Distribution of CoFe2O4 Nanoparticles Inside PNIPAM-Based Microgels of Different Cross-linker Distributions.
Distribution of CoFe2O4 Nanoparticles Inside PNIPAM-Based Microgels of Different Cross-linker Distributions.
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CoFe2O4 纳米粒子在不同交联剂分布的 PNIPAM 基微凝胶内的分布。
DOI：
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发表时间：
2019
影响因子：
3.3
通讯作者：
R. von Klitzing
中科院分区：
文献类型：
--
作者：
Marcus U Witt;Stephan Hinrichs;Nadir Möller;Sebastian Backes;B. Fischer;R. von Klitzing
本研究的目的是定制带正电的聚(N-异丙基丙烯酰胺-共烯丙基胺)(P(NIPAM-co-AA))微凝胶的内部结构，以便更好地控制带负电的磁性铁酸钴(CoFe2O4@CA)纳米粒子(MNPs)在微凝胶中的分布。因此，微凝胶的合成遵循两种不同的策略：(一锅法)间歇法和加料法，前者导致微凝胶核心中交联剂密度较高，后者补偿交联剂和单体不同的反应动力学。后者有望导致均匀的交联剂分布。有关交联剂分布的信息是通过原子力显微镜的压痕实验测量弹性模量来间接获得的。间歇法在微凝胶的中心产生较高的弹性模量，表明微凝胶为核/壳结构，而加料方法使整个微凝胶的弹性模量保持恒定。用透射电子显微镜研究了MNPs的负载量及其分布。透射电子显微镜图像显示，两种微凝胶的MNP分布有很大差异，这与两种微凝胶中交联剂的分布有关。间歇法微凝胶的芯层中的MnP浓度较低。加料方法微凝胶显示出MNPs在微凝胶中的分布更加均匀。后者还表现出较强的电荷反转，这暗示着加料方法微凝胶的载药量更高。动态光散射和电泳迁移率测量表明，对于这两种类型的微凝胶，负载MNPs后，其温度敏感性保持不变。
The aim of this study is to tailor the inner structure of positively charged poly-( N-isopropylacrylamid- co-allylamine) (P(NIPAM- co-AA)) microgels for a better control of the distribution of negatively charged magnetic cobaltferrite (CoFe2O4@CA) nanoparticles (MNPs) within the microgels. Therefore, two different strategies are followed for the microgel synthesis: the (one pot) batch method which leads to a higher cross-linker density in the microgel core and the feeding method which compensates different reaction kinetics of the cross-linker and the monomers. The latter one is expected to result in a homogeneous cross-linker distribution. Information about the cross-linker distribution is indirectly gained by measuring the elastic modulus via indentation experiments with an atomic force microscope. While the batch method results in a higher elastic modulus in the center of the microgel indicating a core/shell structure, the feeding method leads to a constant elastic modulus over the whole microgel. The loading with MNPs and their distribution are studied with transmission electron microscopy (TEM). The TEM images show a large difference in the MNP distribution which is correlated to the cross-linker distribution of both types of microgels. The batch method microgel has a low MNP concentration in the core. The feeding method microgel shows a much more homogeneous distribution of MNPs across the microgel. The latter one also shows a stronger charge reversal which is a hint for a higher loading of the feeding method microgel. Dynamic light scattering and electrophoretic mobility measurements demonstrate that for both types of microgels, the temperature sensitivity is preserved after loading with MNPs.
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影响因子：
3.3
作者：
Gawlitza, Kornelia;Turner, Sarah T.;von Klitzing, Regine
通讯作者：
von Klitzing, Regine
影响因子：
3.3
作者：
Backes, Sebastian;Witt, Marcus U.;von Klitzing, Regine
通讯作者：
von Klitzing, Regine
影响因子：
3.9
作者：
Lange, Holger;Juarez, Beatriz H.;Knorr, Andreas
通讯作者：
Knorr, Andreas
影响因子：
3.9
作者：
Christau, Stephanie;Moeller, Tim;von Klitzing, Regine
通讯作者：
von Klitzing, Regine
影响因子：
5
作者：
Burmistrova, Anna;Richter, Marcel;von Klitzing, Regine
通讯作者：
von Klitzing, Regine