Drs Graham Saunders and Steven Bell of Queen’s University School of Chemistry and Chemical Engineering, together with PhD student, Iain Larmour, have developed a very simple method for treating metals that results in extremely high hydrophobicity using readily available starting materials and standard laboratory equipment in a process that only takes a few minutes.
The significance of the discovery lies in the ease of fabrication and the flexibility of the method. Dr Saunders said, “There have been numerous attempts to emulate the extraordinary water repellency of lotus leaves, but very few synthetic surfaces can match these natural systems. Those that do are unsuitable for practical applications because they are difficult and costly to fabricate or can be applied only to a very limited number of materials. Our method produces robust surfaces displaying hydrophobicity that surpasses that of lotus leaves - ultrahydrophobicity. Furthermore the method is cheap and quick, and can be extended to a wide range of metals.”
It is the structure of lotus leaves – nanohairs on microbumps which are coated with a waxy substance – that causes the hydrophobicity and the Queen’s team’s discovery has successfully mimicked that surface structure. The process is simple. The objects to be treated are immersed in a metal-salt solution which coats them with a textured metal layer, thinner than a human hair, which resembles the structure of lotus leaves. The object is then dipped into a solution of a chemical surface-modifier, which covers the textured coating with a second, even thinner layer of water-repelling molecules. The resulting surface is so hydrophobic that water droplets deposited on the surface form almost perfect spheres and coated objects can be immersed for days but are found to be completely dry when they are pulled from the water.
The flexibility and simplicity of the approach means that the method can be applied to metal objects of any reasonable shape and size. Dr Bell said, “The team experimented with samples of various shapes and sizes and more complex metal objects, including a model of a pond skater made from copper. Pond skaters use superhydrophobic legs to walk on water, and our model, despite being 10x the mass of a pond skater of the same size, when treated, floated comfortably on water. Although this is a light-hearted example it does illustrate how readily our method can be applied.”
Future practical applications of this discovery are likely to include biomedical devices, liquid separation, and reducing turbulent flow in water-bearing pipes, among others.
Lisa Mitchell | alfa
Barely scratching the surface: A new way to make robust membranes
13.12.2018 | DOE/Argonne National Laboratory
Topological material switched off and on for the first time
11.12.2018 | ARC Centre of Excellence in Future Low-Energy Electronics Technologies
Researchers from the University of Basel have reported a new method that allows the physical state of just a few atoms or molecules within a network to be controlled. It is based on the spontaneous self-organization of molecules into extensive networks with pores about one nanometer in size. In the journal ‘small’, the physicists reported on their investigations, which could be of particular importance for the development of new storage devices.
Around the world, researchers are attempting to shrink data storage devices to achieve as large a storage capacity in as small a space as possible. In almost...
The more objects we make "smart," from watches to entire buildings, the greater the need for these devices to store and retrieve massive amounts of data quickly without consuming too much power.
Millions of new memory cells could be part of a computer chip and provide that speed and energy savings, thanks to the discovery of a previously unobserved...
What if, instead of turning up the thermostat, you could warm up with high-tech, flexible patches sewn into your clothes - while significantly reducing your...
A widely used diabetes medication combined with an antihypertensive drug specifically inhibits tumor growth – this was discovered by researchers from the University of Basel’s Biozentrum two years ago. In a follow-up study, recently published in “Cell Reports”, the scientists report that this drug cocktail induces cancer cell death by switching off their energy supply.
The widely used anti-diabetes drug metformin not only reduces blood sugar but also has an anti-cancer effect. However, the metformin dose commonly used in the...
A research team from the University of Zurich has developed a new drone that can retract its propeller arms in flight and make itself small to fit through narrow gaps and holes. This is particularly useful when searching for victims of natural disasters.
Inspecting a damaged building after an earthquake or during a fire is exactly the kind of job that human rescuers would like drones to do for them. A flying...
12.12.2018 | Event News
10.12.2018 | Event News
06.12.2018 | Event News
17.12.2018 | Studies and Analyses
17.12.2018 | Life Sciences
17.12.2018 | Power and Electrical Engineering