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Metallic Nanocrystals (M-NCs) are crucial for developing technological fields such as bioimaging, optoelectronics, and sensing.  They have been at the forefront of scientific research for several decades due to their peculiar optical properties, which have generated significant interest in manipulating them to implement current applications and pave the way for new ones. These properties arise from the phenomenon of the Localised Plasmon Surface Resonance (LSPR). LSPR is the collective oscillation of conduction electrons in metallic nanoparticles when excited by light, resulting in strong absorption at specific wavelengths. This phenomenon is highly sensitive to the nanocrystal`s size, shape, material and surrounding environment. Traditionally, manipulating the LSPR has involved modifying the abovementioned structural parameters, often requiring extensive planning and the development of multiple synthetic approaches to obtain NCs with different LSPR characteristics. On the contrary, we have been focused on post-synthesis NCs manipulation by creating nanocrystal superlattices, materials composed of M-NCs arranged in a periodic, three-dimensional structure. This unique architecture enhances their optical and electronic properties. For this reason, we focused on realising and characterising these superlattices. In detail, we studied the behaviour of oleylamine-capped Au-NCs, Ag-NCs, and Pt-NCs, focusing on how the solvent's capping agent surface density and the dielectric constant of the solvent affect the functionalization process, allowing us to obtain such structures in water. Additionally, we aimed to establish a direct correlation between these superlattices' structure and optical properties. About the speaker: Alessandro Cangiano studied Industrial Chemistry at the University of Naples, and joined Professor Luigi Paduano`s research group as a PhD student. Currently, the research focuses on the understanding of the self-assembly of nanocrystals into highly ordered supramolecular structures using a multi-technique approach mainly focused on Small-Angle Scattering techniques

Liquid foams are assemblies of bubbles within a continuous liquid phase. They are complex fluids, behaving as elastic solids below a yield stress and undergoing plastic flow above, with viscous dissipation. These rheological properties are difficult to relate to physical processes at the scale of bubbles, because foams are opaque. To circumvent this difficulty, we present the first experimental study coupling the controlled deformation of a foam in a rheometer with the simultaneous 3D imaging, using fast X-ray tomography. We quantify all quantities at the bubble scale: displacements, deformation, evolution of their contacts and, for the first time, a measure of the local elastic stress from the geometry of the gas/liquid interfaces. We validate this new measure by comparing it to the applied torque by the rheometer. We apply these descriptive tools to the study of the elementary plastic events in foams, the four-fold neighbour swapping of bubbles. We reveal that such events have a very clear precursor signature on the local stress. We also show that they redistribute the elastic stress in their surroundings with a quadrupolar symmetry, related to the fourfold neighbour swapping. These new experimental results provide unprecedented insight onto the rheology of foams, and more generally of amorphous materials, at the scale of the microstructure. About the speaker: B. Dollet is a CNRS researcher and a part-time Associate Professor at Ecole polytechnique. He obtained a PhD in Physics in 2005 at the Université Joseph Fourier. After two years of post-doc in the group Physics of Fluids at the University of Twente (The Netherlands), he was appointed CNRS research in 2007 at the Institut de Physique de Rennes. He moved in 2017 in the LIPhy lab at the Université Grenoble Alpes. His scientific interests are various between soft matter physics, fluid mechanics and acoustics (acoustics and shock waves in foams, ultrasound contrast agent microbubbles, drops, bubbles and biomimetic studies in microfluidics, surfactant influence on thin film hydrodynamics, damping of sloshing waves...), but the study of foam rheology by image analysis methods has been a regular guideline in his career.

Microbial amphiphiles, known as microbial biosurfactants, are key molecules for the future of surfactants and amphiphiles, not only for their sustainable process of synthesis and production, but also for their chemical functionalities. Due to more and more stringent EU regulations, multinational chemical companies develop strategic production and partnerships for a long-term investment in this field. Indeed, their rich and astonishing phase behavior in water, their responsiveness to external stimuli combined to their sustainable origin, enhanced biodegradtion and mildness to the skin are attractive perspectives for the private sector as well as academia. From a fundamental science perspective, knowledge of the phase behavior and solution properties of microbial biosurfactants is critical to conceive their application plan, as done for classical surfactants and lipids in the past fifty years. However, study of the phase behaviour of microbial biosurfactants is only a recent trend in the field [1] and recent studies from our and other groups have indeed shown curious properties, like a triple surfactant-lipid-gelator behaviour. [2] In this communication, I will discuss these aspects with a special focus on the membrane-forming properties of selected microbial biosurfactants. Structural (SAXS, neutron diffraction) and dynamic (neutron spin echo) aspects will be discussed in detail with a comparison with more classical lipidic amphiphiles (e.g., phospholipids). [1] N. Baccile, C. Seyrig, A. Poirier, S.A. Castro, S.L.K.W. Roelants, S. Abel, Self-assembly, interfacial properties, interactions with macromolecules and molecular modelling and simulation of microbial bio-based amphiphiles (biosurfactants). A tutorial review, Green Chem. 23 (2021) 3842–3944. https://doi.org/10.1039/d1gc00097g. [2] N. Baccile, A. Poirier, C. Seyrig, P. Le Griel, J. Perez, D. Hermida-Merino, P. Pernot, S. Roelants, W. Soetaert, Chameleonic Amphiphile: the Unique Multiple Self-Assembly Properties of a Natural Glycolipid in Excess of Water, J. Colloid Interface Sci. 630 (2023) 404–415. https://doi.org/10.1016/j.jcis.2022.07.130. About the speaker: Niki BACCILE is a physicochemist working in the field of Soft Matter. He received his Master diploma from the University of Padova, Italy and obtained a PhD in Materials’ Chemistry in 2006 at the Université Pierre et Marie Curie (now Sorbonne University), Paris (France). He worked as a post-doc at the Institute Charles Gerhardt in Montpellier (France) in 2007 and at the Max Planck Institute for Colloids and Interfaces, Potsdam-Golm (Germany), in 2008. Since 2008, he is full-time CNRS research fellow at Sorbonne University, Paris. He currently explores the self-organization properties of microbial biosurfactants and their potential use in soft matter.

