Master Projects in Nanoparticle Research Using Cryogenic Electron Tomography
Our lab has developed a method to extract various thermodynamic quantities for dispersions of gold nanoparticles using cryogenic electron tomography (cryo-ET) [ 1 ]. This technique allows for the direct extraction of the 3D spatial distribution of nanoparticles in vitrified samples. With our method now validated, we are ready to explore key questions about nanoparticle behavior in liquids. We are offering two master thesis opportunities:
- Master Project #1: Are 2D and 3D experimental radial distribution functions equivalent?
Traditionally, researchers have used 2D cryo-images to extract thermodynamic parameters, assuming that the 2D radial distribution function (RDF) derived from these images provides the same information as the 3D bulk RDF [ 2 ]. This master thesis aims to test the accuracy and limitations of this assumption. The student will synthesize gold nanoparticles and collect cryo-electron tilt series of dispersions under various conditions. By experimentally measuring both 2D and 3D RDFs, student will determine the validity of the 2D=3D assumption and identify the specific conditions under which this equivalence holds. Additionally, the student will develop a graphical user interface (GUI) to calculate and visualize the results for both 2D and 3D cases. Therefore, we are seeking a candidate with a background in material science and strong computational skills.
- Master Project #2: At what particle size does DLVO theory start to fail for nanoparticles?
DLVO (Derjaguin-Landau-Verwey-Overbeek) theoretical models the interaction potential and predicts the colloidal stability of the dispersions of large particles (>100 nm). However, it is known to fail for smaller particles (1–20 nm) [ 3 ]. The exact particle size at which deviations from DLVO predictions occur remains unclear. This project aims to synthesize gold nanoparticles with finely tuned sizes and apply cryogenic electron tomography (cryo-ET) to analyze the interaction potentials of these particles. The goal is to investigate and establish the limits of DLVO theory’s applicability to nanoparticle dispersions, enhancing our understanding of their behavior and stability.
Who we are looking for:
We are looking for students pursuing a degree in materials science, chemistry, physics or related fields. Knowledge of colloidal chemistry and statistical mechanics is preferred, though a strong motivation to learn is also acceptable. Experience in coding will be advantageous.
Learning Outcomes:
- Gain hands-on experience in synthesizing gold nanoparticles, surface functionalization, and ligand exchange.
- Learn physicochemical characterization methods such as TEM, NMR, UV/Vis spectroscopy, TGA, and zeta potential measurements.
- Acquire skills in cryo-electron microscopy and image analysis techniques including 3D tomographic reconstruction and particle segmentation.
- Depending on project progress, opportunities for publication may arise.
Contact and supervision:
Ekaterina Poliukhina: [email protected]
Dr. Quy Ong: [email protected]
Prof. Francesco Stellacci: [email protected]