Electron diffraction study of the structure of vinylidene fluorideâ•fitrifluoroethylene copolymer nanocrystals

The structures of nanocrystals consisting of 70% vinylidene fl uoride and 30% trifl uoroethylene made by Langmuir–Blodgett deposition were studied using transmission electron microscopy and electron diffraction. Highly ordered nanocrystals with sizes ranging from 100 nm to 4 μm were grown on Langmuir–Blodgett fi lms at a deposition surface pressure of 20 mN m−1. Electron diffraction patterns from individual crystals allowed us to determine the crystal symmetry and lattice parameters. A monoclinic phase had been found with the lattice parameters a = 9.06 ± 0.03 Å, b = 5.18 ± 0.02 Å, c = 20.40 ± 0.05 Å, α = 90° ± 0.3°, β = 93° ± 0.2°, γ = 90° ± 0.2°, consistent with the monoclinic space group C2.