Anthracene-labeled polystyrene

Viovy, Monnerie, and Brochon have performed fluorescence anisotropy decay measurements on the nanosecond time scale on dilute solutions of anthracene-labeled polystyrene( ). In contrast to our results on labeled polyisoprene, Viovy, et al. reported that their Generalized Diffusion and Loss model (see Table I) fit their results better than the Hall-Helfand or Bendler-Yaris models. This conclusion is similar to that recently reached by Sasaki, Yamamoto, and Nishijima 3 ) after performing fluorescence measurements on anthracene-labeled polyCmethyl methacrylate). These differences in the observed correlation function shapes could be taken either to reflect the non-universal character of local motions, or to indicate a significant difference between chains of moderate flexibility and high flexibility. Further investigations will shed light on this point. 

Table 6.1 Critical overlap concentration, C, for polystyrene coils in solution measured by energy transfer between carbazole- and anthracene-labeled polystyrene chains...

Experiments on temporally forcing of phase separation were performed using mixtures of poly(vinyl methyl ether) (PVME) and anthracene-labeled polystyrene (PSA). The phase diagram of this PSA/PVME blend is illustrated in Figure 1 together with the composition dependence of its glass transition... 

Fujita and coworkers [79] smdied fluorescently labeled polyoxyethylene chains and found a good correlation between the concentration dependence of the friction coefficient evaluated from the anisotropy measurements and from the macroscopic viscosity. Fujita developed the fi ee-volume theory which describes reasonably well the concentration dependence of in the whole concentration region, [80] but it does not enable prediction of the parameters at a molecular level. Hyde et al. [81] used the Fujita theory for fairly successful interpretation of the experimental data. An interesting paper has been published by Viovy and Moimerie [82]. The authors studied concentrated solutions of anthracene-labeled polystyrene in toluene. They found good correlation of the local dynamics with the viscosity in the range of high concentrations and made one very important observation the local dynamics are unaffected by the overlap of the polymer chains that occurs at concentrations higher than c (concentration of the first overlap—see chapter Conformational and Dynamic Behavior of Polymer and Polyelectrolyte Chains in Dilute Solutions ). 

D. A. Waldow, M. D. Ediger, Y. Yamaguchi, Y. Matsushita, and I. Noda. Viscosity dependence of the local segmental diffusion of anthracene-labeled polystyrene in dilute solution. Macromolecules, 24 (1991), 3147-3153. 

ABSTRACT - Fluorescence polarization and its application to orientation measurements of uniaxially stretched polymers are described. Results obtained on anthracene labelled polystyrene chains embedded in normal polystyrene and stretched at various temperatures and strain rates are presented and discussed. An improvement of the Doi-Edwards slip-link model is required to account for the results and a modified model is proposed. Finally, an illustration of fluorescence polarization measurements on mobile and oriented polyisoprene networks is shown. 

Anthracene labelled polystyrene chains (called PAP) with a number average molecular weight, M = 287,000, have been incorporated (at 1 % w/w concentration) in a polystyrene matrix (PS 200) with a narrow M.W. distribution (M = 191,000, M = 207,000). The samples moulded under pressure and annealed to obtain transparent bubbleless samples and to avoid any birefringence. Sample size was 8 cm long, 2 cm wide and 0.2 thicko Tg of the resultant polymer blend measured by differential scanning calorimeter at a heating rate 10 C min was 107.5 C. 

Fig, 13 - Comparison of the observed and calculated matrix molecular weight effect on the orientation of an anthracene-labelled polystyrene chain. The full curves represent the calculated behaviour... 

FLUORESCENCE QUENCHING OF ANTHRACENE-LABELLED POLYSTYRENE BY POLY(VINYL-METHYLETHER) A NEW APPROACH FOR THE ANALYSIS OF PHASE SEPARATION PHENOMENA... 

FLUORESCENCE QUENCHING OF ANTHRACENE-LABELLED POLYSTYRENE BY POLY(VINYLMETHYLETHER)... 

---