Well-defined amphiphilic gradient copolymers of poly(ethylene glycol) methyl ether methacrylate (PEGMA) and styrene were successfully synthesized using atom transfer radical polymerization. The relative reactivity ratio of PEGMA to styrene was determined using the Jaacks method. The initial feed ratio of the two monomers had a significant effect on the copolymer's gradient composition. The resultant copolymers were characterized by nuclear magnetic resonance and Fourier transform-infrared spectroscopy to confirm their structures and monomer compositions. The lower critical solution temperature behavior of the copolymers was investigated using ultraviolet-visual spectroscopy. The micellization behavior of the PEGMA and styrene copolymers in aqueous solution was observed by transmission electron microscopy and dynamic laser scattering.
Glasses of B2O3-Na2O-Na2I2 have been prepared over a wide range of compositions on the basis of a fixed O/B ratio and a fixed Na/B ratio, respectively. Raman spectra and the ionic conductivity have been measured to elucidate the role of the iodide. In the fixed O/B ratio, a drastic increase of the conductivity with the addition of iodide is observed. The conductivity results are found to be consistent with the Raman results. In the fixed Na/B ratio, the substitution of iodide does not influence significantly the glass structure as well as the ionic conductivity.
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