چكيده لاتين
Given the escalating global demand for access to clean water and the mounting environmental concerns stemming from oil-contaminated wastewater, the treatment of these effluents has become a critical challenge. In this context, superhydrophobic foam technology has garnered significant attention due to its advantages, including the elimination of chemical additives to the effluent, low energy consumption, and high efficiency. Polyurethane (PU) foams, characterized by their three-dimensional porous structure and high absorption capacity, are recognized as a promising option for oil-water separation. However, challenges such as the complexity of the production process, insufficient stability of the hydrophobic properties, and high costs have imposed limitations on their industrial application.
In this research, flexible PU foams with an open-cell structure were synthesized using hydrophobic raw materials, namely toluene diisocyanate and polypropylene glycol. Subsequently, the surface of these foams was modified with a PU nanocomposite via a dip-coating method to achieve stable superhydrophobicity. The properties of the fabricated foams, including thermal stability, mechanical strength, surface morphology, and performance in oil/solvent-water separation, were evaluated using standard testing procedures.
The results demonstrated that the modified foams retained a high absorption capacity of over 95% even after 50 consecutive cycles of use. These low-density foams (approximately 100 kg/m³) were capable of absorbing oils and organic solvents up to 55 times their own weight and exhibited stable performance under harsh environmental conditions (varying temperatures, acidic, alkaline, and saline environments, and water currents). Furthermore, the continuous and selective separation of oil from water was enabled using a simple vacuum system.
In addition to the performance results, morphological and chemical analyses demonstrated that coating the foam surface with water-based nanocomposites containing fluorinated compounds created uniform micro-nano roughness and strong adhesion between the coating layer and the polyurethane skeleton. This dual structure played an effective role in increasing the contact angle, decreasing the surface energy, and enhancing the superhydrophobicity stability of the foam. The recycling test results indicated that the foams are reusable after several absorption and compression cycles without a noticeable decrease in their absorption capacity. These findings prove that surface modification with a water-dispersion-based approach provides a sustainable and scalable method for producing long-term performing superhydrophobic foams.
This study indicates that PU foams coated with a water-based nanocomposite represent a durable and efficient option for the treatment of oily wastewater and resource recovery on an industrial scale. Key achievements of this research include improved hydrophobic stability, simplified production process, the creation of antibacterial properties, and enhanced flame resistance.
