International context: Materials play an increasingly important role in ...

Title of the thesis: Pillararenes based Multi-stimuli Responsive Macromolecular Assemblies
Team: Unité des Matériaux et Transformations, Equipe ISP, Groupe Pr P. Woisel
International context:
Materials play an increasingly important role in our everyday lives and therefore play an
essential role in every economic cycle. However, with the emergence of the world financial crisis
and also with the rapid development of low cost materials producers, there is increasing
emphasis by regional and national European policy on the need to foster growth in the areas of
smart advanced materials. It is expected that adding innovative functionality offers the best
opportunity for industry to compete with low priced imports, to improve the environment and
quality of life and also to provide wealth creation and commercial success. Thus, in this context,
it is clear that smart responsive polymeric materials, that have the capability to sense its
environment via several control mechanism(s), will undoubtedly play a critical role in this
development.
Challenges in the stimuli-­‐‐responsive polymer materials area
The development and application of multi-­‐‐stimuli responsive polymer materials is a burgeoning
field of study in leading research groups in the USA, Asia and mainland Europe (at present this
field is underrepresented in France). Such soft advanced materials are expected to revolutionize
nano-­‐‐science, engineering and technology and, therefore, they are key to many countries future
technological competitiveness. However, there is no doubt that the creation of such high
performance materials relies directly on our ability to manipulate these “smart” materials in a
controllable, predictable and orchestrated fashion at the molecular level. In this context, as
response to stimuli is ubiquitous in biological processes in living systems, Nature is evidently a
great source of inspiration for scientists. However, unlike most man-­‐‐made smart materials,
materials used in living systems are frequently dynamic, multi-­‐‐adaptative and are built using
'ʹbottom-­‐‐up'ʹ fabrication methods. Hence, creating “equivalent” synthetic polymer systems able to
respond to several environmental changes in a controllable and predictable fashion would be of
great interest, but yet represents a significant challenge. Moreover, despite the recent progress in
designing and synthesizing of well-­‐‐defined macromolecular architectures using precisely
controlled polymerization methods, imparting further complexity and functionality into polymer
architectures has numerous drawbacks using conventional covalent modification (multistep and
time consuming synthetic procedures). Thus, elaborating highly sophisticated polymers via the
orthogonal incorporation of non-­‐‐covalent interactions onto the constituent polymers is
particularly desirable toward advancing the goal of making these materials more functionally
complex and/or responsive. Furthermore, facile and reversible control over the relative motion of
the components is required for the development of polymer systems with bespoke properties and
applications.

Proposed program
During this thesis, the main challenge will be to engineer and study a new class of pillararenes
based polymer materials capable of responding to multiple external stimuli in aqueous media.
Recently, due to their highly symmetrical, rigid, and electron-­‐‐rich cavity, Pillar[n]arenes (n = 5, 6,
7) has indeed emerged as powerful host systems for the fabrication of pseudorotaxane
architectures with electron-­‐‐deficient guests (viologens, ammonium derivatives). Hence, in this
thesis, polymeric building blocks (mainly prepared by Controlled Radical Polymerisation, CRP)
incorporating Pillar[n]arene or viologens/ammoniums units will be orthogonally held together
through pseudorotaxane linkages, thereby offering materials with reversible and switchable
properties. To clarify, the research programme developed in this thesis will be mainly focused on
the creation of i) new multistimuli responsive nanosized self-­‐‐assembled architectures (micelles,
nanotubes and polymersomes) having multiresponsiveness properties (on demand drug release).
and ii) smart surfaces from well-­‐‐defined end functionalized polymer building blocks.
Administrative details:
-­‐‐ Starting date: 10/ 2013
-­‐‐ Required profile: Master 2 in organic/polymer chemistry. The PhD student should be a
polymer chemist with good knowledge in organic chemistry.
-­‐‐ Application: Candidates are encouraged to send by e-mail a motivation letter and a CV
to Pr Patrice Woisel, UMET, Lille, Patrice.woisel@ensc-­‐‐lille.fr, +333 20 43 49 54.
-­‐‐ Amount: around € 1600 monthly net