Magnetic properties of polystyrene‐ b ‐poly(2‐hydroxylethyl methacrylate)/metal hybrids

Hybrids, which were composed of the amphiphilic diblock copolymer polystyrene‐ b ‐poly(2‐hydroxylethyl methacrylate) (PSt‐ b ‐PHEMA) and nickel, cobalt, or a nickel–cobalt alloy, were characterized with infrared absorption spectroscopy and ultraviolet–visible (UV–vis) absorption spectroscopy. UV–vis spectroscopy analysis showed that a redshift happened after the PSt‐ b ‐PHEMA/metal‐ion complexes were reduced by KBH 4 . The PSt‐ b ‐PHEMA/nickel–cobalt alloy hybrids had the biggest redshift [difference of the UV‐vis absorption wavelength between (PSt‐ b ‐PHEMA)/metal ion complex and (PSt‐ b ‐PHEMA)/metal hybrids (Δλ m = 19.9 nm)]. In comparison with the PSt‐ b ‐PHEMA/nickel hybrids (Δλ m = 3.5 nm) and PSt‐ b ‐PHEMA/cobalt hybrids (Δλ m = 9.0 nm). The magnetic properties of PSt‐ b ‐PHEMA/metal were studied with vibrating sample magnetometry. The results of magnetic hysteresis loop studies showed that the obtained PSt‐ b ‐PHEMA/metal hybrids could be categorized as ferromagnetic materials. The results showed that the magnetic susceptibility decreased with increasing temperature in the range of 150–400 K and increased with increasing temperature above 400 K. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006