(679b) Highly Packed Artificial Water Channels in Lamellae Block Copolymer Film

Conference

AIChE Annual Meeting

Year

2015

Proceeding

2015 AIChE Annual Meeting Proceedings

Group

Separations Division

Session

Bioinspired Membranes and Membrane Processes

Time

Thursday, November 12, 2015 - 12:50pm to 1:10pm

Authors

Shen, Y. - Presenter, University of California

Kumar, M. - Presenter, Pennsylvania State University

Highly packed artificial water channels in lamellae
block copolymer film

Yue-xiao
Shen, Manish Kumar*

Department
of Chemical Engineering, The Pennsylvania State University, University Park,
PA, 16802

*Corresponding
Author, Tel.: (814)-865-7519; email address: manish.kumar@psu.edu

The discovery of the high permeability of water
channel proteins aquaporins (AQPs) and their analogs carbon nanotubes (CNTs)
have created an explosion in materials where they are incorporated to develop
novel filtration membranes.¹ AQPs can conduct single channel water
transport with ~3 billion water molecules per second and are being extensively
studied in biomimetic membranes for desalination. The bottlenecks of
large-scale application are high cost of membrane protein production, questions
regarding stability, and challenges in membrane fabrication.¹ CNTs based membranes have much better
chemical stability, but the difficulty in fabricating vertically aligned and
subnanometer diameter CNTs and low packing density in membranes also hold back
commercial applications.²

Artificial water channels are alternative bioinspired
analogues of AQPs created using synthetic chemistry.¹^,³ They combine the advantages of biological
channels and CNTs and improve upon them through their relatively simple
synthesis and chemical stability. In the latest study, we have reported that the
newly designed peptide-appended pillar[5]arene (PAP) artificial water channels (Figure
1a) have similar water conductance compared to AQPs and CNTs.⁴ Furthermore, they are capable of aligning
and forming highly packed two-dimensional arrays in lipid membranes.⁴

In this article, we will present a new method to form
porous and aligned PAP channels in the self-assembled lamellae block copolymer (BCP)
films. We select polybutadiene-polyethylene oxide (PB-PEO) diblock copolymers,
because PAP channels have been seen to be functional in the polymersomes
(Figure 1b). PAP channels have tubular transmembrane structures and an outer
surface which can favorably interact with the hydrophobic region of BCPs. Based
on this theory, we expect that the PAP channels can be densely packed with
orders in these lamellae films after annealing (Figure 1c).⁵ We propose to utilize this functional
porous film to fabricate composite desalination membranes.