Durable Superhydrophobic and Antireflective Surfaces by Trimethylsilanized Silica Nanoparticles-Based Sol−Gel Processing

Abstract

We present a robust and cost-effective coating method to fabricate long-term durable superhydrophobic andsimultaneouslyantireflective surfaces by a double-layer coating comprising trimethylsiloxane (TMS) surface-functionalized silica nanoparticles partially embedded into an organosilica binder matrix produced through a sol-gel process. A dense and homogeneous organosilica gel layer was first coated onto a glass substrate, and then, a trimethylsilanized nanospheres-based superhydrophobic layer was deposited onto it. After thermal curing, the two layers turned into a monolithic film, and the hydrophobic nanoparticles were permanently fixed to the glass substrate. Such treated surfaces showed a tremendous water repellency (contact angle = 168 degrees ) and stable self-cleaning effect during 2000 h of outdoor exposure. Besides this, nanotextured topology generated by the self-assembled nanoparticles-based top layer produced a fair antireflection effect consisting of more than a 3% increase in optical transmittance.

Template free preparation of nanoporous organically modified silica thin films on flexible substrates

“…Antireflective coatings are routinely designed to enhance the light transmission through these surfaces. 15,[32][33][34][35][36][37][38][39][40][41][42] However, antireflective coatings on flexible substrates are still rare. 32 An antireflective coating is based on destructive interference between the reflected light from the air/ film and the substrate/film interfaces.…”

Effect on superhydrophobic surfaces on electrical porcelain insulator, improved technique at polluted areas for longer life and reliability

“…As explained by Cassie [1,3], a liquid droplet residing on the composite surface (here especially for the composite surface of air and solid) has a resulting contact angle in the form of cos θ * = -1+ φ s (1+cos θ), where in above equation 'φ s 'designates the fraction of solid surface being in touch with the liquid drop, and 'θ * ' is the intrinsic contact angle of the flat surface with the same chemical components. Various techniques have been developed to produce the lotus leaf effect such as phase separation [4], chemical vapour deposition [5,6], sol-gel processing [7][8][9][10][11], chemical etching [12,13] electro spinning [14][15][16][17][18], self-assembly [19][20][21][22][23]. Most of the techniques require special equipment and cannot be used on different kind of materials.…”

Physicochemical Characteristics and Droplet Impact Dynamics of Superhydrophobic Carbon Nanotube Arrays

“…Si nanoparticles [1][2][3] Sol-gel Sol gel 165-173 3 1.4x10 5 -1.6x10 6 Si nanopillars [4][5][6] Ca ≤ 3.13x10 -2 , respectively. This condition implies the following: the effect of inertia is stronger than that of gravity, the effect of gravity is comparable to that of surface tension, and the effect viscosity is much less than that of surface tension.…”