title: A Microporous Amic Acid Polymer for Enhanced Ammonia Capture.
abstract: Amic acids, consisting of carboxylic acids and amides, are often utilized as intermediates that can further undergo a dehydration-cyclization step to yield polymeric cyclic imides. Compared with imide-based materials, the presence of Brønsted acidic groups and multiple hydrogen-bond donors and acceptors in materials incorporating amic acids opens up the possibility for a variety of host-guest interactions. Here we report a facile and catalyst-free synthesis of a Brønsted acidic porous poly(amic acid) (PAA) and present its NH3uptake properties using gas adsorption and breakthrough measurements. Simple addition of water as a cosolvent to a mixture of tetrakis(4-aminophenyl)methane and pyromellitic anhydride resulted in the formation of PAA in almost quantitative yield. Further mechanistic studies with model compounds revealed the importance of additive water to generate amic acid species selectively without forming cyclic imides at high temperatures. Gas adsorption isotherms and breakthrough curves obtained under dry and humid conditions demonstrate the enhanced NH3uptake in the case of PAA compared with the related polycyclic imide at both low and high pressures. Furthermore, the results of adsorption/desorption cycling experiments provide insights into the strength of the interaction between ammonia and the polymers.
authors.affiliation: Department of Chemistry, University of California , Berkeley, California 94720, United States.|Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.|Department of Chemistry, University of Copenhagen , 2100 Copenhagen, Denmark.
authors.forename: Ji-Woong
authors.identifier: http://orcid.org/0000-0001-6177-4569
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Department of Chemistry, University of California , Berkeley, California 94720, United States.|Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Gokhan
authors.initials: G
authors.lastname: Barin
authors.affiliation: Edgewood Chemical Biological Center, U.S. Army Research, Development, and Engineering Command , 5183 Blackhawk Road, Aberdeen Proving Ground, Maryland 21010, United States.
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Peterson
authors.affiliation: Department of Chemical and Biological Engineering, University of California , Berkeley, California 94720, United States.
authors.forename: Jun
authors.initials: J
authors.lastname: Xu
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.|Department of Chemical and Biological Engineering, University of California , Berkeley, California 94720, United States.
authors.forename: Kristen A
authors.initials: KA
authors.lastname: Colwell
authors.affiliation: Department of Chemistry, University of California , Berkeley, California 94720, United States.|Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.|Department of Chemical and Biological Engineering, University of California , Berkeley, California 94720, United States.
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Long
keywords: ammonia; gas capture; poly(amic acid); polycyclic imide; porous polymers