title: Hydrothermal Conditioning of Physical Hydrogels Prepared from a Midblock-Sulfonated Multiblock Copolymer.
abstract: Since nanostructured amphiphilic macromolecules capable of affording high ion and water transport are becoming increasingly important in a wide range of contemporary energy and environmental technologies, the swelling kinetics and temperature dependence of water uptake are investigated in a series of midblock-sulfonated thermoplastic elastomers. Upon self-assembly, these materials maintain a stable hydrogel network in the presence of a polar liquid. In this study, real-time water-sorption kinetics in copolymer films prepared by different casting solvents are elucidated by synchrotron small-angle X-ray scattering and gravimetric measurements, which directly correlate nanostructural changes with macroscopic swelling to establish fundamental structure-property behavior. By monitoring the equilibrium swelling capacity of these materials over a range of temperatures, an unexpected transition in the vicinity of 50 °C has been discovered. Depending on copolymer morphology and degree of sulfonation, hydrothermal conditioning of specimens to temperatures above this transition permits retention of superabsorbent swelling at ambient temperature.
authors.affiliation: Department of Chemical & Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: Kenneth P
authors.initials: KP
authors.lastname: Mineart
authors.affiliation: Department of Materials Science & Engineering, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: Joshua D
authors.initials: JD
authors.lastname: Dickerson
authors.affiliation: Department of Chemical & Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: Dillon M
authors.initials: DM
authors.lastname: Love
authors.affiliation: X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA.
authors.forename: Byeongdu
authors.initials: B
authors.lastname: Lee
authors.affiliation: X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL, 60439, USA.
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Zuo
authors.affiliation: Department of Chemical & Biomolecular Engineering, North Carolina State University, Raleigh, NC, 27695, USA.|Department of Materials Science & Engineering, North Carolina State University, Raleigh, NC, 27695, USA.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Spontak
mesh_terms: D000327:Adsorption; D020100:Hydrogels / Q000138:chemical synthesis* / Q000737:chemistry; D007700:Kinetics; D049329:Nanostructures / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D020100:Hydrogels; D011108:Polymers; D014867:Water
keywords: block ionomer; hydrothermal conditioning; multiblock copolymer; physical hydrogel; thermoplastic elastomer