Chitosan-coated magnetic nanoparticles prepared in one-step by precipitation in a high-aqueous phase content reverse microemulsion

• Published in: Molecules (Basel, Switzerland) Vol. 19; no. 7; pp. 9273 - 9287
• Main Authors: Pineda, María Guadalupe, Torres, Silvia, López, Luis Valencia, Enríquez-Medrano, Francisco Javier, de León, Ramón Díaz, Fernández, Salvador, Saade, Hened, López, Raúl Guillermo
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 02-07-2014; MDPI
• Subjects: Aqueous solutions; Chitosan; Chitosan - chemistry; chitosan magnetic nanoparticles one-step; Chlorides - chemistry; Crystallites; Emulsions; Ferric Compounds - chemistry; Ferrous Compounds - chemistry; Fractional Precipitation; heavy metal ion removal; high productivity microemulsion precipitation; Hydrogen-Ion Concentration; Magnetic Phenomena; Magnetization; Metal Nanoparticles - chemistry; Microemulsions; Nanoparticles; Particle Size; Particle size distribution; Precipitation; Productivity; Solvents - chemistry; Surfactants; Thin films; Water - chemistry
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules19079273

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.