Browse Journals

Time profiles of the storage modulus at 2Hz were measured for uncross-linked and cross-linked magnetic elastomers and the effect of cross-linking on the alignment time of magnetic particles was discussed. The time profiles of the storage modulus for both uncross-linked and cross-linked elastomers can be fitted by a linear combination of two exponential functions with distinct characteristic times showing the fast and slow processes for particles alignment. The averaged characteristic time for the fast process was determined to be  for uncross-linked elastomers and  for cross-linked one. The averaged characteristic time for the slow process was around  for uncross-linked elastomers and  for cross-linked one. Using a parallel model, the overall characteristic time at 50mT was determined to be approximately 7.0s for cross-linked elastomers, which was a half of that for uncross-linked elastomers. However, at magnetic fields above 200mT, there was no clear difference in the overall characteristic time for uncross-linked and cross-linked elastomers. A possible mechanism for the fast chain formation observed in the cross-linked magnetic elastomers is discussed. 

elastomer, magnetic elastomer, magnetorheology, stimuli-responsive gel.