An investigation into the mediated control of evaporative self-assembly in carbon nano particle suspensions

This thesis presents the experimental findings of this research project into the self-assembly and deposition patterns of carbon-based nanoparticles in evaporating colloidal droplets. The project aimed to contribute novel insights into nanoparticle behaviour and nanostructure formation under specific experimental conditions, ultimately enabling the prediction and control of these processes. Specific objectives included creating a classification protocol, identifying quantifying methods to characterise deposition patterns.

Key findings are reviewed in relation to the overarching research aims and their broader implications. A standardised nomenclature protocol was introduced, aimed at providing clarity and consistency in describing evaporative deposit morphologies. The efficacy of a cationic surfactant (DTAB) at a specific concentration (29 mM) was demonstrated to mitigate the coffee ring effect in carbon nanotube (CNT) laden droplets, significantly enhancing deposit uniformity across various substrates. The impact of nanoparticle concentration, substrate temperature, and surfactant concentration on deposition patterns was systematically analysed, revealing critical parameters that control pattern formation.

Composite samples of graphene oxide (GO) and carbon black (CB) were also studied, highlighting the interplay between these materials in achieving uniform deposition. Optimal surfactant concentrations and formulation compositions were identified, providing a framework for tailoring deposition processes to achieve desired characteristics.

This chapter emphasises the potential for future research to deepen the mechanistic understanding of nanoparticle self-assembly, expand the range of materials studied, optimise deposition techniques for specific applications, and address scalability and sustainability challenges. The findings provide insights for advancements in nanotechnology applications, such as printed electronics, sensors, and coatings, while highlighting the importance of standardised nomenclature protocols within the field.