Sterical ligand stabilization of nanocrystals versus electrostatic shielding by ionic compounds: a principle model study with TEM and XPS
Sterical ligand stabilization of nanocrystals versus electrostatic shielding by ionic compounds: a principle model study with TEM and XPS
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纳米晶体的空间配体稳定与离子化合物的静电屏蔽：TEM 和 XPS 的原理模型研究
DOI：
10.1039/c6ra27454d
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发表时间：
2017
期刊：
影响因子：
3.9
通讯作者：
M. Osmić
中科院分区：
文献类型：
--
作者：
L. Mohrhusen;M. Osmić
胶体金属纳米颗粒通常是通过液相还原金属盐前驱体化合物制备的。为了防止结块，使用有机封盖剂。通常，当离子化合物存在于混合物中时，它可能会被忽略。然而，我们将证明离子吸附剂在大小和生长控制中起关键作用。我们通过x射线光电子能谱（XPS）和透射电子显微镜（TEM）研究了不同胺配体的金纳米颗粒的两种竞争稳定机制。从单相室温合成开始，获得了金纳米晶体。结果表明，根据配体分子的性质，这种稳定是空间屏蔽和静电屏蔽的结合。我们可以通过简单的液相配体交换程序在中等温度下调整两者的比例，如XPS所示。显然，离子还具有控制不同成熟过程的能力。hrtem研究证明热处理和配体交换对纳米颗粒形貌没有影响。弱立体配体缺乏稳定性的引入为多孔纳米材料的合成提供了一条新的途径。这些新发现表明，共吸附离子化合物的静电稳定对理解各种实验结果起着至关重要的作用，从而使纳米材料的胶体合成总体上出现了新的视角。
Colloidal metal nanoparticles are usually fabricated via the reduction of metal salt precursor compounds in liquid phase. To prevent agglomeration, organic capping agents are used. Commonly, it is neglected that ionic compounds may coadsorb when present in the mixture. However, we shall show that ionic adsorbates play a key role in size and growth control. We present a universal case study on gold nanoparticles with various amine ligands to reveal two competitive stabilization mechanisms via quantitative X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Gold nanocrystals were obtained starting with a single phase room temperature synthesis. The stabilization turned out to be a combination of sterical and electrostatic shielding depending on the ligand molecule properties. We can adjust the ratio of both contributions via simple liquid phase ligand exchange procedures at moderate temperatures as shown with XPS. Apparently, ions further have the power to steer different ripening processes. HR-TEM studies proved that there is no influence on nanoparticle morphology during heat treatment or ligand exchange. Introducing a lack of stabilization by weaker sterical ligands offers an auspicious new way for the synthesis of porous nanomaterials. The novel findings illustrate that electrostatic stabilization by coadsorbed ionic compounds can play a crucial role in understanding various experimental results and thus the colloidal synthesis of nanomaterials in general appears in a new light.
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影响因子：
3.1
作者：
Milena Osmić;J. Kolny-Olesiak;K. Al‐Shamery
通讯作者：
Milena Osmić;J. Kolny-Olesiak;K. Al‐Shamery
DOI：
--
发表时间：
2006
期刊：
影响因子：
--
作者：
Ferdi Schüth Prof.
通讯作者：
Ferdi Schüth Prof.
影响因子：
8.6
作者：
Herrmann, Anne-Kristin;Formanek, Petr;Eychmueller, Alexander
通讯作者：
Eychmueller, Alexander
影响因子：
3.9
作者：
M. Hollamby;J. Eastoe;A. Chemelli;O. Glatter;S. Rogers;R. Heenan;I. Grillo
通讯作者：
I. Grillo
DOI：
10.1016/j.jconrel.2011.10.028
发表时间：
2012-03-10
期刊：
Journal of controlled release : official journal of the Controlled Release Society
影响因子：
--
作者：
You J;Zhang R;Zhang G;Zhong M;Liu Y;Van Pelt CS;Liang D;Wei W;Sood AK;Li C
通讯作者：
Li C