Phd Position Offer: Synthesis Of Interpenetrating Polymer Networks At The Air-Water Interface

22 May 2023

Job Information

Organisation/Company

CY Cergy Paris Université

Research Field

Chemistry » Physical chemistry

Researcher Profile

Recognised Researcher (R2)

Country

France

Application Deadline

1 Sep 2023 - 00:00 (Europe/Berlin)

Type of Contract

Temporary

Job Status

Full-time

Is the job funded through the EU Research Framework Programme?

Not funded by an EU programme

Is the Job related to staff position within a Research Infrastructure?

No

Offer Description

Description of the PhD position: 3D polymer blends are rarely miscible. In order to prevent significantly phase separation and thus combine the properties of the two polymers, one of the strategies is the synthesis of interpenetrating polymer networks (IPNs) where the two polymers are cross-linked in the blend using two different reaction pathways. As part of this thesis, we propose to study the synthesis of IPNs at the air-water interface (2D) from polymer or oligomers films spread over a pure water surface, so-called commonly Langmuir films. These films of monomolecular thickness can then be transferred onto a solid substrate, thus acting as a nanometer-thick coating whose morphology and wettability will be characterized. While materials based on 3D IPNs are widely described in the literature, Langmuir films based on 2D IPNs have not yet been reported 1. Such 2D architectures are expected to ensure the stability of the ultrathin coating against external stimuli (temperature, solvent, pH…) similarly to their 3D analogues 2. In order to synthesize these 2D IPNs at the air-water interface, a preliminary study combining experimental and theoretical work on the pressure- composition phase diagrams will be carried out for several pairs of polymers selected mainly for their different hydrophobicity. It will ultimately allow to identify over the phase diagram the miscibility and phase separation regions and thus to determine the most suitable experimental conditions for the synthesis of homogeneous 2D IPNs. The comparison between the experimental results and the theoretical predictions will provide the key parameters involved in the 2D polymer phase separation. In a second step, the synthesis of 2D single polymer networks will be studied starting from linear polymer Langmuir films. For this purpose, photo-induced free-radical cross-linking, or acid-catalyzed acetalization using a cross- linker agent will be considered 3,4. Multiscale in situ characterizations at the air-water interface will be performed, ranging from the macroscopic scale by compression isotherm then morphology observations by Brewster angle microscopy (BAM) up to the nanometric scale by neutron reflectivity 5,6. The kinetics of polymer cross-linking reactions will be followed in situ at the air-water interface by sum frequency generation spectroscopy (SFG) at the University of Vienna under the supervision of Professor Ellen BACKUS. This non-linear optical spectroscopy method will make it possible to probe the vibrational properties of the different chemical groups involved in the cross- linking reactions.

At the end of this second step, it is planned to synthesize the 2D IPNs from linear polymer blends whose composition will be fixed with respect to the phase diagrams. The polymers will be cross-linked within the blend, either simultaneously or sequentially, and the film morphology will be characterized in both cases. The last objective will be the characterization of the ultra-thin coatings based on 2D IPNs after transfer from the water surface onto a solid substrate. In order to study the influence of the substrate nature (water or solid) on the polymer organization, the vibrational signatures (SFG) of the chemical groups within the coatings will be compared with those obtained at the water- air interface. The morphology of the coatings will be characterized by atomic force microscopy depending on the substrate nature, the composition of the film, the physicochemical parameters and the cross-linking conditions. Finally, the wetting properties of these 2D IPN coatings will be studied by dynamic contact angle measurements of water and other model liquids. The combination of the different in situ and ex situ characterizations of 2D IPNs will provide a better understanding of the influence of polymer cross- linking reactions at the air-water interface on the polymer mixing properties. ̶ ̶ ̶ ̶ ̶̶̶ ̶ ̶ ̶̶̶̶ ̶ ̶ ̶̶̶̶ ̶ ̶ ̶̶̶̶ ̶ ̶̶̶̶ ̶ ̶ ̶ ̶̶̶̶ ̶ ̶̶̶̶ ̶ ̶ ̶ ̶ ̶̶̶̶ ̶ ̶̶̶̶ ̶ ̶ ̶ ̶ ̶̶̶̶ ̶ ̶̶̶̶ ̶ ̶ ̶ ̶ The theoretical part is being carried out by a PhD student currently in the 1st year of his thesis at the LPPI. References : 1 Michalek, L; Bialas, S.; Walden, S.L.; Bloesser, F.R.; Frisch, H.; Barner-Kowollik, C. Adv. Funct. Mater. 2020, 30, 2005328. 2 Wu, X.; He, G.; Yan, X.; Li, X.; Xiao, W.; Jiang, X. in “Micro- and Nano-structured Interpenetrating Polymer Networks: From Design to Applications” Eds:Wiley & Sons, 29-68 (2016). 3 Vaillard, A.-S.; El Haitami, A.; Dreier, L. B.; Backus, E. H. G.; Cantin, S. Langmuir 2020, 36, 862–871. 4 Haroun, F.; El Haitami, A.; Ober, P.; Backus, E. H. G.; Cantin, S. Langmuir 2020, 36, 9142-9152. 5 El Haitami, A. ; Goldmann, M.; Cousin, F.; Dosseh, G.; Cantin, S. Langmuir 2015, 31, 6395–6403. 6 Vaillard, A.-S.; Haitami, A. E.; Dreier, L. B.; Fontaine, P.; Cousin, F.; Gutfreund, P.; Goldmann, M.; Backus, E. H. G.; Cantin, S. Langmuir 2022, 38, 2538 – 2549.

Contract start date : 1st September or 1st October 2023. Supervisors: Sophie CANTIN (LPPI, CY Cergy Paris University); Alae EL HAITAMI (LPPI, CY Cergy Paris University) ; Ellen BACKUS (University of Vienna). Candidate profile : Engineering degree or a Master 2 in physics and/or chemistry. Experience in the field of polymer materials would be appreciated. A good level of English is necessary. Contact person : Mr. Alae EL HAITAMI, e-mail : [email protected] Documents to be sent: 1) CV, 2) letter of interest, 3) M1 and M2 transcripts (or equivalent levels), 4) reference of the M2 internship supervisor, 5) proof of English level.

Requirements

Research Field

Chemistry » Physical chemistry

Education Level

Master Degree or equivalent

Additional Information Work Location(s)

Number of offers available

1

Company/Institute

Laboratoire de Physicochimie des Polymères et des Interfaces (LPPI)

Country

France

State/Province

Val d'oise

City

Neuville sur Oise

Postal Code

95000

Street

LPPI CY University

Where to apply

E-mail

[email protected]

Contact

State/Province

Ile de france

City

Cergy-Pontoise Cedex

Website

https:// www. cyu.fr

Street

33 Boulevard du Port

Postal Code

95011

E-Mail

[email protected]

Phone

0134257058

STATUS: EXPIRED