Nano-opto-electronics with Soapstone

Research shows potential of combining mineral with graphene for the design of new devices.

The development of electronic devices in the nanometric scale depends on the search for materials that have appropriate characteristics, and that are also efficient and inexpensive. This is the case of graphene, a material formed by a single layer of carbon atoms obtained from graphite. Graphene is a conductor with excellent optical and electrical properties that can be easily altered by the incidence of electric fields or light.

In addition, several other interesting structural, electronic and optical properties can be obtained by combining graphene with other materials. These new properties arise due to changes in the electronic structure in the interface of different materials when they are brought into contact. In this scenario, the search for new materials and ways of combining them becomes a natural trend.

>Read more on the Brazilian Synchrotron Light Laboratory (LNLS) website

Image: DOI: 10.1021/acsphotonics.7b01017

Nanotechnology in oil exploration

Research investigates use of nanoparticles for advanced oil recovery.

Brazil is a pioneering country in the exploration of oil in deep waters and a great quantity of this fossil fuel is stored in the porous space of carbonate rocks, especially in the pre-salt layer. These rocks are very heterogeneous and have complex pore systems, bringing great challenges to the extraction of oil and gas.
After drilling an oil or gas reservoir, the natural pressure inside it causes the contents to flow naturally to the surface where the fluid is collected and directed to a tanker. However, a few years after the opening of the well, the amount of oil extracted daily tends to decrease due to the drop in internal well pressure.

One of the ways to continue the exploration is by the injecting water or gas into the well, which helps in the transport of fluids and increases oil production, allowing it to be explored for several years. A more efficient way is, however, through the injection of surfactants, which facilitate the remobilization of oil, even in regions where water and gas have no further effect.
Recently, Tannaz Pak and collaborators from Brazil and the United Kingdom investigated [1] the use of nanoparticles to improve the advanced recovery of oil in carbonate rocks. By means of time-resolved X-ray microtomography, the research showed for the first time how oil droplets, retained in the pores of carbonate rocks, change shape when interacting with silica nanoparticles suspended in water, making it again available for extraction.

>Read more on the Brazilian Synchrotron Light Laboratory website

Image Credit: Geraldo Falcão / Banco de Imagens Petrobras

Inorganic nanoparticles activity as artificial pro-enzymes

Research opens perspective for treatment of several diseases tailored to the needs of each patient

From the biochemical point of view, we are a complex set of interconnected chemical reactions. The molecules that make up our bodies are in constant transformation, and this is what makes it possible for us to get energy from food, to regenerate damage to our tissues, and to synthesize the compounds necessary for life.
These modifications usually occur with the aid of other molecules called enzymes, which promote and accelerate chemical reactions without being consumed during the process.

For the proper functioning of this complex system, the enzymes must act only at the necessary place and time. Hence, nature has developed an ingenious strategy for this to happen: inactive forms of enzymes, known as proenzymes, are continuously produced, but are activated only by specific stimuli.
The occurrence of a problem in the production of these enzymes can result in highly debilitating diseases. However, the treatment of patients by means of enzymatic replacement from natural sources is not always an adequate solution.
Therefore, researchers have been investigating synthetic systems to mimic the action of natural enzymes for biomedical applications and one of the most promising alternatives is the use of nanoparticles.

>Read more on the Brazilian Synchrotron Light Laboratory website

Image: Schematic figure of the action of the ultrafine cerium(III) hydroxide and cerium oxide CeO (2-x) nanoparticles . Back cover image from the Journal of Materials Chemistry B [1].

Yves Petroff takes over as Director of the LNLS

French physicist was Director-General of the largest European synchrotron between 1993 and 2001 and LNLS’ Scientific Director from 2009 to 2013.

In ceremony held on the morning of August 29th, Yves Pierre Petroff became Director of the Brazilian Synchrotron Light Laboratory (LNLS). Yves Petroff was LNLS’ Scientific Director from November 2009 to March 2013. During the ceremony, Rogério Cesar de Cerqueira Leite, Chairman of the Board of Directors of CNPEM, and Antonio José Roque da Silva, CNPEM’s Director-General and former LNLS Director, highlighted Pretroff’s competence and his history within LNLS.

