Teaching
Research at our section
Colloids are small particles with dimensions in the range 1-1000 nm and are therefore much larger than molecules. Since they are still small enough to exhibit thermal motion (Brownian motion) the properties of colloidal solutions (dispersions) are similar to molecular systems; for example both exhibit diffusion, gas-liquid condensation and crystallisation. Contrary to molecules, however, the interactions between colloids can be tuned to the desired strength. Furthermore, due to their relatively large size, colloids are suitable for study with a wide variety of characterisation techniques. For example, the particles can be directly imaged with transmission electron microscopy or light microscopy, and studied (indirectly) by light diffraction, light scattering and/or sedimentation experiments. In addition, magnetic colloids can be further characterised by determining the magnetic properties, as for instance by measuring the magnetic dynamic susceptibility.
One important aspect of the research in our section is the interplay between chemistry and physics; experimental research is conducted to establish the effect of particle shape and interaction on the macroscopic (physical) behaviour of the colloids. To obtain a comprehensive view on the macroscopic features of colloidal systems, the thermodynamics (phase transitions), rheology (fluid dynamics), and diffusion and sedimentation properties are studied. To perform such studies, well-defined model particles with appropriate shape and tunable interactions are required. Consequently, the synthesis and characterisation of colloids is also an important topic within our section.
The van 't Hoff laboratory has developed extensive expertise on the synthesis of inorganic colloids (spherical SiO2, needle-like AlOOH, platelet-like AL(OH)3, and magnetic Fe3O4). Recently, also much attention has been paid to organic polymer colloids as for example polymethylmethacrylate. (Below several electron microscope images are shown).
Besides experimental work, also computer simulations and (statistical mechanics) theory form part of our research activities. The combination of chemical synthesis, physical experiments and theory makes colloid chemistry an attractive and interdisciplinary research area, in which people with different interest work.
Our laboratory is located in the Kruyt building on the seventh floor. You can visit our permanent colloid exhibition, which gives an impression of our research (come around 10:30 or 15:15 and coffee and tea will be available). If you would like to hear more about student projects please contact a member of our group or have a look at the research proposals.
Electron microscope images of several colloidal dispersions
Cryo-TEM image of magnetite (Fe3O4) spheres, showing chains due to strong dipolar attractions.
Hematite (Fe2O3) rods.
TEM image of gibbsite (Al(OH)3) platelets.
Boehmite (AlOOH) rods.
Bachelor thesis (15 ects)
Contact: Janne-Mieke Meijer ( tel. 253 36 50)
Teaching staff: prof.dr. A.P.Philipse
In the experimental part (10 ects) the student will deal with the chemistry and physics describing the behaviour of colloidal systems. The work includes the synthesis and characterization of model particles, which are subsequently used for performing physical experiments. In agreement with the supervisor, the focus of the research can be chosen according to the students interest. The experimental part will be closed by presenting a work discussion (2 ects) and by a written report (3 ects).
For more information on the Bachelor thesis see here.
The Physical Chemistry 2 lecture series is required and the Physical Chemistry 3 lecture series is strongly recommended.
Master thesis (60 ects)
Contact: Janne-Mieke Meijer ( tel. 253 36 50)
The master thesis consists of three parts of which the experimental part is the largest (42ects). During the master project the student will participate in a currently conducted research project. Usually, model particles are synthesized and characterized in a physical-chemical laboratory setting. In agreement with the supervisior the focus can be directed to the chemical or physical part. At the end of the project, a workdiscussion (3 ects) is presented and a research report (6 ects) is written.
The Master course 'Soft Condensed Matter', including the advanced lectures on colloids, is obligatory. See master's programme 'Chemistry and Physics'.
Finally, a literature research project has to be performed (9 ects) about an independently studied literature subject.
For more information on the master thesis see here.
The Physical Chemistry 3 lecture series is strongly recommended.