Scientists Develop Graphene Nanochannels For Filtering Water

Researcher have recently stacked sheets of 2D nanomaterials like grapheneon top of each other and the gaps formed between these sheets are found to wide range application. The latest study published in the journal Nature Communications has a team from Brown University that has found ways to use the gaps termed as nanochannels for filtering water or other liquids with nanoscale contaminants. Lately, an entire new study has been launched against the spaces in between 2D nanomaterials. The researchers believe that things can be stored and grown in such places for further applications. This study is considered to be emerging fields of nanofluidics as the channels are believed to be used for filtering out molecules.

The orientation of the channels could possibly turn out to be an issue when using these nanochannels for filtration. Just like the pages in a notebook, thin graphene sheets are stacked vertically compared to their horizontal length and width. This way of stacking is projected to direct the channels in a horizontal orientation. The horizontal direction is the least preferred as the liquids have to travel long way from one end to another. Thus, the channels being oriented perpendicularly is considered to be a positive option as liquid in such cases has to cross only thin vertical stacks instead of the width and length.

Until now, no researcher has been able to create effective vertically oriented graphene nanochannels. But, researcher Muchun Liu in Hurt's lab hasrecently figured out a newtechnique to do it.Liu stacked sheets of graphene on an elastic substrate with high tension to help stretch it out. The deposition of the sheets results in immediate release of tension from the substrate, which ultimately allows contraction. The graphene sheets then assemble on the wrinkles such that peaks and valleys are formed. The vertical alignment of the channels occurs if the sheets are wrinkled a lot and once the channels are formed they are encased in epoxy on top of each other before being trimmed such that channels are opened all the way through the material. These assemblages are called vertically aligned graphene membranes (VAGMEs). The researchers are trying to transform the short and narrow channels via which only water can travel into large channel through whichorganic contaminants or few metal ions could also pass by. The researchers have their eye set on developing this technology withpotential industrial or household filtering applications.