APS March Meeting 2021
Volume 66, Number 1
Monday–Friday, March 15–19, 2021;
Virtual; Time Zone: Central Daylight Time, USA
Session X04: Polymers and Block copolymers at Interfaces II
8:00 AM–11:00 AM,
Friday, March 19, 2021
Sponsoring
Units:
DPOLY DSOFT
Chair: Reza Foudazi, New Mexico State University
Abstract: X04.00004 : Controlling Block Polymer Interfaces for Next-Generation Membrane Separations
8:36 AM–9:12 AM
Live
Abstract
Presenter:
Bryan Boudouris
(Davidson School of Chemical Engineering, Purdue University)
Author:
Bryan Boudouris
(Davidson School of Chemical Engineering, Purdue University)
Designer macromolecules provide a platform by which to generate structured, multifunctional materials with tailored biochemical, redox, and optoelectronic properties. Furthermore, the solution-processable nature of functional polymers allows for device fabrication procedures that are compatible with high-throughput (e.g., roll-to-roll coating) manufacturing processes. Importantly, in many of these applications, block polymer interfaces play crucial roles in the end-use situations. As such, elucidating the underlying physics associated with these multicomponent macromolecules is critical to long-term engineering success. Here, we show that A-B-C triblock polymers and A-B diblock polymers can be used to modify interfacial interactions in designer water purification membranes. By tuning the molecular weight, molecular weight distribution, block polymer chemical composition, and casting techniques employed, we generate mechanically-robust nanoporous thin films that are well-suited for nanofiltration and membrane adsorber applications. In fact, high-flux separations (i.e., at permeabilities equal to or greater than current commercial membranes) of particles down to ~1 nm in diameter are presented. Additionally, we demonstrate that, through the appropriate selection of the block polymer moieties, the physics of the nanopore walls can be controlled in a direct manner. In addition to observing key physical effects that result due to the large grafting density in confined nanopores, these wall chemistries provide unique functionality to the end-use membranes. In this way, we demonstrate that membranes cast from these materials separate ionic species of similar size. Moreover, these membranes remove >99% of myriad heavy metal cations from aqueous solutions in a manner that is independent of the background electrolyte. Therefore, these tailored macromolecules provide an excellent handle by which to control block polymer interfaces in a technologically-relevant platform.