Continuous Synthesis of Nanocrystals via Flow Chemistry Technology

Abstract

Modern nanotechnologies bring humanity to a new age, and advanced methods for preparing functional nanocrystals are cornerstones. A considerable variety of nanomaterials has been created over the past decades, but few were prepared on the macro scale, even fewer making it to the stage of industrial production. The gap between academic research and engineering production is expected to be filled by flow chemistry technology, which relies on microreactors. Microreaction devices and technologies for synthesizing different kinds of nanocrystals are discussed from an engineering point of view. The advantages of microreactors, the important features of flow chemistry systems, and methods to apply them in the syntheses of salt, oxide, metal, alloy, and quantum dot nanomaterials are summarized. To further exhibit the scaling‐up of nanocrystal synthesis, recent reports on using microreactors with gram per hour and larger production rates are highlighted. Finally, an industrial example for preparing 10 tons of CaCO3 nanoparticles per day is introduced, which shows the great potential for flow chemistry processes to transfer lab research to industry.

Highly reproducible, high-yield flow synthesis of gold nanoparticles based on a rational reactor design exploiting the reduction of passivated Au(iii)

“…In an attempt to address these issues, several authors performed the synthesis of gold nanoparticles in continuous flow reactors, [16][17][18][19][20][21] due to the inherent benefits derived from the use of milli-and microreactors: improved mass and heat transfer, control over mixing conditions and enhanced reproducibility of the product properties. [21][22][23][24][25][26][27] These three major improvements address the most critical problems that one faces when scaling up the batch production of AuNPs. Focusing only on the Turkevich synthesis in continuous reactors, Baber et al 24 developed a coaxial flow reactor composed of an outer glass tube and an inner glass tube where the initial mixing of the gold precursor with the citrate took place, avoiding in this way fouling issues, since the initial stage of the reaction took place at the two streams interface.…”

Automated microfluidic screening of ligand interactions during the synthesis of cesium lead bromide nanocrystals

“…46 This is an important observation, as it makes comparisons between literature data using the hot-injection approach and our microfluidic data meaningful. However, it should not be forgotten that the microfluidic approach has inherent advantages (such as rapid mixing and heat transfer leading to lower polydispersity, 37 excellent batch-to-batch reproducibility 36 and potential for industrial scale-up 68 ) that mark it as a desirable synthesis methodology in itself, and not solely as a means of performing high-throughput screening.…”

Flow Chemistry in Contemporary Chemical Sciences: A Real Variety of Its Applications

“…Then, the development of especially efficient and fast methods for the synthesis of various nanoparticles was the subject of numerous works in the field of flow synthesis. These initially involved inorganic nanoparticles [348][349][350], where metallic nanoparticles found numerous catalytic applications in microflow reactors for organic syntheses [348]. Various nanoparticles and microparticles were synthesized under flow conditions [351], and functionalized nanoparticles [352] were designated for biomedical applications.…”