A Smart Free-blockage Smart Nano-valve Based On Hydrophobicity Switching

With the development of nanotechnology,more and more chemists and engineers have developed nano machines at the molecular level and supramolecular level[1-9].Nano valve,a kind of nano machine that can control the molecules traverse nanopores,has a broad application range in separation,sensor,chemical storage,controlled release and so on.In this paper,a free-blockage nano valve based hydrophobic switching was constructed.Furthermore,the nano valve achieved self-sensing by using the mesoporous invers opal photonic crystal.1.A voltage-responsive free-blockage controlled release system was constructed by modifying the nanopore of MSNs with ferrocene.The modified mesoporous channels can control the release of drug through controlling the wettability of themselves.The system is different from the release system with physical blockage.It not only has the simple process of preparation and drug loading,but also can reduce the potential side effects caused by blockage,which makes them have a strong potential in practical application.2.A pH switchable nano valves were constructed using mesoporous inverse opal photonic crystal,which realized free-blockage nano valves and achieved the sensing of the valve.The valves were hydrophobic enough to prevent solution passing through at pH 7.0,and meanwhile green color was presented.With the decrease of the pH value of the solution,the valves became open and presented yellow to red color because of the protonation of phenylamine groups followed by the invasion of solution.Thus,in this study not only free-blockage valve but also nano sensing valve was constructed.3.A voltage-responsive controlled release film was constructed by grafting ferrocene on the mesoporous inverse opal photonic crystal(mIOPC).The film realized free-blockage controlled release and achieved the sensing of controlled release.The film was hydrophobic enough to prevent solution passing through.Once the voltage was applied,the film became hydrophilic,leading the solution invading in.As a result,the cargos were released and the bandgap of mIOPC was red-shifted.Thus,in this study not only free-blockage controlled release film but also release sensing system was constructed.