A Perspective on Methods to Computationally Design the Morphology of Aerogels

Abstract

Reconstructing aerogel morphology presents significant challenges, in particular, if 3D visualizations of their mesoporous network are desired. Available microscopic and tomographic tools find it difficult to probe into all types of aerogels for the purposes of reconstructing their 3D nanoporous morphology. This is where computational approaches have shown promising efforts. Herein, diverse models that can be applied to describing different aerogels are explored. To begin with, cluster–cluster aggregation models are examined for simulating the sol–gel process and the resulting morphologies in fractal aerogels, e.g., silica‐based. Gaussian random field models and polymerization‐induced phase separation models are explored for modeling organic non‐fractal aerogels, e.g., resorcinol‐formaldehyde (RF) ones. This is followed by Langevin‐dynamics‐based discrete element models that are explored for simulating gelation in fibrillar aerogels, e.g., those from biopolymer sources. Lastly, modified Voronoi approaches are investigated for describing the 3D fibrillar morphology, also of fibrillar aerogels, like those from biopolymers. A perspective is presented highlighting the strengths as well as shortcomings in each of the model approaches. Possibilities to either extend available approaches or explore new ones are briefly discussed at every interval.

The Effect of Particle Necks on the Mechanical Properties of Aerogels

“…Some newer models described the mechanical properties of aerogels with twodimensional (2D) or 3D pore model of constant cross-section [5][6][7] taking also into account network defects, like dead ends, dangling beams, and struts. More details on different modeling methodologies for describing aerogels can be found in the perspective by Rege [8].…”

The effect of synthesis conditions and process parameters on aerogel properties

“…Studies on computational modeling of aerogel structures and their properties has significantly increased since models may enablee engineering of aerogels and enable us to predict aerogel properties before synthesizing them in the laboratory. The modeling approaches of aerogels depend on their morphology, which can be classified as particle-aggregated and fibrillar ( Rege, 2023 ). Inorganic aerogels and some of the organic aerogels, such as RF, MF, and carbon aerogels, show particle-aggregated morphology ( Mulik et al, 2007 ; Sinkó, 2010 ).…”

Super-hydrophobic and resilient hybrid silica aerogels for thermal insulation, energy harvesting, and electrical applications in harsh environments

“…Silica aerogels possess a fractal structure with high tortuosity and limited connectivity. 47 Consequently, when the pore size of the aerogel decreases to a level below the mean free path of air molecules, which is approximately 68 nm, it results in a substantial hindrance to heat transfer through the gas phase. This phenomenon leads to noteworthy enhancements in thermal insulation properties, even though at higher densities, as observed in the case of APH100.…”