Optical, magnetic and dielectric properties of non-liquid crystalline elastomers doped
Antonio Martins Figueiredo Neto
,M. H. Godinho
Instituto de Física, Universidade de São Paulo
Faculdade de Ciências e Tecnologia e CENIMAT, Universidade Nova de Lisboa,
2Liquid Crystal Institute, Kent State University
Magnetic nanoparticles from magnetic colloidal suspensions were incorporated in the urethane/urea elastomer (PU/PBDO) by swelling fully crosslinked elastomer samples with a toluene and ferrofuid mixture. It is shown that ferrofuid grains can be efficiently incorporated into the matrix of elastomers. The dependence of the birefringence of both the pure and ferrofuid-doped elastomer samples on strain is linear. The ratio of birefringence to strain of the ferrofuid-doped samples is greater than that of the pure elastomer samples, indicating that ferrofuid grains are
oriented by the strained polymer network. We propose that this is strain-induced orientation is due to the shape anisotropy of the nanoparticles.