Fluorescent Carbon Nanoparticles Prepared By Atmospheric Cold Plasma Jet

The properties of fluorescent nanoparticles are better than traditional fluorescent dyes. But the cost of fluorescent nanoparticles is high because of its harsh synthesis conditions with certain toxicity (such as CdSe, Si, ZnO, Au, etc.), which limits its application. Therefore, to explore a simple method producing excellent fluorescent nanoparticles is of great significance.Fluorescent carbon nanoparticles is a new type of fluorescent nanoparticles, which was prepared by scientists in recent years.They are easy to realize surface functionalization, light stability, good biocompatibility, low in biological toxicity, so it is considered to be the most ideal fluorescent materials for testing and marking.The research of fluorescent carbon nanoparticles prepared by atmospheric pressure cold plasma jet mainly carries out the following work.(1) To study the effect of electrical characteristic on the plasma jet. Use magnetic switch and auxiliary capacitance to increase discharge uniformity and improve discharge power. We studied the impacting factors of plasma jet length.(2)With anhydrous ethanol as raw material, using PEG-2000and PVP-20000respectively as the surfactant and surface modification agent, the graphite phase fluorescent carbon nanoparticles were prepared by atmospheric pressure cold plasma jet. Its fluorescence intensity was closely related to the reaction time, the type of surface active agent and discharge pattern. The longer the reaction time was, the stronger fluorescence intensity was; the fluorescence intensity of carbon nanoparticles produced by PEG-2000as the surfactant was much higher than which produced by PVP-20000as the surfactant. The quantum yield of carbon nanoparticles was46.58%. This method is simple, economic and can be continuous production, so it has a good application prospect. (3)The fluorescent carbon nanoparticles were produced with plasma etching carbon precursor.①With the coal ash of burned xylene as raw material, the graphite phase fluorescent carbon nanoparticles were prepared by the atmospheric pressure cold plasma jet etching coal ash. The averge size of carbon nanoparticles was5nm, which emitted green light illuminated of365nm. The fluorescence spectrum covered the ultraviolet and visible parts. The quantum yield of carbon nanoparticles was from43.8%to46.6%.②We get fluorescent carbon nanoparticles by pyrolysising polyethylene glycol and then the product was handled with plasma jet. As a result, the size of carbon namoparticles covered from lnm to100nm. The fluorescence intensity increased3.9times after treated with plasma.③With citric acid as the forerunner, then treated carbon nanoparticles prepared by microwave method with plasma discharge, we observed that the discharge treatment lowered the fluorescence intensity of carbon nanoparticles. With the plasma discharge intensity and temperature enhanced, the paticles condenced to be big ones, as a result of the decrease of the fluorescence intensity.