Novel liquid–solid adhesion superhydrophobic surface fabricated using titanium dioxide and trimethoxypropyl silane

The present paper reports the preparation of very simple and inexpensive superhydrophobic surfaces fabricated using titanium dioxide and lower alkyl chain silane (trimethoxypropyl silane) in aqueous or non-aqueous solvent. The superhydrophobic surfaces fabricated in aqueous or non-aqueous solvent had same static water contact angle, but showed different contact angle hysteresis and liquid–solid adhesion. Superhydrophobic surface fabricated in aqueous solvent showed high contact angle hysteresis (CAH). In addition, liquid–solid adhesion of superhydrophobic surface fabricated in aqueous solvent is different in which the water droplet roll on the surface but will not roll off out of the surface during tilting and fell down when turned upside down. The reason for such high contact angle hysteresis and novel liquid–solid adhesion behavior is explained on the basis of measurements on the superhydrophobic surface using water contact angle (WCA) data, profilometry, SEM images, XPS and FTIR-ATR analysis. These results are compared with the superhydrophobic surface fabricated in non-aqueous solvent which showed self-cleaning properties. Based on WCA, XPS and FTIR-ATR analysis, it is shown that the difference in the CAH is more chemical in origin than morphology.