Confinement Effects and Manipulation Strategies of Nanocomposite Membranes towards Molecular Separation

Abstract Materials featuring well‐defined nanoscale channels offer inherent advantages in the selective transport of gases, liquids, and ions, making them pivotal in applications such as molecular separation, catalysis and energy storage. A crucial challenge lies in assembling ordered nanochannel structures and translating these microscopic architectures into macroscopic regular distributions to enhance performance. Nanocomposites provide a promising solution by incorporating nanoscale material (e.g., filler) that significantly enhances macroscale properties of matrix (e.g., polymer). In this review, we spotlight nanocomposite membranes nanocomposite membranes that utilize confinement effects between filler and matrix to precisely control nanochannel apertures, surface properties, and channel distribution for efficient separation of target systems. We discussed the underlying design principles, channel architectures, and strategies for optimizing polymer‐filler interfaces and nanochannel manipulation within functional membranes. Emphasis is placed on the fundamental mechanisms of mass transport, and the structure‐property‐performance relationships within the nanocomposite membranes towards molecular separation. This work aims to provide a comprehensive understanding of how these nanocomposite membranes can be further developed to meet the demands of industrial and environmental applications.