Metamat
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Nanotechnologies

Metamat

We are developing an arsenal of nanomaterials to adress societal issues while describing their formation.

We are a strong team of researchers specialized in nanosciences to build new materials with enhanced optical and mechanical properties.
Our knowledge span from the synthesis of the nanoproducts and their self-assembly to their structural characterization.

Latest News
Happy new year!

Master intership opportunities

14/11/2019

We are looking for motivated candidates for master 2 internships.

One topic concern the continuation of the intership of Kinanti Aliyah (M2 SERP Chem), about following in real time Au@Ag nanoparticles growth. You can find information about the techniques by reading this preprint: https://doi.org/10.26434/chemrxiv.9994940.v1

The other topic is about resolving the 3D structure of plasmonic supercrystals and study the resulting collective optical properties by Surface Enhanced Raman Scattering (SERS) spectroscopy.

If one of those subjects interest you, please contact us.

Plasmonic Oligomers with Tunable Conductive Nanojunctions

We are pleased to share this work in close collaboration with the STEM group at LPS.

Abstract: Engineering plasmonic hot-spots is essential for applications of plasmonic nanoparticles. A particularly appealing route is to weld plasmonic nanoparticles together to form more complex structures sustaining plasmons with symmetries targeted to given applications. However, the control of the welding and subsequent hotspot characteristic is still challenging. Herein, we demonstrate an original method that connects gold particles to their neighbors by another metal of choice. We first assemble gold bipyramids in a tip-to-tip configuration, yielding short chains of variable length and grow metallic junctions in a second step. We follow the chain formation and the deposition of the second metal (i.e. silver or palladium) via UV/Vis spectroscopy and we map the plasmonic properties using electron energy loss spectroscopy. The formation of silver bridges leads to a huge redshift of the longitudinal plasmon modes into the mid-infrared region, while the addition of palladium results in a redshift accompanied by significant plasmon damping.

Source: J. Phys. Chem. Lett. 2019, 10, 7093−7099

We welcome a new team member

01/10/2019

  A Raman microscope has been installed recently in the lab and is now fully operational. 

Multiscale deposition of noble metal nanoparticles

 

2018-09-27

Building nanoscale devices is a crucial step towards the success of nanotechnologies. The assembly of colloidal nanoparticles is a technology in development that may outperform standard lithography techniques in the future. Three-dimensional materials with possibly sub-nanometric inter-distances would be easily manufactured this way. Many groups work towards this goal, but some challenges still need to be addressed, such as the propagation of the order to large length scales. In this work, we demonstrate the organization of anisotropic nanoparticles with controlled local order, which spans the whole sample area.

Two complementary techniques (SAXS and TEM) are used to characterize assemblies of Au/Ag heterostructures. In SAXS, the spot size is macroscopic, about 500×200 µm², while in TEM the characterization is made locally, over hundreds of nanometers. The nanoparticles are pointing toward us in the TEM image, organized here in a square in-plane arrangement that can be modulated according to their cross-section.

In this work we used hybrid Au/Ag particles due to their fascinating optical properties. These nanoobjects consist of gold nanorods encased in silver shells with a thickness that can be controlled from a few atomic layers to tens of nanometers. The section of the nanoparticle, initially octagonal, becomes square for a sufficiently thick silver shell. We aimed at studying the impact of the morphological changes of the building blocks on their assembly into superlattices. Usually, nanoparticle assemblies are characterized locally by transmission electronic microscopy (TEM) and give only a limited picture of the assembly on a larger scale. In addition, we used Small Angle X-Ray Scattering (SAXS) to scan the sample area with a probe having much larger dimensions than the nanoparticles. This structural study shows that the nanorods are oriented in the same direction over the whole sample area, thanks to a well-chosen surface chemistry. Furthermore, hexagonal or square phases were formed depending on the octagonal or square cross section of the nanoparticles respectively, demonstrating a control of the multi-scale organization in the system.

 

Reference: C. Hamon, C. Goldmann and D. Constantin, Nanoscale, 2018, DOI: 10.1039/C8NR06376A.

