Wawra Simon E, Thoma Martin, Walter Johannes, Lübbert Christian, Thajudeen Thaseem, Damm Cornelia, Peukert Wolfgang
Institute of Particle Technology (LFG), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Cauerstrasse 4, 91058, Erlangen, Germany.
Interdisciplinary Center for Functional Particle Systems (FPS), Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Haberstrasse 9a, 91058, Erlangen, Germany.
Eur Biophys J. 2018 Oct;47(7):777-787. doi: 10.1007/s00249-018-1314-2. Epub 2018 Jun 16.
By combining analytical ultracentrifugation (AUC) in liquid phase and scanning mobility particle sizer (SMPS) in the gas phase, additional information on the particle size and morphology has been obtained for rigid particles. In this paper, we transfer this concept to soft particles, allowing us to analyze the size and molar mass of the short side chain perfluorosulfonic acid ionomer Aquivion in a dilute aqueous suspension. The determination of the primary size and exact molar mass of this class of polymers is challenging since they are optically transparent and due to the formation of different aggregate structures depending on the concentration and solvent properties. First, validation of AUC and SMPS measurements was carried out using the well-defined biopolymers bovine serum albumin (BSA) and lysozyme (LYZ) to confirm the reliability of the results of the two unique and independent classifying methods. Then, the ionomer Aquivion was studied using both techniques. From the mean molar mass of 185 ± 14 kDa obtained by AUC, a mean hydrodynamic diameter of 7.6 ± 0.5 nm was calculated. The particle size obtained from SMPS (7.1 nm) agrees very well with the results from AUC showing that the molecule was transferred into the gas phase without significantly changing its structure. In conclusion, the Aquivion is molecularly dispersed in the used aqueous buffer solution without any aggregate formation in the investigated concentration range (< 2 g l).
通过结合液相分析超速离心法（AUC）和气相传感粒径谱仪（SMPS），已获得了有关刚性颗粒粒径和形态的更多信息。在本文中，我们将这一概念应用于软颗粒，从而能够分析稀水悬浮液中短侧链全氟磺酸离聚物Aquivion的粒径和摩尔质量。由于这类聚合物是光学透明的，并且会根据浓度和溶剂性质形成不同的聚集体结构，因此确定其原始粒径和精确摩尔质量具有挑战性。首先，使用定义明确的生物聚合物牛血清白蛋白（BSA）和溶菌酶（LYZ）对AUC和SMPS测量进行验证，以确认这两种独特且独立的分类方法结果的可靠性。然后，使用这两种技术对离聚物Aquivion进行研究。根据AUC测得的平均摩尔质量185±14 kDa，计算出平均流体动力学直径为7.6±0.5 nm。SMPS测得的粒径（7.1 nm）与AUC的结果非常吻合，表明该分子在转移到气相时其结构没有明显变化。总之，在研究的浓度范围（<2 g/l）内，Aquivion以分子形式分散在所使用的水性缓冲溶液中，没有形成任何聚集体。
