Poly , projection conformation

An analogous case, of identical chain conformations as well as of similar unit cell dimensions, have been described for the two crystalline forms of poly-p-phenylene terephtalamide [33-36] (better known with the trade name of Kevlar). The projections along the c axis of the packing of the chains proposed for the two forms [36] has been sketched in Fig. 8, corresponding to the localization of the chain axes in (0,0, z) and (1/2,1/2, z) for the more common polymorph, in (0, 0, z) and (1/2,0, z) for the other polymorph. 

Time-resolved fluorescence spectroscopy and fluorescence anisotropy measurements have been applied to study (i) excimer formation and energy transfer in solutions of poly(acenaphthalene) (PACE) and poly(2-naphthyl methacrylate) (P2NMA) and (ii) the conformational dynamics of poly(methacrylic acid) (PMA) and poly (acrylic acid) as a function of solution pH. For PACE and P2NMA, analysis of projections in which the spectral, temporal and intensity information are simultaneously displayed have been used to re-examine kinetic models proposed to account for the complex fluorescence decay behaviour that is observed. Time-resolved fluorescence anisotropy measuranents of fluorescent probes incorporated in PMA have led to the proposal of a "connected cluster" model for the hypercoiled conformation of this polymer existing at low pH. 

Figure 3. Projection of the minimum energy conformation of poly(MDI-BDO) (111. The fiber repeat is 37.9 A and contains two monomers, that is, the monomer repeat along the fiber axis is 18.95...

Figure 2.5 (a) Schematic diagram showing two adjacent carbons, C and C +i, in the main chain of poly isobutylene, (b) Newman projections of staggered conformations of adjacent carbons in the main chain. 

Recently, AFM has been used for the study of the reconformation of poly(2-vinylpyridine) (P2VP). It was shown that positively charged polymer molecules adsorb strongly onto negatively charged mica leading to a projection of the actual 3D conformation onto the surface. In particular, at pH 2.0 in... 

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