Measuring Structural Inhomogeneity of Conjugated Polymer at High Pressures up to 30 GPa

We present X-ray scattering data from helical poly[9,9-bis(2-ethylhexyl)-fluorene-2,7-diyl] by mapping the sample with 10 mu m spatial resolution at pressures up to 31 GPa. Neon is used as pressure transmitting medium. Reduction of torsion angle between adjacent repeats is observed during compression and found to be reversible upon decompression. Chain conformation does not depend on lateral position of sample in the pressure range from 1 to 7 GPa but depends significantly when pressure is increased from 7 to 31 GPa. Crystallite orientation does not depend on pressure or lateral position. The radiation damage is studied optically ex situ and proved to be insignificant.