Herein we present a novel light-controlled assembly system, which is fabricated by functionalizing silica nanoparticles with coumarin. This system exhibits reversible morphological changes under alternating irradiation with 365 nm and 254 nm light: scattered distribution pattern, firework-shaped pattern, honeycomb pattern and donut-like pattern, due to the reversible photodimerization and photocleavage of coumarin. Furthermore, this system displays reversibly controllable wettability, which can be transformed between hydrophobic and superhydrop...
