Micropatterned superhydrophobic silica based sol-gel surfaces

A composite having a surface that is at least hydrophobic, the composite comprising:

• a. a substrate;
• and b. a hydrophobic coating on at least a portion of the substrate, the hydrophobic coating being formed from a mixture comprising a sol-gel that comprises an alkoxosilane precursor having a general formula of R′2Si(OR)2, R′3Si(OR)3, or (RO)3SiR″Si(OR)3, wherein R is a short chain, branched or unbranched, organic group that comprises no more than 5 carbon atoms in the chain and are the same or different, and R′ and R″ are long chain, branched or unbranched, organic groups that comprise between 6 and 20 carbon atoms in the chain, and comprising a topography that decreases a contact area between the hydrophobic coating and a water droplet thereon.

A superhydrophobic surface, the superhydrophobic surface being formed from a mixture that comprises a sol-gel that comprises an alkoxosilane precursor having a general formula of R′xSi(OR)4-x or (RO)3SiR″Si(OR)3, wherein R and R′ are the same or different and comprise hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted or multiple ring aryl group, or a combination thereof, and R″ is a substituted or unsubstituted alkylene, a substituted or unsubstituted alkenylene, a substituted or unsubstituted alkynylene, a substituted or unsubstituted or multiple ring arylene group, or a combination thereof, and x is 1 or 2, and comprising a topography that decreases a contact area between the superhydrophobic surface and a water droplet thereon so that the water droplet has a contact angle of at least about 160°.

A method of forming a composite having a surface that is at least hydrophobic, the method comprising depositing a hydrophobic coating on at least a portion of a substrate, wherein the hydrophobic coating is formed from a mixture comprising a sol-gel that comprises an alkoxosilane precursor having a general formula of R′xSi(OR)4-x, or (RO)3SiR″Si(OR)3, wherein R and R′ are the same or different and comprise hydrogen, a substituted or unsubstituted alkyl, a substituted or unsubstituted alkenyl, a substituted or unsubstituted alkynyl, a substituted or unsubstituted or multiple ring aryl group, or a combination thereof, and R″ is a substituted or unsubstituted alkylene, a substituted or unsubstituted alkenylene, a substituted or unsubstituted alkynylene, a substituted or unsubstituted or multiple ring arylene group, or a combination thereof, and x is 1 or 2, and comprises a topography that decreases a contact area between the hydrophobic coating and a water droplet thereon.