Yao Shuan, Zhang Heng, Zeng Nan, Ma Hui, He Honghui, Jiang Yuelu
Guangdong Research Center of Polarization Imaging and Measurement Engineering Technology, Shenzhen Key Laboratory for Minimal Invasive Medical Technologies, Institute of Biopharmaceutical and Health Engineering, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
Department of Physics, Tsinghua University, Beijing 100084, China.
Materials (Basel). 2024 Apr 9;17(8):1718. doi: 10.3390/ma17081718.
Porous suspended particles are hazardous to human health due to their strong absorption capacity for toxic substances. A fast, accurate, in situ and high-throughput method to characterize the microporous structure of porous particles has extensive application value. The polarization changes during the light scattering of aerosol particles are highly sensitive to their microstructural properties, such as pore size and porosity. In this study, we propose an overlapping sphere model based on the discrete dipole approximation (DDA) to calculate the polarization scattering characteristics of porous particles. By combining scattering calculations with multi-dimensional polarization indexes measured by a multi-angle polarized scattering vector detection system, we achieve the identification and classification of pore-type components in suspended particles. The maximum deviation based on multiple indexes is less than 0.16% for the proportion analysis of mixed particles. Simultaneously, we develop a quantitative inversion algorithm on pore size and porosity. The inversion results of the three porous polymer particles support the validity and feasibility of our method, where the inversion error of partial particles is less than 4% for pore size and less than 6% for porosity. The study demonstrates the potential of polarization measurements and index systems applied in characterizing the micropore structure of suspended particles.
多孔悬浮颗粒因其对有毒物质的强大吸附能力而对人体健康有害。一种快速、准确、原位且高通量的表征多孔颗粒微孔结构的方法具有广泛的应用价值。气溶胶颗粒光散射过程中的偏振变化对其微观结构特性（如孔径和孔隙率）高度敏感。在本研究中，我们提出了一种基于离散偶极近似（DDA）的重叠球体模型来计算多孔颗粒的偏振散射特性。通过将散射计算与多角度偏振散射矢量检测系统测量的多维偏振指数相结合，我们实现了悬浮颗粒中孔隙类型成分的识别和分类。对于混合颗粒的比例分析，基于多个指数的最大偏差小于0.16%。同时，我们开发了一种关于孔径和孔隙率的定量反演算法。三种多孔聚合物颗粒的反演结果支持了我们方法的有效性和可行性，其中部分颗粒的孔径反演误差小于4%，孔隙率反演误差小于6%。该研究证明了偏振测量和指数系统在表征悬浮颗粒微孔结构方面的潜力。
