A Review on Polymer–Quantum Dots Nanocomposite Membrane and Its Multifunctional Applications

Polymer–quantum dot (QD) nanocomposite membranes represent a new class of advanced separationmaterials that extend the functionality of conventional polymer membranes beyond passive transport. Incorporating QDs with controlled size, composition, and surface chemistry enables simultaneous enhancement of permeability, selectivity, and stability, while introducing active features such as antifouling, antimicrobial activity, photocatalytic self-cleaning, and chemical sensing. This review summarizes recent progress in polymer–QD membranes, focusing on how structural design and interfacial engineering dictate multifunctional performance. Major QD categories carbon-based, semiconductor, and metal oxide are examined with emphasis on dispersion control, compatibility with polymer matrices, and long-term durability. Applications in water and wastewater treatment, gas separation, and barrier technologies are highlighted, illustrating the shift from inert fillers to reactive, performance-driving nanocomponents. The review also outlines emerging design principles, fabrication strategies, and pathways toward scalable manufacturing. Key challenges such as consistent QD synthesis, large-scale membrane production, and operational stability under realistic conditions are critically assessed. Largely, the study provides a unified framework to guide the rational development and practical deployment of polymer-QD nanocomposite membranes for advanced separation and environmental applications.