The three-dimensional arrangement of natural and synthetic network materials determines their application range. Control over the real time incorporation of each building block and functional group is desired to regulate the macroscopic properties of the material from the molecular level onwards. Here we report an approach combining kinetic Monte Carlo and molecular dynamics simulations that chemically and physically predicts the interactions between building blocks in time and in space for the entire formation process of three-dimensional networks. This framework takes into account variations in inter-and intramolecular chemical reactivity, diffusivity, segmental compositions, branch/network point locations and defects. From the kinetic and three-dimensional structural information gathered, we construct structure-property relationships based on molecular descriptors such as pore size or dangling chain distribution and differentiate ideal from non-ideal structural elements. We validate such relationships by synthetizing organosilica, epoxy-amine and Diels-Alder networks with tailored properties and functions, further demonstrating the broad applicability of the platform.

Hyperconnected hybrid organosilicate glass networks formed by hyperstiff precursor molecules with certain geometrical characteristics can lead to exceptional elastic properties superior to that of fully dense silica. Carbon‐ and silicon‐containing precursors with defined molecular planarity are introduced and a new design strategy where both the network connectivity and the precursor geometry are effectively utilized to enhance elastic properties is proposed. The geometrical features rendering a precursor molecule as hyperstiff are identified through molecular dynamics simulations and constraint analyses by calculating the degree of nonaffine deformations. Nonaffine deformations have not been previously examined for organosilicate hybrid glass networks and are a fundamental new approach to reveal the combined impact of precursor geometry and connectivity on the mechanical behavior of hybrid glass networks.

Polyimide hybrid nanocomposites with the polyimide confined at molecular length scales exhibit enhanced fracture resistance with excellent thermal-oxidative stability at low density. Previously, polyimide nanocomposites were fabricated by infiltration of a polyimide precursor into a nanoporous matrix followed by sequential thermally induced imidization and cross-linking of the polyimide under nanometer-scale confinement. However, byproducts formed during imidization became volatile at the cross-linking temperature, limiting the polymer fill level and degrading the nanocomposite fracture resistance. This is solved in the present work with an easier approach where the nanoporous matrix is filled with shorter preimidized polyimide chains that are cross-linked while in the pores to eliminate the need for confined imidization reactions, which produces better results compared to the previous study. In addition, we selected a preimidized polyimide that has a higher chain mobility and a stronger interaction with the matrix pore surface. Consequently, the toughness achieved with un-cross-linked preimidized polyimide chains in this work is equivalent to that achieved with the cross-linking of the previously used polyimide chains and is doubled when preimidized polyimide chains are cross-linked. The increased chain mobility enables more efficient polymer filling and higher polymer fill levels. The higher polymer–pore surface interaction increases the energy dissipation during polyimide molecular bridging, increasing the nanocomposite fracture resistance. The combination of the higher polymer fill and the stronger polymer–surface interaction is shown to provide significant improvements to the nanocomposite fracture resistance and is validated with a molecular bridging model.

The three-dimensional configurational arrangement of natural and synthetic network materials determines their application range. Control of the real time incorporation of each building block, hence, all functional groups is desired so that we can regulate macroscopic properties from the molecular level onwards. Here we interconnect kinetic Monte Carlo simulations from the field of chemical kinetics and molecular dynamic simulations from the field of physics. We visualize for (in)organic network material synthesis how the initial building blocks interact timewise and spatially, accounting for variations in inter- and intramolecular chemical reactivity, diffusivity, segmental compositions, branch/network point locations, and defects. We use the kinetic and three-dimensional structural information to construct structure-property relationships based on molecular descriptors such as the molecular pore size or dangling chain distribution, differentiating between ideal and non-ideal structural elements. The generic nature is illustrated by constructing such relationships for the synthesis of organosilica, epoxy-amine and Diels-Alder based networks.

We explore the structure–property relationships in hybrid organosilicate glasses that form a special class of materials for use in advanced interconnects to improve their mechanical reliability by exploiting the structural characteristics most effectively. Our results show that hybrid organosilicate glasses that are hyperconnected and derived from organic linkers with optimal molecular geometry lead to exceptional elastic and fracture properties. Using molecular dynamics simulations and the min-cut algorithm that is based on a novel graph theory approach, we demonstrate the choice of hyperconnected and cyclic planar organic linkers, such as the 1,3,5-benzene ring, significantly increases the bulk modulus and total fracture bond density, which is directly correlated with fracture energy.