Reversible clustering of pH- and temperature-responsive Janus magnetic nanoparticles

被引：137

作者：

Isojima, Tatsushi ^{[1
]}

Lattuada, Marco ^{[3
]}

Vander Sande, John B. ^{[2
]}

Hatton, T. Alan ^{[1
]}

机构：

[1] MIT, Dept Chem Engn, Cambridge, MA 02139 USA

[2] MIT, Dept Mat Sci & Engn, Cambridge, MA 02139 USA

[3] Swiss Fed Inst Technol, Inst Chem & Bioengn, HCI F135, CH-8093 Zurich, Switzerland

来源：

ACS NANO | 2008年 / 2卷 / 09期

关键词：

functional nanoparticle; Janus nanoparticle; magnetite (Fe(3)O(4)); self-assembly;

D O I：

10.1021/nn800089z

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

Janus nanoparticles have been synthesized consisting of similar to 5 nm magnetite nanoparticles coated on one side with a pH-dependent and temperature-independent polymer (poly(acrylic acid), PAA), and functionalized on the other side by a second (tail) polymer that is either a pH-independent polymer (polystyrene sodium sulfonate, PSSNa) or a temperature-dependent polymer (poly(N-isopropyl acrylamide), PNIPAM). These Janus nanoparticles are dispersed stably as individual particles at high pH values and low temperatures, but can self-assemble at low pH values (PSSNa) or at high temperatures (> 31 degrees C) (PNIPAM) to form stable dispersions of clusters of approximately 80-100 nm in hydrodynamic diameter. The Janus nanoparticle compositions were verified using FTIR and XPS, and their structures observed directly by TEM. Their clustering behavior is analyzed by dynamic light scattering and zeta potential measurements.

引用

页码：1799 / 1806

页数：8

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