Paper out!

This week our paper about clays and organic acids is out in Langmuir!

Clays – the secondary mineral phases formed during weathering processes – and organic molecules rich in acidic functional groups are abundant in soils and sediments, and interact with each other to form soil aggregates. Such aggregates are vital for nutrient cycling and soil productivity, and once unstable, can bring about soil erosion. Organic acids in soils are products of oxidative decomposition of soil organic matter and, as such, comprise a large group of acidic molecules with different sizes, degrees of polymerization, structures, and functional groups. In our work, we target dicarboxylic acids, which are small molecules with a simple structure terminated with carboxylic groups on two ends. But do clay minerals really interact with such small and soluble molecules?

Can small organic acids trapped betwen two clay surfaces enhance clay aggregation? Read more here:

The answer is: no and yes. In our paper, we focused on abundant basal surfaces of mica clay. These surfaces are negatively charged and so are the organic molecules at most pH solution conditions. As a result clays and deprotonated dicarboxylic should electrostatically repel each other when dispersed in water. One may thus expect the ‘no’ answer: dicarboxylic molecules cannot effectively bind to clays and are rather inefficient in forming organo-mineral soil aggregates.

The missing part of the ‘yes’ answer are inorganic cations. It turns out that some multivalent cations, which densely populate the negatively charged clay surfaces, can act as bridges, bonding the deprotonated carboxyls to the Ca2+-rich clay surface. Clearly, that bridging action is extremely important in the formation of soil aggregates and to soil stability! But soil moisture and fluids percolating through soil horizons contain a multitude of other dissolved ions and species. What happens when the calcium ions are depleted and replaced by ubiquitous sodium?

To find out, and learn more about organic acids trapped between two surfaces, check out our paper!

Organic acids decrease adhesion between two clay surfaces to various extent (with respect to pure water), depending on the size of organic acid molecules. Read more in our paper! (image adapted from

Peer review

I freeze in horror. I have just received a decision e-mail about my recent manuscript submission to a well-regarded academic journal. I don’t even want to open it. I close my mailbox and pretend the e-mail is not there. But soon the curiosity takes over and I read ‘… and therefore the data is useless’; ‘… this renders the data measured in the manuscript completely uninterpretable‘; … does not inspire me with confidence that the researchers really know what they are doing‘. Hey, wait a minute… Is an expert in my academic field just trying to tell me with full confidence that I have spent 3 years doing something useless, random, and worthless? Is this a senior, experienced researcher whose professional opinion I should value? Should I pack my bags and quit? Or, perhaps, do I have some enemies? If you ask around, most researchers have gone through this kind of peer review trauma. No wonder that some are getting pretty inventive and opt for a self-peer review.

I value the core idea of a peer review process and I see it as each researcher’s responsibility, but there is something quite wrong with it. I am always looking forward to fellows giving me hints on how to improve my work. But my recent experience with being a reviewer or an author makes me feel pretty confident that there is no other way than the transparent peer review.

I recently reviewed a manuscript for one of Elsevier‘s journals, wrote a report, raised several major points that needed revising, and waited for the authors’ rebuttal. Guess what, I have never seen it and was simply informed that the manuscript had been accepted a few months after. Were my questions answered or ignored? Was my two days-work useful for the authors? Were my suggestions insignificant for the work? Why was I even asked to start a conversation when my opinion did not matter in the later stages of the process? I fully recognize the editor’s superiority in making the final decision, but it still feels unfair. Unfortunately, asking around, I’ve learned that others have a similar experience.

So how does the transparent or open peer review process work? The review reports become publicly available. Also, the reviewing may become no longer single-blinded, with the names of the reviewers not confidential anymore. To me, this sounds like a perfect and effortless solution to do away with most of the rude comments and unfair criticism, and any form of bias towards the authors, especially those at early career stages. In some extreme cases, it may prevent anonymous reviewers from hindering publications on purpose. Who would benefit from it? For sure everyone directly involved, which means all scientists, but also the general public as the transparent peer review can help to track possible scientific misconducts better.

The good news is that a number of academic journals have already started to publish the peer review reports alongside publications. Unfortunately, this is still not an option when submitting to most of the largest academic publishers. The scientific community is also not idle. There are many initiatives, which allow post- or pre-publication community peer-review such as PubPeer, preLights,, the Winnower, Self-journal of Science, or preprint servers like bioXriv. Sounds worth giving it a try!


Last week, I participated in my first virtual academic conference: This year, the annual meeting of the European Geosciences Union in Vienna took place on-line and it was really engaging! Most presentations could be viewed in advance, downloaded, and enjoyed at home; interactions with authors were possible during chat sessions but also by commenting on the uploaded works. I hope this stays and accompanies all physical meetings! It is barely possible to see all >300 posters during huge academic conferences but here the chance to see a bit more of them is bigger!

Session I participated in at #shareEGU20

You can still view and read my work!

