Characterization of size, anisotropy, and density heterogeneity of nanoparticles by sedimentation velocity.
Characterization of size, anisotropy, and density heterogeneity of nanoparticles by sedimentation velocity.
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纳米颗粒的大小，各向异性和密度异质性的表征通过沉积速度。
DOI：
10.1021/ac501722r
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发表时间：
2014-08-05
影响因子：
7.4
通讯作者：
Whetten, Robert L.
中科院分区：
文献类型：
--
作者：
Demeler, Borries;Tich-Lam Nguyen;Gorbet, Gary E.;Schirf, Virgil;Brookes, Emre H.;Mulvaney, Paul;El-Ballouli, Ala'a O.;Pan, Jun;Bakr, Osman M.;Demeler, Aysha K.;Uribe, Blanca I. Hernandez;Bhattarai, Nabraj;Whetten, Robert L.
材料科学中的一个关键问题是胶体无机纳米晶体的尺寸依赖性特性的准确表征。由于合成过程中存在固有的多分散性，此类材料的分散体在密度 ρ、摩尔质量 M 和粒径 d 方面表现出同时的异质性。这些纳米颗粒的密度增量 ∂ρ/∂d 和 ∂ρ/∂M（如果已知）可以提供有关晶体生长和粒径分布的重要信息。对于大多数类别的纳米晶体，在合成过程中添加表面活性剂混合物以控制其形状、尺寸和光学性质。然而，准确确定合成后与颗粒表面结合的钝化配体的量仍然是一个挑战。配体壳的存在妨碍了纳米晶直径的准确测定。使用 CdSe 和 PbS 半导体纳米晶体以及超稳定银纳米颗粒 (M4Ag44(p-MBA)30) 作为模型系统，我们描述了在 UltraScan-III 中实现的自定义网格方法，用于使用沉降速度分析超速离心来表征纳米颗粒和大分子。我们证明了多种参数化是可能的，并且自定义网格方法可以推广为在三个参数中的两个参数中异质的溶质混合物提供高分辨率组成信息。对于这种情况，当第三个属性可以保持不变时，我们的方法可以同时解析流体动力学参数的任意二维分布。例如，在各向异性可以保持恒定的情况下，该方法从沉降速度数据中提取部分比容和摩尔质量，或者如果摩尔质量已知，则提供各向异性和部分比容。
A critical problem in materials science is the accurate characterization of the size dependent properties of colloidal inorganic nanocrystals. Due to the intrinsic polydispersity present during synthesis, dispersions of such materials exhibit simultaneous heterogeneity in density ρ, molar mass M, and particle diameter d. The density increments ∂ρ/∂d and ∂ρ/∂M of these nanoparticles, if known, can then provide important information about crystal growth and particle size distributions. For most classes of nanocrystals, a mixture of surfactants is added during synthesis to control their shape, size, and optical properties. However, it remains a challenge to accurately determine the amount of passivating ligand bound to the particle surface post synthesis. The presence of the ligand shell hampers an accurate determination of the nanocrystal diameter. Using CdSe and PbS semiconductor nanocrystals, and the ultrastable silver nanoparticle (M4Ag44(p-MBA)30), as model systems, we describe a Custom Grid method implemented in UltraScan-III for the characterization of nanoparticles and macromolecules using sedimentation velocity analytical ultracentrifugation. We show that multiple parametrizations are possible, and that the Custom Grid method can be generalized to provide high resolution composition information for mixtures of solutes that are heterogeneous in two out of three parameters. For such cases, our method can simultaneously resolve arbitrary two-dimensional distributions of hydrodynamic parameters when a third property can be held constant. For example, this method extracts partial specific volume and molar mass from sedimentation velocity data for cases where the anisotropy can be held constant, or provides anisotropy and partial specific volume if the molar mass is known.
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通过分析超速离心和总有机碳分析测量溶液中纳米颗粒的嫁接密度。
影响因子：
7.4
作者：
Benoit DN;Zhu H;Lilierose MH;Verm RA;Ali N;Morrison AN;Fortner JD;Avendano C;Colvin VL
通讯作者：
Colvin VL
影响因子：
3.4
作者：
Cao, Weiming;Demeler, Borries
通讯作者：
Demeler, Borries
影响因子：
2.7
作者：
LANGE, H
通讯作者：
LANGE, H
影响因子：
16.6
作者：
Bakr, Osman M.;Amendola, Vincenzo;Stellacci, Francesco
通讯作者：
Stellacci, Francesco
DOI：
10.1007/s00249-003-0319-6
发表时间：
2003-08-01
影响因子：
2
作者：
Cölfen, H;Völkel, A
通讯作者：
Völkel, A