Controlled Self-Assembly Employing Microfluidic Tools: Pathway Selection in Materials Synthesis and Processing

Abstract

Self-assembly is a crucial process in the bottom-up fabrication of hierarchical supramolecular structures and advanced functional materials. However, its control has been merely achieved via synthetic chemistry approaches, following rational molecular designs. This thesis focuses on controlling self-assembly processes via microfluidic technologies. Studies presented in this thesis show that microfluidic devices can allow an advanced spatiotemporal command of reagents; a feature that can strongly affect the outcome of a reaction. First, it is proven that the unique conditions present in microfluidic devices enable to unveil unprecedented synthetic pathways during the self-assembly of functional materials, favouring their controlled defect engineering and yielding new materials’ properties. Then, an advanced control on the structure and supramolecular chirality of self-assembled architectures is demonstrated by harnessing complex hydrodynamic fields with controlled mass transport. Additionally, microfluidic devices are confirmed to be an effective tool for controlling self-assembly process on surfaces. For example, controlled chemical gradients inside single-layer microfluidic devices are exploited to enable unprecedented spatial control while patterning compositional gradients of functional thin films. Finally, a method employing double-layer microfluidic devices is described to accomplish a regioselective localization of multiple functionalities on a single surface and their in-situ analytical characterization.