Superhydrophobic magnetic sponge to help purify water from oil products

March 05, 2020

Scientists of Tomsk Polytechnic University jointly with the University of Lille (France) have developed a new material capable of purifying water effectively from oil products. It is based on an ordinary household polyurethane sponge. The research team made it superhydrophobic - it repels water, while effectively sorbing oil product molecules. The results were published in Separation and Purification Technology (IF: 5,107; Q1).

"New oil production methods, especially the ones related to production on the seabed and ocean floor, raise up the risk of spills. We all know about the environmental impact of the accident that happened on a drilling platform in the Gulf of Mexico in 2010. Therefore, one of the most urgent scientific problems is to obtain selective sorbents capable to extract oil products from a water-oil mixture, avoiding interactions with water.

The latter point is crucially important since interactions with water basically result in some resultant products to end up in the water and affect the ecosystem. Furthermore, water saturation drops the sorbent effectiveness. Therefore, we had to find affordable material and make it hydrophobic and efficient for the mentioned goal. We decided in favor of a regular washing sponge," Pavel Postnikov, associate professor at TPU Research School of Chemistry & Applied Biomedical Sciences, says.

Diazonium salts, special organic compounds, were used to make a sponge hydrophobic. The sponge was placed in an aqueous solution with diazonium salts and heated to 60 °C. The resulting active radicals attacked the sponge and formed on the surface new organic groups with hydrophobic properties, being at the same time sensitive to oil products. They act as sorbents that selectively absorb oil molecules.

"The second issue is to find an efficient way to remove this material from water. We chose a magnetic sorbent collection. We added iron nanoparticles in the structure of the sponge, obtained by our original method and characterized by increased susceptibility to nonpolar molecules. We also added hydrophobic organic groups. As a result, we obtained material that almost does not interact with water despite the fact that it is a sponge," the scientist explains.

Petroleum products in water are in the form of an emulsion. This implies that their microscopic droplets are distributed in another liquid, in our case, in the water. According to the researchers, in practice, such emulsions are often highly stabilized. It means they are difficult to separate into individual components.

"We tested our material with both highly stabilized and low stabilized emulsions. The experiments demonstrated that the material is excellent. We also tested its effectiveness on industrial oils that can pollute natural water bodies. The material also showed its high efficiency," Pavel Postnikov says.

Furthermore, the studies showed that the new material can be reused several times. "In experiments, we used it at least five times and there was no drop in its efficiency," the scientist says.
The study was supported by the Russian Science Foundation (17-73-20066).

Tomsk Polytechnic University

Related Hydrophobic Articles from Brightsurf:

The applications of liquid crystals have been extended to drug encapsulation
Widely used in the manufacture of LCD screens and, more recently, phosphorescent sensors, liquid crystals may also have an important application in biomedicine.

Revealing the identity of the last unknown protein of autophagy
Japanese scientists discovered that Atg9, one of the proteins that function to mediate autophagy, has phospholipid-translocation activity (the lipid scramblase activity) between the two layers of the lipid bilayer?and elucidated that the protein's activity brings about autophagosome membrane expansion.

Probing water for an electrifying cause
An experiment, elegant in its simplicity, helps explain why water becomes electrified when it touches hydrophobic surfaces.

A chemist from RUDN developed a new type of one-molecule thick water-repellent film
A chemist from RUDN University together with colleagues created a new type of two-dimensional nanofilm from an organic material called calixarene.

Research shows potential to improve paints, coatings
New research from Binghamton University, State University of New York could lead to more environmentally friendly paints and coatings.

Novel method of heat conduction could be a game changer for server farms and aircraft
'We are hopeful that the one-way heat transfer of our bridging-droplet diode will enable the smart thermal management of electronics, aircraft, and spacecraft,' said Boreyko.

Pesticides can protect crops from hydrophobic pollutants
Researchers have revealed that commercial pesticides can be applied to crops in the Cucurbitaceae family to decrease their accumulation of hydrophobic pollutants, thereby improving crop safety.

Wrapping up hydrophobic hydration
Studied in detail, the embedding of hydrophobic molecules in water looks quite different than previously assumed.

KIST ensures stability of desalination process with magnesium
A Korean research team found a method to inhibit the fouling of membranes, which are used in the desalination process that removes salt and dissolved substances from seawater to obtain drinking, domestic, and industrial water.

Superhydrophobic magnetic sponge to help purify water from oil products
TPU jointly with the University of Lille developed a new material capable of purifying water effectively from oil products.

Read More: Hydrophobic News and Hydrophobic Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to