A universal approach to stabilize water-oil interface via surfactant self-assembly

Liquid-liquid interfaces represent an advantageous setting for the confinement, manipulation, and controlled assembly of colloids. Stabilizing liquid-liquid interfaces, whether between miscible or immiscible liquids, is crucial for a wide range of applications, including energy storage, microreactors, and biomimetic structures. While most of the attention has been on the adsorption of colloidal or surface-active particles and polymeric complexion, there have been no studies concerning the self-assembly of small molecules like surfactants. Therefore, in this study: First, a novel liquid-in-liquid 3D printing approach is developed to successfully shape extremely soft materials into complex and mechanically robust constructs with internal nanostructures using in situ self-assembly of surfactants. Second, using experimental techniques (visual inspection, small-angle X-ray scattering, rheological measurements, and microscopy) and a simulation technique (dissipative particle dynamics), the ternary phase diagram for the same material system (involving water, surfactant, and polar oil) that was used in liquid-in-liquid 3D printing is established to study the equilibrium phase behavior. The ternary phase diagram obtained from the simulations agrees with the experimental results, specifically in terms of morphological transitions, indicating the robustness of the computational simulation as a supplement to the mesoscale experimental systems. Third, an exhaustive and comprehensive overview of the state-of-the-art research on liquid-in-liquid 3D printing techniques is provided, explaining their fundamental principles, underlying mechanisms, and various material systems. Moreover, the practical features in these 3D printing platforms such as structural, mechanical, optical, magnetic, and communicative properties of prints along with the future potential of the technology and its limitations are discussed in detail. Lastly, the universality and versatility of the use of surfactant self-assembly for stabilizing the water-oil interface are studied for a wide range of surfactant classes and the underlying morphological transition was studied in equilibrium and dynamics conditions using a complementary combination of experimental and computational methods.

Name thesis:degree_name

Ph.D. (Doctor of Philosophy)

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Engineering (UMKC)

Grantor

University of Missouri--Kansas City

Year dc:date.issued

2023

Author dc:creator

• Honaryar, Houman

Advisor dc:contributor.advisor

• Niroobakhsh, Zahra

Handle dc:identifier.uri

https://hdl.handle.net/10355/97821

OAI identifier oai:identifier

oai:mospace.umsystem.edu:10355/97821