Two-dimensional representation of a poly(styrene) matrix (lines) embedding a DiD fluorophore (CPK) that reports on its nanolocal environment.
(a) Fluorescence intensity (squares) and corresponding lifetime (circles) transients of an individual DiD molecule in a thick film of PIBMA at an excitation power of . Data were binned in time interval. The lifetime makes peculiar excursions towards higher values. (b) Correlation plot (top) and fluorescence lifetime distribution (bottom) of the molecule: Asymmetrical fluctuations of the lifetime results in an elongated, cloudy correlation plot and an asymmetric distribution. The lifetime distribution is fitted with a distribution.
(a) Fluorescence intensity (squares) and corresponding lifetime (circles) transients of an individual DiD molecule in a thick film of PIBMA at an excitation power of . Data were binned in time interval. (b) Correlation plot of the molecule. Intensity and lifetime are perfectly correlated, suggesting the aperture of extra-decay channels in the matrix. This correlated behavior has been observed for only two molecules within the 778 investigated molecules.
(a)–(c) Fluorescence lifetime distributions of three individual DiD molecules embedded in a thick film of PIBMA. Each lifetime distribution fitted is with a distribution. As the lifetime distribution gets more symmetric, the shape parameter of the distribution increases [from (a) to (c)]. (d)–(f) Distributions of the shape parameters for DiD molecules embedded in the same film at three different temperatures. Shape parameter values decrease with temperature: the asymmetry of the lifetime distributions becomes more and more pronounced as the temperature increases.
(a) Ratio of the fluorescence lifetime and hole fraction distributions as a function of the hole fraction present in the system. For small hole fractions, the dependence is smoothly linear, which means that both distributions have the same shape. (b) Simulated distribution of hole fraction, characterized by a mean value of 10% and a mean-squared standard deviation of 0.4%. The shape parameter of the distribution is 2.5. (c) Dependence of the fluorescence lifetime of the dye embedded in the matrix on the fraction of holes present in the system. (d) Corresponding distribution of the fluorescence lifetime. has been set equal to to perform the calculation. The shape of this distribution is similar to the one in (b): 2.307.
Number of segments involved in a segmental rearrangement cell as a function of temperature for a PS (close squares, , thick film) and for a PIBMA (open circles, , thick film) matrix. In both cases, the number of segments decreases with temperature. Linear fits and extrapolation of the two curves are also represented on this graph (straight line for PS and dashed line for PIBMA).
Characteristic pressure , volume , temperature , and expansion coefficient for the polymers.
Article metrics loading...
Full text loading...