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The inherent physical, optical and conductivity properties of Ionic Liquid – polymeric membranes : a self indicating, simultaneous response upon coordination to transition metal ions. Andrew Kavanagh MACRO 2010 Glasgow, Scotland 14 th July 2010. Me.

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  1. The inherent physical, optical and conductivity properties of Ionic Liquid – polymeric membranes : a self indicating, simultaneous response upon coordination to transition metal ions. Andrew Kavanagh MACRO 2010 Glasgow, Scotland 14th July 2010

  2. Me.. • Graduated with B.Sc (Hons) in Chemical & Pharmaceutical Sciences, Dublin City University (2008). • PhD. in “Ionic Liquids and their use in the development of potential chemical sensors”. Sept 08’ • Supervisors Dr. Aleksandar Radu & Prof. Dermot Diamond

  3. Outline Ionic Liquids Polymeric Optodes Ionic Liquid – PVC Optodes Vibrational Spectroscopy UV/Vis Characterisation Alternate Detection Techniques Wireless Radio Frequency Detection Electrochemical Impedance Spectroscopy Portable X-Ray Fluorescence

  4. Ionic Liquids • Unique combination of • ions that are liquid at room • temperature • Choice of ion pair can have • dramatic impact on • Density • Viscosity • Miscibility with Solvents

  5. Applications of IL’s • Synthesis & Catalysis in Organic Chemistry • => Good thermal stability • Electrochemistry • => Good Conductivity and a large electrochemical window • Analytical Chemistry • => Stable stationary phase for separations

  6. Polymeric Optodes Typically contain up to 5 components Polymer Inert matrix to house active sensing components Plasticizer Lowers Tg of polymer to produce solid film Ion-Exchanger Facilitates Ion Transfer from aq. to organic phase Ionophore Selectively binds ion of interest Transducer Dye Produces optical response PMMA optodes containing Spiropyran dye A. Radu, R. Byrne, N. Alhashimy and D. Diamond, Abstr. Pap. Am. Chem. Soc., 2006, 231, 41-INOR.

  7. Simple, 2-component optodes Cu2+ Co2+ • [P6,6,6,14][DCA] acts as • plasticizer • ion-exchanger • ligand • transducer dye • Upon exposure to Cu2+ and Co2+ Cu2+/Co2+

  8. Vibrational Spectroscopy νmaxCo-DCA : 2166cm-1 νmaxCu-DCA : 2162 cm-1 IR Raman

  9. Multianalyte Recognition

  10. Stoichiometry Estimation • Best fit was found to be 2M for 1L

  11. Dicyanamide Used to impart low viscosity in a new generation of Ionic Liquids Pseudohalide, shown in literature to bind to an array of TM elements Due to strong electron delocalisation across molecule, resulting in a variety of binding modes Rich binding diversity results in many 1,2 and 3-D co-ordinated networks reported M S. R. Batten, P. Jensen, B. Moubaraki, K. S. Murray and R. Robson, Chem. Commun., 1998, 439-440. S. R. Batten and K. S. Murray, Coordination Chemistry Reviews, 2003, 246, 103-130. DCA

  12. Interference Spectra • DCA- exhibits a higher binding preferentiality for Cu2+ over Co2+ • Ni2+ has been shown to bind to DCA-, yet produces no optical response J. Kohout, L. Jager, M. Hvastijova and J. Kozisek, J. Coord. Chem., 2000, 51, 169-218.

  13. RF Wireless Conductivity Detection • In conjunction with CSIRO Laboratories, • Melbourne, Australia • Works by passing low voltage, low • frequency AC signal from transmitting • to receiving electrodes • Sample is housed in an insulating • container • Conductive sample produces a signal • as it passes through the electrode • field

  14. RF Wireless Conductivity Detection • Depending on pH, polyaniline (PAni) can switch between conductive and non-conductive forms • Ink jet printed Pani dispersion sensitive to both Ammonia and Acetic Acid vapour N. B. Clark and L. J. Maher, Reactive & Functional Polymers, 2009, 69, 594-600.

  15. Wireless Recognition of Conductive Membranes Membrane Group: Ionic Liquid Copper Mix Cobalt PVC: IL (1:2) 52486.14 39292.66 40267.75 43479.93 PVC: IL (1:1) 15879.97 7068.51 9428.30 14908.19 PVC: IL (2:1) 7502.65 0.00 0.00 0.00 • WRF has the required sensitivity • to distinguish between complexed • and non-complexed membranes • “Edge effects” occur as insulating • material first enters and leaves • electrode channel

  16. Screen Printed Electrodes • PET substrate • Ag/AgCl ink used as conducting path • Carbon Paste used as working electrode • Insulating Layer defines the working area • Conducting polymer (Poly (3-octylthiophene)) • is first dropcast to aid ionic to electronic • transition • PVC-IL cocktail dropcast and allowed to dry A. Morrin, A. J. Killard and M. R. Smyth, Analytical Letters, 2003, 36, 2021-2039.

  17. Impedance Spectroscopy • PVC:IL 1:2 (w/w) • PVC:IL (1:1 w/w)

  18. LOD Calcualtions Cu-DCA LOD: 7.62 x 10-4M Co-DCA LOD: 2.91 x 10-4M Cu-DCA LOD: 7.55 x 10-3M

  19. Membrane Copper: Cobalt: Mixture Blank Composition: Copper: Cobalt: Copper: Cobalt: 2642.14 1207.55 (153.38) 2551.91 272.17 80.98 69.59 ( 1. PVC:IL (1:1 w/w) (165.73) (164.43) (83.39) (21.56) 168.57) 16996.25 7652.11 (371.17) 12866.82 1559.59 192.55 < LOD 2. PVC:IL (1:2 w/w) (424.75) (357.98) (179.21) (81.51) 222.53 294.12 202.62 (77.79) (90.91) (88.09) < LOD < LOD < LOD 3. PVC:IL (2:1 w/w) XRF Results • Used to quantify [DCA]- • binding preferentiality • Co levels were found • to be 45% lower • Even as a mixture • (2:1 Co:Cu (vol.)) • Co levels are 88% lower!

  20. Conclusions The Ionic Liquid [P6,6,6,14][DCA] fulfils multiple roles in polymeric optodes Conductive membranes allow for detection via an array of techniques The relative ease of synthesis and diversity allows for the possibility of new IL’s with greater selectivity

  21. Acknowledgements • Dr. Aleksandar Radu and Professor Dermot Diamond • Everyone at ASG • Dr’s. Noel Clarke and Matthius Hilder at CSIRO • Cytec Industries • DCU Research Career Start Fellowship 2008 • Science Foundation Ireland (grant 07/CE/I1147) • Enterprise Ireland (grant 07/RFP/MASF812)

  22. Thanks for listening!

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