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Layered nanocomposites by shear-flow-induced alignment of nanosheets 期刊论文
NATURE, 2020, 580 (7802) : 210-+
作者:  Rollie, Clare;  Chevallereau, Anne;  Watson, Bridget N. J.;  Chyou, Te-yuan;  Fradet, Olivier;  McLeod, Isobel;  Fineran, Peter C.;  Brown, Chris M.;  Gandon, Sylvain;  Westra, Edze R.
收藏  |  浏览/下载:40/0  |  提交时间:2020/07/03

Layered nanocomposites fabricated using a continuous and scalable process achieve properties exceeding those of natural nacre, the result of stiffened matrix polymer chains confined between highly aligned nanosheets.


Biological materials, such as bones, teeth and mollusc shells, are well known for their excellent strength, modulus and toughness(1-3). Such properties are attributed to the elaborate layered microstructure of inorganic reinforcing nanofillers, especially two-dimensional nanosheets or nanoplatelets, within a ductile organic matrix(4-6). Inspired by these biological structures, several assembly strategies-including layer-by-layer(4,7,8), casting(9,10), vacuum filtration(11-13) and use of magnetic fields(14,15)-have been used to develop layered nanocomposites. However, how to produce ultrastrong layered nanocomposites in a universal, viable and scalable manner remains an open issue. Here we present a strategy to produce nanocomposites with highly ordered layered structures using shear-flow-induced alignment of two-dimensional nanosheets at an immiscible hydrogel/oil interface. For example, nanocomposites based on nanosheets of graphene oxide and clay exhibit a tensile strength of up to 1,215 +/- 80 megapascals and a Young'  s modulus of 198.8 +/- 6.5 gigapascals, which are 9.0 and 2.8 times higher, respectively, than those of natural nacre (mother of pearl). When nanosheets of clay are used, the toughness of the resulting nanocomposite can reach 36.7 +/- 3.0 megajoules per cubic metre, which is 20.4 times higher than that of natural nacre  meanwhile, the tensile strength is 1,195 +/- 60 megapascals. Quantitative analysis indicates that the well aligned nanosheets form a critical interphase, and this results in the observed mechanical properties. We consider that our strategy, which could be readily extended to align a variety of two-dimensional nanofillers, could be applied to a wide range of structural composites and lead to the development of high-performance composites.


  
The role of cement service-life on the efficient use of resources 期刊论文
ENVIRONMENTAL RESEARCH LETTERS, 2020, 15 (2)
作者:  Miller, Sabbie A.
收藏  |  浏览/下载:7/0  |  提交时间:2020/07/02
cement  concrete  in-use stock  dynamic materials flow analysis  longevity in-service  resource efficiency  
Mapping and Analyzing Ecological Distribution Conflicts in Andean Countries 期刊论文
ECOLOGICAL ECONOMICS, 2019, 157: 80-91
作者:  Perez-Rincon, Mario;  Vargas-Morales, Julieth;  Martinez-Alier, Joan
收藏  |  浏览/下载:2/0  |  提交时间:2019/04/09
Political ecology  Materials flow analysis  Environmental conflicts  Environmental racism  Post-extractivism  Post-growth