In a landmark study that promises to reshape the landscape of nanoscience, researchers at Chung-Ang University in South Korea have unveiled a groundbreaking theoretical framework to decode the complex growth behaviors of nanoparticles. Nanoparticles, whose diminutive sizes confer unique physical and chemical properties, are foundational elements in cutting-edge technologies such as quantum-dot displays, nanocatalysts, and advanced drug delivery systems. Despite their widespread utilization and intensive study, the precise mechanisms governing the uniform formation and growth of these tiny particles have long eluded scientists. Addressing this enigma, the new theory provides unprecedented insights into the multiphasic and size-dependent dynamics that dictate nanoparticle ensemble growth.
Historically, the classical nucleation theory (CNT) rooted in the Gibbs-Thomson equation has served as the cornerstone for understanding nanoparticle generation and growth over the last century. CNT rationalizes particle formation via thermodynamic considerations, describing how atoms or molecules overcome an energy barrier to nucleate new phases. However, this classical framework falls short in explaining the emergence of narrowly distributed particle sizes and the intricate temporal evolution observed in nanoparticle systems. The inability of CNT to reconcile these observations has propelled researchers to seek alternative models that incorporate more nuanced physical and chemical processes.
The study, spearheaded by Professor Jaeyoung Sung and his interdisciplinary team from the Department of Chemistry and the Global Science Research Center for Systems Chemistry at Chung-Ang University, represents a significant leap forward. By leveraging real-time, in-situ liquid-phase transmission electron microscopy (TEM), the researchers tracked the growth trajectories of hundreds of nanoparticles on the scale of just a few nanometers. These observations revealed that nanoparticle growth is characterized by multiple kinetic phases, each exhibiting distinct statistical behaviors in terms of size distribution and growth rates. Moreover, the data highlighted that nanoparticle coalescence—the process where two or more particles merge—occurs predominantly within a sharply confined time window, an aspect inadequately addressed by previous theories.
The intricate size-dependent growth patterns captured through liquid-phase TEM challenged conventional wisdom and underscored the necessity of a more comprehensive theoretical approach. In response, the team formulated a novel model that integrates six pivotal factors influencing nanoparticle growth: nanoparticle energy states, geometric shape, configurational degeneracy (the number of ways a system’s configuration can be arranged without changing its energy), monomer diffusion coefficients, and monomer association rates on the particle surface. Crucially, the theory transcends previous limitations by incorporating nanoparticle translation, rotation, and vibrational dynamics, as well as interactions with surrounding molecular species—parameters that were notably absent in classical frameworks.
This enriched model elucidates how motion and configurational entropy fundamentally influence nucleation and growth processes, offering an unprecedented quantitative fit to experimental growth trajectories. The robustness of the theory was validated across various nanoparticle systems, including platinum nanoparticles synthesized through multiple precursor chemistries, as well as metal oxide and semiconductor nanoparticles, evidencing broad applicability under diverse experimental environments. Remarkably, the theory predicts a counterintuitive phenomenon wherein smaller nanoparticles continue to grow while larger particles dissolve, directly challenging the conventional Ostwald ripening paradigm that has dominated nanoparticle science for a century. This insight accounts elegantly for the observed size focusing phenomena and the emergence of uniform particle populations.
Professor Jungwon Park of Seoul National University, an expert in liquid-phase TEM involved in the experimental component of the study, emphasized the transformative nature of these findings. The ability to observe and model nanoparticle ensembles in real time lays the groundwork for understanding size distribution dynamics beyond the reach of prior experimental or theoretical techniques. Furthermore, this work paves the way for leveraging fundamental physics to unravel the complexity of nanoparticle systems, thereby enabling predictive control over nanoscale synthesis.
On the theoretical front, Distinguished Professor Taeghwan Hyeon, Director of the IBS Center for Nanoparticle Research, hailed this research as signaling “a fundamental shift” in how the scientific community comprehends nanoparticle formation and evolution over time. Traditionally, nanoparticle growth has been simplified to thermodynamic processes devoid of intricate kinetic and dynamic considerations. By contrast, this new framework acknowledges the multiphase and dynamic nature of real-world nanoparticle growth, capturing the subtleties that govern size distribution and stability.
Beyond materials science, the implications of this theory extend into biological and medical domains. Professor Sung highlighted that the mathematical structure of their model can be adapted to comprehend the formation and aggregation dynamics of biological condensates, implicated in neurodegenerative diseases such as Alzheimer’s. The connection between physical principles delineated in nanoparticle growth and pathological protein aggregation opens promising interdisciplinary research avenues, potentially guiding therapeutic interventions.
The study’s authors also stress the synergy between their theoretical advances and emerging computational methodologies. By combining their model with state-of-the-art artificial intelligence and computational chemistry techniques, they foresee a future where nanoparticle synthesis can be predictively controlled with high precision. This predictive capability marks a milestone toward the rational design of nanoparticles tailored for specific industrial applications, including catalysis, semiconductor manufacturing, and targeted drug delivery systems. The ability to engineer nanoparticles with predetermined size distributions and functional properties holds the promise of revolutionizing multiple technology sectors.
This research was meticulously published in the June 2025 issue of the prestigious journal Proceedings of the National Academy of Sciences. It serves as a testament to the power of integrating experimental innovation with rigorous theoretical development. The combination of in situ liquid-phase TEM observations with the novel multiphasic growth model equips scientists with a powerful toolkit to dissect and manipulate nanoparticle dynamics with hitherto unmatched fidelity.
Overall, the work from Chung-Ang University not only addresses a century-old challenge in nanoscience but also charts a compelling new course for future investigations. As nanoparticle applications continuously expand—from energy conversion to medicine and electronics—the ability to precisely direct their synthesis and growth will become increasingly pivotal. By unveiling the hidden complexities of nanoparticle growth kinetics and providing a robust theoretical framework, this study catalyzes a new era of controlled nanomaterial innovation.
Subject of Research: Nanoparticle Growth Dynamics
Article Title: Multiphasic size-dependent growth dynamics of nanoparticle ensembles
News Publication Date: 4-Jun-2025
Web References:
Chung-Ang University Chemistry Department
PNAS Article DOI
References:
DOI: 10.1073/pnas.2424950122
Image Credits:
PhD student Jingyu Kang, Dr. Ji-Hyun Kim, and Professor Jaeyoung Sung from Chung-Ang University
Keywords
Nanoparticles, Semiconductors, Quantum dots, Materials science, Drug delivery, Nanomaterials, Electron microscopy, Catalysis, Colloids, Physical chemistry
