demonstrate the above described wetting properties.
In particular, Fig. 4 shows photographs of static droplets
on untreated (Fig. 4a) and treated (Fig. 4b and c) silk and Fig. 5 demonstrates the self-/easy-cleaning properties of silk, treated
with appropriate coatings. Any liquid is absorbed by the untreated
silk as shown in Fig. 4a. Superhydrophobicity and superoleophobicity
are achieved when silk is covered by a siloxane + 2% w/w SiO2
coating (Fig. 4b). The dodecane droplet corresponds also to a very
high contact angle in Fig. 4b. Superoleophobicity collapses in Fig. 4c,
which shows droplets on silk coated by a siloxane + 5% w/w SiO2,
but superhydrophobicity is maintained. Dodecane is absorbed by
the treated silk in Fig. 4c