Mussel-inspired chemistry, owing to its unique and versatile functions to manipulate dynamic molecular-scale interactions, has emerged as a powerful tool for the rational design and synthesis of new hydrogels. In particular, possessing a myriad of unique advantages that are otherwise impossible by conventional counterparts, mussel-inspired hydrogels have been widely explored in numerous fields such as biomedical engineering, soft electronics and actuators, and wearable sensors. Despite great excitement and vigor, a comprehensive and timely review on this emerging topic is missing. In this review, we discuss (1) the fundamental interaction mechanisms underpinning the spectacular wet adhesion in natural mussels and mussel-inspired materials; (2) the key routes to engineering hydrogels by leveraging on the interactions of mussel-inspired building blocks; (3) the emerging applications of mussel-inspired hydrogels, especially in the areas of flexible electronics and biomedical engineering; (4) the future perspectives and unsolved challenges of this multidisciplinary field. We envision that this review will provide an insightful perspective to stimulate new thinking and innovation in the development of next-generation hydrogels and beyond.

Mussel-inspired hydrogels: from design principles to promising applications

Stretchable conductive nonwoven fabrics with self-cleaning capability for tunable wearable strain sensor

Superhydrophobic surfaces hold great prospects for extremely diverse applications owing to their water repellence property The essential feature of superhydrophobicity is micro-/nano-scopic roughness to reserve a large portion of air under a liquid drop However, the vulnerability of the delicate surface textures significantly impedes the practical applications of superhydrophobic surfaces Robust superhydrophobicity is a must to meet the rigorous industrial requirements and standards for commercial products In recent years, major advancements have been made in elucidating the mechanisms of wetting transitions, design strategies and fabrication techniques of superhydrophobicity This review will first introduce the mechanisms of wetting transitions, including the thermodynamic stability of the Cassie state and its breakdown conditions Then we highlight the development, current status and future prospects of robust superhydrophobicity, including characterization, design strategies and fabrication techniques In particular, design strategies, which are classified into passive resistance and active regeneration for the first time, are proposed and discussed extensively

Robust superhydrophobicity: mechanisms and strategies

Ultrathin nanofiltration membrane with polydopamine-covalent organic framework interlayer for enhanced permeability and structural stability

Tannic acid-polyethyleneimine crosslinked loose nanofiltration membrane for dye/salt mixture separation

Mussel-inspired chemistry has attracted widespread interest in membrane science and technology. Demonstrating the rapid growth of this field over the past several years, substantial progress has been achieved in both mussel-inspired chemistry and membrane surface engineering based on mussel-inspired coatings. At this stage, it is valuable to summarize the most recent and distinctive developments, as well as to frame the challenges and opportunities remaining in this field. In this review, recent advances in rapid and controllable deposition of mussel-inspired coatings, dopamine-assisted codeposition technology, and photoinitiated grafting directly on mussel-inspired coatings are presented. Some of these technologies have not yet been employed directly in membrane science. Beyond discussing advances in conventional membrane processes, emerging applications of mussel-inspired coatings in membranes are discussed, including as a skin layer in nanofiltra-tion, interlayer in metal-organic framework based membranes, hydrophilic layer in Janus membranes, and protective layer in catalytic membranes. Finally, some critical unsolved challenges are raised in this field and some potential pathways are proposed to address them.

Ming Bang Wu

Papers

Dopamine: Just the Right Medicine for Membranes

Positively-charged nanofiltration membranes constructed via gas/liquid interfacial polymerization for Mg2+/Li+ separation

Wooden composite separators with ultrahigh uranium/vanadium selectivity and antibacterial property for capturing uranium from seawater

Natural Cellulose-based Microspheres Decorated with Amidoxime Groups for Decontamination of Radioactive Wastewater

Amyloid-Like Coatings Decorated Electrodes Boost the Uranium Electro-Adsorption from Seawater