Quantitative determination of the orientational ordering of graphene oxide membranes by the spin probe technique

The orientational alignment of graphene oxide membranes was determined quantitatively using the spin probe technique; the values of the orientational order parameters up to the 6th rank were obtained. It was shown that nitroxide probes as well as Cu(II) complexes adequately reflect the alignment of the membranes. It was estimated that the orientational alignment of the membranes prepared by vacuum filtration using the same material can be significantly different. The membrane prepared by drying the graphite oxide suspension has a very poor orientational alignment in comparison with the membranes prepared by vacuum filtration.