Utrecht University has great ambitions for its teaching quality and study success rates. This also applies to its clear research profiles which are centred around four themes: Dynamics of Youth, Institutions, Life Sciences, and Sustainability. Utrecht University plays a prominent role in our society and contributes to finding the answers to topical and future societal issues.

Postdoctoral Researcher in Theoretical Geochemistry (2.5 years)

The Department of Earth Sciences is now looking for a highly motivated, high-potential applicant to fill a postdoctoral (PD) position within the project CRYSTAL CLEAR: determining the impact of charge on crystal nucleation.

All of the crystals that form in water on Earth are formed through reaction between oppositely charged ions. In these crystals, the ions are present in an ideal, charge-balanced ionic ratio. In contrast, the natural solutions in which they form, contain widely diverging ionic ratios. When crystals nucleate from natural solutions, they will be charged, and the charge has a massive impact on the behaviour of small new crystals. However, most nucleation experiments have been conducted in solutions with charge-balanced ionic ratios and the current nucleation theory is based on water condensation.

In the CRYSTAL CLEAR project, which started in 2019, we aim to determine the impact of ionic ratio on ionic mineral nucleation processes experimentally, computationally and theoretically. The first results of our project show that the current nucleation theory, which is capable of describing crystal formation rates and mechanisms of neutral nuclei, fails in conditions where nuclei are charged. Two experimental PhD candidates investigate the impact of diverging ionic ratios on the nucleation of various minerals (barium sulfate, calcium carbonate and iron (di)sulfide minerals). One postdoctoral Researcher (PD) performs molecular dynamics simulations of the formation mechanism and stability of the nuclei formed, and this advertisement is for the second PD in this project.

The aim of the current PD project is to use the new experimental and simulation results to develop a new nucleation theory that includes the impact of charge on the behaviour of (pre) nucleation clusters during formation and aggregation. This will be approached by unifying colloid theories that successfully describe and predict nanoparticle behaviour in relation to particle charge with nucleation theory, using new expressions obtained in collaboration with the other CRYSTAL CLEAR team members and experts in the field of charge stabilized colloid physics and chemistry and nucleation theory development.


We seek an enthusiastic PD candidate, holding a PhD degree (at the start of the contract) that ensures appropriate background knowledge in colloid or condensed matter physics, physical colloid (geo-)chemistry, nanogeosciences, mineral nucleation and growth, environmental mineralogy, (environmental) chemistry, or material sciences. Experience in theory development and/or numerical modelling is required.

You approach scientific problems with determination and you are eager to develop multidisciplinary skills. You must be willing to travel abroad to present your research to an international research community. As this project requires close collaboration within the research team, candidates are expected to be excellent team players. You also have excellent written and spoken English skills and good general communicational skills.

Terms of employment:

We offer a temporary position (1.0 FTE) for a period of two and a half years. The gross salary - depending on previous qualifications and experience - ranges between €2,790 and €3,619 (scale 10.0-10.6 according to the Collective Labour Agreement Dutch Universities) per month for a full-time employment. Salaries are supplemented with a holiday bonus of 8% and a year-end bonus of 8.3% per year. In addition, Utrecht University offers excellent secondary conditions, including an attractive retirement scheme, (partly paid) parental leave and flexible employment conditions external link (multiple choice model).

About the organisation:

The Utrecht Faculty of Geosciences offers education and research concerning the geosphere, biosphere, atmosphere, and hydrosphere. With a population of 3,400 students (BSc and MSc) and 720 staff, the Faculty is a strong and challenging organisation. The Faculty is organised in four Departments: Earth Sciences, Physical Geography, Sustainable Development, and Human Geography and Spatial Planning.

The Department of Earth Sciences conducts teaching and research across the full range of the solid earth and environmental earth sciences, with activities in almost all areas of geology, geochemistry, geophysics, biogeology, and hydrogeology. The Department hosts a highly international tenured staff of over 45 scientists and more than 110 PhD students and postdoctoral researchers. Our research programme spans four intertwined themes: climate and life, earth interior, earth materials, and environmental earth sciences. We house or have access to a wide variety of world-class laboratories.

Additional information:

For informal questions, please contact the project leader, Dr Mariëtte Wolthers, at m.wolthers@uu.nl.

How to apply:

To apply, please follow this link and the guidelines mentioned there. The application deadline is September 1st, 2021. Evaluations and interviews are planned soon thereafter. We aim to fill the position as soon as possible but no later than April 1st, 2022. Online screening may be part of the selection. Commercial response to this ad is not appreciated.

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posted: 06 May 2021     Please mention EARTHWORKS when responding to this advertisement.