In recent years, the treatment of complex and diverse organic pollutants in water has become a pressing environmental challenge. Conventional methods such as electrochemical oxidation, membrane filtration, and flocculation often suffer from high energy consumption, operational complexity, or secondary pollution. In this context, adsorption-based technologies have emerged as a promising alternative due to their low cost, simplicity, and high efficiency. However, many existing adsorbents lack sufficient mechanical strength, reusability, or broad-spectrum contaminant removal capability. This study presents a novel graphene oxide (GO) and poly(vinyl alcohol) (PVA)-based double-network cross-linked aerogel (GPXA), synthesized via an in situ hydrothermal reaction followed by freeze-drying. The resulting GP16A aerogel exhibits exceptional rigidity and super-elasticity that can be reversibly triggered by water stimuli.
The formation mechanism involves multiple interactions: glutaraldehyde-mediated acetalization between GO and PVA chains, hydrogen bonding, and Ca²⁺-induced ionic cross-linking. These interactions create two interconnected three-dimensional networks, leading to a robust yet flexible structure. Notably, GP16A maintains nearly no volume shrinkage during fabrication—unlike most GO-based aerogels—which enhances dimensional stability. Upon immersion in water, GP16A transforms into a highly elastic state, capable of full recovery after compression. After freeze-drying, it returns to its original rigid form without degradation, enabling repeated use. This reversible rigid-elastic conversion is ideal for solid-liquid separation and easy regeneration through simple squeezing operations.
The adsorption performance of GP16A toward methylene blue (MB), a common cationic dye, was evaluated under various conditions. It achieved an outstanding adsorption capacity of 698.38 mg g⁻¹, significantly outperforming many reported GO-based materials. Equilibrium was reached within 24 hours, and after six adsorption-desorption cycles, the retention capacity remained at 85.62%, demonstrating excellent reusability. Kinetic analysis revealed that pseudo-second-order model best fit the data, indicating chemically controlled adsorption involving valence forces. The process was further governed by electrostatic interaction, π–π stacking, and hydrogen bonding. Additionally, the surface charge and pH dependence confirmed that electrostatic attraction dominates at higher pH values, while competitive H⁺ adsorption reduces efficiency in acidic environments.
To address oil and organic solvent contamination, GP16A was hydrophobically modified using methyltrimethoxysilane (MTMS), yielding GP16A-MTMS.2124-57-4 Formula This derivative exhibited a water contact angle exceeding 143°, confirming strong hydrophobicity. It demonstrated exceptional absorption capacity—up to 286.49 times its own weight—for a wide range of oils and solvents including chloroform, n-hexane, toluene, and pump oil. Repeated absorption-squeezing cycles showed minimal loss in performance, with stable recovery over ten cycles. The regenerated aerogel could be restored to a rigid state upon freeze-drying, making it suitable for continuous, dynamic oil-water separation processes.
Characterization techniques such as SEM, XRD, FTIR, XPS, and nitrogen adsorption-desorption confirmed the structural integrity, chemical composition, and high surface area (141.5119-48-2 InChIKey 65 m² g⁻¹) of GP16A.PMID:33884499 The mesoporous nature and abundant functional groups provided ample active sites for pollutant capture. Furthermore, the synergistic effect of dual-network cross-linking enhanced mechanical resilience and prevented structural collapse during swelling or compression.
This work introduces a scalable, sustainable, and highly efficient aerogel platform with multifunctional capabilities. Its unique combination of dimensional stability, recyclability, solvent resistance, and superior adsorption performance makes it a viable candidate for real-world applications in wastewater treatment, oil spill remediation, and environmental protection. Future efforts will focus on optimizing selectivity for specific contaminants and scaling up production for industrial deployment.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com