Chitosan-Coated Magnetic Nanoparticles Prepared in One-Step by Precipitation in a High-Aqueous Phase Content Reverse Microemulsion

• Main Authors: María Guadalupe Pineda, Silvia Torres, Luis Valencia López, Francisco Javier Enríquez-Medrano, Ramón Díaz de León, Salvador Fernández, Hened Saade, Raúl Guillermo López
• Format: Article
• Language: English
• Published: MDPI AG 2014-07-01
• Series: Molecules
• Subjects: chitosan magnetic nanoparticles one-step; heavy metal ion removal; high productivity microemulsion precipitation
• Online Access: http://www.mdpi.com/1420-3049/19/7/9273

Chitosan-coated magnetic nanoparticles (CMNP) were prepared in one-step by precipitation in a high-aqueous phase content reverse microemulsion in the presence of chitosan. The high-aqueous phase concentration led to productivities close to 0.49 g CMNP/100 g microemulsion; much higher than those characteristic of precipitation in reverse microemulsions for preparing magnetic nanoparticles. The obtained nanoparticles present a narrow particle size distribution with an average diameter of 4.5 nm; appearing to be formed of a single crystallite; furthermore they present superparamagnetism and high magnetization values; close to 49 emu/g. Characterization of CMNP suggests that chitosan is present as a non-homogeneous very thin layer; which explains the slight reduction in the magnetization value of CMNP in comparison with that of uncoated magnetic nanoparticles. The prepared nanoparticles show high heavy ion removal capability; as demonstrated by their use in the treatment of Pb2+ aqueous solutions; from which lead ions were completely removed within 10 min.