###### Abstract
On the other hand, even though the metal foams exhibit high thermal conductivities (>10 W/(m\(\cdot\)K), [30] they must possess an optimal porosity, depending on the PCMs thermal and geometrical specifications, in order to favor efficient heat transfer. Thus, a large number of research studies have reported the development of carbon-based foams, aerogels, or graphene PCMs-composites, synthesized by using biomass, polysaccharides, and synthetic polymers as raw materials and templates [31, 32, 33, 34, 35, 36]. Additionally, lightweight carbon foams have also been considered as the most promising candidates for providing excellent electromagnetic interference (EMI) shielding properties, since they possess a three-dimensional (3D) network structure that enhances the multiple reflections of incident electromagnetic waves and improves the microwave absorption [37, 38, 39]. Generally, metals show good shielding performance, but their composites suffer from several drawbacks, including high densities, high reflection, easy corrosion, and processing difficulties. However carbon-based foams have many other advantages such as low density, good stability, resistivity against chemical corrosion, operational thermal conductivity, high porosity, and the ability to suppress EMI from electronic devices and reduce the risk of electromagnetic fields (EMFs) exposure of people in their houses and workplaces [37, 39, 40, 41]. So far, some studies reported the fabrication of carbon foams utilizing recycled industrial wastes [42, 41]. For instance, carbon foam hybrids were synthesized as lightweight EMI shielding materials, using as raw materials a mixture of dried Red Mud (RM), which is a solid containing metallic oxide impurities that is a waste product of bauvite refinement [41]. The prepared hybrid foam showed excellent EMI SE in the 8.2-12.4 GHz region (51.4 dB at 8.2 GHz) and excellent fire-resistant performance, due to the thermal insulating nature of metal oxides present in red mud. In another study, phenolic foam composites reinforced with red mud microparticles were prepared using a thermal foaming method [43]. The composite foams reinforced with 15 wt% of modified red mud microparticles showed improvement on their tensile and impact strength by \(\sim\)82%, along with enhancement of their flame retardant properties. However, it should be noted that none of these stud ies investigated carbon foams incorporating organic PCMs, and hence did not evaluate the electromagnetic interference shielding effectiveness of these materials in conjunction with their capability for efficient thermal management, including shape stabilization, heat absorption, and thermal conductivity. In this present work, hybrids derived of shape-stabilized organic PCMs into carbon-red mud hybrids were fabricated and studied for the first time, concerning their thermal and EMI shielding properties. It should be noted that as shape stabilizers, carbon foams were prepared according to already published research works [40, 41]. However, our pioneer hybrids, which incorporated organic PCMs into the carbon foam matrices, presented multifunctional properties such as: shape-stabilization of PCMs, latent heat thermal energy storage, good mechanical behavior, light weight, and EMI shielding properties. All these properties mentioned before are of high importance in construction section, where the building components (i.e., gypsum or cement boards) should possess enhanced thermal energy storage and EMI shielding efficiency.