Study On The Preparation And Performance Of Electrospun Fluorescent Nanofibers

In recent years,fluorescent nanofiber materials have attracted extensive interest from researchers due to potential development in textiles and photonic applications.With the advancement of medical imaging,new anti-counterfeiting and other technologies,it is necessary to develop fluorescent materials with good characteristics.At present,great progress has been made in combining fluorescent substances and substrates to obtain fluorescent nanofibers by electrospinning,and more extensive research on fluorescent nanofibers has attracted more and more attention.In this thesis,silk and polyvinylpyrrolidone?PVP?are used as the matrix,doped with three different fluorescent dyes of sodium fluorescein?FS?and rhodamine B?RB?acridine orange?AO?.Nanofibers,systematically study the morphology,aggregate structure,thermal and fluorescent properties of fluorescent nanofibers.The research conclusion is as follows:?1?The spinning solution was prepared with the silk fibroin?SF?-formic acid-fluorescent dye blend system,and the SF fluorescent nanofibers were prepared using electrostatic spinning equipment.The effects of SF concentration,fluorescent dye content and other parameters on the structure and properties of nanofibers were investigated.The experimental results show that the prepared SF fluorescent nanofibers have smooth surfaces and good morphology.As the SF concentration increases from6.0 wt%to 10.0 wt%,the SF-FS nanofiber diameter increases from 419±53 nm to 873±135 nm;the fluorescent dye concentration increases from 0.5 wt%to 2.0 wt%,fiber diameter Reduced from 1200±261 nm to 683±126 nm.The change rules of the diameters of SF-AO and SF-RB nanofibers are consistent with SF-FS.For the analysis of the aggregate structure of fluorescent nanofibers,the FTIR infrared characteristic peaks are mainly located at 1640 cm^-1 and 1520 cm^-1,and the X-ray diffraction peaks are mainly located at 20.8°,which indicates that the secondary structure of SF is mainly?-sheet conformation.The thermal degradation behavior of SF fluorescent nanofibers was observed to be significantly reduced at around 250?,and the weight loss rate of the entire thermal decomposition process reached about 60%-70%.By changing the concentration of different SF and fluorescent dyes,SF fluorescent nanofibers can exhibit different fluorescent effects.?2?PVP-ethanol-fluorescent dye blending system is used to prepare spinning solution,and electrostatic spinning equipment is used to prepare PVP fluorescent nanofibers.The effect of PVP concentration on the structure and properties of nanofibers was investigated.The experimental results are:the surface of the prepared PVP fluorescent nanofibers is smooth,continuous and uniform in shape,the fiber diameter increases with the increase of the PVP concentration,the PVP concentration increases from 9.0 wt%to 13.0 wt%,PVP-AO,PVP-FS,PVP-The diameters of three fluorescent nanofibers from RB increased from 351±119 nm,596±133 nm,and 322±25 nm to 464±100 nm,733±415 nm,and 741±287 nm,respectively.According to the analysis of mechanical properties,the maximum stress of nanofibers is 2MPa,and the maximum strain is 26%.Aggregate structure analysis found that the characteristic peaks of FTIR are located at 1655 cm^-1,1423 cm^-1,and 1289 cm^-1,and the X-RD characteristic peaks are located at 23°and 28°.This peak is a PVP semicrystalline characteristic peak.The thermal degradation behavior of PVP fluorescent nanofibers was observed to be significantly reduced at about 400?,and the weight loss rate of the entire thermal decomposition process reached about 95%.The fluorescence effect of PVP fluorescent nanofiber membrane is obvious,and changing the concentration of PVP will also change the fluorescence effect of nanofibers.Comprehensive analysis shows that electrospinning can achieve continuous and uniform preparation of fluorescent nanofibers,and the surface of the fiber is smooth and uniform in thickness,but the concentration of the spinning solution and the amount of fluorescent dye added can directly affect the fiber diameter and its fluorescent effect,and the aggregation of fibers.The influence of the state structure and thermal performance is small.This study provides research ideas for the controllable preparation of fiber structures,the improvement of the fluorescent properties of materials,and the expansion of their applications in fluorescent labeling,fluorescent identification,and fluorescent anti-counterfeiting.