Fig. 5
From: Nano-materials enhanced protectants for natural stone surfaces

SEM images of blank (a and e), and treated by 101S (b and f), 101S containing 1.5Â mg/mL Al2O3 nano-powder (c and g), and 0.5Â mg/mL SiO2 nano-powder (d and h) Marble surfaces and profiles, respectively