Supramolecular polymer science expands the scope of supramolecular chemistry and enriches the field of polymer science. It is expected to become an important contributor to scientific and technological progress for a sustainable society. A group of 37 international scholars from seven countries and regions, including China, Singapore, Germany, the UK, and the US, including Professor Xi Zhang from Tsinghua University, Professor Xiaodong Chen from Nanyang Technological University, Professor Frank Würthner from the University of Würzburg, Professor Oren A. Scherman from the University of Cambridge, Professor Amar Flood from Indiana University, Professor Feihe Huang from Zhejiang University, and Professor Junqi Sun from Jilin University, review the important progress in supramolecular polymer science in recent years from five perspectives: 1) driving forces of non-covalent polymerization, 2) polymerization methodologies, 3) physical mechanisms, 4) material morphology, and 5) engineering applications. They also raise nine fundamental questions and major challenges that urgently need to be addressed in response to future development needs: 1) synergy, 2) quantification, 3) spatiotemporal observation, 4) theoretical simulation, 5) digitalization, 6) recyclability, 7) healthcare, 8) energy conversion, and 9) large-scale manufacturing. They point out that the integration of new concepts, technologies, and methods, such as artificial intelligence, data-driven design, automated synthesis, and advanced manufacturing, supramolecular polymer science holds the keys to the development of recyclable materials, devices, and intelligent systems for sustainable social progress. This review is not only an in-depth summary and discussion, but also a collaborative initiative for the global multidisciplinary research community. The article was published as an open access Review in CCS Chemistry, the flagship journal of the Chinese Chemical Society.
Why do we need "dynamic" polymers now?
For the past century, covalent polymers have supported numerous fields such as packaging, transportation, aerospace, and biomedicine thanks to their high strength, durability, and ease of processing. However, today, the demands on materials are shifting: they must not only be "strong and durable" but also capable of sensing environmental changes, repairing themselves after damage, altering their structure as needed, and re-entering the cycle at the end of their lifespan. This does not mean that traditional covalent polymers will be replaced, but rather that materials science needs a new logic of connection. Supramolecular polymers maintain their structure through reversible non-covalent interactions such as hydrogen bonds, host-guest interactions, and metal coordination. Individual interactions may not be strong, but multiple interactions can synergistically form a stable system; when conditions such as temperature, light, force, and chemical environment change, these connections can reorganize, thus giving the material the space for "dynamic adaptation."
From "Macromolecules" to "Programmable Materials":
In 1920, German chemist Hermann Staudinger proposed the "macromolecule" theory, initiating modern polymer science research. Since then, supramolecular chemistry has expanded its research perspective from "how molecules connect internally" to "how molecules recognize and assemble." Over the past four decades, supramolecular polymers have moved from conceptual exploration to the interdisciplinary frontier of chemistry, physics, materials science, processing, and devices, demonstrating enormous potential in areas such as tissue engineering, flexible bioelectronics, energy storage, and sustainable materials (Figure 1). More importantly, artificial intelligence-aided design, automated experimental platforms, and intelligent manufacturing are changing research methods: the development of supramolecular polymers is shifting from the past "experience-based trial-and-error exploration" to "precise design and intelligent programming" based on data and mechanisms, which will accelerate the development of the supramolecular polymer field.
Five frontiers converging into a discipline called "Materials Systems Science":
The review summarizes the important advances in recent years into five interconnected levels, which together drive supramolecular polymers from "being able to assemble" to "being controllable, understandable, and applicable" (Figure 2).
1) Polymerization Drivers: Making "Molecular Fasteners" More Diverse. The introduction of interactions such as free radical pairs, halogen bonds, anionic dimers, and cationic-pi has broadened the material basis for constructing supramolecular polymer systems.
