Understanding how nanoparticles interact is key to improve metal nanocatalysts

Nanocatalysts are key for the future of sustainable chemistry, yet, they typically suffer from rapid deactivation caused by a process called sintering. In a recent study led by the ALBA Synchrotron and Ghent University, researchers have developed an integrated approach where they complement the use of several characterization techniques to study platinum nanoparticle sintering at the micro-, meso- and macroscale. The demonstrated approach shows that mesoscale heterogeneities in the nanoparticle population drive sintering. This work will help broaden the fundamental understanding of nanoparticle sintering and thus design better strategies for catalyst fabrication.

Metal nanoparticle catalysts are the workhorses in a broad range of industrially important chemical processes such as producing clean fuels, chemicals and pharmaceuticals or cleaning exhaust from automobiles. These nanocatalysts are key for the future of sustainable chemistry, yet they typically suffer from rapid deactivation caused by a process called sintering. Due to sintering, the average nanoparticle size increases since this is energetically more efficient for the nanoparticles. However, this decreases their catalytic power.

To date, sintering phenomena are analyzed either at the macroscale, to examine averaged nanoparticle properties, or at the microscale, studying individual nanoparticles. However there is a knowledge gap on the nanocatalysts behavior at the mesoscale, the intermediate length scale between the macro and the micro worlds. At the mesoscale, large ensembles with thousands of nanoparticles can be studied as a “population” in which nanoparticles “communicate” – interact – with each other. In this context, nanoparticle sintering can be considered as a dynamic population of interacting nanoparticles, each of them trading and exchanging atoms to gain stability within the nanoparticle hierarchy.

In a recent study led by the ALBA Synchrotron and Ghent University, researchers have developed an integrated approach where they complement the use of several characterization techniques to study platinum nanoparticle sintering at the micro-, meso- and macroscale. More specifically, they used different analytical techniques and X-ray scattering characterization at the NCD-SWEET beamline in ALBA to show that mesoscale heterogeneities in the nanoparticle population drive sintering. Thus, deleting these heterogeneities would help to avoid sintering.

Read more on the ALBA website

Image: Researchers inside the experimental hutch of the NCD-SWEET beamline at the ALBA Synchrotron. From left to right: Zhiwei Zhang (Ghent University), Matthias Minjauw (Ghent University), Matthias Filez (Ghent University – KU Leuven) and Juan Santo Domingo Peñaranda (Ghent University).

Nanoparticles made from marine polymers for cutaneous drug delivery applications

A research led by the University of Porto in collaboration with the ALBA Synchrotron has studied for the first time the interaction of nanoparticles with the skin, using synchrotron light at the MIRAS beamline. The findings unveil the role of the different skin components and the mechanism of the permeation enhancement conferred with nanoparticles, made from marine polymers. A nano delivery system application in the skin will reduce the dosage needed due to controlled drug delivery and allow newer and better-targeting therapeutic strategies towards cutaneous administration.

Cutaneous drug delivery allows the administration of therapeutic and cosmetic agents through the skin. Advantages of this administration route include high patient compliance, avoidance of high concentration levels of the drug when reaching systemic circulation, and far fewer side effects compared to other administration routes.

Still, the peculiar skin structure assures protection to the human organism and hampers drug delivery. To overcome this issue, skin permeation enhancers, such as nanoparticles, can be used. They are pharmacologically inactive molecules that can increase skin permeability by interacting with the stratum corneum, the first layer of the epidermis, which is the outermost layer of the skin. However, the mechanisms of nanoparticles’ interaction with the skin structure are still unknown.

A research project led by the University of Porto (Portugal) in collaboration with the ALBA Synchrotron has studied for the first time the interaction of polymeric nanoparticles with the skin, using synchrotron light.

Read more on the ALBA website

Image: Nanoparticles made visible on human skin – 3D Rendering

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