Modular and Integrated Systems for Nanoparticle and Microparticle Synthesis—A Review

Abstract

Nanoparticles (NPs) and microparticles (MPs) have been widely used in different areas of research such as materials science, energy, and biotechnology. On-demand synthesis of NPs and MPs with desired chemical and physical properties is essential for different applications. However, most of the conventional methods for producing NPs/MPs require bulky and expensive equipment, which occupies large space and generally need complex operation with dedicated expertise and labour. These limitations hinder inexperienced researchers to harness the advantages of NPs and MPs in their fields of research. When problems individual researchers accumulate, the overall interdisciplinary innovations for unleashing a wider range of directions are undermined. In recent years, modular and integrated systems are developed for resolving the ongoing dilemma. In this review, we focus on the development of modular and integrated systems that assist the production of NPs and MPs. We categorise these systems into two major groups: systems for the synthesis of (1) NPs and (2) MPs; systems for producing NPs are further divided into two sections based on top-down and bottom-up approaches. The mechanisms of each synthesis method are explained, and the properties of produced NPs/MPs are compared. Finally, we discuss existing challenges and outline the potentials for the development of modular and integrated systems.

Ag–Ga Bimetallic Nanostructures Ultrasonically Prepared from Silver–Liquid Gallium Core–Shell Systems Engineered for Catalytic Applications

“…Primary gallium is a critical global commodity, widely produced as a recovered metallurgical byproduct from the refining processes of bauxite (alumina) and zinc ores . In terms of end users, gallium (Ga) market has been widely driven by semiconductor applications; however, due to exceptional properties of liquid-phase gallium (Ga (L) ), it is regarded as a promising multifunctional material with high relevance to the domain of nanomaterials and nanometallurgy technologies, such as those in catalysis. − Liquid-state Ga (L) introduces a distinctive advantage as post-transition metal, with the coexistence of metallic and covalent bond characteristics, displaying abundant free electrons and disordered ions that can provide an exceptional reaction medium with unique attributes, such as high surface tension, high ductility, thermal and electrical conductivity, and fluidity. , Ga (L) can be easily shaped, stretched, and patterned while maintaining the metallic properties and remaining highly thermally and electrically conductive. For this reason, Ga (L) has the capability of dissolving other metals, forming liquid metal (LM) alloys, performing as free-standing droplet microreactors, and facilitating the in-droplet liquid–solid interfacial interactions for the development of intermetallic compounds with ordered crystalline phases, − even below the Ga (L) bulk melting temperature ( T m = 29.8 °C).…”

Preparation of Nano/Micro Bimodal Aluminum Powder by Electrical Explosion of Wires

“…However, when mixing powders, the particles of which differ significantly in density, size, and shape, the separation and disturbance of the homogeneity of the mixture are possible. In addition, the separate synthesis of nano- and microparticles requires bulky and expensive equipment that takes up large space and, as a rule, is difficult to operate and requires the involvement of a labor force with specialized knowledge [ 26 ].…”

Importance of Monitoring the Synthesis of Light‐Interacting Nanoparticles – A Review on In Situ, Ex Situ, and Online Time‐Resolved Studies

“…As a result, flow reactors with in situ or online characterization can provide insights into the early stage reaction mechanisms by providing data with microsecond to millisecond time resolution, overcoming the limitations imposed by ex situ characterization. [ 316,317 ]…”

“…As a result, flow reactors with in situ or online characterization can provide insights into the early stage reaction mechanisms by providing data with microsecond to millisecond time resolution, overcoming the limitations imposed by ex situ characterization. [316,317] The first online monitoring of the flow synthesis of nanoparticles was published in 2004, where optical fiber online fluorescence spectroscopy was coupled to a glass microfluidic reactor for the synthesis of CdSe QD. [305] The setup allowed photoluminescence measurements from CdSe QDs at the fixed "observation zone" on the reactor which is effectively a fluorescence flow cell.…”