Polystyrene Size Determination in Polystyrene and Poly(vinyl methyl ether) Using Electronic Excitation Transport

Abstract

Poly(styrene-co-2-vinylnaphthalene) with a 1.25% fraction of naphthyl fluorophores is studied in two polymeric hosts, polystyrene and poly(vinyl methyl ether). In the polystyrene host, measurement of the electronic excitation transport-induced fluorescence polarization anisotropy decay, r(t), in conjunction with a previous quantitative statistical theory of electronic excitation transport on lightly tagged polymer chains, allows a determination of the copolymer radius of gyration. Comparison with light scattering measurements from the literature establishes the θ-condition nature of this solid system. Poly(vinyl methyl ether) forms a compatible polymer blend with polystyrene. Analysis of r(t) data shows that the radius of gyration of a copolymer molecule is expanded in poly(vinyl methyl ether) relative to the θ-condition at room temperature. The synthesis of poly(styrene-co-2-vinylnaphthalene) is detailed.

Energy Migration Study of Random Immobile Anthracene Derivatives by Time-Resolved Fluorescence Anisotropy Decays

“…20,21 Fayer's group has exploited this sensitivity to study changes in polymer chain conformation as well as phase separation in polymer blends. [3][4][5] If the emission depolarization occurs only by energy migration, it can be described by the Fo ¨rster energy transfer mechanism. 20,22,23 In most theoretical treatments of nonradiative energy transfer, the time-dependent anisotropy decay is developed in terms of the survival probability of the initially excited chromophore, Ψ(t).…”

“…It is possible to apply this technique to study a variety of features of polymeric systems at the molecular level. These include studies of polymer chain conformation, phase behavior in polymer blends, − and polymer diffusion in latex films, , as well as the nature of the interface separating the microphase-separated components of block copolymers in bulk − and in micellar solution …”

Phase Separation in Binary and Ternary Polymer Composites Studied with Electronic Excitation Transport

“…However, curves b in both Figures and clearly have different forms than either the isolated chain curves or the spherical nanodomain curves. One possibility is that network-like filaments of PMMA2VN are condensing out of the phase-separating blends, forming aerogel-like structures such as those described in ref , perhaps after an initial stage of spherical droplet-like nanodomain formation 6 Curves a are r ( t ) measured from ternary blends of 0.1% PMMA2VN, 4.9% PMMA, and PVAc annealed for 20 min and 4 h at 77 °C.…”

“…Studies of the compatible polymer composite, PS/PVME, have begun. 23 It may be possible to use chromophores with different R 0 's to analyze the structures of the same polymer systems on various distance scales. The effects of pressure on phase behavior are readily accessible to the "snapshot" method, simply by varying the pressure during annealing in the Carver press.…”

“…However, it is necessary to be able to synthesize a copolymer containing a small number of chromophores that are to be used as the EET probe of the phase-separation process. Studies of the compatible polymer composite, PS/PVME, have begun . It may be possible to use chromophores with different R 0 's to analyze the structures of the same polymer systems on various distance scales.…”