76
nanotimes News in Brief
rior properties, because it is simple and the proper- ties of the resulting aerogels can be varied widely.”
Dr. Jie Cai, Shilin Liu, Jiao Feng, Satoshi Kimura, Masahisa Wada, Prof. Dr. Shigenori Kuga, Prof. Lina Zhang: Cellulose–Silica Nanocomposite Aerogels by In Situ Formation of Silica in Cellulose Gel, In: Angewandte Chemie International Edition Early View, January 24, 2012, DOI:10.1002/anie.201105730:
http://dx.doi.org/10.1002/anie.201105730
12-01 :: January 2012
It came as a complete surprise that, when the re- searchers tried the same with ordinary water, they found that it evaporates without noticing the gra- phene seal. Water molecules diffused through the graphene-oxide membranes with such a great speed that the evaporation rate was the same indepen- dently whether the container was sealed or com- pletely open.
In a report published in Science, a team led by Pro- fessor Sir Andre Geim shows that graphene-based membranes are impermeable to all gases and liquids. However, water evaporates through them as quickly as if the membranes were not there at all.
Professor Geim: “The properties are so unusual that it is hard to imagine that they cannot find some use in the design of filtration, separation or barrier membranes and for selective removal of water.”
The University of Manchester scientists have studied membranes from a chemical derivative of graphene called graphene oxide. Graphene oxide is the same graphene sheet but it is randomly covered with other molecules such as hydroxyl groups OH-. Graphene oxide sheets stack on top of each other and form a laminate. The researchers prepared such laminates that were hundreds times thinner than a human hair but remained strong, flexible and were easy to handle. When a metal container was sealed with such a film, even the most sensitive equipment was unable to detect air or any other gas, including helium, to leak through.
R. Nair, H. Wu, P. Jayaram, V. Grigorieva and A. Geim: Unimpeded Permeation of Water Through Helium-Leak– Tight Graphene-Based Membranes, In: Science, Volume 335, Issue 6067, January 26, 2012, Pages 442-444, DOI: 10.1126/science.1211694:
http://dx.doi.org/10.1126/science.1211694
Researcher at Tyndall Nati- onal Institute, Ireland, de- veloped a new nanosensor technology. The highly ad- vanced sensor technology is based on individual nanowires manufactured on a silicon chip using microelectronic fabrication techniques. The sensor technology can significantly out-perform current commercial detection devices by up to a 1,000 fold, in some cases.
http://www.tyndall.ie/users/alanoriordan
Sometimes total electrical isolation is a good thing – and that’s the idea behind a power-over-fiber
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