Preparation of the coatings
APTES (0.580 g), GPTMS (0.620 g), HO-PDMS-OH (1.800 g), and dibutyltin dilaurate (DBTL, 0.010 g) were thoroughly mixed in a sealed container via stirring at 300 rpm for 24 h. This stirring treatment was performed in order to enhance the homogeneity of the coating. The precursors could be applied onto various kinds of substrates via spray-, dip-, or paint-coating techniques, and the coatings were spontaneously formed at room temperature over a period of 7 days.