Department of Chemistry and Polymer Science , University of Stellenbosch , 7602 Stellenbosch , South Africa.
Anal Chem. 2019 May 21;91(10):6926-6933. doi: 10.1021/acs.analchem.9b01384. Epub 2019 May 6.
With a constantly increasing complexity of macromolecular structures, advanced polymer analysis faces new challenges with regard to the comprehensive analysis of these structures. Today it goes without saying that comprehensive polymer analysis requires selective and robust fractionation methods in combination with a set of information-rich detectors. Thermal field-flow fractionation (ThFFF) has proven to be a powerful technique for the fractionation of complex polymers as well as polymer assemblies. In the present study, ThFFF is coupled to a set of five detectors to simultaneously provide quantitative information on a number of important molecular parameters, including molar mass, molecular size, chemical composition, molecular topology, intrinsic viscosity, and normal and thermal diffusion coefficients. The five-detector setup includes a triple detector device (multiangle light scattering (MALS), differential refractive index (dRI), and differential viscometer (dVis)) that is coupled to an ultraviolet (UV) detector for dual concentration detection and an online dynamic light scattering (DLS) detector. Triple detection consisting of MALS, dRI, and dVis provides information on molar mass, molecular size, and molecular topology. Dual concentration detection offers compositional analysis from a combination of UV and dRI detectors, whereas DLS provides information on diffusion coefficients and hydrodynamic radii. The power of this novel quintuple detector ThFFF (ThFFF-QD) is documented for three important fields of application, namely, the comprehensive analysis of (1) linear and star-shaped polymers, (2) hydrogenated and deuterated polymers, and (3) block copolymer self-assemblies. These applications highlight the novel approach of determining the most relevant molecular parameters, including Mark-Houwink and conformation plots, simultaneously in a single experiment.
随着大分子结构的复杂性不断增加，高级聚合物分析在全面分析这些结构方面面临新的挑战。如今，不言而喻的是，全面的聚合物分析需要选择性强且稳健的分级方法，并结合一系列信息丰富的检测器。热场流分级（ThFFF）已被证明是一种强大的技术，可用于复杂聚合物以及聚合物组装体的分级。在本研究中，ThFFF 与五组检测器耦合，可同时提供有关多个重要分子参数的定量信息，包括摩尔质量、分子尺寸、化学组成、分子拓扑、特性粘度以及正常和热扩散系数。五检测器组包括一个三重检测器装置（多角度光散射（MALS）、差示折射率（dRI）和差示粘度计（dVis）），该装置与紫外（UV）检测器耦合，用于双重浓度检测和在线动态光散射（DLS）检测器。由 MALS、dRI 和 dVis 组成的三重检测可提供摩尔质量、分子尺寸和分子拓扑信息。双重浓度检测提供由 UV 和 dRI 检测器组合的组成分析，而 DLS 提供扩散系数和流体力学半径的信息。这种新型五重检测器 ThFFF（ThFFF-QD）的强大功能在三个重要的应用领域中得到了证明，即：（1）线性和星形聚合物的综合分析；（2）氢化和氘化聚合物；（3）嵌段共聚物自组装体。这些应用突出了在单个实验中同时确定最相关分子参数（包括 Mark-Houwink 和构象图）的新颖方法。
