Polyacrylamide Ferrogels with Ni Nanowires

• Published in: Materials Vol. 12; no. 16; p. 2582
• Main Authors: Safronov, Alexander P, Stadler, Bethanie J H, Um, Joseph, Zamani Kouhpanji, Mohammad Reza, Alonso Masa, Javier, Galyas, Andrey G, Kurlyandskaya, Galina V
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 13-08-2019; MDPI
• Subjects: Aluminum oxide; Anisotropy; Aspect ratio; Composite materials; Domain walls; electrochemical deposition; Electrodes; Electrolytes; ferrogels; Free radical polymerization; Free radicals; Hydrogels; Hysteresis loops; Magnetic fields; Magnetic properties; Magnetization reversal; nanomagnetism; Nanoparticles; Nanowires; Nickel; nickel nanowires; Photon correlation spectroscopy; Polyacrylamide; Polymerization; Scanning electron microscopy; Scientific imaging; Sedimentation & deposition; United States > US; Germany; ferrogels; electrochemical deposition; nanomagnetism; nickel nanowires
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma12162582

Nickel magnetic nanowires (NWs) have attracted significant attention due to their unique properties, which are useful for basic studies and technological applications, for example in biomedicine. Their structure and magnetic properties were systematically studied in the recent years. In this work, Ni NWs with high aspect ratios (length/diameter ~250) were fabricated by electrodeposition into commercial anodic aluminum oxide templates. The templates were then etched and the NWs were suspended in water, where their hydrodynamic size was evaluated by dynamic light scattering. The magnetic response of these NWs as a function of an external magnetic field indicates a dominant shape anisotropy with propagation of the vortex domain wall as the main magnetization reversal process. The suspension of Ni NWs was used in the synthesis of two types of polyacrylamide ferrogels (FGs) by free radical polymerization, with weight fractions of Ni NWs in FGs of 0.036% and 0.169%. The FGs were reasonably homogeneous. The magnetic response of these FGs (hysteresis loops) indicated that the NWs are randomly oriented inside the FG, and their magnetic response remains stable after embedding.