Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Micro-onions and Magnetic Ink

08.08.2011
Microfluidic systems for the easy production of multiphasic emulsion drops and multishelled polymer capsules

Under a microscope they look like miniature onions, in fact, they are new microcapsules introduced by David A. Weitz and Shin Hyun Kim in the journal Angewandte Chemie. The researchers from Harvard University in Cambridge (Massachusetts, USA) have developed a simple method that makes it possible to produce these tiny shell-like objects with a microfluidic system in just one step. Possible applications include magnetic inks and transport systems for multicomponent pharmaceuticals.

By using a sophisticated microfluidic system that consists of multiple glass capillaries with water-repellent and water-attracting coatings, the researchers are able to get opposing streams of immiscible liquids (oil and water) to collide. Tiny droplets are formed as the resulting stream passes through an opening into a collection capillary. Within the droplets, the phase boundaries between the liquids are cleverly disrupted so that—depending on the structure of the system—three- or four-layer emulsion drops are formed. This process is the first to make it possible to produce large numbers of multiwalled emulsion drops of uniform size and structure.

As a sample application, Weitz and Kim produced a “magnetic ink” for displays. The oily phase was a solution of a UV-crosslinking polymer. The researchers produced emulsion drops with a core of polymer solution surrounded by a shell of water, which is in turn contained in another shell of polymer solution. They mixed magnetic particles and black pigments into the polymer solution that makes up the core and added tiny particles of plastic to the aqueous liquid.

After irradiation with UV light, they obtained transparent capsules with a solid shell and a solid, black core that floats freely in the aqueous layer with the plastic particles. In the absence of a magnetic field, the black cores remain at the center of the capsules. A layer of such capsules in a display appears white because the plastic particles scatter light. When a magnetic field is applied, the cores are pulled toward the surface of the display, making the black color visible.

Another practical application for multilayer capsules is the transport of multicomponent pharmaceuticals that would remain separate until sequentially released on target in the body.

Author: Shin-Hyun Kim, Harvard University, http://weitzlab.seas.harvard.edu/
Title: One-Step Emulsification of Multiple Concentric Shells with Capillary Microfluidic Devices

Angewandte Chemie International Edition, Permalink to the article: http://dx.doi.org/10.1002/anie.201102946

Shin-Hyun Kim | Angewandte Chemie
Further information:
http://pressroom.angewandte.org
http://weitzlab.seas.harvard.edu/

More articles from Life Sciences:

nachricht Designer cells: artificial enzyme can activate a gene switch
22.05.2018 | Universität Basel

nachricht Flow of cerebrospinal fluid regulates neural stem cell division
22.05.2018 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: LZH showcases laser material processing of tomorrow at the LASYS 2018

At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.

At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...

Im Focus: Self-illuminating pixels for a new display generation

There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?

At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...

Im Focus: Explanation for puzzling quantum oscillations has been found

So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics

Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...

Im Focus: Dozens of binaries from Milky Way's globular clusters could be detectable by LISA

Next-generation gravitational wave detector in space will complement LIGO on Earth

The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...

Im Focus: Entangled atoms shine in unison

A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.

The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Save the date: Forum European Neuroscience – 07-11 July 2018 in Berlin, Germany

02.05.2018 | Event News

Invitation to the upcoming "Current Topics in Bioinformatics: Big Data in Genomics and Medicine"

13.04.2018 | Event News

Unique scope of UV LED technologies and applications presented in Berlin: ICULTA-2018

12.04.2018 | Event News

 
Latest News

Designer cells: artificial enzyme can activate a gene switch

22.05.2018 | Life Sciences

PR of MCC: Carbon removal from atmosphere unavoidable for 1.5 degree target

22.05.2018 | Earth Sciences

Achema 2018: New camera system monitors distillation and helps save energy

22.05.2018 | Trade Fair News

VideoLinks
Science & Research
Overview of more VideoLinks >>>