Carbon nanotube survivability in marine environments and method for biofouling removal

Abstract

The deep sea survivability and biofouling characteristics of corrosion-resistant bulk carbon nanotubes (CNTs) have been studied after deployment in the Atlantic Ocean over the course of 12 months. Quantification of barnacle count, biofouling density, and non-combustible residue shows cyanoacrylate coatings increase durability and reduce the colonization of biofouling compared to as-received CNTs. Scanning electron microscopy was performed on the biofouled CNTs, and the majority of species were identified as diatoms, consisting of an ordered silica cell wall. Both the as-received and cyanoacrylate-treated CNTs were successfully acid purified to remove biogrowth, leading to complete recovery of tensile strength and electrical transport properties. Thermogravimetric analysis, scanning electron microscopy, contact angle, dynamic mechanical analysis, and current carrying capacity measurements validated the refunctionalization results. Thus, the multifunctional property recovery and enhanced durability confirms that CNTs are electrochemically stable in saltwater environments and are resilient to biofouling conditions in real-world environments after extended exposure.

Keywords:

• Biofouling
• carbon nanotubes
• cyanoacrylate
• purification
• re-functionalization

Acknowledgements

This work was supported by the United States Government. All statements of fact, opinion, or analysis expressed are those of the authors and do not reflect the official positions or views of any U.S. Government agency. The contents of this document should not be construed as asserting or implying U.S. Government authentication of information or endorsement of the author’s views.

Authors’ contributions

The manuscript was written through contributions of all authors. All authors have given approval to the final version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was funded by the United States Government. C. D. Cress acknowledges funding from the Office of Naval Research 6.1 Base Funding.