Rodlike cellulose nanocrystals (CNCs) possess significant potential as building blocks for creating uniform, sustainable materials. However, a critical hurdle lies in the need to enhance existing or devise novel processing that provide improved control over the alignment and arrangement of CNCs across a wide spatial range. Specifically, the challenge is to achieve orthotropic organization in a single-step processing. In this aim, an original combined frontal ultrafiltration (FU) and ultrasound (US) set-up compatible with in situ SAXS observations has allowed revealing for the first time a multilayer orthotropic structuring of CNC suspensions, that mimics the organization of articular cartilage: a first layer composed of CNCs having their director aligned parallel to the horizontal membrane surface, a second intermediate isotropic layer, and a third layer of CNCs with their director vertically oriented along the direction of US wave propagation direction. These results open the way for developing novel orthotropic biomaterials with tunable structured cellulosic organizations for tissue engineering applications. (Semeraro E. F. et al., Colloids Surf. A, 584,124030, 2020 doi.org/10.1016/j.colsurfa.2019.124030 ; Pignon F. et al., J. Phys. Chem. C, 125, 18409-18419, 2021 doi.org/10.1021/acs.jpcc.1c03506). About the speaker:  Frédéric Pignon is Senior Scientist at CNRS in the “Laboratoire Rhéologie et Procédés” UMR 5520 (CNRS, Université Grenoble Alpes, Grenoble-INP). His main research interest is devoted to understand and control the multi-scale structure and flow properties of colloidal suspensions in industrial processes. For example, membrane separation processes combined with ultrasound are studied by in-situ scattering measurements (SAXS, SALS) in order to improve the performance of filtration as well as produce innovative cellulosic composite films with controlled anisotropic textures from nanometric to micrometric length scales.

Surfactants are an important component of commercial hair dyeing formulations, which renders it crucial to understand their interaction with hair dye molecules to facilitate a systematic formulation design. Knowledge about the driving forces for dye-surfactant interaction can be obtained by identifying the location of dye molecules in surfactant micelles. A combination of NMR-spectroscopy and contrast matching in small-angle neutron scattering was successfully employed for this purpose. The complementary use of both techniques permitted to unambiguously identify the location of dye molecules in DTAB micelles. It was furthermore used to discern the solubilisation locus of dye molecules in micelles of the non-ionic surfactant C₁₂E₅ as a function of the pH of the dye-surfactant solution. In the course of the presentation, the co-assembly of dye with DTAB and with C₁₂E₅ and its implication on hair dyeing is discussed. In addition to that, the feasibility of SANS contrast matching for the localisation of dye molecules in micelles of low molecular weight surfactant is demonstrated. Soft Matter 19, 4579–4587 (2023) | Soft Matter 19, 4588–4598 (2023) | Nanoscale Advances 5, 5367–5384 (2023). About the speaker: Wenke Müller graduated from the University of Potsdam in Germany with a master's degree in chemistry and is now completing her PhD-thesis with the title "Solution behaviour of dissociative direct dyes in the presence of surfactants" at the Institute Laue-Langevin (France) in collaboration with the University of Paderborn (Germany) and the company KAO Germany GmbH (Germany).

