Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

University of Konstanz researchers create uniform-shape polymer nanocrystals

13.06.2019

Researchers from the University of Konstanz’s Collaborative Research Centre (CRC) 1214 “Anisotropic Particles as Building Blocks: Tailoring Shape, Interactions and Structures” successfully generate uniform-shape nanocrystals using direct polymerization

A team of researchers from the University of Konstanz’s CRC 1214 “Anisotropic Particles as Building Blocks: Tailoring Shape, Interactions and Structures”, which has been funded by the German Research Foundation (DFG) since 2016, has demonstrated a new aqueous polymerization procedure for generating polymer nanoparticles with a single chain and uniform shape, which, as another difference to previous methods, involves high particle concentrations.


Concept to obtain uniform size and shape particles by controlled polymerization on a molecular as well as particle level. An effective nucleation (N) ensures that particles contain only one active site, and start to grow virtually at the same time. Due to the living character of polymerization, all particles continue to grow for the entire duration of the experiment, to yield particles each composed of a chain of identical length. As the growing chains are immediately deposited on the growing single-crystal particle during this process, particle shape evolves uniformly over time during polymerization

Copyright: Stefan Mecking and Manuel Schnitte

A corresponding paper entitled “Uniform shape monodisperse single chain nanocrystals by living aqueous catalytic polymerization” is due for open access online publication in Nature Communications on 13.06.2019.

Nanoparticles are the building blocks for envisioned nanoparticle-based materials with yet unachieved optical, electronic and mechanical properties. To build nanomaterials, nanoparticles with uniform shapes and sizes are required.

While inorganic metal or metal oxide nanoparticles suitable for assembly can be generated in a variety of shapes, it has been very difficult until now to manufacture polymer nanoparticles in shapes other than spheres, as Stefan Mecking, Professor of Chemical Materials Science at the University of Konstanz’s Department of Chemistry and Vice Speaker of CRC 1214, points out:

“In previous approaches, single-chain particles were prepared by post-polymerization collapse or assembled from solutions of separately synthesized chains. What we have managed to do is to demonstrate direct polymerization to single-chain uniform-shape monodisperse nanocrystals for polyethylene, which is the largest and most important synthetic polymer material”.

One major challenge associated with this approach is to achieve living chain and particle growth that can be sustained for several hours and up to very high molecular weights, ideally yielding single-chain nanocrystals of ultra-high molecular weight polyethylene. To achieve this, the researchers developed advanced catalysts.

“We then conducted a series of pressure reactor tests to identify ideal conditions for maintaining catalytic activity over longer periods of time and to gain insights into the chain and particle growth process”, explains Mecking. “In addition to the novel catalysts, control of the colloidal state of the reaction mixture is another key element in obtaining the desired aqueous particle dispersions”.

In contrast to many post-polymerization procedures, the aqueous polymerization procedure elaborated by Stefan Mecking and his team yields high particle number densities, which are comparable to commercial polymer dispersions used for coatings, paints and other applications.

Using transmission electron microscopy (TEM), the researchers were able to confirm that the particles thus generated are composed of a single chain, display a uniform shape and size distribution and do not aggregate. “While our assemblies may not fully match the extensively optimized assemblies of inorganic nanoparticles, they seem to be very promising”, concludes Mecking.

“In time, our insights into the creation of anisotropic polymer nanocrystals using aqueous catalytic polymerization may enable us to create polymer materials based on nanoparticle assembly”.

Facts:
- Original publication: Manuel Schnitte, Anne Staiger, Larissa A. Casper, Stefan Mecking. Uniform shape monodisperse single chain nanocrystals by living aqueous catalytic polymerization. Nature Communications, 13.06.2019. DOI: https://doi.org/10.1038/s41467-019-10692-1 (DOI will become active after 10:00 BST on 13.06.2019). Licensed under a Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/).
- Team of University of Konstanz researchers led by Professor Stefan Mecking from the Department of Chemistry successfully demonstrates a new aqueous catalytic polymerization procedure for generating anisotropic nanocrystals with uniform shape and size
- Solution to the unresolved problem of uniform particle shape and size in the preparation of polymer nanoparticles
- Tests confirm the nanocrystals’ potential for assembly
- Part of the research carried out by the Konstanz-based Collaborative Research Centre 1214 “Anisotropic Particles as Building Blocks: Tailoring Shape, Interactions and Structures”, funded by the German Research Foundation (DFG) since 2016

Note to editors:
An image is available for download here: https://cms.uni-konstanz.de/fileadmin/pi/fileserver/2019/Bilder/university_of_ko...

