Optimal plasticizer content for magnetic elastomers used for cell culture substrate

The effect of a magnetic field on the water contact angle for magnetic elastomers with various plasticizer contents was investigated. At a plasticizer content below 60 wt %, there was no change in contact angle when a magnetic field of 370 mT was applied. For magnetic elastomers with a plasticizer content above 65 wt %, a change in contact angle of approximately 8.0° was observed (e.g. 38° at 0 mT and 46° at 370 mT for 65 wt % plasticizer content). Dynamic viscoelastic measurements showed that magnetic elastomers with a plasticizer content below 60 wt % demonstrate the magnetorheological (MR) effect with changes in storage modulus higher than ³1 MPa. Atomic force microscopy for magnetic elastomer with a plasticizer content of 50 wt % revealed that the averaged Young’s modulus was 233 « 52.1 kPa at 370 mT and 83 « 5.4 kPa at 0 mT, indicating that the MR effect is caused not only on a bulk but also on a mesoscopic scale. Magnetic elastomers specialized for cell culture were obtained by optimizing the plasticizer content, that exhibit the MR effect with changes in storage modulus from 1.3