In little more than a century, synthetic plastic oligomers have gone from being hailed as a scientific wonder to being reviled as an environmental plague. Plastic is lightweight, tough, transparent, waterproof. These characteristics become a drawback when it was firstly noticed that the degradation of plastic waste can enter the food chain and finally interact with living organisms’ cells. Physicochemical characterization of the effects of synthetic polymers on the structure and dynamics of cell membranes is thus of primary importance. To study the interactions between short chains of polystyrene and model lipid membranes (DPPC, in both gel and fluid phases) we combined a wide spectrum of experimental techniques exploiting neutron and Xrays scattering in combination with PSCM laboratory techniques (calorimetry, Langmuir, QCMD, BAM). We find that doping doses of polystyrene oligomers alter the thermal properties of DPPC, stabilizing the fluid lipid phase. They perturb the membrane structure and dynamics, in a concentration-dependent fashion. Eventually, they modify the mechanical properties of DPPC, reducing its bending modulus in the fluid phase. Our results call for a systematic, interdisciplinary assessment of the mechanisms of interaction of synthetic, everyday-use polymers with cell membranes. About the speaker: graduated in Physics at Sapienza university of Rome, with a master thesis in soft matter physics (NMR applied to frescoes conservation). Approaching the biophysics field, she completed her PhD at Ancona, Università Politecnica delle Marche (UNIVPM Ancona), focusing her research interests on bio-soft matter by means of scattering techniques to study the structural organization and dynamics of biomimetic colloids, in particular protein arrangement and interactions on different length-scales. She moved to Milan for her post-Doc and is now researcher in Università Statale di Milano (UNIMI), characterizing the structural and thermotropic properties of lipid membranes, self-aggregation of peptides and proteins, interaction of peptides and polymers with model membranes.

Soft matter pervades into daily life under several forms: biological matter, foams, food products, ink, tires, and many others. In contrast to their very different appearance, all these systems are governed by the same, fundamental physical laws. Aim of the school is providing an overview of the forces governing the behaviour of soft matter systems and introducing the most relevant techniques to probe such interactions. The school proposes frontal lectures for doctoral students working in the field of soft matter given by recognized experts from all over Europe. Poster sessions will be opened for discussion on research topic and experimental results between students and invited lecturers. Lecture 1: Introduction to colloid and interface science by Emanuel Schneck Lecture 2: Physics of macromolecular systems by Julian Oberdisse Lecture 3: Hierarchical structures in food. Soft matter structure at various length scales by Milena Corredig Lecture 4: Computer simulation of molecular systems – Principles and  example applications by Maria Reif Lecture 5: Introduction to Nuclear Magnetic Resonance by Alicia Vallet Lecture 6: Liquid foams: from the formulation to the characterization techniques by Anne-Laure Fameau Lecture 7: Electron Microscopy in Biology by Guy Schoen Lecture 8: Introduction to neutron scattering applied to soft matter by Sylvain Prevost and Nicolo Paracini      

Non-lamellar lipid aqueous phases, such as reverse cubic or hexagonal phases, have increasingly been used to entrap biomolecules. We here discuss encapsulation of two key types of enzymes of different sizes, namely Aspartic protease (34 KDa) and Beta-galactosidase (460 KDa) [1,2]. Although the curvature of the lipid aqueous interfaces in these phases determines the size of the aqueous cavities and hence the space given to the enzyme, the interaction between the enzyme and the lipid layer is an important factor that controls the efficiency of the encapsulation. We used mixtures of acylglycerides and acyldiglycerides, which are able to form highly swollen sponge phases (L3), with aqueous pores up to 13 nm of diameter [3]. This system can with the help of the dispersing agent polysorbate 80 (P80) form well defined nanoparticles in excess water with an internal L3 structure [4]. These particles adsorb at the interface to form a lipid bilayer as shown by QCM-D and neutron reflectometry [4]. Raman spectroscopy results for the sponge phases show large similarities in lipid chain confirmation and head group interactions as in the lamellar and reverse bicontinuous cubic phase in the same lipid system as all three structures are formed by lipid bilayers [5]. Size exclusion chromatography show efficient encapsulation of both enzymes, yet they retained their enzymatic activity over months, surpassing the storage stability of pure enzymes in solution [1,2]. The reason for this can be understood in terms penetration of the enzymes into the formed lipid bilayer as shown by Raman spectroscopy [1] and neutron reflectometry [6]. This has been confirmed by neutron spin echo and molecular dynamics simulations [7]. [1] M. Valldeperas, M. Talaikis, S. K. Dhayal, M. Velicka, J. Barauskas, G. Niaura, T. Nylander. Biophys. J. 2019, 117, 829-843; [2] J. Gilbert, M. Valldeperas, S. K. Dhayal, J. Barauskas, C. Dicko, T. Nylander. Nanoscale 2019, 11, 21291–21301; [3] M. Valldeperas, M. Wisniewska, M. Ram-On, E. Kesselman, D. Danino, T. Nylander and J. Barauskas, Langmuir 32 (2016) 8650; [4] M. Valldeperas, A. P. Dabkowska, G. K. Pálsson, S. Rogers, N. Mahmoudi, A. Carnerup, J. Barauskas and T. Nylander, Soft Matter 15 (2019) 2178; [5] M. Talaikis, M. Valldeperas, I. Matulaitienė, J. Latynis Borzova, J. Barauskas, G. Niaura and T. Nylander, J. Phys. Chem. B 123 (2019) 2662; [6] M. Valldeperas, Lipid sponge phase nanostructures as carriers for enzymes. Doctoral Thesis, Lund University, Lund, Sweden (2019); [7] J. Gilbert, I. Ermilova, M. Nagao, J. Swenson, T. Nylander. Nanoscale, 2022, 14, 6990–7002 About the speaker:  Prof. Tommy Nylander specialized in Food Technology at LU as an undergraduate before completing his PhD there in chemical engineering and biophysical technology. He completed his PhD in the same topic at Lund University under the supervision of Prof. Kåre Larsson in 1987.  In 1990 he did a postdoc at Australian National University, Department of Applied Mathematics, Canberra, Australia with Prof. Barry Ninham. In 2000 he was appointed senior lecturer at the Div. of Physical Chemistry, LU and in 2007 he was promoted to full professor at the same division. The main theme of Prof. Nylander scientific activity has been to relate interfacial behaviour of surface-active molecules of biological origin to their solution behaviour, many of them focus on food related scientific challenges. He has published 270 scientific articles and book chapters within this area. He has extensive international collaboration both with academia and industry. Tommy Nylander was a member of the first Scientific Advisory Committee for ESS (2008-2011).

