The simple nanomachine-enabled 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: American Chemical Society

Scientists
are reporting development and successful testing of the first
self-propelled “microsubmarines” designed to pick up droplets of oil
from contaminated waters and transport them to collection facilities.
The report concludes that these tiny machines could play an important
role in cleaning up oil spills, like the 2010 Deepwater Horizon incident
in the Gulf of Mexico. It appears in the journal ACS Nano.

Joseph
Wang and colleagues explain that different versions of microengines
have been developed, including devices that could transport medications
through the bloodstream to diseased parts of the body. But no one has
ever shown that these devices—which are about 10 times smaller than the
width of a human hair—could help clean up oil spills. 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. Wang’s team developed so-called microsubmarines, which
require very little fuel and move ultrafast, to see whether these small
engines could help clean up oil.

Tests
showed that the cone-shaped microsubmarines can collect droplets of
olive oil and motor oil in water and transport them through the water.
The microsubs have a special surface coating, which makes them
“superhydrophobic,” or extremely water-repellent and oil-absorbent.
“These results demonstrate the potential of the
superhydrophobic-modified microsubmarines for facile, rapid and highly
efficient collection of oils in oil-contaminated water samples,” say the
researchers.

The
authors acknowledge funding from the National Science Foundation, NATO
Science for Peace and Security Program, Spanish MICINN, Beatriu de Pinós
(Government of Catalonia) and University of Alcalá (Madrid).

Superhydrophobic Alkanethiol-Coated Microsubmarines for Effective Removal of Oil

Source: American Chemical Society