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Superhydrophobic and transparent films would be very useful in optoelectronic applications where non-wetting is desired. Herein, hexamethyldisilazane was used for functionalization of fumed SiO2 nanoparticles via silylation derivatization reaction. Modified fumed SiO2 nanoparticle dispersion was used for fabrication of SiO2-based nanostructured film via drop-casting method. This film exhibited a combination of high optical transmittance in the visible spectrum portion and superhydrophobicity (163° ± 1° and hysteresis as low as ~2°). This was possible to achieve due to the submicrometer-scale roughness (Rq = 252.7 nm) and branched network structure of the film surface with convenient surface chemistry of hydrophobic methyl groups. The method reported herein is not complicated, allows for obtaining large quantities of modified SiO2 nanoparticle dispersions and can be used in combination with other deposition methods.

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Periodic structures of Si(001) and quartz glass master-matrices with the period of 4 µm and the polymer replicas fabricated by imprint lithography and UV light hardening techniques were investigated. The profile of the structures was examined by atomic force microscopy. Diffraction efficiency of the periodic structures was measured experimentally and calculated theoretically employing the integral technique. The results obtained show the diffraction efficiency to be an efficient tool for the control of surface relief formation during etching of master-matrix and its replication. It is shown that the quartz glass master-matrix is more efficient both for the imprint and UV hardening polymer replication as compared to the silicon one.

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This paper presents the first attempt to texturize a fully crosslinked thermoset shape memory polymer using a hot embossing technique. UV-cured thiol-ene films were successfully embossed with anisotropically-etched Si (100) stamps at a temperature of 100 °C, which is about 50 °C above the glass transition temperature of the polymer. The low storage modulus of the polymer in a rubbery state allowed us to permanently emboss random micro-pyramidal patterns onto the surface of the film with high fidelity by applying 30 MPa pressure for 1 h. Atomic force microscopy (AFM) investigation showed perfect replication of the stamp micropattern with typical height of the largest inverted pyramids close to 0.7 µm and lateral dimensions in the range of 1–2 µm. Changes in surface roughness parameters of the embossed thiol-ene films after annealing them at 100 °C for 1 h or storing for 2 months in air at standard room conditions were negligible. The achieved results open new perspectives for the simple and inexpensive hot embossing technique to be applied for the micropatterning of prepolymerized thermoset shape memory films as an alternative to micropatterning using UV casting.

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