Research
Shaping nanomaterials

Construction of nanoscale devices is a crucial step toward the sucess of nanotechnologies in a variety of fields. Although construction by addition of individual building blocks might appear impossible without using nanomachines, it can actually be carried out by simply exploiting the different magnitude of attractive and repulsive interaction forces at the nanoscale. For example, gravity is negligible for nanoparticles, but other forces become dominant and require the nanoparticles to be coated with selected molecules. Thus, one can simply let the solvent evaporate and wait the nanoparticles to organize into ordered structures without any intervention. Such strategy is one of the core of the concept of self-assembly.

Gold and silver nanoparticles

Plasmonic nanoparticles (Au and Ag) have been object of fascination since ancient time for the preparation of stained glass. Such elementary building block are extremly robust and their use in monuments stand the test of time. A not too far example from the laboratory is the "Sainte-Chapelle du Palais" at "l'île de la cité" in Paris (see image, wikipédia). This phenomenon, commonly witnessed by everyone, originates from the electromagnetic properties of metallic nanoparticles. 

 

Optical properties of nanoparticles

The strong optical properties of nanoparticles (e.g. plasmonic or semiconducting) can be tuned across the visible to the mid infra-red range by modifying their size and shape. When such nanoparticles are organized in ensembles, collective properties are obtained that differ from those of individual particles and the resulting optical properties can be further tuned and even amplified. In particular, plasmon coupling in small gaps (1–10 nm) between plasmonic nanoparticles results in intense electric fields (i.e.,hot-spots) that can be exploited for many purposes, such as sensing, biomaterials, metamaterials design, switching devices, and so forth.

Use of light to study nanoparticles self assembly

We use UV/Vis spectrometry and X-ray scattering tecniques (SAXS) to study nanoparticles super-structures. The structural study of the material is the first step before understanding its overall properties and considering applications. SAXS is an experimental technique used to study the structural properties of materials and gives information on the size and orientation of the nanoparticles, their arrangement, the characteristic interdistances and the possible long-range organization. In a scattering experiment, ordered phases give diffraction signals that are called Bragg peaks. Analysis of such signals requires adapting standard methods of crystallography to the nanoscale, as the relevant length scale is much larger than the atomic scale. UV/Vis spectrometry is used complementary to measure the collective optical properties. Both techniques can be used in situ to study self assembly's pathways. 

 

Mesoporous materials

A mesoporous material is a material containing pores with diameters between 2 and 50 nm. We are devising materials containing a mesoporous architecture to enhance size and shape selectivity for guest molecules or to template nanoparticles synthesis. 

Team
Cyrille Hamon

Cyrille Hamon obtained his Ph.D. from the University of Rennes 1 (France) under the supervision of Pascale Even-Hernandez and Valérie Marchi in 2013. He was a postdoctoral fellow in Luis Liz-Marzán laboratory (CIC Biomagune, Spain) from 2014 to 2016. He then joined the laboratories of Gaëlle Charron and Pascal Hersen (MSC, Université Paris 7) from 2016 to 2017.

He has been appointed in 2017 with a permanent CNRS position in the Laboratoire de Physique des Solides in Orsay.

His current interest focuses on devising new plasmonic architectures for sensing and catalytic applications.

 

 

 

Alumni

Kinanti Aliyah - 2019

Kinanti Hantiyana Aliyah earned her Bachelor of Science in Chemistry from Tohoku University, Japan (2017). She worked in Institute for Materials Research for her bachelor thesis, under supervision of Prof. Hitoshi Miyasaka synthesizing novel building blocks for donor-acceptor metal-organic frameworks.

Currently, she is in her second-year master Erasmus Mundus Joint Master Degree SERP+, working on thesis project about synthesis and characterization of anisotropic bimetallic nanoparticles in real time under supervision of Dr. Cyrille Hamon and Dr. Doru Constantin.

Additionally, believing education should be accessible to all, she co-founded and actively maintains an online-based knowledge-sharing platform for Indonesians (ajarbelajar.com).