In recent years, deep eutectic solvents (DESs) have emerged as environmentally friendly alternatives in different technologies, such as separation processes, synthesis of nanostructured materials, and biocatalysis [1]. DESs are green solvents obtained through the combination of cheap and simple organic compounds, where a depression in the melting point allows the mixture to remain liquid at room temperature. Moreover, the combination of different precursors provides fine control over the physicochemical properties of the solvent (e.g., solvent polarity and charge density). Thus, DESs are task-specific “cocktails”, where the properties of the solvent can be tuned to suit particular applications. DESs have recently shown the ability to support ubiquitous physicochemical processes that occur in water, such as the solvophobic sequestration and protein folding [2, 3]. This brings the possibility of developing new responsive biomaterials. In this presentation with controlled function. In this talk, we will walk through the fundamentals aspects that control protein folding in DESs, where solvophobicity, specific ion interactions, and electrostatics rule a world of infinite possibilities [4, 5]. [1] Hansen et al., Chem Rev 2021, 121 (3). [2] Warr and Atkin, Current Opinion in Colloid & Interface Science 2020, 45. [3] Sanchez-Fernandez et al., Phys. Chem. Chem. Phys. 2017, 19 (13). [4] Sanchez-Fernandez, A.; Prevost, S.; Wahlgren, M., Green Chem. 2022, 24 (11). [5] Sanchez-Fernandez et al., J. Am. Chem. Soc. 2022, 144 (51), 23657-23667.   About the speaker:  Dr. Sanchez-Fernandez completed his PhD in Chemistry at the University of Bath (United Kingdom) and moved to Lund University (Sweden) as a Postdoctoral Fellow. Currently, he works at the University of Santiago de Compostela (Spain) after receiving the Maria Zambrano and Marie Skłodowska-Curie fellowships. His research interests cover the assembly of rationally designed systems, ranging from the supramolecular assembly of amphiphiles in deep eutectic solvents to the design and synthesis of novel environmentally friendly surfactants with controlled function. Also, he investigates the development of non-aqueous environments for protein folding, function, and preservation.

The novel class of responsive microgels has recently become very popular since their smart responsivity to external stimuli makes them very attractive for industrial applications and excellent model systems for exploring the exotic behaviours emerging in soft colloids since their softness allows to explore high density states well beyond random close packing. In the last years we have deeply investigated a dual responsive Interpenetrated Polymer Newtork (IPN) microgel composed of poly(N-isopropylacrylamide) (PNIPAM), a temperature sensitive polymer, and poly(acrylic acid) (PAAc), a pH sensitive polymer [1]. The system, with multi-stimuli responsiveness and rationally designed properties, can be finely controlled through different experimental parameters. PNIPAM-PAAc IPN microgels is investigated as a function of sample concentration [2], temperature and PAAC content [3] that permit to tune ad hoc the formation of arrested states. In this talk we will focus on the dynamical behaviour of PNIPAM-PAAc IPN microgels through Dynamic Light Scattering and X-ray Photon Correlation Spectroscopy [2,4] varying concentration, temperature and PAAC content. The slowing down of the dynamics approaching the glassy state has common feature with many glass-formers. [1] V. Nigro et al., Polymers 13, 1353 (2021). [2] V. Nigro et al., Soft Matter 13, 5185 (2017). [3] V. Nigro et al., J. Colloid Interface Sci. 545, 210 (2019). [4] V. Nigro et al., Macromolecules 53, 1596 (2020).

