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李哲123456

新虫 (小有名气)

应助: 0 (幼儿园)
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虫号: 22348120

[交流] 招收CSC博士生

导师人不错，想找一个CSC学生，具体的项目内容如下，如果有想来此的话，可以直接联系老师。
Polymers soft templates for synthesis of catalytic materials
Porous materials own remarkable structural features such as: large specific surface areas and pore volumes, tunable pore sizes and architectures, and a diversity of frameworks. These characteristics position them at the forefront of innovative and sustainable solutions to many of catalysis, energy storage, sensing, and biomedicine’s demands.
Current research on porous materials is facing several challenges, including the generation of well-controlled pore sizes and structures, precise characterization and ensuring their stability under real world conditions, such as harsh chemical environments or high temperatures.
To date, various synthetic protocols have been developed for synthetizing porous materials, including template-free, hard-templating and soft-templating approaches. While template-free strategies typically suffer from difficulties in tailoring the morphology and pore structures, the hard-templating one (such as preformed silica or carbon) suffer from tedious multi-steps procedures limiting their scalability. In contrast, soft templating offers a large versatility and can be ingeniously used for the replica of various functional porous materials [1, 2] with the possibility to easily remove the polymeric matrix in the end.
For example, block copolymers (BCPs), with immiscible blocks, spontaneously assemble in selective solvents leading to nanostructures, such as vesicles, cubosomes and hexosomes. These assemblies are highly robust, have a high loading capacity and form mesopores in a wide scale range.[1] All these properties are advantageous to many host-guest interactions, but not yet fully exploited in the field of functional porous materials. Currently, most reported polymer cubosomes, (well-defined inverse bicontinuous cubic mesophases) consist of polystyrene block copolymers, whose self-assembly parameters are rather well understood. The channels of polymer cubosomes were effectively used in order to synthesize metal organic framework (MOFs) materials. [2] Other recent studies exploited these “soft templates” as versatile platforms for the synthesis of highly ordered nanoporous metal oxide with high specific surface area (up to 123 m2 g-1 for WO3), different well controlled pore structures of sizes ranging between 18 and 78 nm.[3] More interesting, Fe3O4-doped mesoporous carbon materials as cathode for the Li-S batteries were obtained by impregnation of the polymer cubosomes with Fe ions and plant polyphenols, as natural and nontoxic biomass ligands. These metal-polyols complexes are excellent precursors for the fabrication of carbon based materials to be used in electrochemical-systems. [4]
The objectives of this PhD project are:
1.
To use copolymers alternative to polystyrene based ones to prepare polymer assemblies with ordered structures, acting as suitable soft templates for mineral charging.
Changing the chemical nature of the blocks is highly desirable to introduce greater functionality. However, knowledge of the impact of new chemistries on the self-assembly process remains limited and requires further investigation.
We have recently reported on a simple method to obtain controlled three-dimensional hybrid architectures, formed by gold nanoparticles and a double hydrophilic block copolymer, specifically the poly(acrylic acid)-block-poly(N-vinyl-2-pyrrolidone) (PAA-b-PVP) (synthetised by RAFT polymerisation), directly in aqueous medium. [5]
We plan to test the incorporation of naturally occurring polyphenols in order to reinforce and modulate the structure of these assemblies.[6,7] Poly(ethylethylene phosphate)-b-polylactide (PEEP-b-PLA) will also be considered as interesting alternative.[8] This fully degradable copolymer forms highly ordered cubosomes and is particularly attractive for the mineral loading due to the expected favorable interactions with the metallic ions, while also guarantying environmental sustainability.
2.
To prepare inorganic porous materials through the replication of the polymer template. (Figure 1)
The open channels of the ordered cubosomes together with the chemical functions of the polymers are advantageous for host-guest interactions. Impregnation strategies are therefore straightforward and could be applied to produce a diversity of inorganic materials.
The polymer template could be subsequently removed by solubilization, degradation or pyrolysis.
3.
To characterize the formed materials with a particular attention to the effect of the type, strength and dynamic nature of the interactions under varying conditions. Understanding the role of diverse interactions involved will be essential to rationalize the different phenomena which govern the final structure of the material and fine-tune their properties for specific applications.

Profile and skills required :
We are looking for a candidate with a chemistry academic background and if possible knowledge of polymer chemistry and/or materials science. The candidate have to master the characterization techniques commonly used in chemistry (NMR, IR, UV-Vis) and if possible to have knowledge of techniques for the characterization of materials such as transmission electron microscopy (TEM), x-ray diffraction (XRD), etc.

If you are interested in this offer contact Diana Ciuculescu-Pradines (eliza.ciuculescu-pradines@univ-tlse3.fr and Barbara Lonetti (barbara.lonetti@univ-tlse3.fr)

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