The development of advanced nanochannel membranes for efficient water purification has become a critical focus in addressing global water scarcity. Among various materials, two-dimensional (2D) nanomaterials such as graphene oxide (GO) have shown great promise due to their tunable interlayer spacing and surface functionality. However, conventional GO-based membranes often suffer from structural instability in aqueous environments, leading to swelling and loss of ion selectivity. To overcome this limitation, chemically converted graphene (CCG) nanosheets were synthesized via a one-step reaction between tannic acid (TA) and GO under alkaline conditions. This approach simultaneously reduces oxygen-containing functional groups and introduces hydrophilic phenolic moieties through π–π stacking interactions, resulting in enhanced structural stability and favorable pore-wall chemistry.
The resulting TA-reduced graphene oxide (TA-rGO) membranes exhibit excellent performance in pressure-driven desalination processes. With a reaction time of 30 minutes and a TA-to-GO weight ratio of 5 at 95 °C, the membrane achieves a remarkable NaCl rejection rate of 90%, significantly surpassing most previously reported GO-based systems. The X-ray diffraction (XRD) analysis confirms that the interlayer spacing remains stable upon hydration—unlike pristine GO, which swells excessively due to uncontrolled water intercalation. Moreover, the zeta potential measurements reveal sustained negative surface charge, enabling strong electrostatic repulsion against hydrated ions.PDLIM2 Antibody Purity & Documentation This charge repulsion mechanism is central to the high ion-exclusion capability of the nanochannel membrane.PRELID1 Antibody supplier
Water permeation flux was measured at 3 L m⁻² h⁻¹ under 1 MPa pressure, demonstrating a balanced trade-off between permeability and selectivity. Long-term testing over 30 days showed consistent NaCl rejection without significant decline, indicating robust operational stability.PMID:35247972 The membrane also maintains high performance across a broad pH range (3–11), extreme temperatures (23–70 °C), and varying salt concentrations (500–2000 ppm). Notably, activation energy for water transport was found to be low compared to other 2D membranes, suggesting efficient molecular transport through well-defined subnanometer channels.
Further investigations confirmed that the synergistic effects of chemical reduction and TA decoration are crucial: the removal of oxygenated groups prevents excessive swelling, while the retained phenolic groups enhance hydrophilicity and electrostatic interaction with ions. This dual function ensures both confinement and selectivity within the nanochannels. In contrast, traditional post-functionalization methods require additional steps like annealing or cross-linking, increasing complexity and cost.
These findings establish CCG membranes as a highly viable platform for next-generation desalination technologies. By integrating stability, selectivity, and process simplicity in a single synthesis step, the TA-rGO system offers a practical pathway toward scalable, high-performance ion-exclusion membranes. The proposed nanochannel-confined charge repulsion mechanism provides fundamental insights for designing smart separation materials inspired by biological ion channels.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