Table 1 Results of XPS investigations, with surface concentrations given in atomic % (at%), for distinct pristine sapphire samples (average values are given) and for these substrates after contact with 2 wt% G50 formulation either for 17 h and then rinsed 45 min (samples G50-17h) or for 27 h and then rinsed 4 h (samples G50-27h)

From: Interfactant action of an amphiphilic polymer upon directing graphene oxide layer formation on sapphire substrates