Pauw Brian R, Kästner Claudia, Thünemann Andreas F
Federal Institute for Materials Research and Testing (BAM), Unter den Eichen 87, 12205 Berlin, Germany.
J Appl Crystallogr. 2017 Aug 18;50(Pt 5):1280-1288. doi: 10.1107/S160057671701010X. eCollection 2017 Oct 1.
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 and (iii) a Monte Carlo fitting approach using . 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 = 2.76 (6) nm and = 3.20 (4) nm, respectively. The corresponding widths of the lognormal radius distribution of the particles were σ = 0.65 (1) nm and σ = 0.71 (1) nm. The particle concentration determined using this method was 3.0 (4) g l or 4.2 (7) × 10 mol l. 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.
本文介绍了首次全球范围内关于纳米颗粒尺寸测定的小角X射线散射（SAXS）实验室间比对。此次比对的测量量为平均颗粒半径、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组成，周围包裹着聚丙烯酸稳定聚合物壳层。银核主导X射线散射图案，因此可使用（i）广义间接傅里叶变换方法、（ii）使用[具体内容缺失]的经典模型拟合以及（iii）使用[具体内容缺失]的蒙特卡罗拟合方法来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，分别得出一致的平均数量加权和体积加权核心半径，分别为 = 2.76 (6) nm和 = 3.20 (4) nm。颗粒对数正态半径分布的相应宽度分别为σ = 0.65 (1) nm和σ = 0.71 (1) nm。使用该方法测定的颗粒浓度为3.0 (4) g l或4.2 (7) × 10 mol l。这些结果受数据评估程序选择的影响较小，但不受仪器影响：参与比对的同步辐射SAXS光束线实验室、商业仪器和自行设计的仪器均能够提供高度一致的数据。这表明SAXS是一种适用于揭示至少在20 nm以下区域颗粒尺寸分布的方法，而这是大多数其他分析方法无法做到的。
