Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Controlled production of nanometric drops

Abstract:
When a drop falls on a lotus flower it remains on the surface without wetting it. This is due, firstly, to the chemical components of the leaves of this plant, which are hydrophobic and therefore repel water, and, secondly, to the nanostructure of the surface, which augments the repellent effect. Taking these nanostructural properties as a starting point, researchers from the Faculty of Physics at the University of Barcelona have carried out a study - the results of which have been published in the journal Nature Materials - in which they demonstrate the physical conditions required for the controlled production of drops between the micro- and nanoscales.

Controlled production of nanometric drops

Barcelona, Spain | Posted on April 13th, 2011

The study details the different physical conditions needed to destabilize a fluid and create droplets according to the wetting properties of the surface it is in contact with. Ignasi Pagonabarraga, a lecturer with the Department of Fundamental Physics and one of the authors of the study, explains that "the interaction of the fluid with the surface can be used to control the size of the drops and the time they take to form. Although there are other methods for creating micrometric droplets, the affinity of liquids to solid surfaces creates a more versatile environment for the production and control of drops down to the nanoscale".

According to Aurora Hernández-Machado, a lecturer 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, cosmetics 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 dispenser for various substances, allows us to overcome the limitations traditionally associated with drop formation processes and to create submicrometre-scale droplets".

One of the fields to which this type of process is most readily applicable is the development of lab-on-a-chip (LOC) devices, which integrate a range of laboratory analysis functions into a miniaturized chip format and need only very small volumes of liquid to perform the analyses. The dynamics involved in the formation of submicrometre-scale drops have various technological applications in other fields, for example in controlled drug administration or in the creation of emulsions such as those used in certain types of cosmetic products formed by micro-droplets of substances with specific properties within another fluid. Other applications include ink distribution in printers.

In physical terms, the drops are formed due to instability in the fluid. The study describes a wetting-based destabilization mechanism of forced microfilaments that affects adherence to difference surfaces. The researchers have been able to establish the balance of forces that determines the drop emission mechanism, which involves the capillarity of the fluid, 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 drop makes with the contact surface. The greater this angle the higher the degree of hydrophobia of the surface in question.

In 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. Tests have been carried out using a range of supports from hydrophilic surfaces to superhydrophobic substrates, and the authors show how wetting can be used to pinpoint the wetting-controlled emission point. By varying the chemical and nanostructural properties of the surface in question, it is possible to alter the wetting angle and control the drop formation dynamics.

Full bibliographic information

Rodrigo Ledesma-Aguilar, Raul Nistal, Aurora Hernández-Machado e Ignasi Pagonabarraga. «Controlled drop emission by wetting properties in driven liquid filaments». Nature Materials (abril, 2011). DOI: 10.1038/NMAT2998

####

For more information, please click here

Copyright © AlphaGalileo

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Tiny packages may pack powerful treatment for brain tumors: Nanocarrier provides efficient delivery of chemotherapeutic drug May 23rd, 2016

Two-stage nanoparticle delivery of piperlongumine and TRAIL anti-cancer therapy May 23rd, 2016

Rice de-icer gains anti-icing properties: Dual-function, graphene-based material good for aircraft, extreme environments May 23rd, 2016

Graphene makes rubber more rubbery May 23rd, 2016

Physics

Theorists smooth the way to modeling quantum friction: New paradigm offers a strategy for solving one of quantum mechanics' oldest problems May 18th, 2016

How light is detected affects the atom that emits it: An experiment suggests it might be possible to control atoms entangled with the light they emit by manipulating detection May 15th, 2016

Physicists measure van der Waals forces of individual atoms for the first time May 14th, 2016

Atomic force microscope reveals molecular ghosts: Mapping molecules with atomic precision expands toolbox for designing new catalytic reactions May 11th, 2016

Lab-on-a-chip

POSTECH researchers develop a control algorithm for more accurate lab-on-a-chip devices April 6th, 2016

Artificial molecules April 3rd, 2016

New microwave imaging approach opens a nanoscale view on processes in liquids: Technique can explore technologically and medically important processes that occur at boundaries between liquids and solids, such as in batteries or along cell membranes March 16th, 2016

Nanoworld 'snow blowers' carve straight channels in semiconductor surfaces: NIST, IBM researchers report important addition to toolkit of 'self-assembly' methods eyed for making useful devices December 28th, 2015

Discoveries

Physicists create first metamaterial with rewritable magnetic ordering May 23rd, 2016

Tiny packages may pack powerful treatment for brain tumors: Nanocarrier provides efficient delivery of chemotherapeutic drug May 23rd, 2016

Two-stage nanoparticle delivery of piperlongumine and TRAIL anti-cancer therapy May 23rd, 2016

Rice de-icer gains anti-icing properties: Dual-function, graphene-based material good for aircraft, extreme environments May 23rd, 2016

Materials/Metamaterials

Programmable materials find strength in molecular repetition May 23rd, 2016

Rice de-icer gains anti-icing properties: Dual-function, graphene-based material good for aircraft, extreme environments May 23rd, 2016

Graphene makes rubber more rubbery May 23rd, 2016

Graphene: Progress, not quantum leaps May 23rd, 2016

Announcements

Physicists create first metamaterial with rewritable magnetic ordering May 23rd, 2016

Tiny packages may pack powerful treatment for brain tumors: Nanocarrier provides efficient delivery of chemotherapeutic drug May 23rd, 2016

Two-stage nanoparticle delivery of piperlongumine and TRAIL anti-cancer therapy May 23rd, 2016

Rice de-icer gains anti-icing properties: Dual-function, graphene-based material good for aircraft, extreme environments May 23rd, 2016

Water

Mille-feuille-filter removes viruses from water May 19th, 2016

First single-enzyme method to produce quantum dots revealed: Biological manufacturing process, pioneered by three Lehigh University engineers, produces equivalent quantum dots to those made chemically--but in a much greener, cheaper way May 9th, 2016

Understanding tiny droplets can make for better weather forecasts: Climate change models also benefit from understanding fundamental thermodynamics of water droplets May 6th, 2016

Engineers create a better way to boil water -- with industrial, electronics applications May 5th, 2016

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project







Car Brands
Buy website traffic