Yves Petroff is one of the world’s leading specialists in the use of synchrotron light. He received his doctorate in physics from the Ecole Normale Supèrieure of the University of Paris in 1970. Later, he went to the University of California, Berkeley, from 1971 to 1975. During this period, Yves Petroff worked on the investigation of optical properties of solids, having made important developments in the area of Resonant Raman Effect.

In the early 1970s, the first generation of synchrotron accelerators began to be built, focused primarily on particle physics. In 1975, Yves Petroff returned to France to work in the ACO, one of the first synchrotrons in the world, located in Orsay. Pioneering work was performed by Petroff’s team on the use of synchrotron light to understand the properties of solids. His group was also the first in the world to build a Free Electron Laser in the region of visible light.

>Read more on the Brazilian Synchrotron Light Laboratory (LNLS) website.

>Read also an article published on the ESRF website.

 

Unprecedented 3D images of neurons in healthy and epileptic brains

Results open new perspectives for the study of neurodevelopment and neurodegenerative diseases.

A comprehensive understanding of the brain, its development, and eventual degeneration, depends on the assessment of neuronal number, spatial organization, and connectivity. However, the study of the brain architecture at the level of individual cells is still a major challenge in neuroscience.
In this context, Matheus de Castro Fonseca, from the Brazilian Biosciences National Laboratory (LNBio), and collaborators [1] used the facilities of the Brazilian Synchrotron Light Laboratory (LNLS) to obtain, for the first time, three-dimensional images in high resolution of part of the neuronal circuit, observed directly in the brain and with single cell resolution.

The researchers used the IMX X-Ray Microtomography beamline, in combination with the Golgi-Cox mercury-based impregnation protocol, which proved to be an efficient non-destructive tool for the study of the nervous system. The combination made it possible to observe the points of connectivity and the detailed morphology of a region of the brain, without the need for tissue slicing or clearing.
The mapping of neurons in healthy and unhealthy tissues should improve the research in neurodegenerative and neurodevelopmental diseases. As an example of this possibility, the work presents, for the first time in 3D, the neuronal death in an animal model of epilepsy.

The researchers are now working to extend the technique to animal models of Parkinson’s disease. The intention is to better understand the cellular mechanisms involved in the onset and progression of the disease. In the future, with the inauguration of the new Brazilian synchrotron light source, Sirius, the researchers believe that it will be possible to obtain images at the subcellular level, that is, images of the interior of the neurons.

>Read more on the Brazilian Synchrotron Light Laboratory website

Image: X-ray microtomography of the cerebral cortex showing the segmentation of individual neurons. Each color represents a single neuron or a group of neurons.

Synchrotron infrared beamline optics optimized…

…for nano-scale vibrational spectroscopy. First experimental report of a special optical layout dedicated to correct typical aberrations derived from large extraction ports in IR beamlines.

Infrared nanospectroscopy represents a major breakthrough in chemical analysis since it allows the identification of nanomaterials via their natural (label free) vibrational signatures. Classically powered by laser sources, the experiment called scattering Scanning Near-field Optical Microscopy (s-SNOM) has become a standard tool for investigations of chemical and optical properties of materials beyond the diffraction limit of light.

Lately, s-SNOM is achieving unprecedent sensitivity range by exploring the outstanding spectral irradiance of synchrotron light sources in the full range of infrared (IR) radiation. In the last few years, the combination of s-SNOM and ultra-broadband IR synchrotron (SINS or nano-FTIR) has helped studies in relevant scientific fronts involving atomic layered materials, fundamental optics, nanostructured bio-materials and, very recently, it was demonstrated to be feasible to work in the far-IR.

IR ports in synchrotron storage rings can be up to a thousand times more brilliant than classical IR black body sources. This advantage allowed IR beamlines to be the only places capable of performing IR micro-spectroscopy for many years. However, in comparison to X-ray ports, IR beamlines require large apertures for allowing long wavelengths to be extracted. Consequently, IR beamlines typically present optical aberrations such as extended source depth and coma.

>Read more on the Brazilian Synchrotron Light Laboratory website

Images (extracts): Figure 1 – Proposed optical layout, IR extraction chamber indicating the source depth, conical mirror illustration, aberration-corrected focal spot at the sample stage and nano-FTIR experimental scheme in operation in the IR endstation of the LNLS. Figure adapted from R. Freitas et al., Optics Express 26, 11238 (2018).

