Neutron scattering methods for soft condensed matter and food materials

Latest news

January 2024

Wim Bouwman was awarded the prestigious J.B. Westerdijk Prize. He received the prize for his exceptional contributions to education.

December 2023

Since the early development of SESANS we discussed the possibility to do 2D-measurements. In this article we present simulations on a possible method using the spin-echo modulated small-angle neutron scattering method. It is certainly possible, however, it it practical?
Simulations and concepts for a 2-D spin-echo modulated SANS (SEMSANS) instrument
S.R. Parnell, S. van den Berg, G. Bolderink, W.G. Bouwman
Journal of Physics: Conference Series 2481 012007 (2023)

In experimental science instruments are often calibrated against each other. We participated in a large study to investigate the human and software factor in the data analysis of small-angle neutron scattering (SANS) measurements. For more complex samples the effect of the scientist and software can be considerable. More uniformity in the description of the models of software can help to reduce this effect.
The human factor: results of a small-angle scattering data analysis round robin
B.R. Pauw, G.J. Smales, A.S. Anker, V. Annadurai, D.M. Balazs, R. Bienert, W.G. Bouwman, I. Breßler, J. Breternitz, E.S. Brok, G. Bryant, A.J. Clulow, E.R. Crater, F. De Geuser, A. Del Giudice, J. Deumer, S. Disch, S. Dutt, K. Frank, E. Fratini, P.R.A.F. Garcia, E.P. Gilbert, M.B. Hahn, J. Hallett, M. Hohenschutz, M. Hollamby, S. Huband, J. Ilavsky, J.K. Jochum, M. Juelsholt, B.W. Mansel, P. Penttilä, R.K. Pittkowski, G. Portale, L.D. Pozzo, L. Rochels, J.M. Rosalie, P.E.J. Saloga, S. Seibt, A.J. Smith, G.N. Smith, G.A. Spiering, T.M. Stawski, O. Taché, A.F. Thünemann, K. Toth, A.E. Whittenu, J. Wuttke
J. Appl. Cryst. 56 1618-1629 (2023)

October 2023

I published my first "book" on education. With my colleague teachers we wrote an open textbook around the videos we recorded during the pandemic for our introductory course on electricity and magnetism. We added python calculations to illustrate the theory. It is an open book to make it accessible to everyone who understands Dutch.

September 2023

In biophysics the relationship between structure and function is investigated. With spin-echo small-angle neutron scattering (SESANS) we determined the fractal structure of chromatin in the nuclei of rat lymphocytes:
Time-of-flight spin-echo small-angle neutron scattering applied to biological cell nuclei
E.G. Iashina, W.G. Bouwman, C.P. Duif, R. Dalgliesh, E.Y. Varfolomeeva, R.A. Pantina, R.A. Kovalev, N.D. Federova, S.V. Grigoriev
J. Appl. Cryst. 56 1512-1521 (2023)

August 2022

In the development of spin-echo small-angle neutron scattering (SESANS), some colleagues expected the signal to be the isotropic correlation function. However, we have shown that is only a projection along the labelling direction. Some ideas came up to measure the isotropic correlation function with radially symmetric magnetic precession fields. We performed calculations to show that even with radial SESANS one only measures a projection of the correlation function. We have published it in:
Radial spin echo small-angle neutron scattering method: concept and performance
E. Kadletz, W.G. Bouwman, C. Pappas
J. Appl. Cryst. 55 1072-1084 (2022)
We presented it at the International Conference on Neutron Scattering in Buenos Aires, Argentina. You can watch our presentation on YouTube at:

December 2021

I have given an invited lecture at the School of Polarized Neutron Physics on 16 December 2021 online in Gatchina, Russia, with the title "Spin-echo small-angle neutron scattering for multiscale structure analysis of food materials". In the presentation I lecture about the technique of SESANS, the data-interpretation and its application on food systems. You can rewatch it on Youtube:

October 2021

Three article came out in a special issue of Food Structure:

I have written a review article about the application of spin-echo small-angle neutron scattering for food science. I think it is a good introduction for new users of the technique.
Spin-echo small-angle neutron scattering for multiscale structure analysis of food materials
Food Structure 30 100235 (2021)

Cellulose fibers can be a good addition to food, to improve all kind of properties of the food. It is important for the application to understand how the cellulose influences the flow behaviour of the food. With small-angle X-ray scattering we have clarified the mechanism. High-pressure homogenized citrus fiber cellulose dispersions: Structural characterization and flow behavior
M.R. Serial, E. Velichko, T. Nikolaeva, R. den Adel, C. Terenzi, W.G. Bouwman, J.P.M. van Duynhoven
Food Structure 30 100237 (2021)

