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Development of Aqueous Size Exclusion Chromatography Conditions to Characterize Polyzwitterion-block-N-isopropyl acrylamide Copolymers

Published

Author(s)

Phillip Pickett, Sara Orski, Vivek Prabhu

Abstract

Block copolymers that exhibit both an upper critical solution temperature (UCST) and a lower critical solution temperature (LCST) are difficult to characterize due to inherent solubility difference between the two blocks. For example, accurate determination of both the molar mass and molar mass distribution (Ɖ) is challenging for polyzwitterion-block-N-isopropyl acrylamide (NIPAM) copolymers in aqueous solutions due to self-assembly. However, there are a few examples of using size exclusion chromatography (SEC) for characterization, in which hexafluoro isopropanol (HFIP) is used in all cases. Yet, researchers are hesitant to use this technique due to how expensive and hazardous HFIP is. Therefore, alternatives to HFIP for SEC analysis would be desirable. Here, a systematic methodology is demonstrated to apply aqueous SEC using several solvent conditions to enable the elution of polyzwitterion-block-NIPAM copolymers on Agilent PolarGel and Tosoh TSKgel column sets. These SEC conditions include 0.2 M KI in water on the PolarGel columns and 0.2 M KI/ 30% DMF in water on the PolarGel and TSKgel columns. These aqueous systems can be utilized for the characterization of similar water-soluble block copolymers that are relevant for drug delivery and other biomedical applications.
Citation
Journal of Chromatography A
Volume
1628

Keywords

Aqueous Size Exclusion Chromatography, poly(NIPAM), poly(sulfobetaine), block copolymers, Zwitterionic copolymers, UCST, LCST

Citation

Pickett, P. , Orski, S. and Prabhu, V. (2020), Development of Aqueous Size Exclusion Chromatography Conditions to Characterize Polyzwitterion-block-N-isopropyl acrylamide Copolymers, Journal of Chromatography A, [online], https://doi.org/10.1016/j.chroma.2020.461424 (Accessed April 16, 2024)
Created July 21, 2020, Updated January 20, 2023