An in-situ Investigation into the Formation of Solvent-induced Crystalline Phase of poly(9,9-dioctylfluorene) in Solvent Vapor Annealing
writer：3. Hua Yang; Kexin Qu; Haidong Li; He Cheng;* Jidong Zhang*
keywords：solvent vapor anealing, poly(9,9-dioctylfluorene)
source：期刊
specific source：Macromolecular Chemistry and Physics
Issue time：2016年
A new metastable solvent-induced clathrate liquid crystalline phase of β phase (named β’ here) in
crystalline poly(9,9-dioctylfluorene) (PFO) thin film induced by solvent annealing is found by a
combination of in situ ultraviolet and visible spectrophotometry (UV-vis), photoluminescence spectroscopy
(PL), and grazing incidence wide-angle X-ray scattering (GIWAXS). The solvent annealing
process consists of three processes: diffusion of solvent molecules into the film; saturation of solvent
in the film; and drying of the film under nitrogen. The formation of β’ phase with ordered packing of
side chains and disordered packing of backbones occurs during the diffusion process of solvent molecules
into the film. When the solvent molecules penetrate the film, the disordered side chains start to
align themselves to form an ordered structure, and the ordering would gradually in the saturationprocess.
Furthermore, the ordering of side chains drives
an ordered rearrangement of the backbones during the
drying process; however, the crystallinity of the side
chains decreases with the orderly rearrangement of
backbones due to the helical conformation of PFO.