The Preparation Of Photoelectric Cooperation Responsive Slippery Surface Towards Smart Control Of Droplet Motion

Accurate control of droplet motion is a key process in biochip,microfluidic and other industrial applications.However,how to realize in situ rapid reversible switch of the interaction between the liquid and the interface under the external stimuli is the key issue of precise control of droplet motion.Therefore,it is very necessary to develop a new type of smart interface and achieve intelligent control of droplets on them.In recent years,although the development of slippery surfaces has achieved great improvement,there are still many unsolved problems,such as how to design a responsive slippery interface and how to achieve smart control droplet transport,etc.To solve above-mentioned problems,different types of slippery surface were designed.Meanwhile,the smart control of the droplet motion was realized on such slippery surfaces.The research contents are given as follows:1)In this work,we demonstrate photoelectric cooperative responsive ZnO array composite slippery surface.First,the ZnO array films were fabricated by hydrothermal synthesis.To obtain the ZnO composite film,the ZnO film was sensitized by N3 dye,and then hydrophobized by low-surface-energy molecule.After silicone oil was infused into the composite films,the slippery surfaces were achieved.The motion of the intelligent control droplet on the ZnO slippery surfaces was realized by photoelectric synergetic.This work promotes the understanding of the underlying principles of smart control of droplet motion on slippery surfaces and provides a promising interface for biochips and microfluidic systems.2)Although photoelelctric synergetic control of droplet motion on ZnO slippery surfaces was achieved,the inorganic ZnO film is usually fragile and the mechanical property is poor.Meanwhile,isotropic feature of ZnO slippery surface cannot meet the demand of directional transport of liquid droplet.Therefore,we selected conductive polymer with photovoltaic properties to prepare anisotropic porous films by directional freeze-drying technique.Moreover,anisotropic slippery surfaces based on the as-prepared P3HT/PCBM surfaces demonstrated remarkable photoelectric synergetic behavior,which could be used for photoelectric synergetic control of droplets sliding.3)During the above studies,we found that the poor mechanical stability of the interfacial microstructure would lead to unstable material performance.Therefore,we further studied how to improve the mechanical property of polymer gel materials.The superabsorbent OMMT/PPA hydrogels were prepared by UV irradiation polymerization.By adding OMMT,the PAA hydrogels showed excellent mechanical properties.The effects of deionized OMMT and water content on the UV-induced polymerization progress were systematically investigated.OMMT/PAA composite hydrogels with super water absorbency and excellent mechanical properties can be obtained when the initial amount of deionized water is 95.7 wt% and the content of OMMT is 10 wt%.The OMMT/PAA containing 10 % OMMT has excellent elasticity and can be stretched up to 2200 % for a fresh-prepared hydrogel.It can also sustain a load weight of 650 g,and has excellent recoverability.The compressive stress–strain measurements also verify that the OMMT/PAA hydrogel containing 10% OMMT has obviously improved mechanical properties compared to the others.