Amirieh, Estatira2026-03-062026-03-062026-03-062026-03-05https://hdl.handle.net/10012/22966Hierarchical cryogels are a promising class of lightweight, highly porous materials whose multiscale pore architecture can simultaneously enable rapid mass transport and high adsorption capacity, making them attractive for diverse applications. Numerous approaches have been introduced so far to produce hierarchical cryogels. However, these approaches are often processing-intensive, requiring multi-step templating, tightly controlled freezing protocols, or complex drying strategies that can limit scalability and restrict independent control over pore hierarchy. Moreover, most existing approaches rely on the fabrication of structured cryogels from gel-like precursors, which require high solid concentrations, thereby increasing density and compromising lightweight characteristics. This work utilizes a recently introduced technique by our group, namely liquid-streaming (templating), that facilitates the formation of hierarchical cellulose nanocrystal (CNC)-based cryogels through filamentary structuring of CNC aqueous suspension (liquid-like) in an apolar medium. In this approach, an aqueous nanomaterial dispersion is injected into a surfactant-containing hexane bath to produce a filamentous all-liquid network, which is subsequently freeze-dried to yield a worm-like hierarchical cryogel. A central objective of this approach is to simplify the rheological requirements, broaden the range of extrudable materials, and dissociate filament stability from bulk viscoelasticity. By controlling factors such as interfacial tension, interfacial rheological features, extrusion rate, and solid content, one can map the operational “printing window” for producing continuous, shape-persistent filaments even from low-viscosity fluids. Herein, key injection factors governing filament formation, including needle size, nanomaterial concentration, and injection pressure, are investigated to delineate the transition between stable filament formation and breakup behavior. It is also shown how these factors dictate the morphology, e.g., filament diameter, of the structured liquids. A process–structure map is developed to define operating windows that reliably produce filamentous all-liquid systems across a range of conditions, providing practical guidance for reproducible fabrication and architectural control. The resulting worm-like cryogels from the engineered filamentous all-liquid systems exhibit intrinsic hierarchical porosity, with macroporous inter-filament voids coupled with finer porosity on and within the filament structure. To evaluate functional implications of this architecture, worm-like cryogels are compared against conventional bulk cryogel counterparts in oil absorption testing. The worm-like cryogel demonstrates improved uptake performance, achieving a 22% increase in oil absorption efficiency relative to bulk structures. In general, this thesis establishes liquid templating as an accessible and tunable route to CNC-based hierarchical cryogels and provides processing guidelines that link injection conditions to structure and absorption performance.enMaster Thesis