Natural Toolbox–Chemical Engineering Aspect and High‐Value Applications of Janus Cellulose Nanomaterials

Abstract Nanotechnology has emerged as a transformative force, enabling the manipulation and engineering of materials at the nanoscale level, which has led to the discovery and development of novel materials with unique properties and functionalities. Janus cellulose nanomaterials, a product of nanotechnology, have attracted significant attention. This article aims to address the current lack of fundamental mechanistic understanding in Janus cellulose by investigating the intrinsic relationship between structural design and functional performance. Specifically, it begins by elucidating the construction principles of Janus cellulose nanomaterials, with a particular focus on how their asymmetric architectures impart anisotropic physicochemical properties, such as interfacial tension modulation, directional interactions, and selective transport. By integrating multiscale modeling approaches—including molecular dynamics simulations and density functional theory calculations—the underlying interfacial behaviors and assembly pathways are revealed, providing theoretical insight into their conformational stability and dynamic response mechanisms. It also explores how surface functionalization and selective chemical modification strategies can be leveraged to finetune hydrophilicity/hydrophobicity balance and interfacial activity, thereby enabling precise control over Janus cellulose interface configuration and functional attributes. On this basis, it further examines non‐covalent driving forces—including electrostatic interactions, van der Waals forces, and hydrogen bonding—within the self‐assembly process, and systematically maps the relationship between assembly conditions and structural evolution. This work establishes a comprehensive structure–driving force–assembly process–property framework, offering theoretical support and design guidance for the development of high‐performance Janus cellulose nanomaterials in advanced applications such as flexible electronics, smart sensing systems, controlled drug delivery, and energy conversion and storage.