Ingenious construction of three-dimensional porous carbon foams and their polymer composites using template-based strategies

The multifunctional polymer-based composites greatly benefited from the exceptional properties of three-dimensional (3D) porous carbon foams (CFs), which exhibited remarkable electrical and thermal conductivities, as well as offered versatile design possibilities. The template-based strategies enabled the convenient prediction and precise regulation of porous foam by templating carbon nanomaterials into well-organized porous structures, surpassing the limitations of the template-free approaches. The template-based strategies have been proven effective methods to control the elaborated structures of carbon nanomaterials, exhibiting their unique advantages. This review mainly summarized the latest research progress of templating strategies in constructing 3D porous CFs and their polymer composites from four aspects: hard template (including metal template and water-soluble particle template), soft template (including porous polymer sponge, etchable polymer microsphere, expandable polymer microsphere, and porous biomass sponge), ice template (including random, unidirectional, and bi-directional freeze-drying), and emulsion template. The influences of the construction of porous carbon nanomaterials on functional characteristics such as electrical conductivity, thermal conductivity, electromagnetic interference shielding, and piezoresistive sensing properties in polymer-based composites were analyzed. Finally, the challenges and prospects of utilizing template-based strategies for constructing 3D porous CFs and their polymer composites were discussed.