Multi-responsive microgels are widely studied hybrid systems that combine the properties of polymers and colloids. Due to their complex morphology, the microscopic interactions of these soft particles are still not completely understood. Combining rheometry [1,2], differential scanning calorimetry [3] and small angle neutron scattering, we investigated a thermo- and pH-sensitive microgel composed of Interpenetrated Polymer Network (IPN) of poly(N-isopropylacrylamide) (PNIPAM) and poly(acrylic acid) (PAAc) at fixed PAAc content as a function of weight concentration. We found three different rheological regimes characteristic of three different states: a Newtonian shear-thinning fluid, an attractive glass characterized by a yield stress, and a jamming state. A preliminary T- Cw phase diagram is here shown. [1]  S. Franco, et al., International journal of molecular sciences 22 (8), 4032 (2021) [2]  S. Franco, et al., Journal of Physics: Condensed Matter 33 (17), 174004 (2021) [3]  S. Franco, et al., Polymers 14 (1), 115 (2022)

The adaptation of proteins to high pressure is still an open debate, but understanding it could shed light on the origins of life, lead to a better understanding of protein dynamics, and deliver new tools to engineer pressure-resistant enzymes for biotechnological purposes. While the thermodynamic and dynamical properties of model proteins under pressure have been extensively studied, the evolutionary aspects of their adaptation are still unclear. Disentangling the contributions of pressure adaptation from those of another adaptation, such as high or low temperature, is a difficult task and, in fact, genomic studies were unable to determine a clear pattern among the order of Thermococcales. Recent experiments by our group focused on whole cells of two closely related species (Thermococcus barophilus, Tba, and Thermococcus kodakarensis, Tko) that grow at the same optimal temperature (85°C) but differ only for the optimum pressure (400 bar for Tba, 1 bar for Tko), and they highlighted the differences in the dynamics of the two organisms’ proteomes. To take this investigation to the molecular level, we studied the Phosphomannose Isomerase and the Ribosomal protein S24e from the two organisms with Elastic and Quasi-elastic Incoherent Neutron Scattering, 2-D NMR Spectroscopy and X-ray crystallography. Our results evidence that the substitutions of amino acids enhancing pressure stability are those in the hydrophobic core, which eliminate cavities, and those on the surface, which modulate the interaction of the proteins with the surrounding water layer and give them the right flexibility to perform their function under high pressure. About the speaker:  Judith Peters graduated in Physics at the University Joseph Fourier Grenoble 1 and received her PhD in Theoretical Physics in 1988. She then had a post-doctoral position at the University of Heidelberg working on molecular dynamics simulations. After one year as exchange scientist at the University of St. Petersburg, 7 years as assistant professor at the University of Applied Sciences in Berlin and 10 years as scientist at the Helmholtz Zentrum Berlin, she holds now a professorship of Physics at Université Grenoble Alpes. Her research interests comprise dynamical studies of biosystems by neutron scattering techniques, particularly under high pressure conditions.

I will show the power of the off-specular scattering (OSS) technique combined with specular reflection (SR) to probe the properties of buried interfaces between immiscible polymer layers. The combined SR and OSS data analysis, obtained using a quick and robust originally developed algorithm, includes a common absolute scale normalization of both types of scattering, which are intricately linked, constraining the model to a high degree. This, particularly, makes it possible to readily distinguish between different instability scenarios of the interfaces and layers driven by either the nucleation and growth of defects (holes, protrusions, etc.), or by thermal fluctuations of the buried polymer/polymer interface. Finally, the 2D OSS maps will be exposed in different representations allowing to highlight particular features on the OSS maps. The use of those representations pave the way for qualitative interpretation of OSS data and to formulate a realistic model for the in-plane structure including long-range order, correlated roughness, bulk defects etc., by a simple eye inspection of different OSS maps prior to their quantitative refinement. About the speaker:  After graduating in physics at Technical University Darmstadt, Philip Gutfreund obtained his PhD from Ruhr-University Bochum working on solid-liquid interfaces under shear, mainly using neutron reflectometry at the ILL. Since 2011 he is instrument scientist at the ILL, currently responsible for the FIGARO reflectometer. His main research interest is devoted to the microscopic structure and dynamics of polymeric liquids in out-of-equilibrium or in confinement, mainly using Neutron Scattering techniques. He also works on the development of the reflectometry technique per se, notably off-specular and grazing incidence scattering.

