Self-assembled amphiphiles spectroscopy

Norman LL, Barrett CJ. 2002. Solution properties of self assembled amphiphilic copoly mers determined by isomerization spectroscopy. J Phys Chem B 106(34) 8499 8503. 

A. Dong, C. Pascual-Izarra, S. Pas, A. J. Hill, B. Boyd and C. J. Drummond, Positron annihilation lifetime spectroscopy as a characterisation technique for nanostructured self assembled amphiphile systems , J. Phys. Chem., in press. 

Air-Water Interface. Organized films of surfactants and phospholipids at the air-water interface are of interest in biophysics, general interfacial chemistry, and have relevance to the self-assembling aggregates, which are viewed as having potential applications in non-linear optics and as microelectronic devices (122). FT-IR spectroscopy has recently been applied to the problem of obtaining information about amphiphiles at the air-water interface. 

In this section, the EPR spectroscopic characterization of thermoresponsive polymeric systems is presented. The polymeric systems are water-swollen at lower temperatures and upon temperature increase the incorporated water is driven out and the system undergoes a reversible phase separation. Simple CW EPR spectroscopy (see above), carried out on a low-cost, easy-to-use benchtop spectrometer, is used here to reveal and characterize inhomogeneities on a scale of several nanometers during the thermal collapse. Further, neither any physical model of analysis nor chemical synthesis to introduce radicals had to be utilized. Adding amphiphilic TEMPO spin probes as guest molecules to the polymeric systems leads to self-assembly of these tracer molecules in hydrophilic and hydrophobic regions of the systems. These probes in different environments can be discerned and one... 

In another work, silica nano helices have been prepared from the organic self-assemblies of -tartrate amphiphiles by sol-gel transcription. Then this chiral nanostructures were functionalized with (3-aminopropyl)-trietho)y-silane (APTES) or (3-mercaptopropyl)triethoxysilane (MPTES) and decorated with gold nanoparticles of various diameters (1-15 nm) resulting in nanohelix hybrid structures (Fig. 25). ° It was found that the surface plasmon resonance intensity of these nanohybrid systems increased with gold particle size. Gold nanoparticles of 10-14 nm diameter have clearly showed a surface enhanced effect on Raman spectroscopy. This sj tem is a unique example of the 3D hybrid network that could be used as ultrasensitive chemical and biological sensors for detection of molecules of interest in liquids by accumulation under flow. 

D NOESY NMR spectroscopy were used to examine the manner in which ionic liquid amphiphile self-assembles with an ionic surfactant in solution. ... 

The self-assembly of amphiphilic block copolymers and polyelectrolytes is amply treated in other chapters of this book. The individual studies will not be discussed in detail in this part. We will pursue a different line of thought. We will compare the enormous research potential of fluorescence spectroscopy with other currently used experimental methods to show its specific features and advantages for self-assembly studies. 

The fourth and fifth sections deal with amphiphiles at solid-liquid interfaces. Section four on Amphiphiles at Electrode Surfaces contains a collection of important applications. The first by Rusling illustrates how surfactant films on electrode surfaces may be fabricated to electrocatalyze a variety of reactions. Koglin and coworkers provide some exciting new surface enhanced Raman spectroscopy results that contravene some of the reigning dogma on how cationic surfactants assemble on anionic surfaces. Kaifer presents a concise review of self-... 

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