Doctoral student in Physical Chemistry - Hiring in process/Finished, not possible to apply

Subject description

Physical Chemistry involves research relating to molecular issues. The experimental and theoretical methods used often originate from physics. The emphasis in Physical Chemistry at the Department of Chemistry is on research, both experimental and theoretical, within surface and colloidal chemistry and with a special focus on self-aggregating systems. The systems studied include tensides, polymers and biomolecules.

The current project focus on Soft Matter, in particular on the study of the flow properties of compressible colloids, microgels, combining scattering techniques with rheology.

Work duties

During the 4 years of this project (2 financed by Lund University, 2 financed by the Institut Laue – Langevin, ILL, in Grenoble, Frace), the PhD student will use pNIPAM-based microgels as a model system for soft spheres to investigate the interplay between the ordering and resulting macroscopic properties of the suspensions under flow, and the compressibility of individual particles. These particles have been extensively used to study the impact of softness on the phase behaviour and flow properties of soft materials. We will combine rheological experiments with small-angle neutron and x-ray scattering measurements. The use of the 1,2-shear cells available only on D22 at the ILL is fundamental. This cell will allows us to collect fundamental information in the flow direction that is the most sensitive to deformations and bending of the samples. These data will be complemented by SANS and SAXS measurements using a conventional rheometer to have the full 3D characterization of the structure under flow. The information on the individual particle response under flow will be obtained using SANS with contrast variation.

The main objectives of this project are: (i) Probe the shape and architecture of individual microgels under flow; (ii) characterize the structure of the microgels solutions under flow; (iii) probe the structure of the suspension with time and spatial resolution to clarify the nature of the band formation and phase separation observed under shear. Due to lack of investigations in the 1,2-plane, there is a deficit of universal models to describe the effects of structuring, e.g., shear banding or deformation, on the macroscopic viscoelastic properties of soft materials. The use a well-defined model system will allow us to understand the fundamental principles ruling the flow of soft spheres. By precisely quantifying the softness using parameters we previously defined, we also plan to compare our results with other experiments on different soft colloids such as single chain nanoparticle, polymer rings, star-like polymers, antibodies, and bio-compatible nanoparticles to identify common trends. Furthermore, our findings might be of interest for a better understanding of materials that undergo shear during application, for example paints and drug delivery systems.

The total duration of the project will be 4 years. The PhD student will start the project (1-to-1.5 year) in Scotti’s group (Lund University, Sweden). In this period the student will be introduced to the basics of rheology and the first rheological characterization will be performed. Characterisation will be conducted mainly with SAXS using both the in-house instruments and the SAXS machines (coSAXS and ForMAX) at MAX- IV, the synchrotron operative in Lund. Then the student will spend 2 years located at ILL (Grenoble, France) focusing on rheo-scattering experiments (with short visits to Lund). For the final part of the project the PhD student will return to Lund to finalise the writing of the thesis and the PhD defence.

The main duties of doctoral students are to devote themselves to their research studies which includes participating in research projects and third cycle courses. The work duties can also include teaching and other departmental duties (no more than 20%).

Admission requirements

A person meets the general admission requirements for third-cycle courses and study programmes if the applicant:

• has been awarded a second-cycle qualification, or
• has satisfied the requirements for courses comprising at least 240 credits of which at least 60 credits were awarded in the second cycle, or
• has acquired substantially equivalent knowledge in some other way in Sweden or abroad.

A person meets the specific admission requirements for third cycle studies in Physical Chemistry if the applicant has:

• A master’s degree (or equivalent) in physics or physical chemistry.

Additional requirements:

• Very good oral and written proficiency in English.
• Previous experience at large scale facilities.
• Good knowledge and skills relevant to the thesis project and the work duties.
• Ability to work independently and to formulate and tackle research problems.

Assessment criteria

Selection for third-cycle studies is based on the student’s potential to profit from such studies. The assessment of potential is made primarily on the basis of academic results from the first and second cycle. Special attention is paid to the following:

1. Knowledge and skills relevant to the thesis project and the subject of study.
2. An assessment of ability to work independently and to formulate and tackle research problems.
3. Written and oral communication skills
4. Other experience relevant to the third-cycle studies, e.g. professional experience.

Other assessment criteria:

• Proved experience at large scale-facility using neutron-based techniques.
• Proved capability of independently perform analysis of data obtained from neutron or x-ray experimenrts.
• Previously followed courses in Condensed Matter Science, Computational Physics, Experimental Physics and Computing.
• Experience in using Matlab/Python for data analysis.

Consideration will also be given to good collaborative skills, drive and independence, and how the applicant, through his or her experience and skills, is deemed to have the abilities necessary for successfully completing the third cycle programme.

Terms of employment

Only those admitted to third cycle studies may be appointed to a doctoral studentship. Doctoral studentships are regulated in the Higher Education Ordinance (1993:100), chapter 5, 1-7 §§.

Instructions on how to apply

Applications shall be written in English and include a cover letter stating the reasons why you are interested in the position and in what way the research project corresponds to your interests and educational background. The application must also contain a CV, degree certificate or equivalent, and other documents you wish to be considered (grade transcripts, contact information for your references, letters of recommendation, etc.).