Chapter 13 - Magnetic composites: fundamentals, synthesis, and applications

Abstract

Magnetic separations are a contemporary and efficient solution to a variety of industrial and environmental issues. It was developed as an environmental protection process for treating steel mill's effluent, separating mining ores, refining sewage and radioactive waste, filtering cooling water from nuclear reactors, and purifying drinking water. This chapter describes recent advances in the search for new magnetic materials as adsorbents for metal recovery and contamination control and their application in microfluidic and sequential injection systems. It focuses on the magnetic classification of materials and magnetic separation techniques. Magnetic compounds, their synthesis procedures, protection routs, functionalization ways, and application as well as the magnetic properties of nanostructures are also highlighted. Substantial advances have been made in the development of magnetic nanoparticles (MNPs) by upgrading and varying their fabrication methods such as coprecipitation, thermal breakdown, sonochemical creation, polyols, hydrothermal synthesis, and laser pyrolysis. Corrosion protection remains the main challenge, so the focus is on suitable protection strategies. Passivation and surface stabilization through polymer, silica, noble metal, and carbon coatings for MNPs are discussed as protective approaches. The accurately protected MNPs can be used to fabricate several functional systems, and their industrial, environmental, and biotechnology applications are concisely discussed.