Multiwalled carbon nanotube-titanium dioxide (MWNT-TiO₂) nanohybrids (NHs), a promising support for electrocatalysts, have a high likelihood of environmental release. Aggregation of these NHs may or may not be captured by the sum of their component behavior, thus necessitating a systematic evaluation. This study probes the “part-whole question” by systematically evaluating the role of TiO₂ loading (C:Ti molar ratios of 1:0.1, 1:0.05 and 1:0.033) on the aggregation behavior of these NHs. Aggregation kinetics of these in-house synthesized (using a sol–gel method) NHs and the components is investigated with time-resolved dynamic light scattering in the presence of mono- and divalent cations and with and without Suwannee River humic acid. A deviation in the aggregation behavior from classical electrokinetic theory has been observed which indicates that the material complexity has a strong influence in the observed behavior; hence other material attributes (e.g., fractal dimension, surface roughness, charge heterogeneity, etc.) should be carefully considered when studying such materials. The sum of the aggregation behavior of the parts may not capture that of the whole (i.e., of the NHs); aggregation depends on the TiO₂ loading and also on the hybridization process and the background aquatic chemistry.

中文翻译：

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多壁碳纳米管-二氧化钛纳米杂化物的聚集行为：探讨部分整体问题

多壁碳纳米管-二氧化钛（MWNT-TiO ₂）纳米杂化物（NH）是一种很有前景的电催化剂载体，很可能会释放到环境中。这些 NH 的聚集可能会或可能不会被其组成行为的总和所捕获，因此需要进行系统评估。_{本研究通过系统评估TiO 2}负载量（C:Ti 摩尔比为1:0.1、1:0.05 和1:0.033）对这些NH 聚集行为的作用，探讨了“部分-整体问题” 。在存在单价和二价阳离子以及有或没有 Suwannee River 腐殖酸的情况下，通过时间分辨动态光散射研究了这些内部合成（使用溶胶-凝胶法）NH 及其组分的聚集动力学。观察到聚集行为与经典电动理论的偏差，这表明材料的复杂性对观察到的行为有很大影响；因此，在研究此类材料时，应仔细考虑其他材料属性（例如，分形维数、表面粗糙度、电荷异质性等）。部分聚合行为的总和可能无法反映整体（即 NH）的聚合行为；聚集取决于TiO ₂负载量以及杂交过程和背景水生化学。