Working from home

This March and April scientists all over the world are working remotely. Although most changes in the academic community take lots of time, the quick response to the virus threat brings optimism. Some conferences are held online, Ph.D. defences have turned digital, meetings and discussions continue. Hopefully, our experience of virtual conferences will push for maintaining some part of the scientific discussions via online communities and platforms – no better way to reduce scientists’ carbon footprint. While some might doubt that large-scale digital networking will ever work, perhaps it is partly because they have never had a chance to experience it before.

The forced home-office might also redefine one’s working routine for good. As now it is a time to focus on manuscript and proposal writing, experiments planning, analysing, and all sorts of creative work, we might discover that a shared office and more or less fixed working time was never helpful. Of course, this is a completely individual matter, so if you are struggling, some words of advice: daily short morning online meetings that we practice at AIP set me in a right working mode;there is no point in feeling guilty about engaging in little distractions as the best ideas may come when idle; and, above all, a good soundtrack never fails.

Experiments in synchrotron!

This November I had a great opportunity to visit DESY (Deutsches Elektronen-Synchrotron DESY) in Hamburg. Among 18 larger synchrotron facilities in Europe, Petra III in DESY is equipped with the biggest and most brilliant storage ring for X-ray emission.

Such a powerful X-ray beam can be produced by generating and manipulating accelerated electrons: Electrons travel inside a synchrotron’s storage ring only a little bit slower than the speed of light. The high-speed and high-energy electrons, when forced to change their trajectory by a set of specialized magnets, emit radiation at X-ray wavelengths (0.01 to 10 nm). This wavelength range is suitable to study interatomic distances within solids, and thus to reveal their structural properties. X-rays produced synchrotron are orders of magnitude more brilliant than those produced by commonly used X-ray tubes: this means that photons at X-ray wavelengths in the synchrotron X-ray beam are highly directed and have a very high concentration per unit area.

High-energy synchrotron X-ray sources open up possibilities to study complex samples with the best spatial precision and resolution. One of our goals was to get more insight into mineral transformations in confinement: the Surface Forces Sensor setup (SFS) designed at the Vienna University of Technology in Applied Interface Physics group combined with the X-ray beam allowed us to get more complete information about the confined region between reactive mineral surfaces. SFS was used to create and control spatial confinement and to measure normal and shear surface forces acting between two mineral surfaces. Information about mineral phases and changes in their crystallinity were obtained from X-ray scattering.

X-SFS setup from TU Wien Applied Interface Physics group installed at DESY, Petra III beamline.

In the X-SFS setup, a micrometer-sized X-ray beam can be directed very precisely through the most confined region between two probed surfaces. This is also the same region where the surface forces are measured by SFS. Any major changes in surface forces related to the reactivity of solid surfaces can be directly correlated with changes in phase or crystallinity of these solids, as interpreted from the scattered X-rays. Our preliminary findings from these experiments show that mineral transformations can be enhanced by shearing two surfaces against each other, which is relevant to fault zones and other geological environments where friction occurs. Stay tuned for more!

Literature search and review

Going through heaps of hits in academic search engines may be discouraging, as well as skipping the very one, most useful article, perhaps appearing on page 20 of search results. How to rerank the search hits, and how to quickly find the research we need? Some time ago, I attended a workshop by PhD Breakfast Club at the University of Oslo, and I’ve learned a couple of useful tricks.

If searching with Google Scholar, use filters. GS is undoubtedly handy, and thus the preferred search engine of many of my colleagues, but it is more likely to output older and more cited articles first, even though some newer works are definitely more relevant to your search. As a result, recent publications that haven’t been cited yet can be easily overlooked. A simple solution is to remember to only display the articles published since a certain year or to sort the search output by date.

Use the same keywords in several search engines. Various scientific search engines are based on different databases and use different algorithms to match results to the keywords you use. It is useful to keep track of the keyword combinations you use and create a search methodology. This will prevent overlooking the useful works.

Try some less popular search engines. Some less known search engines may have extra functions to aid your search. One example is JANE: this search engine lets you paste article abstracts and look for related works based on large chunks of texts. You can also look for other authors from your field and for journals that are most related to your research.

Display related works. Some essential articles can be easily traced by going through the works cited by a few key articles in your review. Use this at any stage of the review, at the start to explore the topic, and at the end, to avoid skipping important works. GS has a handy functionality to display citing works.

Measuring forces between mineral surfaces

We currently have a multitude of experimental methods to investigate isolated mineral surfaces immersed in water, even down to a molecular scale! Yet, it is still not so straightforward to measure what happens when two such surfaces are placed in very close proximity – nanometers apart from each other. This is especially the case when the two solid surfaces become reactive in contact with an undersaturated solution. As the gap between the surfaces is very narrow, the spatial confinement can modify how equilibration with the thin solution film progresses: dissolution and recrystallization may become affected by the transport of ionic species in the gap. This may in turn influence adhesive and repulsive forces between the surfaces. And it is definitely useful to find out how.

Nucleation and crystal growth in confinement happen everywhere: in sedimentary or metamorphic rocks, in buildings and monuments, but also in living organisms. If uncontrolled, it can cause substantial damage and can even act as a precursor to earthquakes. But studying how reactive surfaces interact with each other at small scales, requires special experimental methods. Recently, during a stay at the University of Oslo, I’ve learned how to measure these interactions with the Atomic Force Microscopy (AFM).

