Title :
Magnetic properties of Fe3O4 nanoparticles encapsulated with poly(D,L lactide-Co-glycolide)
Author :
Jeong, Jong-Ryul ; Lee, Seung-Jun ; Kim, Jong-Duk ; Shin, Sung-Chul
Author_Institution :
Dept. of Phys., Korea Adv. Inst. of Sci. & Technol., Daejeon, South Korea
fDate :
7/1/2004 12:00:00 AM
Abstract :
We have investigated the magnetic properties of Fe3O4 nanoparticles encapsulated with poly(D,L lactide-Co-glycolide) (PLGA) prepared by an emulsification-diffusion technique. The size of nanoparticles was reduced down to 90 nm through the optimization of the preparation condition such as homogenizer and agitator speed. Zero-field-cooled (ZFC)/field-cooled (FC) magnetization, magnetic hysteresis, and relaxation measurement were performed using a superconducting quantum interference device (SQUID) magnetometer from 5 K to 300 K to investigate the magnetic properties of nanoparticles. The SQUID measurements show superparamagnetism of nanoparticles with a blocking temperature of 120 K. By measuring the magnetic relaxation of the magnetization at 5 K, we obtained magnetic viscosity of PLGA-encapsulated Fe3O4 nanoparticles.
Keywords :
SQUID magnetometers; magnetic particles; magnetic relaxation; nanoparticles; organic compounds; paramagnetism; 5 to 300 K; 90 nm; Fe3O4; MRI contrast agent; PLGA; PLGA-encapsulated nanoparticles; SQUID magnetometer; agitator speed; blocking temperature; emulsification-diffusion technique; encapsulated nanoparticles; field-cooled magnetization; homogenizer speed; magnetic hysteresis; magnetic nanoparticles; magnetic properties; magnetic relaxation; magnetic resonance imaging; magnetic viscosity; poly(D,L lactide-Co-glycolide); preparation condition optimization; relaxation measurement; superconducting quantum interference device; superparamagnetic particle; zero-field-cooled magnetization; Iron; Magnetic field measurement; Magnetic hysteresis; Magnetic properties; Magnetization; Nanoparticles; Performance evaluation; SQUIDs; Superconducting devices; Superconducting magnets; Blocking temperature; D,L lactide-Co-glycolide; MRI; PLGA; contrast agent; emulsification-diffusion technique; magnetic nanoparticles; magnetic resonance imaging; poly; superparamagnetic particle;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2004.829265
