Poly- , blocks, circular

Fig. 25.—Circular Dichroism for Blocks of Poly(L-guIopyranuronate) Poly(o-...

Circular surface micelles have also been observed for non-ionic block copolymers. Li et at. (1993) reported TEM and AFM of starfish micelles formed by PS-poly(n-butyl methacrylate), PS-poIy(rm-butyl methacrylate) and poly(fer<-butyl acrylate) diblock copolymers. Plateaus observed in surface/area isotherms of the Langmuir-Blodgett films at the air-water interface were consistent with the formation of surface micelles. 

We have chosen to investigate, primarily by circular dichroism measurements, a series of oligomers of adenylic acid (including the high polymer) as well as the closely related poly-A -hydroxyethyladenylic acid. The latter is of interest because the blocking of the nitrogen should prevent the formation of hydrogen-bonded double-strand helices under all conditions. 

We have studied the structure of AB block copolymers polybutadiene-poly (y-benzyl-L-glutamate) (BG), polybutadiene-poly(e-carbo-benzoxy-L-lysine) (BCK), polystyrene-poly(y-benzyl-L-glutamate) (SG), polystyrene-poly(e-carbobenzoxy-L-lysine)(SCK) with polypeptide compositions between 18 and 84 % and ABA block copolymers poly(y benzyl L-glutamate)-polybutadiene-poly(y-benzyl-L-glutamate) (GBG) with polypeptide compositions between 55 and 86 %, by X ray diffraction, electronmicroscopyinfrared spectroscopy and circular dichroism. 

Many biological polymers are collected of different variety but stmcturally correlated with other monomer residues e.g. DNA polynucleotide, it contains different subunits of nucleotides. The block copolymers polystyrene— poly(Z-L-lysine) solid-state structures were determined by the polymer architecture and with the help of circular dichroism, electron microscopy, quantitative small and wide-angle X-ray diliiaction to confirm the secondary stmcture of polypeptide [5]. 

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