Committee Members:
Prof. Mark Losego, Advisor, MSE
Prof. Faisal Alamgir, MSE
Prof. Matthew McDowell, MSE/ME
Prof. Ryan Lively, ChBE
Prof. Marta Hatzell, ME
Vapor phase modifications of polymers have diverse technological applications. Vapor phase infiltration is an emerging technology that generates hybrid organic inorganic materials by infiltrating inorganics into a polymer matrix. During vapor phase infiltration, inorganic species sorb and diffuse through the polymer bulk. VPI previously emerged from atomic layer deposition. However, unlike atomic layer deposition which generates homogenous films, VPI imbeds molecular inorganic structures within the polymer. As a result, there are unique challenges to probing the inorganic structure within vapor phase infiltrated material. The lack of understanding of infiltrated inorganic species' structure has hindered wider adoption of VPI technology. This research proposal aims to address this gap in the literature through three fundamental questions. Firstly, how can the structure of infiltrated inorganics be characterized, and how is this structure affected by processing conditions? Innovative analytical approaches and spectroscopic techniques will be employed to comprehensively understand the structure and probe the effects of processing on inorganic structure in infiltrated membranes.
Secondly, this thesis will address the question: How does the chemistry of the inorganic species selected for infiltration contribute to the structure of the hybrid? The contribution of inorganic chemistry to the hybrid material's structure will be explored. The relationship between precursor chemistry and the thermodynamics of oxide/hydroxide formation, inorganic connectivity, and polymer/precursor binding energies will be investigated to inform the design of tailored VPI systems for various applications, including membranes.
Lastly, how do these structural changes affect material properties, notably the solvent stability, membrane permeance, and selectivity? The impact of structural changes on material properties, particularly solvent stability, membrane permeance, and selectivity, will be clarified. Establishing clear links between inorganic structure and material properties will enable a comprehensive understanding of process-structure-property relationships in hybrid materials. This knowledge will facilitate the optimization of processing conditions to achieve desired material properties, leading to enhanced membrane performance within PIM-1 hybrid membranes.
The importance of this thesis is that it will develop experimental spectroscopy approaches to characterize the structure of infiltrated inorganics and gain new insights into the physicochemical structure of the inorganic in these infiltrated hybrid materials. This new structure knowledge will bridge the gap between processing-structure and structure-property relationships in a host of applications including infiltrated PIM-1 membranes. The findings from this research will advance the understanding of vapor phase infiltrated materials and optimize VPI technology for various applications, particularly in membrane science.