‘Microsubmarines’ designed to help clean up oil spills

May 4, 2012

The microsubmarine oil collection method is based on modifying microtube engines with a superhydrophobic layer able to adsorb oil by means of its strong adhesion to a long chain of self-assembled monolayers (SAMs) of alkanethiols created on the rough gold outer surface of the device (credit: M. Guix et al./ACS Nano)

Self-propelled “microsubmarines” designed to pick up droplets of oil from contaminated waters have been developed by scientists at the University of California San Diego (UCSD), the University Autónoma of Barcelona, and the University of Alcalá.

There is an urgent need for better ways of separating oil from water in the oceans and inside factories to avoid releasing oil-contaminated water to the environment. For example, the 1989 Exxon Valdez and 2010 Deepwater Horizon incidents spilled millons of gallons of crude oil.

The cone-shaped microsubs have a special surface coating that makes them “superhydrophobic,” or extremely water-repellent and oil-absorbent. Tests showed that the microsubs can collect droplets of olive oil and motor oil in water and transport these oils through water.

Practical large-scale oil cleaning operations would require the use of motors propelled by their own natural environment or driven by an external (magnetic or electrical) control, researchers say.

Micromotors for environmental remediation. (A) A polycarbonate membrane is used as a template (a), PEDOT and platinum layers are electroplated on the template (b), gold and nickle layers are sputtered by e-beam (c), and a superhydrophobic layer is formed on the microsubmarine surface. (B) SEM image of the resulting microsubmarine (a) with a zoom-in of the zone highlighted with a yellow arrow (b). (Credit: Maria Guix et al., ACS Nano)

Ref.: Maria Guix, et al., Superhydrophobic Alkanethiol-Coated Microsubmarines for Effective Removal of Oil, ACS Nano, 2012; DOI:10.1021/nn301175b