Reference number ESD-81647

Apply

The European Spallation Source (ESS) is one of the largest science and technology infrastructure projects being built today. ESS will soon be the world’s most powerful source of neutrons, providing researchers with unique opportunities to explore the structure of materials at the atomic level. Neutron scattering at ESS will address critical questions in physics, chemistry, geology, materials science and life science.

We are now inviting applications for a Postdoctoral Researcher in Small-Angle Neutron Scattering of Biocompatible Microgels. Small-angle neutron scattering (SANS) is a powerful technique for investigating the structure and dynamics of scientifically and technologically important soft and complex materials across nanometre-to-micrometre length scales. Energy materials, biomaterials, colloidal systems, and functional nanostructures are prime examples of systems whose properties and performance depend critically on hierarchical structures and processes occurring over these length scales.

SANS studies have historically been constrained by limitations in neutron flux, restricted accessible time scales, and challenges associated with complex sample environments. Experiments requiring time resolution, spatial resolution, weakly scattering samples, or measurements under flow and processing conditions have often been difficult or impossible at existing facilities. The LOKI instrument at the ESS will overcome many of these limitations. Designed specifically for soft matter, biology, and materials science, LOKI combines a very high neutron flux with an exceptionally broad simultaneous q-range, enabling rapid measurements across multiple length scales without changing instrument configuration. This capability will make it possible to study dynamic and non-equilibrium processes with unprecedented time resolution, including systems under shear, flow, temperature change, or chemical transformation.

This project focuses on developing and characterising a new class of biocompatible thermoresponsive microgels for biomedical and soft matter applications. The work combines neutron scattering, rheology, advanced sample environments, and molecular simulations to understand how the internal structure and softness of poly(N-vinylcaprolactam) (PVCL) microgels influence their behaviour in dense suspensions and under flow.

The goals are:

• Develop an understanding of the structure, mechanics, and flow behaviour of PVCL microgels
• Develop and implement a 1,2-shear cell for rheo-SANS and rheo-SAXS experiments at ESS and MAX IV, that will allow to measure scattered intensity in the velocity-gradient plane, the most sensitive to shear-induced deformations.
• Combine neutron scattering experiments with molecular simulations to establish predictive models for soft colloidal systems relevant to biomedical applications

To achieve these goals, the postdoctoral researcher will develop proof-of-concept experiments and computational workflows centred around the LOKI at ESS:

• Synthesise and characterise PVCL microgels with varying crosslinking conditions and architectures to study how synthesis affects particle morphology and responsiveness
• Use SAXS and SANS, including contrast variation methods, to determine internal particle structure, deformation, and compressibility
• Develop and commission a custom 1,2-shear cell for rheo-SANS/rheo-SAXS measurements that enables access to the shear plane during flow experiments
• Investigate the structure and rheology of concentrated microgel suspensions under shear, including shear-induced structural transitions and anisotropy
• Perform molecular dynamics and coarse-grained simulations of microgels and dense suspensions to quantitatively interpret scattering data and establish universal models for soft colloids
• Study the relationship between microgel architecture, collective behaviour, and macroscopic rheological response relevant for applications, such as 3D printable biomaterials and responsive nanocarriers

The Opportunity
We are seeking an independent and highly motivated postdoctoral researcher with experience in microgels - particularly synthesis and/or neutron scattering techniques.

You will be part of the Large Scale Structures Division at the ESS in Lund and supervised by the ESS LOKI team (Judith Houston). You will benefit from research supervision and collaboration with the Laurati group at the University of Fluorence (https://www.csgi.unifi.it/person.php?p=330), who are experts in soft colloid synthetic procedures, and their characterisation using scattering and rheology techniques, and the Zaccarelli group at the Sapienza University of Rome (https://www.roma1.infn.it/~zaccarel/curriculum.htm) who are experts in molecular dynamic simulations. The collaboration will involve the first year based in Italy for knowledge transfer, training and supervision, sample preparation, and access to their laboratories.

Your Role and Responsibilities

• Collaboration with research groups at ESS, the University of Florence, and Sapienza University of Rome.
• Laboratory work involving synthesis, characterisation, and rheological measurements of PVCL microgels
• Neutron and x-ray scattering experiments at ESS, MAX IV, and international large-scale facilities
• Develop and commission a custom 1,2-shear cell for rheo-SANS/rheo-SAXS measurements. Test and validate the developed sample environment at ESS and leading neutron (e.g., ILL, ISIS) and X-ray facilities (e.g. Diamond, MaxIV), ensuring reliability and robustness.
• Perform molecular dynamics and coarse-grained simulations of microgels and dense suspensions to quantitatively interpret scattering data and establish universal models for soft colloids
• Conduct and develop independent research in line with the LOKI science case.
• Author scientific and technical publications
• Present scientific and technical research at relevant conferences and workshops.
• Contributing to the commissioning and scientific development of ESS instrumentation

Required Qualifications:

• Ph.D. in Physics, Chemistry, Materials Science, or a related field.
• Strong experience in the characterisation of soft colloids
• Experience as a user of large-scale X-ray and/or neutron facilities, including experience in data analysis.
• Ability to work both independently and collaboratively within interdisciplinary teams.
• Proficiency in scientific writing and presentation in English, as evidenced by a strong publication record.
• Willingness and ability to travel internationally for collaborative research and beamtime.

Desirable Qualifications:

• Strong research background in small-angle x-ray and/neutron scattering of soft colloids.
• Programming experience (e.g. Python, Matlab) for data analysis and to perform molecular dynamics and coarse-grained simulations.
• Proficiency in synthesis, characterisation, and rheological measurements of soft colloidal systems.

Duration and Location
The position is a 3-year full-time position located in Florence, Italy for the first year and Lund, Sweden for the remaining 2 years.

Application & Contact
A career at ESS gives you the opportunity to contribute to the future discoveries within neutron science at a stunning, brand-new workplace filled with innovative minds and brilliant people from across the globe. We offer market competitive, individualised compensation which is differentiated according to role, responsibilities, individual skills, abilities and achievements as well as monthly pension contributions on top of your salary.

If you see yourself in what we’re looking for, please provide your CV and motivation letter in English by clicking on “apply” and following the instructions. Please be aware that we can only accept direct applications made via the ESS website. Submit your application as soon as you can, no later than October 7, 2026.

The recruitment process will have one round of initial interviews via Zoom in mid-October and onsite interviews at ESS in the first weeks of November. Part of the onsite interview will be to hold a scientific talk (seminar) that will be open to all ESS employees.

For further information regarding the position, please contact Talent Acquisition Specialist Louise Jönegård on [email protected] or Hiring Manager Andrew Jackson on [email protected].

For trade union information, please contact Unionen representative Nuno Elias on [email protected] or SACO/Swedish Association of Graduate Engineers representative Marc Kickulies at [email protected]

We look forward to receiving your applications soon!

URL to this pagehttps://europeanspallationsource.se/careers/vacancies?rmpage=job&rmjob=2044&rmlang=UK

Apply