Preparation And Functionalization Of Janus Nanofibers

Materials with Janus structure have two connected surfaces and each has different chemical elements and property.The structural advantage of this materials make it widely used in solid surfactants,artificial nanometer engines,and composites,etc.In this paper,PAN/PVP Janus nanofibers were successfully obtained through the electrospinning technology and combined with the design of spinneret.By adjusting the concentration of two kinds of spinning solution and the parameters in the spinning process,the PAN/PVP nanofibers with perfect Janus structure were prepared.The Janus nanofibers prepared by this method with obvious contrast and can be realized by large-scale.According to this characteristic of Janus NFM,the function of the Janus NFM was designed by adding functional particles to the spinning solution.The application of Janus NFM in drug release and magnetic-fluorescent bifunctional composites were studied.1.Preparation of PAN/PVP Janus nanofibers and its self-supporting property.The Janus nanofibers were obtained by adjusting the spinning solution concentrations.Water soluble test results showed that Janus NFM had good self-supporting property.2.Double fluorescent Janus nanofibers and its application on drug-release.The same amount of dexamethasone were added to the spinning solution to prepare the drug-loaded nanofibers and two fluorescent molecules perylene(PMI)and 1,8-naphthalene anhydride(1,8-NACD)were added to the two spinning solutions,respectively.The Janus nanofibers had good biphasic release property.The two fluorescent molecules(PMI and 1,8-NACD)can be used to track the release rate of two polymer(PAN and PVP),respectively.PVP side showed a faster release rate in the early release with the total release efficiency of 40.2%within 1 h and PAN showed a sustained release with the total release of more than 70%after 12 h.3.Magnetic-fluorescent Janus nanofibers.Magnetic-fluorescent Janus nanofibers were prepared by adding a magnetic suspension of CoFe2O4 into PAN spinning solution and 1,8,8-NACD to PVP spinning solution.CoFe2O4 magnetic nanoparticles and fluorescent molecules can be effectively isolated and the interference to the fluorescence intensity from the magnetic nanoparticles can be reduced.It was found that the fluorescence intensity of Janus nanofibers was stronger than that of composite nanofibers.