HKUST Engineering Uncovers Key Mechanism of Liquid-Liquid Phase Separation
Have you ever wondered how mussels instantly glue themselves to rocks, allowing them to survive the crushing force of ocean waves? They complete this process in under 30 seconds. Yet, in a laboratory, replicating this process of molecular self-assembly, known as liquid-liquid phase separation (LLPS), typically takes dozens of minutes, if not hours. A research team of The Hong Kong University of Science and Technology (HKUST) has recently solved this long-standing puzzle using large-scale molecular dynamics simulation and theoretical analysis, revealing the secret to nature’s incredible speed and providing implications for instant biocompatible surgical glues.
This theoretical breakthrough, published in Nature Communications in the title of “Mixing protocols determine liquid–liquid phase separation dynamics in polyelectrolyte complex coacervation”, fundamentally changes our understanding of how charged polymers form complex structures. The study was conducted by Prof. CHEN Shensheng (co-corresponding author), Assistant Professor of the Department of Chemical and Biological Engineering at HKUST, and his PhD student WU Zongpei (first author), in collaboration with Prof. WANG Zhen-Gang, Dick and Barbara Dickinson Professor of Chemical Engineering at California Institute of Technology.
This latest study builds on the previous successes of Prof. Chen and his team’s work. Using a powerful, custom-built simulation platform that tracks over one million charged particles, the researchers were the first to simulate the entire LLPS process from start to finish, explicitly modeling both hydrodynamic and electrostatic forces. They discovered that mimicking nature’s “Flux Pathway”—in which molecules mix at a target spot—creates an electrochemical “superhighway” that drives assembly at an incredible rate. Under this particular pathway, the condensed domain in LLPS dynamically grows with time following a power law of t2/3, whereas classical theory predicts a scaling of t1/3. This difference in scaling leads to a staggering result: simulations show that forming a half-centimeter adhesive droplet takes just 10 seconds using nature’s method, while conventional laboratory techniques would require over 47 years.
Prof. Chen said: “Nature has been our ultimate inspiration. The disconnect between the slow pace in experimental labs and the ultrafast assembly in marine life was a critical problem we had to solve. Our earlier work first discovered that there is a fundamental difference between LLPS dynamics of polyelectrolyte systems and classical theories, but this new study provides the practical blueprint. By simulating the entire process at unprecedented length and time scales, we have moved beyond theory to demonstrate how nature achieves such remarkable speed. This finally gives us a hint to create materials that can assemble on demand, with significant implications ranging from instant, biocompatible surgical glues to programmable smart materials.”
This latest breakthrough builds upon Prof. Chen’s foundational work in Physical Review Letters in 2023, which was the first to fundamentally challenge the decades-old classical theory of droplet coarsening in charged polymer systems. That pioneering study established that the dynamics of charged polymers (including most disordered proteins) follow entirely different pathways and scaling laws, effectively rewriting the rules of liquid-liquid phase separation. The current work in Nature Communications fully realizes the vision of that earlier research, providing definitive computational evidence and a clear, actionable mechanism to explain these new rules.
About The Hong Kong University of Science and Technology
The Hong Kong University of Science and Technology (HKUST) (https://hkust.edu.hk/) is a world-class university known for its innovative education, research excellence, and impactful knowledge transfer. With a holistic and interdisciplinary pedagogy approach, HKUST was ranked 6th in the QS Asia University Rankings 2026, 3rd in the Times Higher Education’s Young University Rankings 2024, and 19th globally and 1st in Hong Kong in the Times Higher Education’s Impact Rankings 2025. Eleven HKUST subjects were ranked among the world’s top 50 in the QS World University Rankings by Subject 2026. In addition, in the Times Higher Education World University Rankings by Subject 2026, HKUST’s Computer Science discipline which encompasses areas such as artificial intelligence and machine learning, has been ranked No. 1 in Hong Kong for ten consecutive years. Our graduates are highly competitive, consistently ranking among the world’s top 30 most sought-after employees. In terms of research and entrepreneurship, over 80% of our work was rated “internationally excellent” or “world leading” in the Research Assessment Exercise 2020 of the Hong Kong’s University Grants Committee. As of January 2026, HKUST members have founded over 1,900 active start-ups, including 10 Unicorns and 21 exits (IPO or M&A).
(This news was originally published by the HKUST Global Engagement and Communications Office here.)
