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.