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

Figure 3

Evaporation patterns of PTFE colloidal droplets on glass slides with different roughness: (a) smooth glass; (b)–(f) increasing surface roughness, achieved using sandpaper with mesh sizes of 1500, 1000, 800, 400, and 200, respectively (scale bars represent 100 μm).

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(b)

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