Preparation method of silicon dioxide coated fluorescent carbon quantum dot composite microspheres

Abstract

The invention belongs to the technical field of luminescent materials, and particularly relates to a preparation method of silicon dioxide coated fluorescent carbon quantum dot composite microspheres.The method comprises the following steps: preparing carbon quantum dots by using a microwave reactor through a hydrothermal method, transferring the carbon quantum dots into an organic solvent through an extraction method, then adding ethanol, dispersing the carbon quantum dots into the ethanol solvent through solvent replacement, finally, adding carbon quantum dots in hydrolysis reaction of tetraethoxysilane under ammonia-alkali conditions, and coating the carbon quantum dots in situ in the growth process of silicon dioxide to obtain the silicon dioxide coated carbon quantum dot fluorescentcomposite microsphere. The preparation method is energy-saving, rapid, efficient and high in quantum dot coating rate, and the prepared fluorescent composite microsphere is regular in shape, uniform and adjustable in particle size, good in light-emitting stability and long in service life.

Description

Technical field [0001] The invention belongs to the technical field of luminescent materials, and specifically relates to a method for preparing silica-coated fluorescent carbon quantum dot composite microspheres. Background technique [0002] Carbon quantum dots (CQDs) are a class of spherical nanoparticles with a size less than 10nm, which are composed of sp 2 Carbon core and surface functional groups. Compared with traditional organic dyes and quantum dots, carbon quantum dots have unique optical properties, good biocompatibility, low toxicity, resistance to photobleaching, and chemical and physical inertness. Since the discovery of carbon quantum dots in 2004, researchers have made great progress in their applications in bioimaging, biosensing, drug delivery, and light-emitting devices. [0003] In recent years, people have developed a series of methods for preparing carbon quantum dots, which can adjust the emission wavelength of fluorescent carbon quantum dots by adjusting t...

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Problems solved by technology

[0005] Aiming at the disadvantages of existing carbon quantum dots such as poor luminescence stability and short service life, the present invention provides a preparation method of silica-wrapped fluorescent carbon quantum dot composite microspheres, which can be simply improved Methods The technology for preparing silica microspheres is replaced by ethanol solution of carbon quantum dots The anhydrous ethanol in the method, promptly utilizes fluorescent carbon quantum dot ethanol dispersion system to replace the commonly used ethanol solvent when hydrolysis of ethyl orthosilicate, through the active group on the surface of carbon quantum dots and the intermediate product of hydrolysis of ethyl orthosilicate Weak interaction wraps carbon quantum dots into silica microspheres to prepare silica-wrapped carbon quantum dot fluorescent luminescent microspheres. This method is energy-saving and efficient, and the prepared fluorescent luminescent microspheres have better luminescence stability and long service life

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