Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Drexel reserchers roll out new method for making the invisible brushes that repel dirt

24.03.2016

Polymer crystal 'turf' improves nanobrush-making process

You might not be aware of it, but invisible carpets of polymers are keeping things from being sticky right now. The lenses of your glasses might be coated with them to stave off smudges. They're keeping the underbellies of ships from corroding, artificial joints from locking up and medical devices from gathering germs. The name "polymer nanobrush" doesn't seem fitting because these bristly materials aren't used to sweep away debris, they actually prevent it from accumulating at all.


Drexel materials scientist Christopher Li, PhD, reports a new way for making polymer nanobrushes that equates to growing a lawn by rolling out sod instead of planting seeds.

Credit: Drexel University

The science behind their production sounds a lot like turf management on a golf course. But for years it's been done one blade -- or bristle -- at a time, or by sprinkling some seeds and hoping for the best. Materials scientists from Drexel University have planted a new idea -- that they can make better brushes by rolling them out like sod.

Until recently, polymer brushes have been made in two main ways. One, called "grafting-from," is like sprinkling seeds on soil and waiting for grass to take root. The other, "grafting-to" is more like transplanting individual blades of grass. In a recent edition of Nature Communications, Christopher Li, PhD, a professor in Drexel's College of Engineering, explains his new method for brush making that's gives scientists a higher degree of control over the shape of the brush and bristles, and is much more efficient.

Li's approach involves growing a functional two-dimensional sheet of polymer crystals -- similar to a nanoscale piece of double-sided tape. When the sheet is stuck to an existing substrate, and the crystals are dissolved, the remaining polymer chains spring up, forming the bristles of the brush.

"The past few decades witnessed exciting progresses in studies on polymer brushes, and they show great promises in various fields, including coating, biomedical, sensing, catalysis to name just a few," said Li, whose research in the Drexel Soft Materials Lab focuses on materials that have complex structural and dynamic properties -- like polymer brushes. "We believe that our discovery of a new way to make polymer brushes is a significant advance in the field and will enable use of the brushes in exciting new ways."

Polymer brush materials are especially useful in situations where pieces need to fit tightly together but need to be able to move without friction throwing a wrench in the works. They are also effective for keeping important surfaces free of particles, chemicals, proteins and other fouling agents. Polymer brushes have been used to coat everything from eyeglass lenses, boats and medical devices -- where they keep away smudges, damaging chemicals and germs -- to artificial joints and mechanical components in vehicles -- where they act as a lubricant.

The relative amount of friction that can be reduced by the brushes has to do with how long and rigid the polymers are and how far apart they're spaced. Li's method is significant because he can precisely tune all of these characteristics because he can control the formation of the two-dimensional crystal sheets. In the paper he reports the creation of the most densely packed polymer brushes to date, with bristles less than a nanometer apart.

"These surface-functionalized 2D single crystals provide a unique opportunity for the synthesis of well-defined polymer brushes," Li said. "The key step in our method is pre-assembling polymers into polymer single crystals before coupling them onto the substrate."

For Li's group -- which has pioneered research in growing spherical crystals, and solid polymer electrolytes for energy storage -- controlling the formation of crystalized polymers for an application like this is almost second nature.

According to the paper, the team is even able to create polymer crystals with anchor points on both ends so they form a loop, which is a much sturdier bristle formation than a single-anchored polymer.

"What this all means is that one day engineers will be able to tailor-make incredibly durable polymer brush coatings to extend the usage lives of all kinds of uniquely shaped joints and couplings," Li said. "This shifts the way we look at making the brushes and I think it will have a lasting impact on this area of research."

Media Contact

Britt Faulstick
bef29@drexel.edu
215-895-2617

 @DrexelNews

http://www.Drexel.edu/ 

Britt Faulstick | EurekAlert!

More articles from Materials Sciences:

nachricht New design improves performance of flexible wearable electronics
23.06.2017 | North Carolina State University

nachricht Plant inspiration could lead to flexible electronics
22.06.2017 | American Chemical Society

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Supersensitive through quantum entanglement

28.06.2017 | Physics and Astronomy

X-ray photoelectron spectroscopy under real ambient pressure conditions

28.06.2017 | Physics and Astronomy

Mice provide insight into genetics of autism spectrum disorders

28.06.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>