Harnessing lignocellulose hydrogels for efficient and antifouling nanoplastic-capture membranes

Lignocellulose is indispensable to environmental self-remediation, and its inherent hierarchical heterogeneity can be harnessed to achieve superior immobilization of specific pollutants. Here, lignocellulose was facilely disintegrated into its component nanofibrils and transformed into structurally tunable hydrogels, which demonstrated high efficacy in capturing ubiquitous aquatic nanoplastics (NPs). We employed an integrated multiscale approach to reveal how the topological architecture and rheological behavior of lignocellulose hydrogels govern the transport dynamics of colloidal NPs. With this theoretical foundation, the lignocellulose hydrogel can be fabricated on demand for the highly efficient removal of broad-spectrum NPs (>95%) coupled with a high water flux exceeding 70 L/m²·h. Furthermore, functionalizing petroleum-based filter membranes with a reconfigurable lignocellulose hydrogel overcame the critical limitations of conventional ultrafiltration in capturing aquatic nanoparticles, namely low efficiency, membrane fouling, and secondary pollution. Additionally, we proposed a low-environmental-risk and cost-effective disposal strategy for spent NPs-laden lignocellulose hydrogels by integrating them into pulp fibers as a reinforcing and plasticizing agent to fabricate strong, water-resistant, and thermally stable molded products. In summary, our work presents a viable lignocellulose-based solution addressing key challenges in NPs ultrafiltration.