Rapid synchronized fabrication of vascularized thermosets and composites

Abstract

Bioinspired vascular networks transport heat and mass in hydrogels, microfluidic devices, self-healing and self-cooling structures, filters, and flow batteries. Lengthy, multistep fabrication processes involving solvents, external heat, and vacuum hinder large-scale application of vascular networks in structural materials. Here, we report the rapid (seconds to minutes), scalable, and synchronized fabrication of vascular thermosets and fiber-reinforced composites under ambient conditions. The exothermic frontal polymerization (FP) of a liquid or gelled resin facilitates coordinated depolymerization of an embedded sacrificial template to create host structures with high-fidelity interconnected microchannels. The chemical energy released during matrix polymerization eliminates the need for a sustained external heat source and greatly reduces external energy consumption for processing. Programming the rate of depolymerization of the sacrificial thermoplastic to match the kinetics of FP has the potential to significantly expedite the fabrication of vascular structures with extended lifetimes, microreactors, and imaging phantoms for understanding capillary flow in biological systems.

Rapid Preparation of Dual Cross-Linked Mechanical Strengthening Hydrogels via Frontal Polymerization for use as Shape Deformable Actuators

“…In this regard, frontal polymerization (FP) demonstrates unique advantages, such as simple operation, fast reaction speed, and energy saving. FP has been widely studied for synthesizing a variety of polymer materials, including polyurethanes, thermoset polymers, − gradient materials, and functional hydrogels. − Once a local reaction is initiated, no further energy input is required. The released heat can propagate and trigger the polymerization of unreacted monomers.…”

Quantum Dots-Loaded Self-Healing Gels for Versatile Fluorescent Assembly

“…It should be noted that FP is driven by the enthalpy of polymerization. Once ignited, the polymerization process can be self-propagated without an external energy supply, which promises to revolutionize the future of manufacturing due to its energy-saving potential [ 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 ]. Compared to conventional batch polymerization, FP has several advantages including ease of operation, energy and time efficiency, and it is environmentally friendly [ 32 , 33 ].…”

“…Compared to conventional batch polymerization, FP has several advantages including ease of operation, energy and time efficiency, and it is environmentally friendly [ 32 , 33 ]. So far, great efforts have been devoted to the development of FP; these have sparked the creation of new integrated FP techniques [ 34 , 35 , 36 , 37 ] and a series of functional polymers [ 38 , 39 , 40 ], especially smart gels [ 41 , 42 , 43 ].…”

Solar‐Initiated Frontal Polymerization of Photothermic Hydrogels with High Swelling Properties for Efficient Water Evaporation

“…[ 34 ] Typically, after the front initiates with a energy stimulus, no further energy input is desired and the localized reaction front can propagate throughout the entire system based on this highly exothermic reaction. [ 35–37 ] Notably, this rapid exothermic process is also conducive to the formation of well‐defined larger macropores within the as‐prepared hydrogels, so as to augment their swelling property. [ 38–40 ] Until now, various forms of energy stimulus have been introduced to initiate the FP, including conventional thermal, [ 41 ] UV light, [ 42 ] plasma, [ 43 ] ultrasound, [ 44 ] laser, [ 45 ] and photothermal energies.…”