Breakthrough for body heat-powered technologies

One of the biggest challenges for the advancement of wearable devices, embedded to clothing and accessories, which would be capable, for example, of continuously measuring and transmitting vital sign data, is the availability of power without the need for large batteries.

Thermoelectric materials – in which a temperature difference between two points of the material creates an electric current or vice versa – make it possible to obtain the electrical energy used by the device from the temperature difference between the surface of the human body and the ambient air.

The efficiency of these materials is characterized by their figure of merit zT, which is directly proportional to the electrical conductivity and the absolute temperature of the material and inversely proportional to its thermal conductivity. Thus, obtaining new materials with high value for zT at room temperature and low thermal conductivity is a key element for the development of a new generation of wearable devices based on thermoelectric heat recovery.

>Read more on the LNLS website

Young talent from LNLS awarded at international conference

Work on components for Sirius was elected best poster.

Gabriel Vinícius Claudiano, member of the Brazilian Synchrotron Light Laboratory (LNLS), was awarded the prize for best poster in the category “young engineer under 30” during the tenth edition of the MEDSI (Mechanical Engineering Design of Synchrotron Radiation Equipment and Instrumentation) conference, which was held in Paris, France, between June 25th and 29th.

Gabriel’s work is related to the development of components for the beamlines of the new Brazilian synchrotron light source, Sirius. These components are located at the interface between the storage ring and the beamlines, which is called front-end, and their function is to absorb part of the synchrotron light beam to protect sensitive equipment.

>Read more on the LNLS website

Picture: Gabriel Vinícius Claudiano.

Sirius ever closer to reality

Construction works are at 84% and the electron accelerator begins to be assembled in March.

The construction of Sirius, the new Brazilian synchrotron light source, is advancing. In March, the first of the three electron accelerators begins to be installed: the LINAC, or linear accelerator, which is responsible for the initial emission and acceleration of the electrons. The building, now 84% completed, will soon be in the right conditions to receive installation of the remaining electron accelerators: booster and storage ring.

Sirius is the largest and most complex scientific infrastructure ever built in Brazil. Sirius will be a state-of-the-art scientific tool, open to the research community from Brazil and abroad. The new synchrotron light source will open new perspectives for research in strategic areas such as health, agriculture, energy, biotechnology, nanotechnology, and many others.

Construction Challenges
The 68,000-square-foot Sirius building is among the most sophisticated constructions ever built in the Brazil, with unprecedented mechanical and thermal stability requirements.
In December 2017, the most critical phase of the construction was completed: the installation of the floor where the electron accelerators will be installed.

>Read more on the Brazilian Synchrotron Light Laboratory website

Image: Comparison between Sirius simulation when project (top) and photo of civil works in February 2018 (bottom).

Structure and Catalytic Activity of Copper Nanoparticles

Research investigates the addition of ceria on the activity of catalysts for the water-gas shift reaction

Catalysts are substances that promote and accelerate chemical reactions without being consumed during the process and are widely used in industrial processes to produce various chemicals.

Catalysts based on copper nanoparticles dispersed in an oxide support benefit various reactions, such as the synthesis of methanol, the alcohol dehydrogenation, or the water gas shift (WGS) reaction which is one of the main processes for hydrogen production on an industrial scale. In this reaction, carbon monoxide reacts with water to produce carbon dioxide CO2 and hydrogen gas H2.

>Read more on the LNLS website

Figure 1: Correlation between the bond length of CuO and the catalyst turnover frequency (TOF) for the catalysts analyzed under WGS conditions with different proportions of copper and ceria.

 

A new x-ray technique to unravel electronic properties of actinide compounds

A new research demonstrates a direct and selective way to investigate 5f electrons in actinide compounds as well as their interaction with other valence electrons

Actinides are a series of chemical elements that form the basis of nuclear fission technology, finding applications in strategic areas such as power generation, space exploration, diagnostics and medical treatments, and also in some special glass. Thorium (Th) and Uranium (U) are the most abundant actinides in the Earth’s crust.

Read more on the LNLS website.

Image: X-ray Magnetic Circular Dichroism (XMCD) measurements for UCu2Si2 and UMn2Si2 performed at temperatures of 10 K and 300 K, respectively.

