Abstract
The relationship between the diameter or the number density of magnetic-particle columns and the magnetorheological effect has been investigated using carrageenan gels containing iron oxide particles. The diameter and the number density of the columns were changed by magnetic fields applied while gelation. The column diameter increased with the magnetic field, and the number density of columns decreased with the field. The Young's modulus of the gels synthesized at higher magnetic fields than 0.5 T was approximately 2 MPa, which was higher than the gel at 0.05 T. In addition, the change in Young’s modulus for the gel synthesized at 0.5 T was 0.19 MPa upon magnetization, which is 8 times larger than that at 0.05 T. The results revealed that the gels with thick columns demonstrate high Young's modulus and remarkable magnetorheological effect.
