Controllable Preparation Of Nanoscale Dyes By High Gravity Technology And Its Application Performance Research

In recent years,there are many types of dyes on the market,which are widely used.However,many dyes have hydrophobic problems,such as disperse dyes and organic fluorescent dyes,which greatly affect their application properties.With the development of nanotechnology,the preparation and modification of dyes nanoparticles can improve the solubility and the dispersity of dye in water,thereby achieve the better application properties.In this thesis,the dispersions of disperse dye organic fluorescent dye were respectively prepared by a high-gravity antisolvent precipitation combined with in-situ surface modification.The effects of various process conditions on the size and dispersibility of dye nanoparticles were explored.In addition,their application properties were also investigated.The main research contents and results were as follows:1.The nanodispersion of disperse yellow 54 was prepared by high-gravity antisolvent precipitation method combined with in-situ surface modification.The effects of various experimental factors on the morphology and size of the dye particles were investigated.The optimum process conditions were obtained:the amount of dispersant A was 50 wt.%,system temperature was 25?,the concentration of dye dispersion was 10 mg/mL,the RPB speed was 1500 rpm,the antisolvent/solvent ratio was 5,the amount of protection agent in the spray drying process was 50 wt.%,and the feed flow rate in the spray drying process was 300 mL/h.Under optimal conditions,the average size of the disperse yellow 54 nanoparticles was about 130 nm.The centrifugal stability was 96.07%,indicating that the dispersion stability was high.After making dye into nanoparticles,the contact angle of disperse yellow 54 was reduced from 98° to 30°,indicating that its wetting performance was greatly improved.The XRD results showed that the crystallinity of the disperse dye was significantly decreased,and close to an amorphous state.Compared with the traditional stirred tank method,the product obtained by the high-gravity method had a smaller size,a narrower particle size distribution and a higher dispersion stability.The dyeing performance results showed that compared with the corresponding commercial microsized dye,the dyeing rate of disperse yellow 54 nanoparticles was increased by 11%,and the performance of lifting force was slightly improved when the amount of dye was 1-2%owf.Moreover,the soaping fastness and sublimation fastness were higher.2.The nanodispersion of the organic fluorescent dye Nile red(NR)was also prepared by high-gravity antisolvent precipitation method combined with in-situ surface modification.The effects of various experimental factors on the morphology and size of the dye particles were investigated,and the optimal process conditions were obtained:Tween 80 concentration was 0.8 mg/mL,antisolvent/solvent ratio was 7,NR concentration was 10 pg/mL,system temperature was 25?.The NR nanoparticles prepared under optimal conditions had a spherical shape with an average size of about 35 nm and a saturation solubility of 3.28 ?g/mL,which was about 41 times higher than that of the raw materials,indicating that the water solubility of the prepared NR nanoparticles was significantly improved.The fluorescence performance results showed that the NR nanodispersion could emit strong fluorescence in the aqueous solution.The maximum excitation wavelength of the NR nanodispersion in the ultraviolet wavelength range was 265 nm,the maximum excitation wavelength in the visible wavelength range was 550 nm,and the maximum emission wavelength was 640 nm.Compared with the traditional stirred tank method,the product prepared by the high-gravity method had a smaller particle size,more uniform particle size distribution,higher dispersion stability,and better fluorescence performance.3.The application properties of NR nanodispersions were further studied.First,the NR nanodispersion was used for in vitro cell imaging.The results showed that NR nanoparticles had a good biocompatibility and low cytotoxicity.NR nanoparticles could be efficiently taken up by cells,which demonstrated that NR nanoparticles were capable of cellular labeling.Secondly,the NR nanodispersion was mixed with polyvinyl alcohol(PVA)to prepare a fluorescent composite film.The results showed that,the fluorescence intensity of NR/PVA fluorescent composite films increased with increasing the content of NR nanoparticles,but their transmittance decreased gradually.Finally,the NR nanodispersion was also mixed with commercial ink to draw a pattern on paper.The results showed that the pattern was "invisible" under the daylight,but it showed clear red fluorescence under the UV lamp,indicating that it had a great potential application in counterfeit labeling.