Caption: Concept to obtain uniform size and shape particles by controlled polymerization on a molecular as well as particle level. An effective nucleation (N) ensures that particles contain only one active site, and start to grow virtually at the same time. Due to the living character of polymerization, all particles continue to grow for the entire duration of the experiment, to yield particles each composed of a chain of identical length. As the growing chains are immediately deposited on the growing single-crystal particle during this process, particle shape evolves uniformly over time during polymerization
Copyright: Stefan Mecking and Manuel Schnitte

Contact:
University of Konstanz
Communications and Marketing
Phone: + 49 7531 88-3603
Email: kum@uni-konstanz.de

- uni.kn/en

Originalpublikation:

Manuel Schnitte, Anne Staiger, Larissa A. Casper, Stefan Mecking. Uniform shape monodisperse single chain nanocrystals by living aqueous catalytic polymerization. Nature Communications, 13.06.2019. DOI: https://doi.org/10.1038/s41467-019-10692-1 (DOI will become active after 10:00 BST on 13.06.2019). Licensed under a Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/).

Julia Wandt | idw - Informationsdienst Wissenschaft

More articles from Life Sciences:

nachricht Spinal disc under scrutiny - EU project 'iPSpine': One million euros for researchers in Ulm
13.06.2019 | Universität Ulm

nachricht Checkmate for hepatitis B viruses in the liver
12.06.2019 | Helmholtz Zentrum München - German Research Center for Environmental Health

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Determining the Earth’s gravity field more accurately than ever before

Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.

The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...

Im Focus: Tube anemone has the largest animal mitochondrial genome ever sequenced

Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.

The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs....

Im Focus: Tiny light box opens new doors into the nanoworld

Researchers at Chalmers University of Technology, Sweden, have discovered a completely new way of capturing, amplifying and linking light to matter at the nanolevel. Using a tiny box, built from stacked atomically thin material, they have succeeded in creating a type of feedback loop in which light and matter become one. The discovery, which was recently published in Nature Nanotechnology, opens up new possibilities in the world of nanophotonics.

Photonics is concerned with various means of using light. Fibre-optic communication is an example of photonics, as is the technology behind photodetectors and...

Im Focus: Cost-effective and individualized advanced electronic packaging in small batches now available

Fraunhofer IZM is joining the EUROPRACTICE IC Service platform. Together, the partners are making fan-out wafer level packaging (FOWLP) for electronic devices available and affordable even in small batches – and thus of interest to research institutes, universities, and SMEs. Costs can be significantly reduced by up to ten customers implementing individual fan-out wafer level packaging for their ICs or other components on a multi-project wafer. The target group includes any organization that does not produce in large quantities, but requires prototypes.

Research always means trying things out and daring to do new things. Research institutes, universities, and SMEs do not produce in large batches, but rather...

Im Focus: 2D crystals conforming to 3D curves create strain for engineering quantum devices

A team led by scientists at the Department of Energy's Oak Ridge National Laboratory explored how atomically thin two-dimensional (2D) crystals can grow over 3D objects and how the curvature of those objects can stretch and strain the crystals. The findings, published in Science Advances, point to a strategy for engineering strain directly during the growth of atomically thin crystals to fabricate single photon emitters for quantum information processing.

The team first explored growth of the flat crystals on substrates patterned with sharp steps and trenches. Surprisingly, the crystals conformally grew up and...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

 
Latest News

University of Konstanz researchers create uniform-shape polymer nanocrystals

13.06.2019 | Life Sciences

Spinal disc under scrutiny - EU project 'iPSpine': One million euros for researchers in Ulm

13.06.2019 | Life Sciences

Determining the Earth’s gravity field more accurately than ever before

13.06.2019 | Earth Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>