Advanced Carbon-Based Composite Foams for Enhanced Dehumidification: A Novel Materials Approach

Dehumidification is vital for air quality, but current technologies are energy inefficient. This research addresses the need for advanced materials like novel carbon-based foams synthesized from glucose under autoclaving, incorporating calcium chloride. The as-obtained foams were characterized using TG, SEM, and FTIR spectroscopy to confirm their promising morph-structural properties for dehumidification. In TG curves, mass loss occurs in two main stages. The first loss is primarily attributed to CaCl₂ x XH₂O decomposition. The second mass loss is caused by the oxidation of the glucose-derived carbon structure. The exothermic peaks observed at temperatures over 270°C indicate a minimum of four partially superimposed sub-stages. The CaCl₂ content in the analyzed samples was calculated to be 45 - 60%. Humidity test experiments were conducted at ambient temperature for water vapor absorption using a concentrated calcium chloride solution to regulate the partial pressure of water vapor in the gaseous mixture. The absorption capacity is greater than 98% in 2 hours with an air flow of 300 cm³/min. Liquid formed by absorption wets the cellular walls of the foam, increasing the geometric surface area of the liquid-gas interface, which contributes to an increase in the water vapor absorption rate. This work presents a cost-effective synthesis for these novel carbon-based foams, establishing their potential for enhanced dehumidification. This work was supported by a grant of the Ministry of Research, Innovation, and Digitization, CCCDI-UEFISCDI, project number PN-IV-P8-8.3-PM-RO-BE-2024-0004 within PNCDI IV.