LPPI

Postdoc : TiO2 macrostructuresurface for microfluidic applications

two-year postdoctoral position

A two-year postdoctoral position is opening at the Physicochemical Laboratory of Polymers and Interfaces (LPPI) of the University Paris-Seine (Cergy-Pontoise)

Context

Microfluidics is now emerging as one of the most dynamic emerging areas in the world of biotechnology and the field of analytical sciences. Microfluidics is defined as the fluid manipulation atsmall scale. The objective of this study is to develop new microfluidic materials based on the use of light. Indeed, it has been shown that it is possible to move a drop with the help of light. To induce this displacement, it is necessary that one end of the droplet is on a hydrophobic surface and the other end is ona hydrophilic surface. In this case, the drop will slip from the hydrophobic surface to the hydrophilic surface. We have developed a hybrid material based an inorganic substrate and a photosensitive organic surface. These new materials have surface properties that can be modulated using light irradiation. That is, the surface of these materials can pass superhydrophobicto superhydrophilic after 2 minutes of UV irradiation. The performances of these new materials are superior to those encountered in the literature. Indeed, our materials present an excellent compromise between the large modulation of surface angle and switching times. Nevertheless, in order to exalt wetting modulation, we favouredthe rough substrates. Except the roughness of these substrates limits the sliding of the drops. Indeed the liquid remains anchored in the asperities of the material. In this study, we proposed to develop new inorganic matrices with a morphology favouringthe sliding of liquids. We want to develop new macrostructuredsurfaces to obtain a model of Cassie-Baxter with water while current surfaces present a model of Wenzel. Macrostructured substrates based on TiO2 are already used in the field of photocatalysisfor example. Syntheses, in particular by sol-gel, are perfectly described and transposable to our hybrid systems.

Candidate tasks

The candidate will be in charge of developing macrostructured matrices based on TiO2 (other oxides may be tested). These new matrices will be characterized by scanning electron microscopy, atomic force microscopy and contact angle measurements. The candidate will then associate these matrices with an azoïc compound to test hybrid photosensitive systems. The wetting properties before and after irradiation will be determined. The measurement of the advancing and receding angles will also be made to predict the drop movement.

The candidate will collaborate with a PhD student synthesizing new photosensitives organics molecules.

Candidate Profile

  • Education: PhD in Chemistry or materialscience
  • Competencies:
  • Relevant research experience and demonstrated competencies in inorganics material (synthesis and microscopy characterisation). Experience on macrostructuredoxide would be an asset.
  • Track record of researcher dissemination including peer-reviewed publications
  • Ready to work according to best chemical laboratory practices including lab safety.
  • Excellent projectmanagement, analytical, and report writing skills.
  • Excellent communication skills (oral, written, presentation).
  • Demonstrated ability to generate new ideas, concepts, models and solutions.
  • Collaborative skills, initiative, result oriented, organization, and capacity to work in an interdisciplinary environment.
  • Language: French and/or English

Contact:

Xavier SALLENAVE: (xavier.sallenave@u-cergy.fr)

Sébastien PERALTA: (sebastien.peralta@u-cergy.fr)

Locate:

Physicochemical Laboratory of Polymers and Interfaces (LPPI) of the University Paris-Seine, (Cergy-Pontoise). 

Partager :