in the middle or outer interfacial regions, which is surprising because C343 is polar enough that it would be expect to preferentially migrate into the water cor
Dynamical Behavior of Probe Molecules and Dominant Role of Cosurfactants in Reverse Micelles
Reverse micelles (RM) are nanopools of water surrounded by surfactant molecules in a non-polar solvent. Our studies investigated properties of RM probe molecules in the interfacial boundary between water and non-polar solvents. Reichardtâs dye, a probe molecule, was used to uncover properties of RM. UV/vis spectroscopy of Reichardtâs dye reveals information about polarity and the dyeâs approximate residential location and also helps confirm molecular orbital energy diagram. We discovered an interesting phenomenon with Reichardtâs dye in RM. Surprisingly, the UV/vis spectrum of Reicahrdtâs dye in CTAB RM with octanol as a cosurfactant exhibits decreasing absorbance and a blue shift. Reichardtâs dye in solely octanol shows an irreversible color change and similar UV/vis spectrum. Consequently, we conclude that Reichardtâs dye resides near the interfacial layer/solvent boundary. Other cosurfactants do not result in the time dependent behavior suggesting a more dynamic interaction between octanol and Reichardtâs dye
Investigating Sucrose and D-trehalose in AOT Reverse Micelles
Reverse micelles are nanosized structures that encapsulate small water pools and allow us to investigate the fundamental interactions of small organic molecules in nanoconfinement. The behavior of small organic molecules, sometimes referred to as osmolytes, differs in bulk solution and confinement. Because reverse micelles are a good model for biological nanoconfinement, investigating osmolytes in reverse micelle systems can help us to better understand the role they play in biological systems. Optical spectroscopy such as UV-Vis, Fluorescence, and Red Edge Excitation (REES) was used to probe the environment of the reverse micelles. Three small organic molecules were studied: a monosaccharide, d-glucose, and two disaccharides, d-trehalose and sucrose. Spectroscopy results indicate that nanoconfinement affects the interactions had by the osmolytes. Dynamic Light Scattering was used to determine the size of the reverse micelles. Size data results suggest that size increases as w0 increases, and as the concentration of saccharide added decreases, the variability of size increases
Dynamical Behavior of Probe Molecules and Dominant Role of Cosurfactants in Reverse Micelles
Reverse micelles (RM) are nanopools of water surrounded by surfactant molecules in a non-polar solvent. Our studies investigated properties of RM probe molecules in the interfacial boundary between water and non-polar solvents. Reichardtâs dye, a probe molecule, was used to uncover properties of RM. UV/vis spectroscopy of Reichardtâs dye reveals information about polarity and the dyeâs approximate residential location and also helps confirm molecular orbital energy diagram. We discovered an interesting phenomenon with Reichardtâs dye in RM. Surprisingly, the UV/vis spectrum of Reicahrdtâs dye in CTAB RM with octanol as a cosurfactant exhibits decreasing absorbance and a blue shift. Reichardtâs dye in solely octanol shows an irreversible color change and similar UV/vis spectrum. Consequently, we conclude that Reichardtâs dye resides near the interfacial layer/solvent boundary. Other cosurfactants do not result in the time dependent behavior suggesting a more dynamic interaction between octanol and Reichardtâs dye
Mentoring Strategies To Recruit and Advance Women in Science and Engineering
Supporting faculty with professional development resources at all career stages is vital to the success of faculty members, their students, and academic institutions. In science and engineering fields where women are underrepresented, practices that promote career advancement, such as formal and informal mentoring programs, can be effective in both increasing the visibility and numbers of senior women and also encouraging female students to pursue technical majors and careers. A symposium at the March 2010 National Meeting of the American Chemical Society will feature an array of successful mechanisms for enhancing the leadership, visibility, and recognition of women faculty members using various mentoring strategies. Supporting faculty with professional development resources at all career stages is vital to the success of faculty members, their students, and academic institutions. In science and engineering fields where women are underrepresented, practices that promote career advancement, such as formal and informal mentoring programs, can be effective in both increasing the visibility and numbers of senior women and also encouraging female students to pursue technical majors and careers. A symposium at the March 2010 National Meeting of the American Chemical Society will feature an array of successful mechanisms for enhancing the leadership, visibility, and recognition of women faculty members using various mentoring strategies
Development of a Horizontal Peer Mentoring Network for Senior Women Chemists and Physicists at Liberal Arts Colleges
Our research project focuses on the distinctive environments of undergraduate liberal arts institutions and the challenges faced by senior women faculty on these campuses to attain leadership roles and professional recognition. The project involves the formation of five-member alliances of senior women faculty members at different institutions for the purpose of -âŹĆhorizontal mentoring.-⏠Three of the alliances are comprised of full professors of chemistry, the fourth involves full professors of physics. We have formed these alliances to test a -âŹĆhorizontal mentoring strategy-⏠that aims to enhance the leadership, visibility, and recognition of participating faculty members. Alliance members participate in discussions, workshops, and activities focused on career and leadership development through periodic gatherings of alliance members at various locations across the country and through electronic communication via online collaboration tools. The alliances are networked to augment the peer-support structure with a larger cohort of senior women scientists. Outreach activities on home campuses extend the impact of the career development expertise attained by project participants. This NSF-ADVANCE-PAID project is also working to identify and create resources that address career development issues for senior women at liberal arts institutions and disseminate best practices on horizontal mentoring strategies for academic women. We have explored how our institutional structure and culture can profoundly influence the career challenges of academic women and how our mentoring strategy can operate particularly effectively for women from liberal arts colleges