The Role of Nanosponges in Oil Spill Cleanup

Marine oil spills cause severe ecological damage by contaminating water, disrupting marine biodiversity, and harming aquatic life through ingestion and physical entrapment. Therefore, effective and sustainable remediation technologies are needed.

Image Credit: Vectorpocket/Shutterstock.com

Since the 1940s, over 25 major oil spills have occurred worldwide, with six large spills (>700 tons) and four medium spills (7–700 tons) recorded last year alone.¹ Traditional remediation methods, such as skimmers, dispersants, and in situ burning, often fail to fully restore affected environments due to limitations in oil recovery efficiency, secondary pollution, and environmental toxicity.

To address this, nanosponges have emerged as a more efficient and sustainable alternative, offering superior oil absorption, reduced waste generation, and enhanced long-term remediation outcomes.²

Structure and Properties of Nanosponges

Nanosponges are hyper-cross-linked polymeric structures with nanosized cavities typically ranging from 50 to 100 nm. Their overall diameter is usually less than 4 μm. Their highly porous, mesh-like architecture enables efficient encapsulation of hydrocarbons while maintaining selective capture properties—specifically, attracting oil while repelling water.

These sponges comprise hydrophobic and oleophilic compounds, including carbon-based polymers, silica, fluorinated compounds, and functionalized graphene, ensuring effective oil removal without water uptake.³

Mechanisms of Oil Absorption in Nanosponges

Nanosponges remove oil spills through three primary processes:

1. Capillary Action

Nanosponges use capillary forces to draw oil into their porous structure. This surface phenomenon allows liquid to flow into small spaces due to surface tension, overcoming external forces like gravity. Their nanoscale pore dimensions further enhance this effect, enabling efficient oil capture with minimal leakage.

2. Adsorption

Oil molecules adhere to the nanosponge surface, forming a thin, oily film. This surface-based process occurs through either physical adsorption—driven by Van der Waals interactions, hydrophobic forces, and electrostatic attraction—or chemical adsorption, where covalent bonds strengthen oil attachment while preventing water retention.

3. Absorption and Oil Retention

Following adsorption, oil absorbs into the internal structure, preventing further environmental spread. The hydrophobic composition ensures selective oil capture without water uptake, enhancing oil removal efficiency from contaminated surfaces.³

Advantages Over Traditional Oil Spill Cleanup Methods

Nanosponges demonstrate significant advantages over conventional oil cleanup methods:

• Superior Absorption Capacity: Their high surface area and porosity enable absorption of multiple times their weight in oil, substantially outperforming conventional sorbents.
• Reusability: Unlike single-use materials, nanosponges can undergo multiple-use cycles through squeezing or heating to recover absorbed oil, reducing waste generation and operational costs.
• Environmental Safety: Nanosponges remove oil without introducing additional toxins into ecosystems, unlike chemical dispersants that can cause secondary contamination.
• Highly Tunable Properties: Their structure and pore dimensions can be precisely controlled through cross-linker and polymer adjustments, optimizing adsorption capacity and selectivity for specific applications.^3,4

Real-World Application: Oleo Sponge and Marine Oil Spill Cleanup

Argonne National Laboratory researchers developed the Oleo Sponge, an advanced oil-absorbing foam that outperforms conventional technologies by removing oil from the entire water column, not just the surface.

The researchers used modified polyurethane foam coated with a metal oxide primer through sequential infiltration synthesis (SIS), allowing for the strong attachment of oil-absorbing molecules. This structure provided high oil sorption capacity, material reusability, and efficient recovery.

In April 2018, Oleo Sponge underwent real-world testing at the Coal Oil Point Seep Field in the Santa Barbara Channel, California—an active marine seepage site releasing over 100 barrels of petroleum daily. The research team deployed 2-foot-by-2-foot sponge sections from a small fishing vessel, targeting oil sheen (micron-thin surface oil layers) that conventional skimmers and in situ burning techniques cannot effectively remove.

The sponge successfully eliminated surface sheen without leaving visible residue, demonstrating its capacity to address persistent oil contamination.^5,6

Soaking up oil spills with spongesPlay

Emerging Technologies and the Future of Nanosponges in Oil Spill Cleanup

Nano-Welded CNT Sponges for Enhanced Oil Spill Remediation

Carbon nanotube (CNT)-based sponges offer high surface area, superhydrophobicity, and reusability. However, traditional organic binders and sonication fabrication methods compromise their chemical stability and scalability.

