RSC Applied Interfaces publishes interdisciplinary work with an applied focus, which can be read for free here. To celebrate the excellent articles that have been published so far in our journal, we asked some of our authors to discuss their work in more detail.
In this post, we hear from Maryam Bonyani, Ronak Ansaripour and Sitaraman Krishnan as they discuss their recently published article entitled ‘Nanoclay-enhanced self-healing of polyurethane–urea coatings enabled by disulfide exchange‘.
An introduction from the authors
Polyurethane coatings are widely used to protect materials in demanding environments, but once damaged, they often require repair or replacement. In this work, we developed a self-healing polyurethane–urea coating that combines dynamic disulfide chemistry with amine-functionalized nanoclay to achieve both high mechanical strength and autonomous repair.
A particularly significant finding was that the reactive nanoclay not only reinforced the polymer but also accelerated the healing process. This is noteworthy because increasing stiffness typically restricts polymer chain mobility and slows self-healing. Our results show that reactive nanoclay can overcome this long-standing trade-off, enabling coatings to recover their mechanical properties both in air and under water.
Why Interfaces Matter
Interfaces are central to both damage and healing in our material. When a coating cracks, healing occurs at the newly created polymer–polymer interface, where the separated crosslinked polymer networks must reconnect to restore mechanical integrity. Equally important is the interface between the polyurethane–urea matrix and the amine-functionalized nanoclay. Rather than serving as an inert reinforcing filler, the amine-functionalized nanoclay is chemically integrated into the polyurethane–urea network through urea linkages that can participate in reversible covalent bond exchange, creating a reactive polymer–nanoclay interface that reinforces the material while contributing to the dynamic network rearrangements responsible for self-healing. These findings demonstrate that carefully engineering interfaces, from molecular bonding within the polymer network to the polymer–nanoclay interface, provides an effective strategy for controlling the structure, mechanics, and healing behavior of multifunctional polymer materials.
What Excites Us About This Work
- We combined density functional theory (DFT) with experiments to reveal how different dynamic covalent chemistries contribute to self-healing in aqueous environments.
- We developed amphiphilic polyurethane–urea coatings capable of efficient self-healing in both air and under water at room temperature.
- Amine-functionalized nanoclay simultaneously reinforced the polymer and accelerated self-healing by chemically integrating into the polymer network.
- Without requiring external stimuli, the best-performing nanocomposite recovered nearly all of its original toughness in air and more than 80% under water under near-ambient conditions, demonstrating that mechanical reinforcement and efficient self-healing need not be mutually exclusive.
What’s Next?
A major next step is understanding how molecular-scale bond exchange and interfacial interactions translate into macroscopic properties such as fracture resistance, self-healing, and long-term durability. Self-healing polymers span multiple length and time scales, from reversible chemical bond exchange to crack propagation and mechanical recovery, making it challenging to connect molecular mechanisms with bulk performance. An important question is the relative contributions of reversible urea exchange and hydrogen-bond rearrangement to the healing process.
We are particularly intrigued by the polymer–nanoclay interface. The nanoclay used in this study combines surface functionalities that promote both polymer compatibility and chemical integration into the polymer network. In both this work and our previous research, this distinctive surface chemistry has produced remarkable improvements in macroscopic properties, including a six-fold increase in tear resistance in HNBR nanocomposites. Understanding how these different surface functionalities control interfacial chemistry and how they can be deliberately engineered may provide new strategies for designing multifunctional polymer materials that overcome traditional trade-offs between strength, toughness, and self-healing.
Meet the authors
 Maryam Bonyani |
Maryam Bonyani is a Ph.D. candidate in Chemical Engineering at Clarkson University in Professor Sitaraman Krishnan’s research group. Her research combines polymer synthesis, nanocomposite design, and DFT simulations to understand how molecular-scale interactions govern the mechanical and self-healing behavior of polymeric materials. Her interests include dynamic covalent polymer networks, sustainable polymer composites, and multifunctional nanomaterials. She has also conducted industry-collaborative research with The Estée Lauder Companies and is currently a Polymer Chemistry Intern at Eastman Kodak Company, where she develops advanced adhesive and primer systems for functional polymer coatings.
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 Ronak Ansaripour |
Ronak Ansaripour has a background in chemical engineering, materials science, and bioengineering. She earned her M.S. in Chemical Engineering from Clarkson University and her Ph.D. in Bioengineering from Northeastern University. Her work encompasses self-healing polymer networks, tissue engineering, and biomaterials development. She has focused on designing functional materials through dynamic molecular and interfacial interactions, as well as developing complex in vitro models and assays for biomedical research.
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 Sitaraman Krishnan |
Sitaraman Krishnan is a Professor in the Department of Chemical and Biomolecular Engineering at Clarkson University. His research focuses on understanding how molecular- and nanoscale interfacial phenomena govern the properties of functional materials. His work spans molecular modeling, polymer chemistry, electrochemistry, and surface science, with applications in sustainable materials, energy, water, and semiconductor manufacturing.
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Nanoclay-enhanced self-healing of polyurethane–urea coatings enabled by disulfide exchange
Ronak Ansaripour; Maryam Bonyani; Sitaraman Krishnan
RSC Appl. Interfaces (2026). https://doi.org/10.1039/d6lf00078a
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RSC Applied Interfaces is a dedicated, interdisciplinary reference journal for cutting-edge research on the applications of surfaces and interfaces. In addition to the applied focus, work considered for publication in RSC Applied Interfaces is expected to be highly original and of top quality. The journal seeks to report major scientific advances beyond the state of the art, at the cutting edge of this interdisciplinary field. |