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 Climate Impact Research in Hannover: Small Plants against Large Waves
17.08.2018 | Leibniz Universität Hannover

nachricht First transcription atlas of all wheat genes expands prospects for research and cultivation
17.08.2018 | Leibniz-Institut für Pflanzengenetik und Kulturpflanzenforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Smallest transistor worldwide switches current with a single atom in solid electrolyte

17.08.2018 | Physics and Astronomy

Robots as Tools and Partners in Rehabilitation

17.08.2018 | Information Technology

Climate Impact Research in Hannover: Small Plants against Large Waves

17.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>