11-04 :: April/May 2011
nanotimes News in Brief
Drop Emission // Controlled Production of Nanometric Drops
R
esearchers from the Faculty of Physics at the University of Barcelona, Spain, have carried
out a study in which they demonstrate the physical conditions required for the controlled production of drops between the micro- and nanoscales.
According to Aurora Hernández-Machado, a lec- turer with the UB’s Department of Structure and Constituents of Matter and co-author of the study, “miniaturization in liquids is important in increasing efficiency and optimizing the rate of consumption of substances such as pharmaceutical products, cos- metics and ink, which would enable us to lower the cost of processes associated with the production and control of these products. In addition, the physical model, which we could define as a microfluidic dis- penser for various substances, allows us to overcome the limitations traditionally associated with drop for- mation processes and to create submicrometre-scale droplets”.
The researchers have been able to establish the balance of forces that determines the drop emission mechanism, which involves the capillarity of the flu- id, the viscous friction of the solid surface and gravity. This balance and the size of the liquid filaments determine the size of the drops emitted, which in some cases are nanometric. It has also been observed that the emission of drops depends to a great extent on the static wetting angle, that is, the angle that the
61
drop makes with the contact surface. The greater this angle the higher the degree of hydrophobia of the surface in question.
Image: The experiments carried out for the study, focusing on water in air, the team of researchers has demonstrated the operation of the microfluidic model and created drops at the micrometre scale, but the model is also capable of producing nanometric droplets. © UB
Rodrigo Ledesma-Aguilar, Raul Nistal, Aurora Hernández- Machado e Ignasi Pagonabarraga: Controlled drop emis- sion by wetting properties in driven liquid filaments, In: Nature Materials, Nature Materials, Vol. 10(2011), No. 5, May 2011, Pages 367-371, DOI:10.1038/NMAT2998:
http://dx.doi.org/10.1038/NMAT2998
http://www.ub.edu
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