A new x-ray technique to unravel electronic properties of actinide compounds

A new research demonstrates a direct and selective way to investigate 5f electrons in actinide compounds as well as their interaction with other valence electrons

 

Actinides are a series of chemical elements that form the basis of nuclear fission technology, finding applications in strategic areas such as power generation, space exploration, diagnostics and medical treatments, and also in some special glass. Thorium (Th) and Uranium (U) are the most abundant actinides in the Earth’s crust.

A deeper understanding of the properties of uranium and other actinides is necessary not only for their more efficient use in existing applications but also for proposing new applications. Several open questions remain, progress in this area usually limited in part by the difficulty in handling these materials safely.

The distribution of electrons in the outer orbital of the atoms that make up a given material is what defines whether they are electrical insulators, conductors or semiconductors, as well as whether they are hard or malleable. Other structural, electronic and magnetic properties are also defined by these valence electrons which may undergo electronic hybridization with other orbitals. Such mixture of orbitals modifies material properties influencing oxidation states, the way bonding between atoms takes place, and hence the geometrical arrangement formed in crystals and molecules with actinide elements.

 

>Read more on the Brazilian Synchrotron Light Laboratory website

 

LNLS’ Users get together at the 27th RAU

The event had 140 participants from November 22nd to 24th, 2017, on the CNPEM campus.

The Annual Users Meeting of the Brazilian Synchrotron Light Laboratory (LNLS) attracts Brazilian and foreign researchers every year to the debate, exchange of experiences and integration of the community of users of the Laboratory.

The 27th edition of the event was held from November 22nd to 24th, 2017, on the campus of the Brazilian Center for Research in Energy and Materials (CNPEM), in Campinas, Brazil. The meeting was attended by 140 participants from different countries.

The meeting began with an overview of the Laboratory facilities by the LNLS Director, Antonio José Roque da Silva, who gave participants the opportunity to get a closer look at the future plans for LNLS, in particular the ongoing construction of the new synchrotron light source Sirius. Sessions throughout the meeting discussed the projects for the Sirius beamlines and for the IT infrastructure, including the control, acquisition and processing of data in the experimental stations of the new source.

LNLS members are awarded

Awards were given in the international conferences ICALEPCS and WIRMS

Two members of the LNLS were recently awarded at international conferences. The engineer Daniel Tavares received the first award granted to early-career professionals by the conference ICALEPCS, related to control systems for large scientific facilities. The researcher Francisco Carlos Barbosa Maia received the award for best poster during the WIRMS event, which brings together staff and users of infrared beamlines from laboratories around the world.

 

New catalysts for the synthesis of organic compounds

Research proposes new mechanism for Suzuki-type C-C homocoupling reaction catalyzed by palladium nanocubes

 

The production of chemical compounds from simpler organic molecules is of great importance for various industrial processes. It is based on the bonding between carbons of the precursor organic compounds, aided by catalysts (typically transition metals). These reactions make it possible to obtain natural and synthetic substances for the development of new materials, such as polymers and pharmaceuticals.

In particular, the so-called carbon-carbon (CC) cross-coupling reactions, in which two different precursor molecules are bound to form the final chemical compound, are of such importance that their development granted the 2010 Nobel Prize in chemistry to researchers Richard F. Heck, Ei-ichi Negishi and Akira Suzuki.

Another type of coupling reaction is the C-C homocoupling reaction, in which two similar precursor molecules bond forming a symmetrical final compound. These reactions began to gain prominence due to their similarities to cross-coupling reactions, which allowed the optimization and development of new catalysts for both mechanisms.

 

>Read more on the Brazilian Synchrotron Light Laboratory website

 

Improving the treatment of industrial waste

Research uncovers the mechanism of memory effect of lamellar double hydroxides (LDH).

Synthetic dyes are in constant use in a wide variety of industries, from textile to cosmetics. Both the production and use of these substances can lead to environmental problems if they are not properly degraded or removed from industrial effluents. Among the many physical, chemical or biological processes that can be used for the treatment of such wastes, the adsorption processes are noteworthy for combining low cost and high removal rates.

R. M. M. Santos et al. [1] used the LNLS facilities to investigate the properties of lamellar double hydroxides (LDH), a family of anionic clays with high adsorption capacity, for the removal of synthetic dyes.