Elucidating Macromolecular Design and Membrane Fabrication Principles for Multifunctional Water Treatment Sorbents
Abstract
Motivation: The overall goal of this proposal is to generate the fundamental knowledge that enables the creation of multifunctional membrane sorbents empowered for the rapid, selective, and high-capacity capture of toxic industrial chemicals and materials (TIC/TIMs). A critical need exists for technologies that enable Soldier-portable devices to purify water from varied sources. This aim necessitates the development of versatile, lightweight purification devices that can actively detect and mitigate the health hazards posed by TIC/TIMs. In this regard, significant opportunities exist for membrane-based sorbent filters. Traditional adsorbents rely on thick receiving media (e.g., granulated activated carbon) to maximize the active surface-area-to-volume ratio and afford high capacity. However, these form factors rely on diffusive transport to bring the target solutes from the bulk solution to the active binding sites, leading to slow response times and poor capture efficiency. Membrane sorbents, in contrast, employ solutions that flow through the substrate containing the active sites. In this configuration, adsorption is subject to diffusion lengths on the scale of nanometers, which increases capture efficiency dramatically. Membrane sorbents have been produced in several ways, and though the resulting films take advantage of rapid mass transfer, they tend to have low binding capacities due to limited pore wall functionalities. Methods to be Employed: Our collaborative research team will integrate expertise in polymer chemistry, membrane manufacturing, and separation science to reveal the fundamental knowledge that enables the development of membrane sorbents with tunable chemistries, high capacities, and high affinities. This will be accomplished through the molecular design of reactive poly(arylene ether sulfone) (PAES) polymers containing structural units with ?clickable? moieties, which are transformed into high surface area substrates using a scalable SVIPS (surface-segregation and vapor induced phase separation) process. Crucially, while the structural control enables fast uptake and high capacity, the ?clickable? moieties of the PAES platform enables diverse chemical functionality to be introduced post-fabrication such that sorbents with tailored affinities (e.g., ones with the ability to capture dilute solutes from complex environments) can be created. Our distinct capabilities will allow us to develop quantitative relationships between molecular descriptors, nanoscale structures, and the bulk properties of sorbents. As such, we will: 1. Develop a design framework for nanostructured membrane substrates by identifying the key factors in PAES architecture that control thin film assembly. 2. Elucidate the interdependencies between the nanostructure of SVIPS-fabricated membranes, the ?click? chemistry modification schemes, and the functionality of the resulting sorbents. 3. Quantify structure-property relationships for membrane sorbents to develop rigorous design rules for these purification devices during field-relevant applications. Scientific Objectives: We will be able: 1) to synthesize PAES polymers with precisely controlled compositions, architectures, and ?clickable? functionality; 2) to manufacture nanoporous membranes from the PAES polymers using SVIPS processes and tailor their pore wall chemistry post-fabrication; and 3) to correlate the TIC/TIM removal performance of membrane sorbents with their nanostructure and functionality. Significance: Our approach has the potential to revolutionize the development of membrane sorbents by elucidating the critical relationships that enable the molecular design of a reactive PAES platform. Ultimately, this fundamental information will enable the scalable manufacturing of tailor-made sorbents with optimal mass transport, a high density of selective capture sites, and
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 02, 2023
- Source ID
- W911NF2310309
Entities
People
- William A Phillip
Organizations
- Army Contracting Command
- United States Army
- University of Notre Dame