Preparation of thermo-responsive superhydrophobic TiO2/poly(N-isopropylacrylamide) microspheres

Here we reported a facile method that combined sol–gel and surface-initiated atom transfer radical polymerization (ATRP) to prepare thermo-responsive superhydrophobic TiO2/poly(N-isopropylacrylamide) microspheres with core–shell structure. The surface coated with microspheres show hydrophilic properties (CA = 90.5 ± 2.3°) at 27 °C, it changes to superhydrophobicity (CA = 150.2 ± 2.3°) while the temperature rises up to 42 °C. This performance is attributed to lower critical solution temperature (LCST) phenomenon of Poly (N-isopropylacrylamide). Five cycle measurements of water droplet reversible switch between hydrophilicity and superhydrophobicity were demonstrated temperature-responsive surface property. The changes were rapid and significant. The as-prepared particles have been characterized by scanning electron microscopy, transmission electron microscopy, thermal gravimetric analysis, FT-IR analysis, and dynamic light scattering.