Fabrication of mesoporous nanoparticle structures via co-solvent evaporation

过渡金属介孔材料在催化、传感、锂离子电池等领域具有广阔的应用前景。通常，这些介孔结构是通过两亲表面活性剂和过渡金属纳米颗粒(NP)的溶剂挥发诱导自组装(EISA)获得的。由于NPs在溶液中的高反应性，NP-NP和NP-表面活性剂之间的相互作用强烈地依赖于溶剂的浓度。由于这些浓度相关的相互作用在蒸发过程中有所不同，结构形成的动力学也变得与过程有关。在这个项目的继续中，我们将设计一个新的模拟方案来捕捉这些过程相关的特征，并研究TM介孔薄膜的形成动力学。用连续介质模型研究了共溶剂蒸发，其中两种溶剂浓度是通过数值求解带有移动边界条件的扩散方程得到的。随后，这些与时间相关的溶剂浓度将被用来表征粒子模拟中NP-NP和NP-单体的相互作用，粒子模拟使用了计算高效的、软的、粗粒度的模型。在较小的溶剂浓度下，NP-NP和NP-表面活性剂之间发生强烈的相互作用，导致不可逆的聚集，这以交联键为代表。这种计算效率高的连续介质模型和粒子模拟的结合将使我们能够探索、理解和优化制造有序TM介观结构的工艺条件。

Transition metal mesoporous materials have promising applications in catalysis, sensing, and lithium-ion batteries. Typically these mesoporous structures are obtained by solvent evaporation induced self-assembly (EISA) of amphiphilic surfactants and transition metal nanoparticles (NP). Due to the high reactivity of NPs in solution, the interactions between NP-NP and NP-surfactants strongly depend on the solvent concentrations. Since these concentration-dependent interactions vary in the course of evaporation, the kinetics of structure formation becomes process-dependent.In this continuation of project, we will devise a new simulation scheme to capture these process-dependent features and study the formation kinetics of TM mesoporous thin films. The co-solvent evaporation is investigated by continuum models, where the two solvent concentrations are obtained by numerically solving diffusion equations with a moving boundary condition. Subsequently, these time-dependent solvent concentrations will be employed to characterize the NP-NP and NP-monomer interactions in particle simulations, which use a computationally efficient, soft, coarse-grained models. Strong interactions between NP-NP and NP-surfactants, which occur at small solvent concentrations, give rise to an irreversible aggregation, which is represented by crosslinks. This computationally efficient combination of continuum model and particle simulation will allow us to explore, understand, and optimize the process conditions for the fabrication of well-ordered TM mesostructures.