In modern society, water purification, ion separation, energy storage, and environmental protection are facing unprecedented challenges. Membrane technology, with its efficient and precise separation characteristics, has become a key technology for solving these problems.

However, designing multifunctional membranes with high selectivity and long-term stability remains one of the bottlenecks in global membrane technology development. Recently, Chen Ximeng and Li Zhan's research team at the Rare Isotope Frontier Science Center of Lanzhou University have made a revolutionary breakthrough in this field, proposing a two-dimensional biomimetic membrane technology based on charge assembly and hydrogen bonding. This innovative technology not only excels in precise ion separation but also shows great potential in uranium extraction, pushing the forefront of membrane technology applications.

Research Background

Membrane technology, as a highly efficient separation method, has been widely used in water treatment, energy recovery, and environmental protection. The selective separation ability of membrane materials is particularly crucial in seawater desalination, wastewater treatment, and uranium extraction. In recent years, two-dimensional materials, such as graphene oxide (GO), have become the focus of membrane material research due to their extremely high surface area, adjustable pore structure, and excellent mechanical properties. However, the interlayer interaction of GO membranes mainly relies on van der Waals forces and π-π stacking, leading to structural damage under high pressure or long-term use, which restricts its feasibility in practical applications.

To overcome these limitations, researchers have attempted to enhance the mechanical strength and stability of membranes by combining them with biomaterials. Especially when introducing biomaterials such as bacteria into membrane materials, maintaining the ordered stacking of membrane layers becomes a huge challenge due to the flexibility of their structure and the diversity of their functions. Inspired by the natural phenomenon of plant cell walls reorganizing into stronger and denser structures under pressure, researchers found that applying external pressure can compress and reorganize flexible three-dimensional biomaterials, allowing them to tightly bind with GO layers, thus significantly improving the stability and mechanical properties of the membrane.

Research Breakthrough

The research team at Lanzhou University proposed an innovative and simple strategy in this area. By utilizing the charge repulsion between GO and engineered bacteria, the researchers successfully induced the formation of a liquid crystal structure and achieved layer-by-layer self-assembly on the polyethersulfone membrane surface. This two-dimensional biomimetic membrane compresses the bacteria flat by applying interlayer pressure, removing interlayer water, and ultimately forming a dense structure. This compression effect not only reduces the distance between functional groups but also constructs a strong hydrogen bond network through hydrogen bonding, significantly improving the mechanical properties of the membrane (tensile strength increased by 12.42 times). More importantly, the compression process maintains the activity of the uranium-binding protein (SUP) on the bacterial surface, allowing it to selectively bind with uranyl ions (UO2²+), achieving efficient screening and capture of uranium ions.

Research Value and Significance

This groundbreaking research provides an efficient and sustainable technological path for uranium extraction from seawater. With the increasing demand for uranium in the nuclear energy industry, the SUP-based composite membrane can not only efficiently recover uranium resources from seawater but also provides new ideas for other ion separation and resource extraction. In addition, this technology has broad application prospects, not only applicable to uranium extraction from seawater but also to water treatment, wastewater recovery, and energy recovery, helping to solve global problems such as resource scarcity, energy crises, and environmental pollution. With continuous technological optimization and industrialization, this two-dimensional biomimetic membrane technology is expected to be widely used in multiple fields and to promote the development of membrane technology towards greater intelligence and efficiency.

Conclusion

Through this groundbreaking research, the research team at Lanzhou University has not only opened up new directions for the development of membrane technology but also provided innovative solutions for the energy, environmental protection, and resource recovery fields. With further improvement and promotion of the technology, two-dimensional biomimetic membranes will have a profound impact worldwide, providing strong support for addressing energy and environmental challenges. With the emergence of more innovations and interdisciplinary collaborations, two-dimensional biomimetic membrane technology is expected to achieve wider applications in the future and play a crucial role in achieving global sustainable development goals.

Information Source: Frontiers in Polymer Science