Synthesis, Manipulation and Characterisation of Nano- and Micro-Particles in Continuous-Flow Microfluidic Systems.

by Guido Bolognesi (UCL, London, UK)

Tuesday 23 May 2023, 15:00 → 16:00 Europe/Rome

Aula Careri (Dip. di Fisica - Edificio G. Marconi)

Nano-/micro-particles play an increasingly important role in a broad range of technological applications, such as drug delivery, diagnostics, biosensing, imaging, energy storage, catalysis, food production and cosmetics. Therefore, the exploration of innovative methods for the synthesis, manipulation and characterisation of nano-/micro-particles has attracted great attention from scientists and engineers in recent years. Compared to conventional methods, microfluidic systems offer several advantages, including lower reagent/sample consumption, higher precision, reproducibility and energy efficiency, improved sensitivity, and lower costs. In this talk, I will present microfluidic approaches for the synthesis, manipulation and characterisation of synthetic and biological particles for bioanalysis, drug-delivery, thermal energy storage, water decontamination and synthetic biology applications. The first part of the talk will focus on diffusiophoresis and diffusioosmosis, namely the transport of colloids and liquids by salt concentration gradients. By combining experimental analysis and numerical simulations, I will discuss new transport mechanisms for the reversible trapping and accumulation of particles within dead-end pores and for the focusing of particles within straight open channels under continuous flow settings. I will then showcase proof-of-concept microdevices that exploit these mechanisms for the continuous size-based separation and size detection of nanobeads as well as for the measurement of zeta potential and charged lipid composition of small unilamellar vesicles (SUVs). The second part of the talk will focus on the use of microfluidic droplet generators for the synthesis of nano- and micro-particles by photopolymerization, solvent evaporation and hydrodynamic focusing. Different devices and flow configurations can be used to manufacture a variety of monodispersed particles with tightly controlled properties, including microgels, liposomes, porous magnetic Janus microparticles with asymmetric surface topology, core-shell microparticles encapsulating phase change materials and with photocatalytic property.