In a typical AFM experiment, we usually use an extremely sharp silicon tip, with a typical spike radius of several nanometers. This lets us resolve details of the interfacial structure of minerals immersed in water. But in order to understand the effects of confinement, we need a mesoscale experimental setup: our surfaces should be at least microns-large, but we should be able to bring them into contact with nanometer-distance resolution. With such good distance resolution, we should be able to resolve even weak forces acting between the surfaces. Since there are no commercial calcite-modified AFM cantilevers, we have to prepare one.

Preparation of an AFM calcite probe

The recipe is not too difficult: We use tipless AFM cantilevers that can be customized with various particles and surfaces. We place such cantilever above the freshly cleaved calcite surface inside the AFM and look for micron-sized particles that lie on the surface. Once a suitable particle is located, we pick a small amount of epoxy glue. We then quickly go back and press the glue-wet cantilever against the chosen particle. After several hours, the calcite AFM probe is ready. You can read about the application of this method in several recent works: (1, 2, 3).

Although the shape of this custom calcite probe varies between experiments and the probe’s resolution is limited in comparison with sharp AFM tips, the method is highly relevant for geological environments and mineral-based materials. We can now probe reactions in confinement, which can have a decisive influence on the mechanical properties of solid contacts.

Dziadkowiec, J. et al. (2019). Scientific Reports, 9(1), 8948. 
Javadi, S., & Røyne, A. (2018). Journal of colloid and interface science, 532, 605-613. 
Pourchet, S. et al. (2013). Cement and Concrete Research, 52, 22-30. 
Røyne, A. et al. (2011). Journal of Geophysical Research: Solid Earth, 116(B4). 
Söngen, H. et al. (2018). Physical review letters, 120(11), 116101. 


Last week I had a pleasure to attend Fysikermøtet 2019 – a meeting of Norwegian physicists in academia, industry, and schools. The plenary talks, starting from the story about lasers given by the 2012 Nobel laureate Serge Haroche and ending with not-so-impossible-anymore visions of smart farming and transport by Bjørn Tore Orvik, were a proper boost of inspiration. So hearing about all this state-of-the-art progress in fusion, superconductors, imaging of atoms, or solar energy, I should ask myself why studying mineral materials? Is there still any progress to be made? Can the same material that is used to produce blackboard chalk be also used to manufacture extremely durable ceramics?

At Fysikermøtet 2019, you could chat with me about contacts between reactive solids.

My take on this is rather optimistic as advanced materials based on abundant minerals already exist and are produced on a global scale. Unfortunately, this rarely happens in industrial processes, but it is mastered by organisms when they produce functional biominerals. Marine organisms produce their skeletons and functional devices from what they can find locally and in abundance. These might be not the best existent materials for a given specific function, but they are possible to get with little effort; an example for us to follow.

Although the way to go might seem still long, we learn more and more about reactive mineral particles, which comprise the smallest building blocks of mineral-based materials. Some very recent findings show that the interactions between these particles can be affected by the amount and type of even the most common ionic species dissolved in waters, not to mention the more complex interactions with organics. Experiments like that, are necessary to develop a meticulous recipe of how to control interactions between mineral particles; having it, will bring us closer to engineer the materials we need.

bye Oslo, hello TU Wien

A day after my Ph.D graduation held in the UiO Aula, I packed my bags and left Njord for my 2-years FRIPRO Mobility to AIP TU Wien. I was welcomed by a bunch of enthusiastic interface scientists and set out to work on my first individual fellowship (from the Research Council of Norway) in one of the best SFA labs!

Got my diploma!

But what is the whole project all about? Titled ‘Solid-solid interfaces as critical regions in rocks and materials: probing forces, electrochemical reactions, friction, and reactivity”, the project aims to investigate key interfacial processes that contribute to the mechanical strength of granular solids. Often, the overall strength of such solids is associated with what happens in tiny spaces between contacting individual grains. These are frequently the most reactive regions, in which minerals can grow or dissolve in the presence of water or more concentrated salt solutions. The growth and dissolution frequently determine if contact will be strong or weak, as they may cement solid grains together or push the grains away from each other. Thus, the overarching goal I set for this project is to recognize which of these processes make the solid-solid interfaces weak, and how to convert the weak interfaces into the strong ones.

Although we see the destructive effects of weak interfaces at a macroscopic scale (earthquakes, rock compaction and subsidence, general material failure), the very mechanisms governing the interfacial strength are frequently operating at much smaller scales (10-9m). To learn about these mechanisms, and to be able to modify them, we need new analytical methods that enable us to investigate the relevant nano and micro-scale processes. In my experimental project, I’ve chosen to work with the Surface Forces Apparatus (SFA). SFA allows studying of a multitude of interfacial processes, and all in one go: surface forces (adhesion and repulsion), friction between surfaces that move laterally, surface reactivity or even electrochemical surface corrosion! If you are looking forward to reading more, stay tuned, and follow the project’s progress!