One-Pot Synthesis of Carbon-Based Composite Foams with Tailorable Structure

Dehumidification plays a vital role across industrial, commercial, and residential settings, where controlling moisture is essential for maintaining air quality, protecting materials, and ensuring comfort. Calcium chloride (CaCl2) is a widely used, low-cost desiccant, but it suffers from a critical drawback: under humid conditions, particles tend to agglomerate, which reduces their ability to absorb water. In addition, when the salt dissolves in hydration water, its contact surface with moist air decreases, and corrosive liquid leakage can occur. Embedding CaCl2 into hydrophilic porous matrices offers a solution by dispersing particles more effectively, preventing agglomeration, increasing the contact area, and retaining liquid within the pore network to suppress leakage. In this study, we introduce a novel approach for fabricating carbon-based foams impregnated with CaCl2, produced through the thermal decomposition of glucose under self-induced pressure. These foams exhibit a composite architecture that integrates CaCl2 and calcium carbonate, enabling controlled porosity through selective dissolution. Importantly, the in situ transformation of CaCl2 into calcite refines the internal structure, improving both stability and acids absorption performance. FTIR confirmed the strong hydrophilicity of the foam walls, which enhances water vapor uptake while preventing leakage of saturated salt solutions. The carbon matrix further suppresses salt particle agglomeration during moisture absorption, resulting in high efficiency. These multifunctional foams not only capture water vapor and volatile acids but also show potential as phase change materials. Mechanical testing revealed tunable behavior among the fabricated foams, ranging from high-stiffness structures with superior energy absorption (e.g., C2) to more compliant foams with extended strain capacity (e.g., A2), illustrating their versatility for practical applications.