PhD Position (8) TW12 - Department of Chemical engineering and technical chemistry, Ghent University

over 2 years ago | Deadline: 2012-04-30 17:00


PhD Position (8)
  • Last application date: 2012-04-30 17:00
  • Department: TW12 - Department of Chemical engineering and technical chemistry
  • Contract: bepaald
  • Occupancy rate: 100%
  • Vacancy Type: wp

Job Description

Model guided design of multi-step one pot synthetic sequences for functional polymer materials.

Aim

In this PhD project, the development of multi-step one pot synthetic sequences to synthesize linear, branched and cross-linked polymer materials will be explored using amine-thiol-ene conjugation chemistry. Guided by theoretical calculations and kinetic modeling, the project aims at defining reaction conditions that allow to fully control the polymer microstructure.

Context

‘Click’ chemistry is a powerful tool to make new functional polymer materials with a broad range of applications in medicine, electronics, coatings, etc. To optimize the benefit of ‘click’ chemistry to link polymer molecules together in complex functional architectures, multi-step one pot synthetic sequences have to be envisaged, since they make laborious work-up and purification obsolete. A very promising accelerated protocol for the synthesis of several types of polymeric architecture is shown in the right figure.  A thiolactone entity serves as a precursor for thiols (latent functionality) in a one-pot amine-thiol-ene reaction: the thiolactone ring opens upon aminolysis (nucleophilic reaction) and the in situ generated thiol reacts with a double bond (radical, photo-initiated process), already present in the same pot, resolving important issues concerning the instability and availability of thiols. Currently, the very promising synthetic strategy is still in its pioneering stage. A detailed study of the amine-thiol-ene conjugation will allow to further exploit its potential. The obtained insights will enable to define the possibilities and limitations, especially when targeting functional polymer materials with well-defined architectures.

Program

  • Development of a versatile kinetic model for low molar mass model compounds that will enable to manipulate the relative importance of the radical and nucleophilic pathways of the generated thiol. In general, the conjugation efficiency will strongly depend on the chemical structure of the reactants, but some characteristic issues are inherent to the mechanism. E.g., in the radical reaction pathway, several side reactions can occur between the amine and the radical fragments originating from the photoinitiator. This reduced level of orthogonality necessitates further research on the initiation as such and on the prevention of amine interference. Quantum chemical calculations will be performed to derive structure-reactivity relations.
  • Determination of the optimal synthesis strategy and reaction conditions to control the incorporation of the latent thiolactone in a polymer backbone, while minimizing the experimental efforts and maximizing monomer versatility. Starting from the gained knowledge on low-MW model compounds, the kinetic model will be extended to account for effects of molecular diffusion on the reaction rates, allowing to tune the copolymer microstructure (copolymer composition, chain length, end- and mid-group functionality, …) and, hence, the copolymer properties, and to explore the efficiency of post-polymerization.
  • Advisor: Marie-Françoise Reyniers
    Funding: Foundation for Scientific Research Flanders (Science and Technology)


    Profile

    PhD Fellowships are available in the following domains:

    • Biomass Conversion
    • Transient Kinetics
    • Metal catalyzed reactions
    • Radical Polymerization
    • Pyrolyis and Steam cracking
    • Computational Fluid Dynamics coupled with kinetics

    Typical activities during a 4 year PhD project:

    • Experimental acquisition of intrinsic reaction rate data.
    • Model construction based on reaction mechanisms and estimation of kinetic parameters by data regression and/or quantum chemical calculations.
    • Scale-up of lab data and simulation of industrial processes by developing and implementing reactor models accounting for transport next to reaction. Development and application of Computational Fluid Dynamics models in that context.
    • Normal duties will apply, including the preparation of scientific reports and publications and assisting in supervising of MSc students.

    Requirements

    Applicants must possess a MSc in Chemical Engineering or related subject and a TOEFL certificate ( minimum score of 580(paper)/92(iBT)/237(computer)) or equivalent. Relevant experience in the area of reactor engineering, kinetics, and/or computational chemistry is strongly recommended. Candidates must have a strong mathematical background and be willing to focus on obtaining quantitative rather than qualitative results. Excellent candidates with a PhD in the above domains and willing to spend between 1 and 3 years at LCT can also apply for a postdoctoral fellowship.


    Apply

    Any additional information can be obtained by contacting Guy B. Marin. Any application should enclose a C.V., a one page justification of your interest and at least two references.

    Guy.Marin@UGent.be

    09 264 45 17



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