Reports: B548050-B5: In Situ Spectroscopic Studies of the Behavior of Polyelectrolyte/Surfactant Mixtures at the Water/TiO2 Interface Using Attenuated Total Internal Reflection Fourier Transform Infrared Spectroscopy (ATR-FTIR) and Multivariate Least Squares Data Analysis

Dion A. Rivera, Central Washington University

During the past funding year ending 8/31/12 the PI has published work that was partially funded by the PRF under the grant referenced above. The citation of the work is "Investigations of the interaction and phase transfer to a TiO2 surface of water soluble dyes with polyelectrolyte/surfactant complexes using ultraviolet-visible spectroscopy and multivariate least squares analysis." Brittany Holms, Janaki Swanson, Kathleen Buck and Dion Rivera Colloids and Surfaces A 2012, 404, 36-46. Funds from the 1 year extension of the PRF grant helped to ensure this paper was published. In addition one student, David Bryce, continued work on aPRF related projects during the course of the academic year. David's work involved the surface modification of silica surfaces with polyelectrolyte materials and the characterization of these materials using ATR-FTIR, UV-Vis, and QCM. David presented his data at the National ACS meeting this past spring in San Diego in the undergraduate poster session for the colloids and surface science division. David is now working at Pacific Northwest National Labs using ATR to understand transport of heavy metal ions in aqueous solution.

In addition to the research outlined above a patent application was filed based on work with polyelectrolyte/surfactant systems that was partially inspired by research pertaining to this PRF grant (Heacock, G.; Rivera, D Color changeable dyes for indicating exposure, methods of making and using such dyes and apparatuses incorporating such dyes. US Patent Application 24499US01). The rights to this patent are owed by Sensor, LLC. which is a company that makes specialized biomedical devices. Subsequent contracts between Sensor, LLC and the PI have lead to the development of other materials whose patent applications are pending. While development of technology that is relevant to the biomedical industry was the furthest thing from the PIs mind when the PRF grant was written, development of this technology was aided by research done under the PRF grant.

The PI applied for an NSF grant during the PRF funding period. This grant employed much of the research done under the PRF grant as the base for the new directions of the research. While was not funded the reviews were generally very positive. The PI hopes to have preliminary data soon that will address some of the reviewers concerns and the grant will be resubmitted.

Finally, the PI has been preparing work for publication that was partially supported by the PRF on the effects of ionic strength on the formation of polyelectrolyte surfactant complexes in solution and their subsequent adsorption to a TiO2 surface. These complexes show significantly different behavior at high ionic strength as compared to low ionic strength. In addition, the interaction of these complexes with guest molecules such as dyes is greatly influenced by the ionic strength of the solution. The PI hopes to have a manuscript ready for submission to the journal Colloids and Surfaces A by the December/January time frame. .