▎ 摘 要
Usually, positive magnetoresistance (PMR) is observed in graphene foam (GF) under all temperature and magnetic field range. Herein, large negative magnetoresistance is observed under a temperature range 300-200 K which switches to PMR under a temperature range 200-5 K in graphene foam (GF)Ecoflex (R) specimen. The GF-Ecoflex (R) shows NMR in highly crosslinked specimen, while lightly crosslinked shows PMR at room temperature. This indicates that the sign of magnetoresistance can be controlled by controlling viscoelasticity of Ecoflex (R) in GF-Ecoflex (R) specimens, which is very useful for wearable magnetoelectronics. (C) 2019 Elsevier B.V. All rights reserved.