Computational design of biopolymer aerogels and predictive modelling of their nanostructure and mechanical behaviour

Abstract

To address the challenge of reconstructing or designing the three-dimensional microstructure of nanoporous materials, we develop a computational approach by combining the random closed packing of polydisperse spheres together with the Laguerre–Voronoi tessellation. Open-porous cellular network structures that adhere to the real pore-size distributions of the nanoporous materials are generated. As an example, κ-carrageenan aerogels are considered. The mechanical structure–property relationships are further explored by means of finite elements. Here we show that one can predict the macroscopic stress–strain curve of the bulk porous material if only the pore-size distributions, solid fractions, and Young’s modulus of the pore-wall fibres are known a priori. The objective of such reconstruction and predictive modelling is to reverse engineer the parameters of their synthesis process for tailored applications. Structural and mechanical property predictions of the proposed modelling approach are shown to be in good agreement with the available experimental data. The presented approach is free of parameter-fitting and is capable of generating dispersed Voronoi structures.

Soft-Tissue-Mimicking Using Hydrogels for the Development of Phantoms

“…Until now, different materials such as silicones, hydrogels, or photopolymer resins were studied [ 6 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]: PVA, PHY, agar, gelatine, alginate, hydrogels or Sylgard 527 (PDMS) and Sylgard 184 (Silicone Elastomer), as well as photopolymer resins for Additive Manufacturing (e.g., VeroWhite+, a rigid general purpose, high resolution, opaque white material; and TangoPlus+, which simulates thermoplastic elastomers with flexible, rubber-like qualities; both of them developed by Stratasys ® ). Additionally, it is worth mentioning that there are other biopolymeric materials such as aerogels that can be used for tissue engineering and regenerative medicine [ 24 , 25 ]. For example, Yahya et al [ 24 ] highlighted the main challenges of biopolymer-based scaffolds and the prospects of using these materials in regenerative medicine.…”

DEM-Based Approach for the Modeling of Gelation and Its Application to Alginate

“…There also exist applications of DEM on the macroscopic scale; however, here, the material microstructure is not properly described . Additionally, micromechanical modeling of similar structures has been performed in the context of finite element modeling and beam theory. , …”

“…22 Additionally, micromechanical modeling of similar structures has been performed in the context of finite element modeling and beam theory. 23,24 In the context of the alginate model system, a variety of simulation approaches have been applied to better understand the system, which were typically centered around MD and density functional theory (DFT). The original "egg-box" model for ion-mediated gelation was proposed by Grant et al 25 and has been the basis over the past decades.…”

Constitutive Modeling of the Densification Behavior in Open-Porous Cellular Solids

“…To find a solution towards modeling such materials by accounting for the variability in the cell structure, an alternative approach is presented in the form of finite element methods [16][17][18]. There, Voronoi-based modeling approaches are found widely in the literature [19][20][21][22]. By subjecting the Voronoi-based representative volume elements to large deformations, the densification behavior can be captured.…”