Swiss
Polymers are utilised to form synthetic materials for industry, most notably in plastics. Although current mass-market techniques are reliant on linear structures, a German-Japanese team of researchers working in Switzerland have proven that a two-dimensional bonding pattern within a polymer can be engineered. If refined, this surprising breakthrough may herald a next generation of molecule-thin, sheet-like materials
dimensional polymers Synthesising two-
Humanity chronicles its evolutionary progress with reference to the materials it masters. Stone, bronze and iron are all granted ‘ages’ by the history books. Perhaps the twentieth century, in retrospect, will ultimately be regarded as the ‘plastic age’. In 1920, German chemist Hermann
Staudinger helped initiate a new era for chemical science by postulating the existence of macromolecules connected in a linear ‘chain’ found within substances like starch, proteins and polyisoprene. Polyisoprene is a natural rubber and was involved in much of the experimentation that proved the polymer concept. This revelation paved the way for a greater understanding of their properties and, consequently, human agency over their microscopic matter, allowing the development of plastics decades later. The macromolecules, or large polymers, could be artificially devised through the connection of repeating units, called monomers. By arranging
these carbon-containing
compounds in various configurations, their attributes could be adjusted to meet the needs of diverse applications. Now, 100 years on Professor Dieter
Schlüter, a specialist in polymer chemistry working at the same institution as Staudinger – Zurich’s ETH (Eidgenössische Technische Hochschule), is heading a team which has pioneered the genesis of
two dimensional
polymers. Whereas linear polymers used in conventional plastics comprise an interlinked string – rather like a chain of paperclips – the 2D variant can be likened to an extremely fine web, or grid. To attain 2D status, the interconnects must be regularly positioned, and three or more bonds must exist at the periphery of each structural unit. “This is an amusing historic coincidence,” muses Schlüter. “You can now apply Staudinger’s
48
famous principle, and expand it into the next dimension. Professionally, and emotionally, this is extremely significant for me, after three decades as a synthetic chemist.”
The first ever 2D polymers Working in conjunction with his ETH senior associate PD Dr Junji Sakamoto, the Professor’s work sought to create the first synthetic two-dimensional polymer structure. Viewed at a microscopic level, this resembles a fine
honeycomb and,
significantly, is ultra-slim in the horizontal aspect: only a molecule thick. The ETH researchers experimented on a crystal containing individually layered strata of hexagonal, photo-sensitive monomers. The monomer crystals were irradiated to transform them into polymer. They then boiled these irradiated crystals in a solvent, which causes exfoliation, meaning the separate sheets could be extracted to create the first ever examples of 2D polymers.
By streamlining and industrialising this
technique, a host of exciting possibilities are created. Because of
their slenderness and
potentially limitless expanse, large areas of such polymers (or a ‘molecular carpet’) could possibly be generated using tiny amounts of raw material. “Cost, in this respect, might not play a significant role, as the sheets are only one monomer thin,” explains Dr Sakamoto. “In terms of mass, outlay is theoretically very low. With a modified strategy you can create huge sheets, in principle, which could cover the expanse of Lake Zurich for an almost trivial price.” Several potential applications have been proposed for the technology. Scratch- and wear-resistant molecular have
widespread appeal; while
coatings would other
utilisations include ultra-sensitive pressure monitors, components in electronic systems, and ultra-efficient barriers as found in water filtration. Total control, at the tiniest scales, is paramount. “If you want to use 2D
The two dimensional polymer concept Insight Publishers | Projects
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132