Nanofiller/elastomer nanocomposites as strategically important materials have attracted intensive attentions due to high elasticity{Liu, 2011 #46}. However, due to the limitation of conventional two-dimensional characterization methods, the multi-scaled dispersion structure of nanofiller in elastomer nanocomposites hasn’t been comprehensively understood. Here, we established a highly-objective method to comprehensively quantify the three-dimensional (3D)-dispersion of nanoparticle in elastomer matrix. 3D-scanning transmission electron microscope (STEM) was applied to get the intrinsic 3D-dispersion structure of nano-silica (SiO₂) in solution-polymerized styrene-butadiene rubber (SSBR). Equivalent sphere and fractal branch models were created to further quantify the poly-dispersity, inner connectivity and morphology of SiO₂. A two-stage agglomeration evolution schematic was proposed to elucidate the development of nanosized dispersion structure of SiO₂. With the increase of SiO₂ volume fraction (Φ_silica), the number, size and branching degree of SiO₂ simultaneously increase (namely, self-agglomeration). Further increase Φ_silica, adjacent SiO₂ interconnect with each other, leading to sharp increases of connectivity and branching degree of SiO₂ (namely, external agglomeration). This two-stage agglomeration mode interprets the well-known “Payne effect” well, which has not been quantified by 3D dispersion structure parameters before.

纳米填料/弹性体纳米复合材料作为具有战略意义的材料，因其高弹性而备受关注{Liu，2011＃46}。然而，由于常规二维表征方法的局限性，纳米填料在弹性体纳米复合材料中的多尺度分散结构尚未得到全面的理解。在这里，我们建立了一种高度客观的方法来全面量化纳米颗粒在弹性体基质中的三维（3D）分散。应用3D扫描透射电子显微镜（STEM）获得纳米二氧化硅（SiO ₂）在溶液聚合的丁苯橡胶（SSBR）中。建立了等效球体和分形分支模型，以进一步量化SiO ₂的多分散性，内部连通性和形态。提出了两阶段的团聚演化示意图，以阐明SiO ₂纳米分散结构的发展。用的SiO的增加₂体积分数（Φ_二氧化硅）时，数量，尺寸和支化度的SiO ₂同时增加（即，自我结块）。进一步增加Φ_二氧化硅，相邻的SiO ₂互连互相的SiO的导致连接的急剧增加和支化度₂（即外部集聚）。这种两阶段的团聚模式很好地解释了众所周知的“派恩效应”，以前尚未通过3D色散结构参数对其进行量化。