Low-dimensional nanoparticle clustering in polymer micelles and their transverse relaxivity rates.
Low-dimensional nanoparticle clustering in polymer micelles and their transverse relaxivity rates.
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DOI：
10.1021/nn400824b
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发表时间：
2013-07-23
期刊：
影响因子：
17.1
通讯作者：
Park SJ
中科院分区：
文献类型：
--
作者：
Hickey RJ;Meng X;Zhang P;Park SJ
氧化铁纳米粒子的一维或二维阵列在两亲性聚合物的胶体组件中形成。电子断层扫描成像显示，纳米颗粒排列成磁胶束中的一维串或磁核/壳组件中的二维片。独特的定向组装行为归因于相对于纳米颗粒-聚合物相互作用的颗粒间相互作用，这通过改变用于溶液相自组装的共溶剂来调节。具有不同结构参数的磁核/壳组件是由一系列不同尺寸的合成纳米颗粒形成的。确定了一系列不同组件的横向磁弛豫率 (r2)，以检查纳米颗粒排列对磁弛豫率的影响，以了解其在 MRI 中的潜在应用。结果表明，聚合物胶束中纳米粒子的组装结构显着影响周围水的r2，为控制磁弛豫率提供了一种方法。
One- or two-dimensional arrays of iron oxide nanoparticles were formed in colloidal assemblies of amphiphilic polymers. Electron tomography imaging revealed that nanoparticles are arranged into one-dimensional strings in magneto-micelles or two-dimensional sheets in magneto-core/shell assemblies. The distinct directional assembly behavior was attributed to the interparticle interaction relative to the nanoparticle–polymer interaction, which was modulated by varying the cosolvent used for the solution phase self-assembly. Magneto-core/shell assemblies with varying structural parameters were formed with a range of different sized as-synthesized nanoparticles. The transverse magnetic relaxivity rates (r2) of a series of different assemblies were determined to examine the effect of nanoparticle arrangement on the magnetic relaxivity for their potential applications in MRI. The results indicated that the assembly structure of nanoparticles in polymer micelles significantly affects the r2 of surrounding water, providing a way to control magnetic relaxivity.