Bingquan Peng

Abstract Hydrogels do not have observable responses to external magnetic fields as they are conventionally thought to be diamagnetic. These materials require additives for magnetic control, limiting biomedical applications due to potential side effects. Here we show that calcium cations can induce strong paramagnetism of hydrogels rich in groups containing carbon–oxygen double bonds, including alginate, carboxymethyl chitosan, polyacrylamide and N-isopropyl acrylamide.

1 Introduction 2D graphene oxide (GO) membranes have attracted substantial interest for their precise ionic sieving, with applications in water desalination and purification,[1-6] gas and ion separation,[7-10] biosensors,[11] proton conductors,[12] lithium-based batteries[13] and super-capacitors.[14] Both an ultrahigh water permeance and capability of precise sieving of GO membranes[15-18] are crucial for their extensive future filtration applications.

Research Article This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record.