Fig. 6
From: Nano-materials enhanced protectants for natural stone surfaces
SEM images of blank (a and e), and modified by 101S (b and f), 101S containing 2.0Â mg/mL Al2O3 nano-powder (c and g), and 2.0Â mg/mL SiO2 nano-powder (d and h) Qingshi surfaces and profiles, respectively