Kinanti is now doing her PhD at the Paul Scherrer Institut (Switzerland)

Emmanuel Beaudoin

Emmanuel Beaudoin is an Associate Professor in University Paris-Saclay. He obtained his PhD at the “Laboratoire de Physico-Chimie des Polymères” in « Université de Pau » in 2001, and his HDR (Habilitation à Diriger des Recherches) in « Université de Marseille » in 2014, the same year he has joined the Laboratoire de Physique des Solides. He is involved in physical and physico-chemical studies of nanostructured and hybrid polymeric materials. He is interested in the relationship between structure and physical properties of these materials, at rest and under strain. The main techniques he uses are Small Angles X-ray scattering (with laboratory equipment and synchrotron - ESRF, SOLEIL), optical microscopy, Differential Scanning Calorimetry, UV-vis spectroscopy and spectrofluorimetry.

Jieli Lyu

Jieli Lyu completed her M.S. degree at the Key Laboratory of Applied Surface and Colloid Chemistry of Shaanxi Normal University. She studied under the supervision of Prof. Junxia Peng and Prof. Yu Fang, and her main research topics were (1) synthesis and characterization of amphiliphic compounds; (2) formulation and performances of the emulsions; (3) emulsion-templated preparation of porous materials and their catalytic performance.

She started her PhD in october 2018. Her research interest focuses on nanomaterials with a multiscale organization as well as shedding light on the self-assemblies pathways using light scattering techniques. 

 

 

Patrick Davidson

 

After graduating with a chemical engineering degree from Ecole Supérieure de Physique et Chimie Industrielles de la ville de Paris, a PhD and an Habilitation à diriger des recherches, Patrick Davidson was appointed CNRS Research Director, in 2003, at Laboratoire de Physique des Solides of Université Paris-Sud in Orsay.

His research work focuses on the structural and physical properties of complex fluids such as molecular and polymer liquid crystals, colloidal suspensions and surfactant solutions. He has also recently been involved in the study of hybrid systems prepared by doping liquid-crystalline matrices with mineral nanoparticles. His favorite techniques are X-ray scattering, polarized-light microscopy, and magneto- and electro-optics. His research activity involves frequent contacts with chemists and theoretical physicists.

He is also presently in charge of the “Soft matter and biophysics” research axis of the LPS.

 

Marianne Impéror-Clerc

Marianne Impéror-Clerc has a permanent position at CNRS as ‘directrice de recherche’. She studied Physics at the ENS de Saint-Cloud (1986-1990) where she passed the ‘aggrégation de Physiques’ (1989) before obtaining her PhD (1992) and HdR ‘Habilitation à diriger des recherches’ (2007) at the Université Paris-Sud in Orsay.

Her research is devoted to structural studies of self-assembled systems and her favorite experimental tool is Small Angle Scattering using X-rays or neutrons (SAXS and SANS). 

For example, for mesoporous materials, the control of the architecture of the porosity allows to optimize transport properties. Main goal is to control the nanostructure during the synthesis of such materials. For this, time-resolved scattering experiments allow to follow in real time the formation of the materials and to elucidate the mechanisms involved. Her research thus lies at the frontier between Soft Matter and Materials Chemistry.

She is alos regularly involved in activities about Crystallography for education and the general public (http://www.cristallo2014.u-psud.fr/)

 

 

 

Team MATRIX

 

We are all working in the team MATRIX at the Laboratoire de Physique des Solides (LPS) in Orsay. The LPS is part of the vibrating Paris region fostering interaction with fellow researchers and visiting scientist.

Doru Constantin

Doru Constantin is co-director of the MATRIX research group.

He studied physics at the University of Bucharest and at the Ecole Normale Supérieure de Lyon and was awarded his PhD at the latter institution in 2002. After a Marie Curie Individual Fellowship at the University of Goettingen he obtained a permanent CNRS position at the LPS in 2005.

His activity revolves around the characterization of soft matter systems, often composed of an anisotropic medium doped with nanoparticles.

These studies are performed using modern, synchrotron-based techniques, such as time-resolved, dynamic, or surface-sensitive X-ray scattering and involve a substantial amount of modelling and analysis, using statistical theory or continuum media models.