Study of the α-Conformation of the Conjugated Polymer Poly(9,9-dioctylfluorene) in Dilute Solution

Abstract

In this work, the α-conformation (individual locally separated chain) of the conjugated polymer poly(9,9-dioctylfluorene) (PFO) in dilute solution is studied by the following three points: the Mark-Houwink exponent a, the fractal dimension D, and the form factor R(g)/R(h). From the result of a, the α-conformation of PFO is considered to have a semirigid chain conformation in dilute solution. We establish the mathematical relationship between the Mark-Houwink exponent a and the fractal dimension D in dilute solution. To prove the rationality of this mathematical relationship, the classic polymer polystyrene (PS) is used for comparison. According to the result of D, it can be known that the α-conformation of PFO has a relatively loose and extended chain conformation. Moreover, we use light scattering to get the form factor R(g)/R(h) of the PFO solution in which the α-conformation and β-conformation coexist. It is found that R(g)/R(h) increases with the proportion of α-conformation, which indicates that the α-conformation of PFO has a loose and extended chain conformation, and this result agrees well with the conclusions drawn from a and D. On the basis of the fact that the β-conformation (ordered conformation) and α-conformation of PFO can transform into each other in solution, this work is significant for the control of the β-conformation and will have a potential meaning to increase the charge carrier mobility and efficiency from the PFO solution to films.

Shape Characteristics of Complex Single Chain and Aggregation by Exponential Law

“…而理想的树枝状高分子 的 d f 接近于 3, 即接近于三维球体. 我 们 组 [47] 9 Schematic description of the scattering data and proposed structures of PFs in toluene: (a) a network-like structure with cross-linked nodes; (b) a structure of rodlike particles forming Gaussian coils (scenario I) or sheet-like aggregates (scenario II) in the longer length scales, and (c) a structure of fully dissolved rod like particles (essentially single polymer chains) [48] 38 in methanol, ethanol and isopropanol solvent. I(h) is the scattering intensity and h is the scattering vector.…”

Targeted β-Phase Formation in Poly(fluorene)–Ureasil Grafted Organic–Inorganic Hybrids

“…[12][13][14] The rich phase behavior of poly(9,9-dioctylfluorene) (PFO), an archetypical member of this materials class, has been well-studied. PFO is polymorphic, with the most prevalent states including an amorphous α-phase, 15 a weakly-ordered planar β-phase 16 or the more recently discovered monoclinic γ-phase, 17 which is intermediate between the two. These states do not represent phases in the true thermodynamic sense (i.e.…”

Systematic investigation of self-organization behavior in supramolecular π-conjugated polymer for multi-color electroluminescence

“…21 The Rh spectra distribution of PPFOH in the THF solution (5 mg/ml) also consisted of three peaks with the lower Rh of about ~20 nm and ~300 nm, attributing to the individual PPFOH chains and nanoscale-aggregate, together with an additional relaxation and slowest mode with the larger Rh ranging to ca.~1.5 μm. 16 Therefere, it is concluded that PPFOH has larger-scale random aggregation in type II solutions than in type I solutions. In this regard, polymer chains showed folded and tangled conformational orders in "Globule" or hyper branched cluster type aggregate solution for the stronger non-covalent interaction between polymer chain and THF molecules.…”