Direct visualization of nano and microscale polymer morphologies in as-prepared and dialyzed polyampholyte hydrogels by electron microscopy techniques


The structure of polymer networks in hydrogels determines the properties. In this study, we investigated the structure of a charge-balanced polyampholyte, poly(4-vinylbenzenesulfonate-co-[3-(methacryloylamino) propyl] trimethylammonium chloride). From as-prepared samples, nanoscale globules were visualized in polyampholyte hydrogels for the first time. The impact of dialyses processes on polymer structures were also studied. In deionized water, salt ions are leached out, thus polymer chains undergo zipping process to form cellular structure with micrometer-thick polymer walls that allow mechanical toughness to the hydrogel. Samples dialyzed in 6 M potassium hydroxide solution did not show such cellular structure, as in the case of as-prepared samples.

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The authors gratefully acknowledge funding from a NSERC DG (RGPIN 435914). Material characterization was partly done in the shared facility of the NanoFAB in the Faculty of Engineering at the University of Alberta. The use of the Advanced Photon Source was supported by the US DOE under Contract DE-AC02-06CH11357.

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Correspondence to Hyun-Joong Chung.

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Li, X., Charaya, H., Nguyen Thanh Tran, T. et al. Direct visualization of nano and microscale polymer morphologies in as-prepared and dialyzed polyampholyte hydrogels by electron microscopy techniques. MRS Communications 8, 1079–1084 (2018).

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