Scattering models are traditionally developed for monodisperse well-defined objects. Food is heterogeneous, polymorphic and polydisperse, which requires a completely different approach. For meat substitutes we have developed a general model to quantitatively describe the scattering:
Scattering from oriented objects analysed by the anisotropic Guinier–Porod model
B. Tian, J.R. Heringa, W.G.Bouwman
Food Structure 30 100221 (2021)

6 July 2021

The last year we had to adapt our teaching to the corona rules. The student associations appreciated our creativity and didactics to adapt our teaching. The faculty has announced that I am the teacher of the year for Applied Physics:

22 March 2021

We published with several Danish groups together a paper on the spatial distribution of polymers in medical silicon. This knowledge will help to produce better materials for medical applications:
The microscopic distribution of hydrophilic polymers in interpenetrating polymer networks (IPNs) of medical grade silicone
G.N. Smith, E. Brok, M. Schmiele, K. Mortensen, W.G. Bouwman, C.P. Duif, T. Hassenkam, M. Alm, P. Thomsen, L. Arleth
Polymer 224 123671 (2021)

4 March 2021

This morning I gave an invited talk at the online conference: Science and Technology for Meat Analogues in Wageningen. You can watch my presentation on youtube:

1 February 2021

We have a long running collaboration with the McStas-team in Copenhagen on the simulation of SE(M)SANS. Last winter during a short sabbatical at DTU we managed for the first time to include a realistic scattering sample in the simulations. This work is now published:
Simulations of foil-based spin-echo (modulated) small-angle neutron scattering with a sample using McStas
W.G. Bouwman, E.B. Knudsen, L. Udby, P. Willendrup
J. Appl. Cryst. 54 195-202 (2021)
The simulation codes can be retrieved from

4 November 2020

Due to the corona pandemy we had to do the teaching of the BSc course Introduction Electricity and Magnetism mainly online. We have put all our video lectures on, so everybody can watch and use them.

19 Octobre 2020

We published measurements we performed on small spherical shells. The SESANS made it possible to measure the shell thickness without destroying the granules.
Structural characterization of spray-dried microgranules by spin-echo small-angle neutron scattering study
Priyanka Biswas, Debasis Sen, W.G. Bouwman
Powder Technology 378 680-684 (2021)

1 July 2020

We published a summary of the PhD-thesis of Bei Tian in Dutch in the Dutch journal of physics:
Betere textuur vleesvervangers met neutronenverstrooiing
B. Tian, A.J. van der Goot, W.G. Bouwman
Nederlands Tijdschrift voor Natuurkunde 86 8-11 (2020)

24 April 2020

We got on the front cover of with our article
Mesoporous silica formation mechanisms probed using combined Spin-Echo Modulated Small Angle Neutron Scattering (SEMSANS) and Small Angle Neutron Scattering (SANS)
J. Schmitt, J.J. Zeeuw, J. Plomp, W.G. Bouwman, A. Washington, R.M. Dalgliesh, C.P. Duif, M.A. Thijs, F. Li, R. Pynn, S.R. Parnell, K.J. Edler
ACS Applied Materials & Interfaces 12 28461-28473 (2020)

8 April 2020

With SANS measurements we have quantified the anistropy on different length scales in model meat replacements. The measurements show cleary at which length scales the fibre formation starts.
Small angle neutron scattering quantifies the hierarchical structure in fibrous calcium caseinate
B.Tian, Z. Wang, L. de Campo, E.P. Gilbert, R.M. Dalgliesh, E. Velichko, A.J. van der Goot, W.G. Bouwman
Food Hydrocolloids 106105912 (2020)

2 April 2020

We have published an article on the inclusion of SESANS data-analysis in the user friendly programme This makes it possible to use all conventional SANS models to analyse SESANS measurements. This makes it for users much easier to analyse their SESANS data.
Analysis of SESANS data by numerical Hankel transform implementation in SasView
J.H. Bakker, A.L. Washington, S.R. Parnell, A.A. van Well, C.P. Pappas, W.G. Bouwman
J. of Neutron Research 2257-70 (2020)

11 February 2020

I was invited by the League of advanced European neutrons sources to give in the Solvay library in Brussels a colloquium on the use of neutrons for sustainable food production.

27 January 2020

Bei Tian obtained her PhD title by defending her thesis on fibrous calcium caseinate gels as meat replacements.

