polymer – Lightsources.org

Mind the gap – ESRF tracks defects triggered by composites in root fillings

2021/12/212021/12/22

Polymer composite fillings of root-canal treated teeth can fail over time. Scientists led by the Charité University in Berlin (Germany) have found that this is not because of the dentist’s lack of skills but rather because of stresses that build up and deform the biomaterial just after it is placed. The results are published in Acta Biomaterialia.

It is one of the most peculiar images that can come to mind: a dentist restoring severely destroyed teeth and placing fillings on a beamline at a synchrotron. It is, however, exactly what happened on beamline ID19 a while back, when a team from the Charité and TU Universities in Berlin and the ESRF examined how well composite fillings adapt to cavities in the tooth root canal orifice.

To treat cavities in teeth, dentists expose solid tooth tissue prior to “filling” the volume of missing structure with rigid biomaterials that sustain chewing forces. In the past, dentists used metals such as amalgam or gold, but today they mostly use composite materials, made of polymer and glass. Such materials, which are well resistant to damage and highly aesthetic, allow rapid recovery of tooth function. However, composites tend to fail in the long run, especially in root-canal filled teeth.

Diamond celebrates 10,000th paper – A breakthrough in chiral polymer thin films research

2021/01/202021/01/21

This could fundamentally change the technology landscape by enabling a new generation of devices

A recent paper in Nature Communications by an international team of collaborative researchers marks the 10,000th published as a result of innovative research at Diamond Light Source, the UK’s national synchrotron. This study presents disruptive insights into chiral polymer films, which emit and absorb circularly polarised light, and offers the promise of achieving important technological advances, including high-performance displays, 3D imaging and quantum computing.https://player.vimeo.com/video/502596383

Chirality is a fundamental symmetry property of the universe. We see left-handed (LH) and right-handed (RH) mirror image pairs in everything from snails and small molecules to giant spiral galaxies. Light can also have chirality. As light is travelling, its internal electric field can rotate left or right creating LH or RH circular polarisation. The ability to control and manipulate this chiral, circularly-polarised light presents opportunities in next-generation optoelectronics (Figs 1a and 1b). However, the origin of the large chiroptical effects in polymer thin films (Figs 1c and 2) has remained elusive for almost three decades. In this study, a group of researchers from Imperial College London, the University of Nottingham, the University of Barcelona, the Diamond Light Source and the J.A. Woollam Company made use of Diamond’s Synchrotron Radiation Circular Dichroism beamline (B23) and the Advanced Light Source in California.

Read more on the Diamond website

Image: In situ chiroptical response of ACPCA and cholesteric chiral sidechain polymers (CSCP) thin ﬁlms. In situ CD spectra recorded during heating and cooling of ACPCA (F8BT: aza[6]H) and CSCP (cPFBT) thin ﬁlms (note blue represents low temperatures and red represents high temperatures), (c) and (d) the CD intensity recorded at 480nm as a function of temperature during heating (red) and cooling (blue), and (e) and (f) CD intensity of thin ﬁlms held at 140°C as a function of time for [P] (turquoise) and [M] (purple) systems (note the different time on-axis).

Powering the future of clean energy

2020/10/262020/10/27

Hydrogen gas can be used to power vehicles and has the potential to provide electricity to homes

The global quest for clean energy is championed by researchers in Canada who are focused on harnessing the potential of hydrogen.

The idea of the hydrogen economy was first proposed 50 years ago as a way to combat the negative effects of fossil fuels. Its future is the focus of new research from the University of Toronto’s Thermofluids for Energy and Advanced Materials (TEAM) lab, whose work relied on the Canadian Light Source (CLS) at the University of Saskatchewan to visualize performance.

Read more on the Canadian Light Source website

Image: Adam Webb (CLS), Sergey Gasilov (CLS), Manojkumar Balakrishnan (U of T), Jason Keonhag Lee (U of T), Denise Miller (CLS), Kieran Fahy (U of T) on the BMIT beamline at CLS.

A polymer coating makes Metal Organic Frameworks better at delivering drugs

2020/06/262020/07/14

Researchers use Synchrotron InfraRed microspectroscopy to study the dynamics of drug release from MOFs

How to efficiently deliver targeted, controlled and time-released doses of drugs is a significant challenge for biomedicine. Finding solutions to this challenge would result in substantial benefits for patients, including more effective drug therapy and fewer undesirable side effects. The porous nature of metal-organic frameworks (MOFs) makes them attractive candidates for drug-delivery systems as they can be tailored to hold and transport a variety of encapsulated guest molecules. To this end, employing MOFs as a drug delivery vehicle could offer potential solutions to accomplish the targeted and controlled release of anti-cancer drugs. However, understanding the precise chemical and physical transformations that MOFs undergo as these guest molecules are released is challenging. In work recently published in ACS Applied Materials & Interfaces, researchers from the University of Oxford, University of Turin, and Diamond Light Source used a combination of experimental and theoretical techniques to address this problem. They show how the combination of hydrophilic MOF-encapsulated drug with a hydrophobic polymeric matrix is a highly promising strategy to tune the drug release rate for optimal delivery. Their results demonstrate that high-resolution synchrotron InfraRed microspectroscopy is a powerful in situ technique for tracking the local chemical and physical transformations, revealing the dynamics underpinning the controlled release of drug molecules bound to the MOF pores.

Read more on Diamond Light Source website

Image: Using synchrotron infrared radiation to track the drug release process from MOF/Polymer composites.

A highly promising sustainable battery for electric vehicles

2020/06/23

McGill University researchers show that affordable materials could prove key for improving the batteries used in electric vehicles. The breakthrough was analyzed and confirmed with the Canadian Light Source (CLS) at the University of Saskatchewan. The research was funded by NSERC and supported by Hydro-Quebec.

As we move to greener technologies, the need for affordable, safe and powerful batteries is increasing constantly.

Battery-powered electric vehicles, for example, have much higher safety standards than our phones, and to travel the long distances required in Canada, lighter weight, high-energy capacity batteries make a world of difference.

Current rechargeable batteries tend to use expensive non-abundant metals, like cobalt, that carry an environmental and human rights toll under the poor labour conditions in mines in Africa. All are barriers to wider adoption.

The battery’s cathode, or positive electrode, is one of the best candidates for Li-ion battery improvement. “Cathodes represent 40 per cent of the cost of the batteries that we are using in our phones right now. They are absolutely crucial to improve battery performance and reduce dependency on cobalt,” says Rasool.

Read more on the Canadian Light Source website

Image : Lithium ion silicate nanocrystals coated in a conducting polymer known as PEDOT enhance battery performance even after 50 cycles, paving the way for high energy density cathodes.