Small-angle X-ray and neutron scattering have been popular methods to characterize trans-bilayer structures of phospholipid vesicles for several decades. The gradual improvement of data quality in large scale facilities as well as brought along models of increasing complexity, one of them being the SDP (scattering density profile)-model, published by Kučerka et al. (2008). It parses the lipid into quasimolecular fragments and describes their location within the bilayer in a probability-density based approach, which then determines the scattering length density profile for any X-ray or neutron contrast. This enables to jointly analyze X-ray and neutron data, and to include lipid-specific information from volumetric studies and molecular dynamics simulations. In a recent study (Frewein et al. 2021) we extended the original SDP-model to lower q-regions by including a vesicle form factor via the separated form factor method, as well as a headgroup-hydration layer of higher density. In this Soft Matter Café session we will present a Python software package including this extended SDP-model and the possibility to analyze data using either least-squares fitting or a Bayesian probability-based Markov chain algorithm. About the speaker:  Moritz Frewein studied physics at the Technical University of Graz and started working in membrane biophysics in his bachelor thesis project about protein partitioning in heterogeneous lipid bilayers. In the following he was involved in the development of a theoretical model for SAXS-analysis of hexagonal lipid phases at the University of Graz. Currently, he is working on his PhD-project on the characterization of asymmetric lipid vesicles mainly by neutron and X-ray scattering under the supervision of Lionel Porcar (ILL) and Georg Pabst (Uni Graz).

Part 1: What is the difference between foamability and foam stability? How do liquid fraction, foam volume, and bubble size evolve as a function of time for stable and unstable foams, respectively? How can I study foams reproducibly? Under which circumstances can I compare the properties of foams generated with different surfactants? The first part of this presentation will answer these questions! Part 2: Although it is known that foaming a surfactant solution results in a depletion of the surfactant in the bulk phase, this effect is often overlooked and has never been quantified. Thus we studied the influence of surfactant depletion on foam properties. We measured the surfactant loss of the bulk solution via surface tension measurements and then compared our data with the results of purely geometric considerations. Under conditions where depletion plays a role our approach can also be used to estimate the bubble size of a foam of known volume by measuring the surfactant concentration in the bulk solution after foaming [1]. Part 3: Do intermolecular H-bonds between surfactant head groups play a role for foam stability? To answer this question we looked at the foam stability of various surfactants with C12 alkyl chains but different head groups and we found that stable foams are only generated when hydrogen bonds can form between the head groups [2,3]. Formation of hydrogen bonds between surfactant head groups – i.e. of a “hydrogen belt” at the interface – gives rise to a short-range attractive interaction that may render the surfactant layer more rigid (in the sense that the mobility of the molecules is restricted) and more elastic (in the sense that deformations can be counteracted). We expect an enormous impact on the future design of surfactants which must take intersurfactant H-bonds into account! [1]  On how Surfactant Depletion during Foam Generation Influences Foam Properties, J. Boos, W. Drenckhan, C. Stubenrauch, Langmuir, 2012, 28, 9303-9310 [2]  On How Hydrogen Bonds Affect Foam Stability (Review), C. Stubenrauch, M. Hamann,  N. Preisig, V. Chauhan, R. Bordes, Adv. Colloid Interf. Sci., 2017, 247, 435-443 [3]  Intersurfactant H-bonds between Head Groups of n-Dodecyl-D-Maltoside at the Air-Water Interface, M. Kanduč, E. Schneck, C. Stubenrauch, JCIS, 2021, 586, 588-595 Register here.  

In the congested environment of cells and tissues, the interaction between the surfaces of biomolecular assemblies -- notably biomembranes -- is of paramount importance for numerous biological processes. This lecture reviews various mechanisms underlying the interaction between lipid-based membranes in their aqueous (physiological) surroundings. The lecture covers van der Waals interactions, electric double-layer forces, solvent- and solute-mediated forces, as well as undulation-induced forces and forces associated with the conformation of membrane-associated polymers. Experimental aspects as well as continuum-theoretical descriptions and atomistic computer simulations are discussed. Register here.

The atomic force microscope (AFM) is an invaluable tool not only to obtain high (sub-nanometer)-resolution topographical images, but also to determine certain physical properties of specimens, such as stiffness and adhesion, surface charge and even chemical surface composition. The AFM has the advantage over other forms of microscopy in terms of spatial and temporal resolution and possibility of imaging almost any type of surface, including polymers, ceramics, composites, glass, and biological samples. In addition to the wide range of applications, from materials science to biology, this technique can be operated in a number of environments as long as the specimen is attached to a surface, including ambient air, ultra-high vacuum, and, most importantly for biology, in liquids. This lecture will first introduce the viewer to the fundamental aspect of AFM. Then, basic principles of operation of an AFM, the associated instrumentation and methodology; and the fundamental aspects how this high-resolution surface typography images and maps of surface forces can be obtained will be discussed. Main AFM operation modes; pro and cons of each mode, as well as representative results from the literature highlighting a variety of application areas will be also shown. Finally, some representative AFM artefacts and other examples of the applications of AFM imaging and force spectroscopy will be illustrated. Register here.

In this lecture, I will first introduce some concepts related to the definition of an interface, long range surface forces, disjoining pressure and adsorption. In the second part, I will discuss some aspects of the physics of wetting. Energetics of: a) liquid drops on solid substrates and b) solid particles at liquid interfaces, will be described in different length scales: from the macroscopic down to the nanoscale. Finally, I will describe the stability of a liquid foam, considered as an interfacial material rather than a gas in liquid dispersion. Register here.

