Abstract
Microfluidic systems are promising alternatives for continuous synthesis of nanoparticles in controlled environments, overcoming challenges of conventional methods. Stable nanoparticles within a narrow range of size and shape distribution can be reliably produced by controlling geometrical configuration of microfluidic devices and optimizing various operational parameters. This chapter provides an overview of fundamentals and advances in microfluidic synthesis of nanoparticles, categorizing devices into continuous and segmented flow microfluidic platforms. Strategies for functionalization of nanoparticles are explained, and their diverse applications in various fields are elaborated. Future prospects and underlying challenges are also examined for the commercialization of microfluidic devices for nanoparticle synthesis.
TopConventional Nanoparticle Synthesis Methods
Nanotechnology has grabbed the attention of the researchers due to immense potential in numerous fields such as electronics, coatings, cosmetics, energy devices, and sensors (Banerjee & Kar, 2016a). The exceptional properties of the nanomaterials are due to high surface to volume ratio. The synthesis of the nanomaterials follows two basic approaches: top-down and bottom-up. In top-down approach, bulk material is converted into the small particles by several methods such as mechanical grinding, laser ablation, etching, and sputtering. In other approach, the nanomaterials are fabricated utilizing different routes such as sol-gel, chemical vapor deposition, solvothermal, hydrothermal, and reverse micelles. Overall, the synthesis of nanomaterials can be classified in three broad methodologies, namely, physical, chemical, and biological methods. In physical methods, ball milling, melt mixing, chemical vapor deposition, and arc discharge are common whereas, in chemical methods the nanomaterials are synthesized by sol-gel, co-precipitation, and solvothermal method of synthesis (Baig et al., 2021). In biological routes of synthesis, the nanomaterials are synthesized using microorganisms, algae and plant extracts.
Key Terms in this Chapter
Advection: Movement of molecules through a medium by bulk flow, typically driven by a pressure gradient or a concentration gradient.
Nanoparticles: Nanoparticles are referred to particles having at least one dimension in the size scale of 10 -9 m i.e., nano scale.
Nanostructures: This is a term indicating materials with structural elements, crystals or clusters having dimensions within the size range 1–100 nm.
Nanotechnology: Nanotechnology refers to a technology of materials having size in the nanometric range or it is the technology discussed on the properties of any material in the nanometric size scale.
Laminar Flow: Fluid flow in which the fluid particles move parallel to each other, with no mixing or crossflow between adjacent layers.
Diffusion: Motion of molecules from high concentration to low concentration region, driven by the natural tendency of the molecules to distribute evenly in space.
Microfluidics: Study and manipulation of fluids in channels with dimensions ranging from tens to hundreds of micrometers.