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Aqueous Self-Assembly with Cucurbit[n]urils: From Solution to Emulsion 10.17863/CAM.18794 Groombridge, Alexander S. 0000000319177909 Scherman, Oren A. Abell, Chris Making use of the non-covalent bond to make materials is of great interest in many fields of research. This PhD thesis describes a variety of highly interdisciplinary research undertaken at the interface between chemistry, materials science, physics and engineering. Chapter 1 is an introductory chapter into the core concepts underlying this thesis. Supramolecular chemistry as a broad research field is briefly reviewed, followed by a focus on host-guest chemistry. The macrocyclic cucurbit[n]urils (CB[n]s) in particular are highlighted with a discussion on their recent applications since their discovery. Emulsions and their controlled generation with microfluidic techniques are then reviewed, as they have been used as templates for self-assembly processes throughout this thesis. A study into the synthesis of extended polymer networks composed entirely from small molecules held together by non-covalent interactions is described in Chapter 2. These highly dynamic and responsive supramolecular polymer networks have not yet been constructed with CB[n] host-guest chemistry. The ability of the larger CB[8] macrocycle to encapsulate multiple guest molecules in a stepwise fashion was taken advantage on in designing the synthesis of branching monomers. The monomers had two (A$_2$) or three (B$_3$) terminal guest moieties for CB[8], which upon combination formed branching supramolecular polymers that were multi-stimuli responsive. However, the polymers precipitated from solution at high concentrations rather than form a cross-linked network, due to competing intra-chain cyclisation and the limited water solubility of CB[8]. By confining these polymers to microfluidic droplets, directed assembly to the liquid-liquid interface could drive polymerisation to form an interfacial cross-linked gel that was both elastic and self-healing. Chapter 3 follows on from these results, describing attempts into constructing hyperbranched supramolecular polymers from an AB$_2$ guest molecule and CB[8] that would form globular polymers. Intramolecular complexation dominated with the guest molecules synthesised (A and B complexing within the molecule), evidenced by a variety of characterisation. Compared to previous works that relied on linear molecules to form a folded conformation for intramolecular complexes, these molecules were pre-organised with a unique cooperative complexation pathway. The stimuli-responsiveness of the complexes was probed, and the formation of self-sorting mixtures was demonstrated with multiple CB[n] and additional guest molecules. Controlling the self-assembly of semi-conducting nanocrystals with CB[7] is detailed in Chapter 4, a process that typically requires harsh conditions or extensive time-scales. Semi-conducting nanocrystals could be assembled instantaneously from water into extended networks that were highly porous with excess CB[7], retaining their nanoscale properties. Limiting quantities of CB[7] could then form nanoscale aggregates that remained in solution. Confinement of these assemblies within microfluidic droplets allowed the synthesis of dense microparticles, that retained their shape after re-dispersal in water. By simply including metallic nanocrystals as a minor component, mixed aggregates could be synthesised analogously. Finally, Chapter 5 draws overall conclusions from the results of this thesis, looking broadly at the potential for future prospects in these areas of research. University of Cambridge 2018-04-07 Thesis Doctoral Doctor of Philosophy (PhD) en This work was supported by the EPSRC Cambridge NanoDTC, EP/G037221/1. https://www.repository.cam.ac.uk/handle/1810/271800 https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/27bb80c3-239a-45ca-b1dd-f098f9ecc0ed/download 87eda9de84448d1f82354d60eee3eb5f https://apollo8-f-pro.lib.cam.ac.uk/bitstreams/14aecc08-da89-4de0-9005-feb0a1c4fe80/download 920dc31fe762b96c10a13e483fcd4780 https://creativecommons.org/licenses/by-nc-sa/4.0/ Supramolecular chemistry Self-assembly Microfluidic Cucurbit[n]uril Quantum dot Nanoparticle Macrocycle