Hydrophobic Group‐Directed Self‐Assembly of Gradient Porous Antireflective and Superhydrophilic Coatings on Photovoltaic Glass

ABSTRACT

Coatings for photovoltaic glass urgently require antireflection, self‐cleaning, and durability. Herein, we leveraged the surface free energy minimization effect of n ‐butyl hydrophobic groups in n ‐butyl glycidyl ether (BGE) to design a directed induction strategy, and successfully fabricated a gradient porous superhydrophilic and antireflective coating (BTKS‐3). This effect drove the spontaneous migration of hydrophobic groups to the surface, creating a vertical concentration gradient that modulated the local chemical environment and solvent evaporation behavior during film formation, ultimately directing the formation of a gradient porous architecture. As a result, a gradient porous architecture formed spontaneously, going from a dense bottom layer to a porous top layer. Such a gradient enables stepwise refractive index matching from the glass substrate to air, boosting transmittance to 94.61%, which significantly outperforms bare glass and commercial antireflective coatings. Meanwhile, surface hydroxyl groups and nanoscale roughness endow the coating with superhydrophilicity (contact angle < 10°) and self‐cleaning ability, along with good abrasion resistance and UV stability. Over, this work achieves synergistic optimization of optical, self‐cleaning, and durability properties, offering a new paradigm for high‐performance functional coatings on photovoltaic glass.