Ultrastrong and multifunctional aerogels with hyperconnective network of composite polymeric nanofibers

Abstract

Three-dimensional (3D) microfibrillar network represents an important structural design for various natural tissues and synthetic aerogels. Despite extensive efforts, achieving high mechanical properties for synthetic 3D microfibrillar networks remains challenging. Here, we report ultrastrong polymeric aerogels involving self-assembled 3D networks of aramid nanofiber composites. The interactions between the nanoscale constituents lead to assembled networks with high nodal connectivity and strong crosslinking between fibrils. As revealed by theoretical simulations of 3D networks, these features at fibrillar joints may lead to an enhancement of macroscopic mechanical properties by orders of magnitude even with a constant level of solid content. Indeed, the polymeric aerogels achieved both high specific tensile modulus of ~625.3 MPa cm3 g−1 and fracture energy of ~4700 J m−2, which are advantageous for diverse structural applications. Furthermore, their simple processing techniques allow fabrication into various functional devices, such as wearable electronics, thermal stealth, and filtration membranes. The mechanistic insights and manufacturability provided by these robust microfibrillar aerogels may create further opportunities for materials design and technological innovation.

Hybrid assembly of polymeric nanofiber network for robust and electronically conductive hydrogels

“…Dispersing ANFs in dimethyl sulfoxide (DMSO) followed by solvent exchange with water generates hydrogels with highly connective 3D fibrillar networks, serving as templates for the assembly of conducting polymers. Incorporating polyvinyl alcohol (PVA) during the processing of hydrogels helps to weld the fibrillar joints via extensive hydrogen bonding, providing enhanced mechanical strength for the nanofiber network 29 , 30 . Next, monomers (e.g., pyrrole, Py) were infiltrated into the nanoporous hydrogels in an aqueous media (Fig.…”

Bio-Inspired Aramid Fibers@silica Binary Synergistic Aerogels with High Thermal Insulation and Fire-Retardant Performance

“…The statistical results indicate the thickness of silica coating, physical properties, mechanical properties, and thermal properties of aramid fibers@silica aerogels could be controlled by the time of CVD ( Table 1 ). In addition to that, ANFs/TEOS aerogels inherit the high tensile strength due to silica nodes connected aramid nanofibers ( Figure 8 b) [ 51 ]. As shown in Figure 8 b, the regular tetrahedral molecular structure results in very stable chemical properties of silica and excellent corrosion and heat resistance.…”

The Rising Aerogel Fibers: Status, Challenges, and Opportunities

“…These hyper‐connective features at fibrillar joints may result in an improvement of the macroscopic mechanical properties of the fibers. [ 89 ] Besides, mechanically interlocked molecules are also likely to contribute to mechanical robustness. Due to the inherent host–guest interaction, aerogel fibers constituted of these locked molecular skeletons may achieve a combination of superior mechanical strength, responsiveness, and multiple functionality.…”