Subscriber access provided by READING UNIV
Article
Development and Performance Characterization of a Polyimine Covalent Organic Framework Thin-Film Composite Nanofiltration Membrane Lauren Valentino, Michio Matsumoto, William R. Dichtel, and Benito J. Marinas Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.7b04056 • Publication Date (Web): 20 Nov 2017 Downloaded from http://pubs.acs.org on November 21, 2017
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
Environmental Science & Technology is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 26
Environmental Science & Technology
3
Development and Performance Characterization of a Polyimine Covalent Organic Framework Thin-Film Composite Nanofiltration Membrane
4
Lauren Valentino§, Michio Matsumoto†, William R. Dichtel†, Benito J. Mariñas*§
5 6
§Safe Global Water Institute, Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801
7
†Department of Chemistry, Northwestern University, Evanston, IL 60208
8
*Corresponding author [phone: +1-217-333-6961; e-mail:
[email protected]]
9
ABSTRACT – Two-dimensional covalent organic frameworks (COFs) were used to create the
10
first asymmetric, thin-film composite (TFC) nanofiltration (NF) membrane with a COF active
11
layer. NF membrane active layers of polyimine COF were synthesized via the interfacial
12
polymerization (IP) of terephthalaldehyde and tris(4-aminophenyl)benzene monomers on top of
13
a polyethersulfone (PES) ultrafiltration membrane support. Rutherford backscattering
14
spectrometry and Fourier transform infrared spectroscopy analyses confirmed the presence of an
15
imine-linked film with a thickness of ~10 nm that was formed reproducibly. The rejection
16
efficiencies of the COF NF membrane for a model organic compound, Rhodamine-WT, and a
17
background electrolyte, NaCl, were higher than those of the PES support without the COF film.
18
This enhanced solute rejection is the first successful demonstration of a TFC membrane with a
19
thin COF active layer. However, this work also demonstrates the need for COF NF membranes
20
with smaller active layer pores and alternative support materials. The former should result in
21
greater solute rejection, and the latter is key because the PES used for support in the COF
22
membranes is incompatible with the organic solvents used for the COF IP process.
23
KEYWORDS: membrane, nanofiltration, covalent organic framework, COF, polyimine
1 2
24
ACS Paragon Plus Environment
1
Environmental Science & Technology
25
Page 2 of 26
INTRODUCTION
26
The global demand for water is projected to increase by 55% over the next 30 years as a
27
result of population growth, urbanization, economic development, and climate change.1
28
Inadequate sanitation in the developing world, combined with an increasing demand to reuse
29
wastewater in developed countries, has resulted in an expanding set of contaminants that
30
negatively impact water resources and public health. Both the need to provide safe drinking
31
water from complex sources polluted by multiple contaminants and environmental concerns
32
about conventional treatment methods have motivated the development of novel membrane
33
technologies in recent decades.2-5 Nanofiltration (NF) and reverse osmosis (RO) are membrane
34
processes commonly used for drinking water treatment because they offer an effective single-
35
step barrier that removes both pathogens and most organic and inorganic contaminants.
36
For several decades, thin-film composite (TFC) membranes with polyamide (PA) active
37
layers 50-250 nm thick have dominated the pressure-driven membrane technology sector.6-8
38
These PA active layers are fabricated with interfacial polymerization (IP) reaction methods,
39
which are advantageous because of their scalability for commercial production and capacity to
40
produce thin (
