Liquid-Templating Aerogels

Modern materials science has witnessed the era of advanced fabrication methods to engineer functionality from the nano- to macroscales. Versatile fabrication and additive manufacturing methods are developed, but the ability to design a material for a given application is still limited. Here, a novel strategy that enables target-oriented manufacturing of ultra-lightweight aerogels with on-demand characteristics is introduced. The process relies on controllable liquid templating through interfacial complexation to generate tunable, stimuli-responsive 3D-structured (multiphase) filamentous liquid templates. The methodology involves nanoscale chemistry and microscale assembly of nanoparticles (NPs) at liquid-liquid interfaces to produce hierarchical macroscopic aerogels featuring multiscale porosity, ultralow density (3.05-3.41 mg cm-3), and high compressibility (90%) combined with elastic resilience and instant shape recovery. The challenges are overcome facing ultra-lightweight aerogels, including poor mechanical integrity and the inability to form predefined 3D constructs with on-demand functionality, for a multitude of applications. The controllable nature of the coined methodology enables tunable electromagnetic interference shielding with high specific shielding effectiveness (39 893 dB cm2 g-1), and one of the highest-ever reported oil-absorption capacities (487 times the initial weight of aerogel for chloroform), to be obtained. These properties originate from the engineerable nature of liquid templating, pushing the boundaries of lightweight materials to systematic function design and applications. An aerogel production methodology through freezing and lyophilization of engineerable liquid templates, generated via interfacial complexation through electrostatic interactions between the nanoparticles (NPs) and ligands, is introduced. The coined approach enables tuning of the multiscale porosities, 3D architecture, and characteristics of the aerogels by engineering the composition and arrangement of liquid templates toward advanced applications and functions.image

Automated summary

This article introduces a novel method for the manufacturing of ultra-lightweight aerogels with desired characteristics through the controllable liquid templating and interfacial complexation. The engineered liquid templates, formed by the assembly of nanoparticles and microspheres at liquid-liquid interfaces, result in hierarchical macroscopic aerogels with multiscale porosity, ultralow density, high compressibility, and elastic resilience. The controllable nature of this approach enables the tuning of the aerogels' properties for advanced applications and functions, pushing the boundaries of lightweight materials.