Electron diffraction study of the structure of vinylidene fluoride-trifluoroethylene copolymer nanocrystals

The structures of nanocrystals consisting of 70% vinylidene fluoride and 30% trifluoroethylene 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 films 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 A,b = 5.18 ± 0.02 A,c = 20.40 ± 0.05 A,α = 900 ± 0.30,β = 930 ± 0.20,γ = 900 ± 0.20, consistent with the monoclinic space group C23