TY - JOUR
T1 - Characterization on magnetophoretic velocity of the cluster of submicron-sized composite particles applicable to magnetic separation and purification
AU - Kohama, Natsuki
AU - Suwabe, Chika
AU - Ishii, Haruyuki
AU - Hayashi, Kumiko
AU - Nagao, Daisuke
N1 - Funding Information:
This research was mainly supported by the Ministry of Education, Culture, Sports, Science and Technology (JSPS KAKENHI Grant Numbers 17K19020 and 17H02744 ).
Publisher Copyright:
© 2019 Elsevier B.V.
PY - 2019/5/5
Y1 - 2019/5/5
N2 - Submicron-sized magnetic composite particles with low polydispersity were prepared to examine the relation between the magnetophoretic velocity and the clustering state of composite particles under application of magnetic field. Five different magnetic composite particles in a size range of 70–470 nm were employed to measure the magnetophoretic velocity. Since the smallest composite particles had colloidal stability insufficient to measure the magnetophoretic velocity, the rest of composite particles was observed with an optical microscope under a magnetic field. Magnetic composite particles larger than 300 nm formed pearl chains of magnetic composite particles under the magnetic field. The velocity of pearl chains was increased by the number of composite particles in a pearl chain. The ratio of the velocity of pearl chain to that of a single composite particle was employed to quantify the increase in magnetophoretic velocity with the clustering of composite particles. The velocity ratio for the large particles was in good agreement with the theoretical one correlated with the number of composite particles in a pearl chain. On the other hand, composite particles smaller than 200 nm formed random clusters of composite particles. Since a single small particle could not be directly observed with the optical microscope, the number of small composite particles in a cluster was estimated with an assumption that the small composite particles formed an ellipsoidal shape with a random filling factor of 0.64. Similarly to the large composite particles, the velocity ratio of random clusters composed of the small composite particles was also increased by clustering the small MCPs. Comparison of the velocity ratios between different composite particles indicated that the clusters of small particles have a tendency of exhibiting velocity ratios higher than that of large particles. A good correlation of the velocity ratio with the estimated number of composite particles in a cluster revealed that the number of composite particles is an important factor to quantify the magnetophoretic velocity of random clusters.
AB - Submicron-sized magnetic composite particles with low polydispersity were prepared to examine the relation between the magnetophoretic velocity and the clustering state of composite particles under application of magnetic field. Five different magnetic composite particles in a size range of 70–470 nm were employed to measure the magnetophoretic velocity. Since the smallest composite particles had colloidal stability insufficient to measure the magnetophoretic velocity, the rest of composite particles was observed with an optical microscope under a magnetic field. Magnetic composite particles larger than 300 nm formed pearl chains of magnetic composite particles under the magnetic field. The velocity of pearl chains was increased by the number of composite particles in a pearl chain. The ratio of the velocity of pearl chain to that of a single composite particle was employed to quantify the increase in magnetophoretic velocity with the clustering of composite particles. The velocity ratio for the large particles was in good agreement with the theoretical one correlated with the number of composite particles in a pearl chain. On the other hand, composite particles smaller than 200 nm formed random clusters of composite particles. Since a single small particle could not be directly observed with the optical microscope, the number of small composite particles in a cluster was estimated with an assumption that the small composite particles formed an ellipsoidal shape with a random filling factor of 0.64. Similarly to the large composite particles, the velocity ratio of random clusters composed of the small composite particles was also increased by clustering the small MCPs. Comparison of the velocity ratios between different composite particles indicated that the clusters of small particles have a tendency of exhibiting velocity ratios higher than that of large particles. A good correlation of the velocity ratio with the estimated number of composite particles in a cluster revealed that the number of composite particles is an important factor to quantify the magnetophoretic velocity of random clusters.
KW - Clustering
KW - Magnetic composite particles
KW - Magnetophoresis
KW - Monodispersity
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U2 - 10.1016/j.colsurfa.2019.02.011
DO - 10.1016/j.colsurfa.2019.02.011
M3 - Article
AN - SCOPUS:85061367981
VL - 568
SP - 141
EP - 146
JO - Colloids and Surfaces A: Physicochemical and Engineering Aspects
JF - Colloids and Surfaces A: Physicochemical and Engineering Aspects
SN - 0927-7757
ER -