superhydrophobic coatings enabled by the nanocomposite materials of graphene, [5,6] polydimethylsiloxane (PDMS) and TiO 2 , [7] fluoropolysiloxane and TiO 2 , [8] Fe 3 O 4 nanoparticles (NPs), [9] nanocellulose, [10] melanin NPs, [11] cellulose-based derivatives, [12] stoichiometric silanization, [13] fluorinated nanodiamonds, [14] carbon microflowers with MoO 3 NPs, [15] polytetrafluoroethylene, [6] composite microspheres of polystyrene and SiO 2 , [16] SiO 2 and epoxy resin, [17] and fluorinated SiO 2 NPs, [18] SiO 2 NPs embedded with electro-spun fibrous mats, [19] and so on. Mesoporous SiO 2 NPs is one of the most widely studied nanostructures. Researchers have mainly focused on the design of SiO 2 NP-based superhydrophobic nanocomposite materials with various properties including fluorine-free, self-cleaning, environmentfriendly, and antifogging characteristics. [20] For example, superhydrophobic surfaces have been successfully prepared by onestep spray or spin-coating using SiO 2 NPs combined with various supramolecules, including silicone-acrylic copolymer, [3] poly(methyl hydrogen)siloxane, [21] PDMS, [22] organic silicon glass resin prepolymer, [23] 1H,1H,2H,2H-perfluorooctyltriethoxysilane, [24] polystyrene, [16,25] polymethylmethacrylate, and hexadecyl trimethoxy silane. [26] The superhydrophobic efficiency of composite materials depends on the improved performance of A potential application of spiky SiO 2 nanoparticles (NPs) with tubular and rough surfaces is investigated as superhydrophobic coatings, for their unique transparent, fluorinate-free, and environmentally friendly properties. This study demonstrates a facile method for the successful fabrication of superhydrophobic coatings and SiO 2 @polydimethylsiloxane (PDMS) using spiky SiO 2 NPs, N-coordinated boroxines, and PDMS. Combined with spray coating technology, this method of superhydrophobic coating can be simply applied to both hydrophilic and hydrophobic surfaces, including wood, fabric, glass, metal, sponge, and paper. The nanocomposite coating on the glass surface showed both excellent superhydrophobicity and high transparency, with a contact angle of 165.4 ± 1.0° and 96.93% transmittance at 550 nm, respectively. SiO 2 @PDMS-modified glass substrate is found to be resilient to UV irradiation, water, and high temperature treatments at ambient conditions. Experimental data demonstrated that the simple but effective combination of N-boroxine-PDMS and spiky SiO 2 NPs produces a layered coating material that exhibits many good integrated surface properties, including stability, transparency, superhydrophobicity, and oil-water separation.