Self-assembly is a ubiquitous phenomenon in science, being observed in solution for surfactants, copolymers, or proteins – and, of course, in combinations thereof with other colloidal systems. Accordingly, self-assembly is at the heart of many important scientific processes, such as detergency, formulations in pharmacy or cosmetics, biomembranes, biological systems, etc. Therefore, it is very important to understand the principles of self-assembly and especially how they are related to the molecular composition of the systems and how this translates into the properties of such systems. In this lecture this will be discussed for the case of surfactants, which can become organised in the form of small spherical micelles or worm-like micelles, where the latter may exhibit several orders of magnitude higher viscosity and viscoelastic properties. Another example concerns the solubilisation of hydrophobic molecules in aqueous solutions, which is important for instance for cleaning or tertiary oil recovery, but also for rendering otherwise insoluble drug molecules soluble. The lecture will deal with the basic principles of surfactant self-assembly and use this understanding to rationalise some simple applications of surfactants. Register here.  

This lecture will introduce the listeners to Monte Carlo and Molecular dynamics simulation methods using classical energy functions, and the most commonly used algorithms to perform free energy calculations. Emphasis will be given to the concepts that a non-specialist must have to be able to critically read a report of a simulation study. Register for the webinar.

The lecture will be focused on the direct measurement of thermodynamic properties that are free energy derivatives. In particular the partial molar quantities will be described. Based on some case studies, we’ll explore the relevance in colloidal systems about methods to access directly thermodynamic quantities. In particular, the dilemma on enthalpy changes in supramolecular aggregates: van’t Hoff vs direct methods will be described. Volumetrv analysis of complex systems will be presented based also on its predictive ability toward pressure effect. Experimental tips and case studies will help the audience in a proper planning of measurements. Register here.

Phospholipases (PLAs) are lipolytic enzymes that hydrolyze phospholipid substrates at specific ester bonds. They are widespread in nature and play very diverse roles right from signal transduction and lipid mediator production to membrane phospholipid homeostasis. Phospholipases vary considerably in their structure, function, regulation, and mode of action therefore a deeper understanding of their dynamics and kinetics can be very crucial. The present study encompasses employing neutron reflectivity including other physical/chemical techniques to better understand the principles underlying the substrate specificity of phospholipases. We here, studied in detail the effect of the acyl chain length and unsaturation of phospholipids on their hydrolysis by type A1-PLA1 (sourced from Aspergillus oryzae), that was expressed in E.Coli and purified in its pure form thus allowing us to understand the key factors that regulate its activity. About the speaker: Giacomo Corucci graduated in Molecular and Applied Biology at Università Politecnica delle Marche (UNIVPM Ancona) and his Master thesis was focused on “RECOMBINANT CROTAMINE PRODUCTION AND STRUCTURAL ANALYSIS BY SMALL-ANGLE X-RAY SCATTERING OF ITS INTERACTIONS WITH MODEL MEMBRANE”. Later, he moved to Grenoble, France, for his PhD studies.

Calorimetry is a powerful physicochemical methodology for measuring the thermal properties of a variety of substances, including soft-materials, and is the only technique for direct determination of the enthalpy change of the processes. Among calorimeters, differential scanning calorimetry (DSC) and isothermal titration calorimetry (ITC) are widely used in many fields of sciences. DSC, giving direct thermodynamic information, has proved to be very useful in clarifying the energetics of macromolecule transitions and in characterizing their thermal stability. On the other hand, ITC is very suitable to study the energetics of molecular interactions, giving the binding constant, the stoichiometry and all the thermodynamic parameters. Here basic principles, common instrumentations, data analyses and some applications will be discussed. Specifically, two examples of calorimetric applications to study the thermodynamics of secondary nano-emulsion formation and the energetics of ligand-receptor binding affinity on endothelial cells will be discussed. Register here.

One of the relevant topics nowadays is an applied science direction called microfluidics. As wide as the field of application of microfluidic devices is, there are just as many manufacturing methods, but not all of them are fast, accessible and cheap. Our task is to create a simple and inexpensive experimental microfluidic device and sample environment. For the development of X-ray beamlines sample environment and experiments carried out, single products with a specific design are needed. Thus, rapid prototyping methods, which allow creating a device within one day, and if necessary quickly modify it, are in high demand. So now, I turned to one of the additive technologies elements - 3D printing, to develop and createmicrofluidic devices in a format that is suitable for mounting on the micro diffractometers installed on the ESRF’s MX beamlines, is compatible with the Sample Exposure Unit for BioSAXS, and is suitable for carrying out in-chip experiments on other soft matter samples. About the speaker: After getting his master of engineering diploma at Moscow Power Engineering Institute (Technical University) in 2009, Anton started his work as a research engineer in the Department of Applied Nanotechnology at the Kurchatov Center for Synchrotron Radiation and Nanotechnology (National Research Centre Kurchatov Institute). In this department, he was working on different topics, like microscopy, superconductivity, microelectronics, additive manufacturing, microfluidics using different lab equipment and got his scientist position. In March 2019, Anton defended his Ph.D. thesis on the topic "Microfluidic devices for studying the structure of proteins and the mechanisms of their crystallization at a synchrotron radiation source" in the field "Devices and methods of experimental physics". He was developing a production string that would make it possible to build up, quick and cheap, microfluidic devices for conducting experiments using both a laboratory and a synchrotron. The main demand has arisen in the field of Life sciences. Starting May 2019, Anton continued his scientific work as a post-doctoral fellow at the ESRF, in the Department of Structural Biology, where they, in collaboration with PSCM, develop microfluidics.  