2) Polymerization Methodologies: Making Assembly Processes More Controllable. The establishment of polymerization methodologies such as controlled polymerization of supramolecular monomers, living supramolecular polymerization of kinetically inert monomers, fuel-driven dissipative polymerization, and concerted covalent-supramolecular polymerization provides effective pathways for the controllable construction of supramolecular polymers.
3) Physical Mechanisms: Bridging the Explanation Chain from Microscopic to Macroscopic. Applying theoretical methods from classical polymer physics to supramolecular polymer systems opens up entirely new research perspectives for deepening our understanding of their structure-property relationships.
4) Material Morphology: From Elastomers to Glasses and Crystals. Precise control over the short-range or long-range ordered structure within polymers has significantly propelled the creation of supramolecular polymer materials.
5) Engineering Applications: Entering the Fields of Life Sciences, Electronics, Energy, and Recycling. Supramolecular polymer systems have spurred broad application and transformation prospects in areas such as tissue engineering, flexible bioelectronics, lithium-based batteries, and the recycling of polymers.
The real watershed - Can the nine challenges be solved?
For a new material research direction to mature, it's not enough to simply look at "what has been achieved"; it's also crucial to answer the question of "whether it can be accurately measured, calculated, stably reproduced, and manufactured on a large scale." The nine challenges identified in the review correspond to the complete chain from basic discovery to application. Behind each challenge lies a new research opportunity (Figure 3).
1 ) Synergy: How to evolve from trial and error to the synergistic regulation of covalent and non-covalent interactions to construct supramolecular polymers with controllable structure and properties;
2 ) Quantification: How to move from semi-empirical application to quantitative selection of thermodynamic and kinetic properties to program multi-level supramolecular polymer systems;
3 ) Spatiotemporal Observation: How to integrate multiple characterization tools to detect supramolecular polymer structures at different spatiotemporal scales in situ with high resolution;
4 ) Theoretical Simulation: How to establish a controllable compromise between generality and specificity to study multi-level dynamics, thereby building a framework for supramolecular polymer physics;
5 ) Digitalization: How to establish standardized databases and data sharing platforms to empower data-driven supramolecular polymer chemistry;
6 ) Recyclability: How to develop economically valuable and environmentally friendly methods to recycle and process supramolecular polymer materials;
7 ) Precision Medicine: How to fully utilize the dynamic adaptability and compatibility of supramolecular polymers to develop diagnostic and treatment methods;
8 ) Energy Conversion: How to balance the binding and dissociation within supramolecular polymers to regulate carrier migration and achieve efficient transport;
9 ) Large-scale Manufacturing: How to improve the stability and reproducibility of large-scale preparation of supramolecular polymers to promote their transformation and application.
The biggest opportunity - Closed loop formed by interdisciplinary research:
Future breakthroughs in supramolecular polymer science may not solely stem from stronger non-covalent interactions, but rather from a closed loop encompassing "data-model-design-experiment-manufacturing." This review outlines the future development path of supramolecular polymer science from various dimensions (Figure 4). In the future, through deep integration with AI-enabled design, intelligent manufacturing, and green circular economy concepts, supramolecular polymer science is expected to propel polymer materials from the traditional era of "stable structures" to a new era of "dynamic intelligence," providing crucial support for building more sustainable future material systems.
Conclusions: The future of materials is not just about being "stronger":
The fascinating aspect of supramolecular polymer science lies in its ability to transform our understanding of materials: materials are no longer merely passive load-bearing structures, but can potentially sense, respond, repair, and reorganize like dynamic systems. At the same time, the closer we get to real-world applications, the more specific the questions become: How can performance be quantified? How can mechanisms be verified? Is recycling economical? Can manufacturing be repeated? How can safety be assessed?
Therefore, this review is more like a roadmap: basic science determines how deep we can go, data and tools determine how fast we can go, and sustainability and large-scale manufacturing determine how far we can ultimately go. The competition for next-generation polymers may shift from simply pursuing "stronger and more durable" to "smarter, more adaptable, and easier to return to the cycle."
