How Sapienza University of Rome accelerates research with the Xeuss SAXS/WAXS instrument from Xenocs

By 17 January 2020 January 21st, 2020 No Comments

One year after being installed in the department of Chemistry of Sapienza University of Rome, the Xeuss 2.0-QXoom with SWAXS module meets all expectations in boosting the university research projects. Dr Alessandra Del Giudice from the Department of Chemistry tells us how.

Why we invested in a SAXS/WAXS/GISAXS facility
U La Sapienza

From left to right: Anita Scipioni, Olga Russina, Mauro Giustini, Luciano Galantini, Elisa Tasca, Alessandra Del Giudice, Jacopo Cautela, Claudia Marconi.

The Xeuss 2.0-QXoom with SWAXS module was acquired as a shared facility (SAXSlab Sapienza) available for all researchers of the Sapienza University of Rome as well as for external users and collaborators. Research groups of several departments such as Chemistry, Biochemistry, Physics, Engineering or Earth Sciences gave their subscription to the project since they could benefit from the SAXS/WAXS/GISAXS experiments, spanning many topics from soft-matter research to energy materials characterization.

Our group led the acquisition of the SAXS instrument at Sapienza University. We use light scattering, spectroscopy and SAXS techniques for our research. Before having the Xeuss we could collect the SAXS data during beamtimes at synchrotrons or through collaborations with Lund University which runs a Ganesha instrument from SAXSlab, now part of Xenocs.

The idea to write a proposal for the acquisition of a SAXS/WAXS/GISAXS instrument came from the versatility of these techniques which are applied in a large variety of research fields for material characterization. The fact that a heterogeneous and large community of researchers within Sapienza could benefit from the possibility to perform these experiments made such a platform the choice for an investment by the University.

Some of the research questions the Xeuss helps us answer

Research projects which have so far took advantage of the new facility include: the study of structures formed by the self-assembly of amphiphilic molecules in solution, the study of the structure of ionic liquids and deep eutectic solvents and their solubilization properties, the characterization of nanoparticles, the characterization of purified recombinant protein samples, the study of the interaction between DNA nanostars, the study of orientation of solid phases grown on surfaces,…

Having a Xeuss in our lab has made it possible to answer research questions with quickly accessible experiments, without having to wait for the availability of less handy facilities. This can speed up some steps of the research quite a lot.

Due to the large variety of systems investigated, the information sought after varies accordingly. The most common experiments in our group involve the extraction and interpretation of the average form factor of the nano-objects dispersed in the aqueous solvent, in order to deduce the average morphology of the self-assembled structures (nanotubes, fibrils, tapes, globular aggregates, liquid crystalline phases) in different conditions and measure dimensional parameters. Most challenging experiments have involved the study of quite dilute solutions of low-scattering nano-tapes, however with appropriate signal averaging the results were satisfying to answer our questions without the necessity to go to the synchrotron.

Developing new collaborations

Many researchers from other groups outside Sapienza University were also interested in SAXS/WAXS/GISAXS experiments to answer some questions in their research projects and the SAXSlab Sapienza has stimulated new collaborations and internationalization.

It is the first SAXS facility of this kind available in an Italian University, and many groups which were used to long-distance collaborations and travels for X-ray scattering experiments benefit from it, including ours.

In addition, the birth of the SAXSlab Sapienza has stimulated teaching of the small angle scattering technique in the master and PhD courses of the Chemistry department and students started to use the newly available techniques for their thesis projects.

Insight on how the Xeuss is being used

The instrument is hosted by the Chemistry department, with a trained post-doc who runs the experiments and assists the users.

In one year of operation we have already used all sample holders we have to satisfy the necessity of measuring solids, liquids, slurries, gels, powders, surfaces, fibers bundles. The setup we have been using the most is the thermalized capillary holder. We easily characterized the empty and solvent-filled capillary cells and, thanks to the reliability of the system, for many of the experiments requiring background subtraction we can easily use data from our database.

Regarding technical details, essential features for our work with the Xeuss are the automatically changeable sample-detector distance with the Q-Xoom, the possibility of beamstopless experiments with simultaneous transmitted beam measurement and very reliable absolute intensity scaling, and the extensive programmability of the experiments via SPEC macros. A good plus is the additional detector close to the sample to measure WAXS at the same time as SAXS, very useful for kinetics experiments.

The Xenocs support has always been very helpful in general and promptly intervened to solve problems. I would say that the support service has been fundamental for us. I have the impression that a process of improvement of software and hardware is going on at Xenocs also collecting feedback from customers. We will likely continue to benefit from software upgrades and hopefully be able to enrich our sample environments collection in the future.

About the Sapienza University of Rome and the Department of Chemistry

With over 700 years of history, over 112,000 students, 4000 teachers and 2000 employees, technicians and librarians, in addition to 2000 administrative staff in university hospitals, Sapienza is the largest university in Europe. Our mission is to contribute to the development of a knowledge society through research, excellence, quality education and international cooperation.

Sapienza includes 59 departments belonging to 11 faculties of all academic disciplines, most of them being within the walls of the same University campus. This organization represents a fertile ground for multidisciplinary research.

Over the last five years, Sapienza has implemented an investment policy to develop the Sapienza Research Infrastructure: laboratories and large equipment to support excellence in research activities and promote innovation, technology transfer and local business incubation.

SAXSlab Sapienza operating the X-ray diffractometer Xenocs XEUSS 2.0 Q-Xoom, is part of this plan, providing a laboratory capable of Small Angle X-Ray Scattering (SAXS), Wide Angle X-ray Scattering (WAXS) and Grazing Incidence Small Angle Scattering (GISAXS) experiments, techniques that are widely applicable for the characterization of matter at the nano- and meso-scale.

The laboratory is hosted and managed by the Department of Chemistry. The team mainly running the facility has its research interests in the structural study of soft-matter systems, including self-assembled nanostructures for applications, and has a background in scattering techniques and optical spectroscopies.

Nicolae Viorel Pavel: nicolaeviorel.pavel@uniroma1.it
Luciano Galantini: luciano.galantini@uniroma1.it
Alessandra Del Giudice: alessandra.delgiudice@uniroma1.it

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(2) Travaglini, L.; di Gregorio, M. C.; Severoni, E.; D’Annibale, A.; Sennato, S.; Tardani, F.; Giustini, M.; Gubitosi, M.; Del Giudice, A.; Galantini, L. Deoxycholic Acid and L-Phenylalanine Enrich Their Hydrogel Properties When Combined in a Zwitterionic Derivative. J. Colloid Interface Sci. 2019, 554, 453–462. https://doi.org/10.1016/j.jcis.2019.07.019.

(3) Cautela, J.; Severoni, E.; Redondo-Gómez, C.; di Gregorio, M. C.; Del Giudice, A.; Sennato, S.; Angelini, R.; D’Abramo, M.; Schillén, K.; Galantini, L. C-12 vs C-3 Substituted Bile Salts: An Example of the Effects of Substituent Position and Orientation on the Self-Assembly of Steroid Surfactant Isomers. Colloids Surfaces B Biointerfaces 2019, 110556. https://doi.org/10.1016/j.colsurfb.2019.110556.