Cyclodextrins play an important role in the self-assembly systems of amphiphiles. Among the distinguished physicochemical properties provided by the hollow shape of the cyclodextrins, the ability to form inclusion complexes with a variety of compounds has led to their wide application in different fields, as pharmaceuticals, environmental, cosmetic, food and nanotechnology industries. Surfactants are attractive candidates for host molecules due to their relevance, variety, versatility, and responsiveness. Moreover, the cyclodextrin-surfactant systems are an attractive research field, not only because of the versatility, but also due to the tendency of forming highly ordered biocompatible supramolecular aggregates. This presentation will introduce the thermodynamics aspects of the polyethylene oxide alkyl ether carboxylic acids and cyclodextrins host-guest complexes and discuss some structural aspects of the responsive supramolecular aggregates spontaneously formed. About the speaker: Larissa dos Santos Silva Araújo graduated in chemistry in 2016 at the Federal University of Ouro Preto, Brazil, where she started working with surface active systems. In 2019, she obtained the master’s degree in Environmental engineering at the same university working with the optimization of biosurfactant production and the bioproduct application in a soil recovery process. Since 2019, Larissa has been working towards the PhD degree at Università degli studi di Palermo within a partnership with ILL. Her main research interests include the thermodynamic analysis and structural characterization of surfactant and polysaccharide supramolecular assemblies using small-angle neutron scattering.

The use of microfluidics for sample preparation and experiments on X-ray beamlines has seen a steady growth over the last years. In comparison with traditional approaches, microfluidics provides access to shorter length and timescales while using smaller quantities of sample material. The construction of microfluidic devices for use on synchrotron beamlines however is often a time consuming multi step process. Recent developments of 3D printing technology using Digital Light Processing have opened possibilities for rapid fabrication of complex microfluidic devices. We have modified a standard desktop printer to gain better control over the UV resin polymerisation and thus improve the quality of microfluidic devices. We have printed and tested different microfluidic components which were integrated into devices used for crystallisation of a biomineral and proteins. The presentation will explain how the printing method was improved and show the current status of microfluidic developments. About the speaker: After engineering school in Eindhoven, Peter worked for five years at the High Field Magnet Laboratory of Nijmegen University on the development of cryogenic sample cooling down to 1.2 Kelvin and measurements of resistivity and magnetisation in fields up to 25 Tesla. He came to the Grenoble High Field Magnet Laboratory in 1994 where he worked on dilution refrigeration down to 15 milliKelvin and measurement methods for use in static magnetic fields up to 30 Tesla and pulsed magnetic fields up to 60 Tesla. In 2003 Peter joined the ESRF where he developed amongst others miniature pulsed magnets up to 30 Tesla, different cryogenic systems such as the Dynaflow cryostat and the sample cooling for ID16A and ID32-RIXS, and flash freezing of biological crystals under pressures up to 2kbar. Since 2016 Peter works at the PSCM on the development of 3D printed microfluidics.

Coordination complexes are metal-containing compounds showing very interesting redox, photochemical and catalytic properties. In this talk I will present my past research activity on energy conversion (from light to electricity and chemical potential, and from electricity to light), catalysis and surface modification using such compounds. The aim is to present my background in chemical synthesis and in several analytical techniques, to see how it could fit in the ongoing activity at ILL or generate new collaborations. About the speaker: Martina Sandroni graduated in Chemistry at the University of Torino (Italy), then she moved to Nantes, France for a Ph.D. on copper(I) complexes for solar energy conversion (artificial photosynthesis and dye-sensitized solar cells), that she obtained in 2012. Afterwards, she continued her research on coordination complexes during post-docs in Canada (Sherbrooke) and France (Brest, Grenoble). Part of her activity focused again on energy conversion, with complexes for electroluminescent devices and inorganic nanoparticles (quantum dots) for hydrogen photoproduction in water. On the other hand, she also synthesized iron complexes for bio-mimetic oxygen reduction. In 2018, she spent one year at ESRF in Grenoble as electrochemistry laboratory responsible, and providing support to the users of a surface diffraction beamline. In October 2019, she joined ILL in the Soft Matter Science and Support group as chemistry laboratories manager.