The strength and versatility of graphene continue to dazzle us-all the time, exciting new applications are being discovered, and now scientists have discovered a way to manipulate wonderful materials so that it can be better removed from the water Filter out impurities.
Two-dimensional materials composed of carbon atoms have been studied before as a method of purifying water, but this new method can provide the most promising method to date. It all depends on the use of the so-called van der Waals gap: when two-dimensional nanomaterials are stacked on top of each other, tiny gaps appear between them.
These nanochannels can be used in many ways, scientists are now exploring, but the thinness of graphene can cause filtration problems: the liquid must spend a lot of time traveling along the horizontal plane instead of the vertical direction, much faster.
To solve this problem, the new research team used an elastic substrate to compress the graphene layer into a series of microscopic peaks and valleys. This means that the liquid can slide down the vertical direction of the peak instead of traversing the open plain in the horizontal direction (all nanometers of course).
Muchun Liu, a materials scientist at the Massachusetts Institute of Technology (MIT), said: “When you start to wrinkle graphene, you are tilting the flakes and channels out of the plane.
“If there are a lot of wrinkles, the channels will end up almost vertically aligned.”
In order to complete the effect, the graphene and the substrate are fixed in epoxy before trimming the peaks and valleys. It allows liquids to pass through graphene faster while still filtering.
Liu and her colleagues named this new material VAGMEs (Graphene Membrane Vertically Arranged), and further found a use that can make drinking water safe to drink.
Robert Hurt, a chemical engineer at Brown University, said: “What we end up with is a membrane that has short and narrow channels through which only very small molecules can pass.”
“So, for example, water can pass, but organic contaminants or certain metal ions will be too large to pass. So you can filter them out.”
The next step will be put into practice and work out a practical filtration system, but the theory is reasonable. The material passed one of its first tests by allowing water vapor to flow through while trapping larger hexane molecules.
Scientists say that these VAGMEs can eventually find use in industrial or domestic filtration systems-just one of many promising ways graphene is used in a variety of different scientific fields.
Experts say that as for nanochannels running between ultra-thin 2D materials (such as graphene), there is also great potential here. The more scientists observe these nanomaterials, the more they will discover.
Hutt said: “In the past ten years, entire fields have emerged to study these spaces formed between two-dimensional nanomaterials.”
“You can grow things in it, you can store things in it, and in the emerging field of nanofluids, you are using these channels to filter some molecules while letting others pass.”
The research has been published in Nature Communications.