“There’s a great future in plastics.” That’s what the guy told Benjamin (Dustin Hoffman) in the classic 1967 film, The Graduate. Today, scientists from the National University of Singapore are researching two-dimensional graphene-like polymers that surpass plastic’s utility for conductivity and energy storage.
Plastic and other useful polymers — large molecules built from similar sub molecular units bonded together — are typically created in three- and one-dimensional molecular chains. The Chinese research team is overcoming the challenges of chemically building flat, or two dimensional, polymer carbon sheets.
“In sciencedaily.com Professor Loh Kian Ping, NUS’ head of 2D Materials Research, says: ‘In the last century, scientists have successfully developed molecules which can be crosslinked to form one-dimensional and three-dimensional polymers. These are used to produce a wide range of technological products. However, making 2D polymers has met with little success, as most molecules are not flat and they tend to rotate in solution, making it difficult to control their linking to a 2D plane.’”
One of the most promising commercial applications of the research is in the area of sodium ion batteries. Because of sodium’s abundance, these kind of batteries are far less costly to make than lithium batteries, commonly used in cell phones. Problem is, they discharge quickly. Professor Loh’s breakthrough 2D polymer has the potential for commercial scale production. As the electrode material for sodium batteries, its graphene-level conductivity could charge these low-cost batteries efficiently for much longer periods
In a method that recalls the technique for capturing graphene with common scotch tape, sciencedaily.com reports: “The NUS researchers discovered that by applying heat to the set of carefully designed, flat monomers which are pre-packed in a specific way, a 2D crystalline polymer is formed. The 2D polymer consists well-defined pores and channels, through which sodium ions can diffuse in and out for energy storage. An individual sheet of this material can be readily peeled using adhesive tape, yielding ultra-thin sheets which are of less than a nanometre.”
Source: National University of Singapore. “Two-dimensional polymer breakthrough that could revolutionize energy storage.” ScienceDaily. ScienceDaily, 13 March 2017.
Publication Journal: Kian Ping Loh et al., A two-dimensional conjugated aromatic polymer via C–C coupling reaction. Nature Chemistry, 2017; DOI: 10.1038/nchem.2696