Surface modification of γ-Fe₂O₃ nanoparticles with aminopropylsilyl groups and interparticle linkage with α,ω- dicarboxylic acids

An investigation was carried out on the surface modification of γ-Fe₂O₃ nanoparticles with aminopropylsilyl (APS) groups in 3-aminopropyltriethoxysilane and the interparticle linkage with α,ω-dicarboxylic acids (succinic acid and suberic acid) through the terminal amino groups of APS moiety at the surface of γ-Fe ₂O₃ nanoparticles. It was demonstrated that the change in interparticle distance caused by these surface modifications influences the magnetic property of the composites. When γ-Fe₂O₃ nanoparticles were modified with APS groups, coercivity increased and when they were further modified with α,ω-dicarboxylic acids, the larger decrease in coercivity was observed with the longer dicarboxylic acid.