自组装界面膜驱动的无传统两亲性表面活性剂反向微乳液法制备高稳定QD@SiO2OA

The efficient silica coating of quantum dots(QDs)has long been hindered by the fluorescence quenching problem caused by traditional surfactants.The fundamental reason lies in the competitive adsorption of the hydrophobic chains of surfactants and the surface ligands of QDs,resulting in ligand detachment and the formation of surface defect states.This paper proposes a"soap-free"reverse microemulsion method(Surfactant-Free Reverse Microemulsion,SFRM),completely eliminating traditional amphiphilic surfactants and using isopropanol/ethylene glycol as dual cosolvents to form a stable interface film at the oil-water interface.A nano-reactor without traditional amphiphilic surfactants is constructed,successfully achieving efficient silica coating of CdSe/ZnS quantum dots.Systematic studies show that the photoluminescence quantum yield(PLQY)of QD@SiO2 composites remains at 78.7%～80.6%(average 79.6±0.78%),which is much higher than 26%of the traditional Triton X-100 method.Transmission electron microscopy(TEM)shows that the thickness of the SiO2 shell layer is uniform(14.7 nm)and the particle dispersion is excellent.Based on the initial power(1.0 mW at t=0),the green light power retention rate after 250 h anti-blue light aging test is 93%,significantly better than 55%of the traditional method.This study clarifies the formation mechanism of the nano-reactor without traditional amphiphilic surfactants from the perspective of interface thermodynamics and kinetics,and the protection mechanism of the optical properties of quantum dots.It provides a new path for the controllable synthesis of high-brightness and long-life quantum dot composite materials.