Nanoparticle size distribution quantification: results of a small-angle X-ray scattering inter-laboratory comparison.
Nanoparticle size distribution quantification: results of a small-angle X-ray scattering inter-laboratory comparison.
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DOI：
10.1107/s160057671701010x
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发表时间：
2017-10-01
影响因子：
6.1
通讯作者：
Thünemann AF
中科院分区：
文献类型：
--
作者：
Pauw BR;Kästner C;Thünemann AF
小角度X射线散射实验室之间的广泛的循环实验提供了一个全球性的不确定性估计的被测量的纳米粒子分散。无论仪器谱系如何，分布平均值、宽度和体积分数均可分别以1%、10%和10%的准确度确定。本文介绍了小角X射线散射（SAXS）的纳米粒子尺寸的第一个全球性的实验室间比较。该比较中的被测量是平均颗粒半径、尺寸分布宽度和颗粒浓度。所研究的样品由分散的银纳米颗粒，由聚（丙烯酸）的稳定聚合物壳包围。银核在X射线散射图案中占主导地位，从而使用（i）广义间接傅立叶变换法，（ii）使用SASfit的经典模型拟合和（iii）使用McSAS的Monte Carlo拟合方法确定其半径尺寸分布。将这三种方法应用于从各个实验室收集的数据集，得到一致的平均数和体积加权核半径，分别为Rn = 2.76（6）nm和RV = 3.20（4）nm。 粒子的对数正态半径分布宽度分别为σ n = 0.65（1）nm和σ v = 0.71（1）nm。 用这种方法测得的粒子浓度为3.0（4）g l − 1或4.2（7）× 10 − 6 mol l − 1。 这些结果受到数据评估程序选择的轻微影响，但不受仪器的影响：参与同步加速器SAXS光束线的实验室，商业和内部设计的仪器都能够提供高度一致的数据。这表明，SAXS是一种合适的方法，用于揭示粒度分布在20 nm以下的区域（至少），超出了大多数其他分析方法。
An extensive round robin experiment between small-angle X-ray scattering laboratories has delivered a global uncertainty estimate for the measurands of a nanoparticle dispersion. Irrespective of the instrument pedigree, the distribution mean, width and volume fraction could be determined with an accuracy of 1, 10 and 10%, respectively. This paper presents the first worldwide inter-laboratory comparison of small-angle X-ray scattering (SAXS) for nanoparticle sizing. The measurands in this comparison are the mean particle radius, the width of the size distribution and the particle concentration. The investigated sample consists of dispersed silver nanoparticles, surrounded by a stabilizing polymeric shell of poly(acrylic acid). The silver cores dominate the X-ray scattering pattern, leading to the determination of their radius size distribution using (i) the generalized indirect Fourier transformation method, (ii) classical model fitting using SASfit and (iii) a Monte Carlo fitting approach using McSAS. The application of these three methods to the collected data sets from the various laboratories produces consistent mean number- and volume-weighted core radii of R n = 2.76 (6) nm and R v = 3.20 (4) nm, respectively. The corresponding widths of the lognormal radius distribution of the particles were σn = 0.65 (1) nm and σv = 0.71 (1) nm. The particle concentration determined using this method was 3.0 (4) g l−1 or 4.2 (7) × 10−6 mol l−1. These results are affected slightly by the choice of data evaluation procedure, but not by the instruments: the participating laboratories at synchrotron SAXS beamlines, commercial and in-house-designed instruments were all able to provide highly consistent data. This demonstrates that SAXS is a suitable method for revealing particle size distributions in the sub-20 nm region (at minimum), out of reach for most other analytical methods.