Preparation Of Flexible Luminescent Janus Nanofiber Film Through Space Isolation To Control Energy Transfer

Flexible display is one of the most popular research topics in the field of display.In the field of flexible display,many key technologies need to be further improved.For example,light and color control scheme,flexible substrate selection,and light-emitting cell miniaturization.Electrospinning can be used to prepare thin and soft films simply and efficiently,and the fiber scale inside the film can reach nanometer level.It can also make structural and functional design of nanofibers conveniently,so that the prepared fiber film can be applied to many fields.In this paper,a series of flexible light-emitting nanofiber films including white light were prepared by controlling the fluorescence resonance energy transfer(FRET)with the technology of electrospinning and spinneret design.The specific work is as follows:1.The solution of tricolor fluorescent substance:rhodamine B(R),coumarin 6(G)and anthracene(B)was prepared,and the mechanism of fluorescence resonance energy transfer(FRET)was studied by blending them with different concentrations.The results show that there is a large area of excitation emission spectrum over-lap between BG and GR,and the direction of energy transfer is from donor to receptor,namely B→G→R.The fluorescence quenching of the donor was caused when the fluorescent molecules were simple blended together with a near molecular distance because of the high efficiency FRET.2.Then the Janus nanofibers were prepared by the needle design and the double channel electrospinning method.The tricolor fluorescent substances were grouped and electrospun into Janus nanofibers.Fluorescence properties of these Janus nanofibers were compared with those nanofibers that fluorescent substances were simple blended and electrospun with traditional single needle.The results show that the prepared Janus nanofibers have two phase heterogenous structure,and the nanofiber film has the advantages of light weight,ability of bending and arbitrary tailoring.After the rational separation of donor receptor fluorescence molecules,the energy transfer efficiency can be successfully controlled,and nanofiber films with a changeable fluorescent color in large color gamut can be prepared.A flexible white Janus nanofiber film with CIE coordinate value of(0.32,0.35)can be prepared by adjusting the amount of fluorescent substance.3.Finally,we explored the applications of Janus fluorescent nanofiber membrane in colorful light-emitting and flexible photoelectric thin films.A patterned light-emitting film was prepared by adjusting some parameter like the speed of the double channel spinning,the movement of the needle or the receptor and so on.Then we designed and prepared a flexible circuit,co-encapsulated the white light-emitting Janus nanofiber film with the circuit and different miniature light bulbs.The encapsulated flexible film can emit light with different color when it’s electrified.The research content of this paper provides new ideas for the fields of organic light-emitting flexible display and fluorescent anti-counterfeiting.