Nanoporous Membrane Self-Assembly Ion Blocking

The patent applies preliminary action by first forming nanochannels with controlled dimensions (10-200 nm) through anodization of aluminum oxide, then subsequently filling these channels with self-assembled monolayers of functionalized nanoparticles. This two-stage approach allows precise control over final pore size (<10 nm) by selecting appropriate nanoparticle diameters, while avoiding the need for complex direct fabrication methods. The self-assembly process automatically organizes nanoparticles to define the final pore structure without requiring additional lithography or etching steps.

The patent utilizes porous materials by employing anodized aluminum oxide as the base membrane material, which provides a naturally porous structure with controllable pore sizes. The functionalized nanoparticles are then introduced into these porous channels and self-assemble to further reduce the effective pore diameter. This approach leverages the inherent porosity of the aluminum oxide structure rather than requiring completely dense membranes, simplifying the overall fabrication process while achieving the desired ion blocking capability.

The patent applies local quality by creating a heterogeneous structure where the base membrane has larger nanochannels (10-200 nm) that allow high water flux, while the interior surfaces of these channels are locally modified with self-assembled monolayers of functionalized nanoparticles. These nanoparticles selectively block ion transport pathways without completely sealing the channels, thereby maintaining water flux while achieving high salt rejection. The local presence of nanoparticles creates different transport characteristics for water and ions within the same channel structure.

The patent employs composite materials by combining anodized aluminum oxide with functionalized nanoparticles to create a hybrid membrane structure. The aluminum oxide provides the mechanical support and base porosity, while the nanoparticles introduce selective ion blocking capability. This composite approach allows the membrane to simultaneously achieve high water flux (from the aluminum oxide matrix) and high salt rejection (from the nanoparticle functional groups), resolving the traditional trade-off between these two performance parameters.

The patent applies self-service by utilizing the self-assembly phenomenon, where functionalized nanoparticles automatically organize themselves into ordered monolayers on the interior surfaces of nanochannels without requiring external directing fields or complex processing equipment. The nanoparticles self-position based on their functional groups interacting with the aluminum oxide surface, creating the desired nanoporous structure through spontaneous organization. This eliminates the need for time-consuming lithography, etching, or deposition techniques, significantly improving production efficiency while maintaining precise structural control.

The patent employs parameter changes by controlling the diameter of functionalized nanoparticles (2-20 nm) and the concentration of nanoparticle solutions to achieve the desired final pore size and membrane performance. By adjusting these parameters, the membrane structure can be optimized for different applications without changing the fundamental fabrication process. This approach allows for flexible production of membranes with tailored properties using a simple, scalable methodology that maintains high productivity.