Stable superhydrophobic surface: fabrication of interstitial cottonlike structure of copper nanocrystals by magnetron sputtering

Figures & data

Parameters of prepared and performance of copper films.

Copper film	a	b	c	d	e
Thickness (nm)	5100	3500	1200	510	Polished copper
Working pressure (Pa)	0.5	0.5	0.5	0.5	–
Sputtering power (W)	400	300	200	100	–
Target-substrate distance (cm)	6	6	6	6	–
Water contact angle	101.3°	138.2°	160.5°	151.2°	73.8°
Surface roughness (nm)	62	79	161	112	–
Air-liquid contact fraction (f2)	–	–	0.94	0.81	–

Figure 1 (A) SEM image of hydrophobic copper film with nanoparticles prepared at 200 W power. (B) Photograph of a water drop on the superhydrophobic copper surface in (A).

Figure 2 SEM images of copper films prepared at various sputtering powers. (a) 400 W, (b) 300 W, (c) 200 W and (d) 100 W. (e) and (f) High-resolution SEM images of copper prepared at sputtering power of 200 W.

Figure 3 Water contact angles measured on the surface of copper film at various sputtering powers: (a) 400 W, (b) 300 W, (c) 200 W, (d) 100 W and (e) polished copper film. The water contact angles are 101.3°, 138.2°, 160.5°, 151.2° and 73.8°, respectively.

Figure 4 XRD patterns of copper films prepared at different sputtering powers. (a) 400 W, (b) 300 W, (c) 200 W and (d) 100 W.

Figure 5 XPS spectra of copper films prepared at sputtering powers of 100 and 200 W.