A general approach for superhydrophobic coating with strong adhesion strengthElectronic supplementary information (ESI) available: Schematics of the bonding process and the surface smoothing effect, optical images of a water droplet of 3 μL on surfaces by assembling sub-micro/nano silica particles without or with the addition of acidic silica sol, SEM images of surfaces by assembling sub-micro/nano silica particles without or with the addition of acidic silica sol, the changes of the surface che

Superhydrophobic coatings with strong adhesion strength, high chemical stability and good self-cleaning function are fabricated by a new colloid assembly method. This method involves the utilizing of dual-sized particles to achieve a micro/nano structure, and an acidic silica sol to bond the particles with substrates. The resulting coating has a contact angle higher than 160° and a hysteresis angle of 2°, showing excellent superhydrophobic properties. The adhesion strength of the coating is proved to be strong according to the ASTM international standard. The smoothing effect of the bonders can be completely overcome by adjusting the ratios and sizes of the dual-sized silica particles. Because of its flexibility and simplicity, the present colloid assembly method may be suitable for large-scale coating. A superhydrophobic coating with strong adhesion strength, high chemical stability and good self-cleaning function has been fabricated by a general colloid assembly method.