The multiple effects of organoclay and solvent evaporation on hydrophobicity of composite surfaces

A superhydrophobic high-density polyethylene (HDPE)/organoclay composite material with a water-static contact angle of $\sim $162$^{\circ}$ and low hysteresis (7$^{\circ})$ was prepared by a simple solution-intercalation technique. This one-step method consists of the insertion of organoclay, produced through cation exchange with cetyltrimethylammonium bromide (CTAB), in the polymer matrix at 120 $^{\circ}$C in xylene. In this process, evaporation of the solvent and organoclay amount are key factors for the achievement of superhydrophobicity. We characterized composite material with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and contact angle measurements. The characterizations showed that the organoclay provides a place for the formation of small polymer aggregates and facilitates the evaporation of the organic solvent. The technique described here is simple and does not require any complicated process.