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Thermodynamic And Structural Characterization Of Amino Acid-Linked Dialkyl Lipids., Stephanie Tristram-Nagle, Ruthven Lewis, Joseph Blickenstaff, Michael Diprima, Bruno Marques, Ronald Mcelhaney, John Nagle, James Schneider Aug 2014

Thermodynamic And Structural Characterization Of Amino Acid-Linked Dialkyl Lipids., Stephanie Tristram-Nagle, Ruthven Lewis, Joseph Blickenstaff, Michael Diprima, Bruno Marques, Ronald Mcelhaney, John Nagle, James Schneider

Prof. Stephanie Tristram-Nagle Ph.D.

Using differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), we determined some thermodynamic and structural parameters for a series of amino acid-linked dialkyl lipids containing a glutamic acid-succinate headgroup and di-alkyl chains: C12, C14, C16 and C18 in CHES buffer, pH 10. Upon heating, DSC shows that the C12, C14 and annealed C16 lipids undergo a single transition which XRD shows is from a lamellar, chain ordered subgel phase to a fluid phase. This single transition splits into two transitions for C18, and FTIR shows that the upper main transition is predominantly the melting of …


Conduction And Thermal Properties Of A Proton Conducting Polymer Electrolyte Based On Poly (Epsilon-Caprolactone), Siti Rohana Majid, Woo H. J., Arof A. K. Dec 2010

Conduction And Thermal Properties Of A Proton Conducting Polymer Electrolyte Based On Poly (Epsilon-Caprolactone), Siti Rohana Majid, Woo H. J., Arof A. K.

Siti Rohana Majid

A proton conducting polymer electrolyte based on poly(epsilon-caprolactone) (PCL) complexed with different concentrations of ammonium thiocyanate (NH(4)SCN) salt has been investigated. The ionic conductivity of the solid polymer electrolyte (SPE) of pure PCL obtained at room temperature is 1.86 x 10(-11) S cm(-1). The maximum ionic conductivity achieved in the solution-cast films at room temperature is 1.01 x 10(-4) S cm(-1) for PCL incorporated with 26 wt.% NH(4)SCN. The calculated dielectric constant at selected frequencies follows the same trend as conductivity, concluding an increase in number density of ions with the salt content. DSC thermogram shows that the degree of …