Magnetoresponsive polymers

Polymers that respond to the presence or absence of magnetic fields can exist as free chains in solution, can be immobilized to surfaces, or can be cross-linked 

Most examples of magnetoresponsive polymer systems involve noncovalent interactions between polymer chains and magnetic particles [125, 127, 128]. However, recent synthetic advances have facilitated covalent immobilization of polymer chains directly to the surface of magnetic particles. Pyun et al. have employed nitroxide-mediated radical polymerization (NMP) to prepare well-defined polymeric surfactants that stabilize magnetic nanoparticles. By casting nanoparticle 

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It is difficult to pinpoint the specific macromolecular characteristics that allow response to ultrasound. Many polymers of varying composition, architecture, polarity, Tg, and so on, have been demonstrated to alter their behavior when exposed to ultrasonic stimulation. As opposed to magnetoresponsive polymers, foreign additives are not required [136]. However, polymers existing in a few specific physical states are mostly considered. Polymeric systems that respond to ultrasound have generally been gels or other nonswoUen macroscopic solids, polymeric micelles, or layer-by-layer (LbL) coated microbubbles. 

Physical stimuli will affect the energy level and/or distribution within the materials and change the molecular interactions at a critical onset point (Gil and Hudson, 2004). Within the scope of this chapter, photoresponsive, thermoresponsive, electrorespon-sive, and magnetoresponsive polymers that respond to variation of light, temperature, electrical field, or magnetic field, respectively, will be discussed. Nevertheless, other... 

There is a growing interest in the use of magnetic fields as the selective stimuli for the development, fabrication, and application of smart materials. Magnetoresponsive polymers show a magnetic-active effect in response to a magnetic field. 

G.U. Marten, T. Gelbrich, H. Ritter, and A.M. Schmidt, A magnetoresponsive drug dehv-ery system via P-cyclodextrin functionalized magnetic polymer brushes. Magnetics, IEEE Transactions, 49 (1), 364-372,2012. 

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