Enhanced Coffee-Ring Effect via Substrate Roughness in Evaporation of Colloidal Droplets

Figure 5

Evaporation dynamics of PTFE droplet on rough substrate, (a)–(p) correspond to different evaporation time. The mesh of sand paper used is 200 (scale bars represent 100 μm).

(a)

(b)

(c)

(d)

(e)

(f)

(g)

(h)

(i)

(j)

(k)

(l)

(m)

(n)

(o)

(p)