Fig. 7

Comparison of manuscripts treated with CNF B in variant 4 (left) and variant 5 (right). Left: the CNF network was formed in the last step, hence only a few particles were visible at the surface. Right: many particles were deposited onto the CNF network surface, which was formed in the first step of the treatment. The EDX spectra of the small particles showed the presence of calcium and phosphorus (for EDX cf. Additional file 1: Figure S2)