A recent study in the Journal of Cleaner Production introduced an energy-efficient foaming method using hydrazine hydrate and ethanol to create porosity in CNT sheets. The researchers used nanoscale welding to enhance the ultimate compressive strength and modulus by 109 % and 113 %, respectively.

The resulting sponge exhibited an oil absorption capacity exceeding 200 times its weight and absorbed 130 times its weight in organic solvents like dichloromethane and chloroform.⁷

Nano-Engineered Sponge for Oil Spill Cleanup in Cold Arctic Waters

Due to paraffin crystallization, crude oil thickens significantly in cold Arctic waters, rendering conventional cleanup methods ineffective. Addressing this challenge, researchers developed specialized sponges coated with paraffin-like nanocoatings that mimic crude oil’s molecular structure, enabling efficient adsorption in extreme environments.

Laboratory testing demonstrated the removal of up to 99 % of Texas raw crude oil from 100 milliliters of water at 5 °C within three hours, maintaining removal efficiencies between 90 % and 99 % over 10 consecutive use cycles. In addition, the sponge retained its structural integrity and absorption capacity throughout the cycles, ensuring consistent performance in challenging polar environments.⁸

Eco-Friendly Nanographene-Luffa Sponges

Graphene-based sorbents exhibit high surface area and hydrophobicity but face cost and scalability challenges, necessitating biodegradable alternatives. Recently, a study modified luffa sponges coated with graphene nanosheets and natural waxes (carnauba and beeswax), achieving superoleophilic and superhydrophobic properties with water contact angles reaching 158 °.

The thermogravimetric analysis confirmed thermal stability up to 497.2 °C, with optimized formulations achieving 11.92 g/g sorption capacity and 91.32 % efficiency over 10 cycles.

This demonstrates their potential for efficient and reusable oil spill remediation, offering a biodegradable and cost-effective solution for large-scale environmental applications.⁹

With continued innovation and deployment, nanosponges may transform oil spill response protocols worldwide, providing effective, sustainable solutions for preserving marine ecosystems and protecting coastal communities from the devastating effects of oil contamination.

To learn more about how nanomaterials are enhancing environmental sustainability and industrial applications, explore:

References and Further Reading

1. ITOPF. (2025). Oil Tanker Spill Statistics 2024. [Online] ITOPF. Available at: https://www.itopf.org/knowledge-resources/data-statistics/oil-tanker-spill-statistics-2024/
2. Singh, H., Bhardwaj, N., Arya, S. K., Khatri, M. (2020). Environmental impacts of oil spills and their remediation by magnetic nanomaterials. Environmental Nanotechnology, Monitoring & Management. https://doi.org/10.1016/j.enmm.2020.100305
3. Yamini, Rao, V.S., Mishra, N., Kumar, S. (2023). Environmental Applications of Nanosponges (NSPs) to Clean up Oil Spills. Gulati, S. (eds) Nanosponges for Environmental Remediation. Springer, Cham. https://doi.org/10.1007/978-3-031-41077-2_19
4. Bi, H., Mulligan, C. N., Lee, K., Zhang, B., Chen, Z., An, C. (2025). Nanotechnology for oil spill response and cleanup in coastal regions. Environmental Science: Nano. https://doi.org/10.1039/D4EN00954A
5. Lerner, L. (2017). Argonne invents reusable sponge that soaks up oil, could revolutionize spill cleanup. [Online] University of Chicago. Available at: https://news.uchicago.edu/story/argonne-invents-reusable-sponge-soaks-oil-could-revolutionize-spill-cleanup
6. Jo Napolitano. (2018). Oleo Sponge successful in real-world conditions off California coast. Argonne National Laboratory. [Online] Available at: https://www.anl.gov/article/oleo-sponge-successful-in-realworld-conditions-off-california-coast
7. Sehrawat, M., Singh, V., Rani, M., Kalra, C., Bharadwaj, S., Rani, R., Bisht, A., & Singh, B. P. (2024). Nano-welded carbon nanotube sponges for efficient oil spill remediation. Journal of Cleaner Production. https://doi.org/10.1016/j.jclepro.2024.142841
8. Cherukupally, P., Sun, W., Williams, D. R., Ozin, G. A., Bilton, A. M. (2021). Wax-wetting sponges for oil droplets recovery from frigid waters. Science Advances. https://doi.org/10.1126/sciadv.abc7926
9. Heidari, M. K., Fouladi, M., Sooreh, H. A., & Tavakoli, O. (2022). Superhydrophobic and super-oleophilic natural sponge sorbent for crude oil/water separation. Journal of Water Process Engineering. https://doi.org/10.1016/j.jwpe.2022.102783

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