The applicability of positron annihilation lifetime (PAL) spectroscopy to identify volumetric changes in nanostructured polymer/filler substances is first verified at the example of commercially available dimethacrylate-based dental restorative composites Charisma® (Heraeus Kulzer GmbH, Germany) affected to light-curing photopolymerization and one-year dry physical ageing. Principal channel governing PAL spectra in these nanocomposites is recognized as mixed positron-Ps trapping, where positronium Ps (i.e. bound positron-electron state) decay occurs in free-volume holes localized preferentially in polymer matrix, while free positron self-annihilation is character for interfacial voids at the surface of filler-particles assemblies in the filler and/or mixed filler-polymer environment. Methodological algorithm for experimental PAL spectra refinement referred to as the x3-x2-CDA (coupling decomposition algorithm) is validated for these nanocomposites, obeying changes in atomic-deficient structure due to direct conversion between positron-trapping and Ps-decaying sites. Straightforward parameterization of the reconstructed PAL spectra allows meaningful identification of free-volume entities responsible for nanostructurization-driven transformations.

正电子at没寿命（PAL）光谱法用于鉴定纳米结构聚合物/填料物质体积变化的适用性首先在受光固化光聚合影响的可商购的基于二甲基丙烯酸酯的牙科修复复合材料Charisma®（德国Heraeus Kulzer GmbH）的示例中得到验证和一年的干燥身体老化。这些纳米复合物中控制PAL光谱的主要通道被认为是混合正电子-Ps俘获，其中正电子Ps（即键合正电子-电子态）的衰减发生在优先位于聚合物基质中的自由体积空穴中，而自由正电子的自ni灭是在填料和/或混合的填料-聚合物环境中，填料-颗粒组件表面的界面空隙。针对这些纳米复合材料，验证了用于实验PAL光谱细化的方法算法，称为x3-x2-CDA（耦合分解算法），服从了由于正电子俘获位点和Ps衰变位点之间的直接转换而导致的原子缺陷结构的变化。重构的PAL光谱的直接参数化可以有意义地识别负责纳米结构化驱动的转换的自由体积实体。