Laboratoire Charles Coulomb (L2C) , Université de Montpellier, CNRS , F-34095 Montpellier , France.
Solvay Silica , 15 rue Pierre Pays BP52 , 69660 Collonges au Mont d'Or , France.
Langmuir. 2018 Mar 6;34(9):3010-3020. doi: 10.1021/acs.langmuir.7b03932. Epub 2018 Feb 20.
A new method based on the combination of small-angle scattering, reverse Monte Carlo simulations, and an aggregate recognition algorithm is proposed to characterize the structure of nanoparticle suspensions in solvents and polymer nanocomposites, allowing detailed studies of the impact of different nanoparticle surface modifications. Experimental small-angle scattering is reproduced using simulated annealing of configurations of polydisperse particles in a simulation box compatible with the lowest experimental q-vector. Then, properties of interest like aggregation states are extracted from these configurations and averaged. This approach has been applied to silane surface-modified silica nanoparticles with different grafting groups, in solvents and after casting into polymer matrices. It is shown that the chemistry of the silane function, in particular mono- or trifunctionality possibly related to patch formation, affects the dispersion state in a given medium, in spite of an unchanged alkyl-chain length. Our approach may be applied to study any dispersion or aggregation state of nanoparticles. Concerning nanocomposites, the method has potential impact on the design of new formulations allowing controlled tuning of nanoparticle dispersion.
提出了一种新的方法，基于小角散射、反蒙特卡罗模拟和聚集识别算法的组合，用于表征纳米颗粒悬浮液在溶剂和聚合物纳米复合材料中的结构，允许详细研究不同纳米颗粒表面修饰的影响。使用与最低实验 q-向量兼容的模拟盒中的多分散颗粒构型的模拟退火来再现实验小角散射。然后，从这些构型中提取感兴趣的性质，例如聚集状态，并对其进行平均。该方法已应用于具有不同接枝基团的硅烷表面修饰的二氧化硅纳米颗粒，分别在溶剂中和浇铸到聚合物基质中。结果表明，硅烷官能团的化学性质，特别是单官能度或三官能度（可能与斑块形成有关），会影响给定介质中的分散状态，尽管烷基链长度保持不变。我们的方法可用于研究纳米颗粒的任何分散或聚集状态。对于纳米复合材料，该方法可能会对设计允许控制纳米颗粒分散的新配方产生影响。