26 December 2019

Neutron scattering quantifies the effect of enzymes on degumming of crude vegetable oils:
Impact of water degumming and enzymatic degumming on gum mesostructure formation in crude soybean oil
T. Nikolaeva, T. Rietkerk, A. Sein, R. Dalgliesh, W.G. Bouwman, E. Velichko, B.Tian, H. van As, J. van Duynhoven
Food Chemistry 311 126017 (2020)

16 October 2019

Evgenii Velichko obtained his PhD title by defending his thesis on Small-angle scattering by cellulose.

30 July 2019

We have published a study to show the relation between the macroscopic fibre formation and the microscopic dynamics of caseinate dispersions. This will help to rationaly redesign more sustainable food processing methods.
Fibre formation in calcium caseinate influenced by solvent isotope effect and drying method - A neutron spectroscopy study
B.Tian, V. Garcia Sakai, C.P. Pappas, A.J. van der Goot, W.G. Bouwman
Chemical Engineering Science 207 1270-1277 (2019)

16 May 2019

We published a nice study on oil-water emulsions that can be use for enhanced oil recovery. It is the work of two MSc-students Applied Physics in collaboration with Shell. They have performed the neutron measurements in Delft and at Larmor in ISIS.
Systematically quantifying oil-water microemulsion structures using (spin-echo) small angle neutron scattering
M. Mulder, X.X. Li, M.M. Nazim, R.M. Dalgliesh, B. Tian, M. Buijse, J. van Wunnik, W.G. Bouwman
Colloids and Surfaces A575 166-175 (2019)

28 March 2019

Wim Bouwman presents the work of the group at a workshop Neutrons for the Biotech Industry in Zaragoza in Spain. You can get an impression of the meeting at

13 March 2019

An article got published on the SESANS measurements on the evolution of polymer nanocomposites in an extruder. In the analysis the results were combined with SANS and optical microscopy to obtain a multilevel structural image of the structural evolution.
Evolution of dispersion in the melt compounding of a model polymer nanocomposite system: A multi-scale study
H. Gaspar, R. Santos, P. Teixeira, L. Hilliou, M.P. Weir, C.P. Duif, W.G. Bouwman, S.R. Parnell, S.M. King, J. A. Covas, G. Bernardo
Polymer testing 76 109-118 (2019)

29 December 2018

We have published an article on a special shear cell to study soft matter, for example food materials, with all kind of small-angle scattering techniques. This article presents one of the main themes of our food scattering project.
A versatile shear cell for investigation of structure of food materials under shear, E. Velichko, B.Tian, T. Nikolaeva, J. van Duynhoven, J. Koning, W.G. Bouwman, Colloids and surfaces A 566 21-28 (2019),

16 October 2018

Bei Tian and Evgenii Velichko present their work on proteins and cellulose at the fifth Neutrons and Food workshop held in Sydney Australia.

18 May 2018

Bei Tian published an article on air bubble characterisation in fibrous gels with several techniques. Air bubbles seem to be important for fibre formation in the gel, which gives a good texture, which is important for meat replacements. Each technique has its own strong features.
Air bubbles in fibrous caseinate gels investigated by neutron refraction, X-ray tomography and refractive microscope, B.Tian, Z. Wang, A.J. van der Goot, W.G. Bouwman, Food Hydrocolloids 83 287-295 (2018)

9 April 2018

Evgenii Velichko and Bei Tian present their posters at the 17th Food Colloids Conference: Application of Soft Matter Concepts at the University of Leeds. Evgenii's poster presents the flexible shear cell to use in both X-ray and neutron scattering with several geometries. Bei's poster presents the quantification of air bubbles in a fibrous gel.

13 March 2018

A beautiful paper is published on the state diagram of short ranged attractive colloids with longer ranged repulsions: The interactions were tuned by the addition of salt and polymers. Highly intriguing equilibrium gelling phenomena were observed in the system, that can be explaned by their interaction potential. The interaction potential is quantitavely characterised with SANS and SESANS.

The extended law of corresponding states when attractions meet repulsions, K van Gruijthuijsen, M. Obiols-Rabasa, P. Schurtenberger, W.G. Bouwman, A. Stradner, Soft Matter (2018), Advance Article,

15 November 2017

Wim Bouwman presented at the EFFoST International Conference, Food Science and Technology Challenges for the 21st Centruy - Research to Progress Society in Sitges a talk on what Neutron Scattering can do for Food Science. There was a special session for neutrons and synchrotrons at this multidisciplinary conference.

7 April 2017

At the SasView code camp VI in Grenoble the team succeeded to have the SESANS transformation included into the GUI. From now on it is possible for users to use SasView and SASFit to analyse SESANS measurements.