Morphology control of biphasic silica/polystyrene nanoparticles: Towards colloidal molecules

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University of Science and Technology of Bordeaux, France G FUNCTIONALIZED MATERIALS

1 Morphology control of biphasic silica/polystyrene nanoparticles: Towards colloidal molecules Prof Etienne DUGUET Bordeaux Institute of Condensed Matter Chemistry/CNRS University of Science and Technology of Bordeaux, France G FUNCTIONALIZED MATERIALS GROUP F l u o r i n e, H y b r i d M a t e r i a l s a n d N a n o p a r t i c l e s

2 Colloids: Towards higher complexity and functionality Colloidal stability Size Size-polydispersity Chemical composition Surface groups Morphology spherical colloids can be treated as if they were atoms and molecules form more complex materials than do atoms Self-assembly Linkability Colloidal Molecules H H H H Van Blaaderen, Science , 470

3 Template-directed self-assembly route 2 µm ~ 30 µm Combined effect of geometrical confinement and attractive capillary forces 2 µm Yin and Xia, Adv. Mater , 267 Yin, Lu and Xia, J. Am. Chem. Soc , µm

µm PMMA Manoharan, Elsesser and Pine, Science, 2003 301,

4 Emulsion-confined self-assembly route surfacecharged PS particles toluene droplet water PS silica scale bar : 1 µm PMMA Manoharan, Elsesser and Pine, Science, , 483 Pine and coll., Adv. Mater , 1204 scale bar : 1 µm

5 Our route based on the controlled surface nucleation of PS latex particles onto silica seeds

6 Emulsion polymerization background

7 Styrene emulsion polymerization Our polymerizing system Monomer : styrene Surfactant : NP30 H 19 C 9 O CH 2 CH 2 OH n ~ 30 n CMC = 0.15 g.l -1 Initiator : Na 2 S 2 O 8 S 2 O SO - 4

8 Styrene emulsion polymerization 90% 300 experimental [styrene] = 100 g/l [NP30] = 20*CMC [Na 2 S 2 O 8 ] = 0.5 g/l T = 70 C 80% 70% % 200 monomer conversion 50% 40% 150 average diameter of latex nm 30% % 10% 50 0% time min

9 Styrene emulsion polymerization 16 experimental [styrene] = 100 g/l [NP30] = 20*CMC [Na 2 S 2 O 8 ] = 0.5 g/l T = 70 C latex number L time min

Styrene emulsion polymerization 15 What happens in the

maximal conversion experimental [styrene] = 100 g/l

5 g/l T = 70 C [bare silica] = 5 g/l 10 5 0 450 nm 127

10 Styrene emulsion polymerization 15 What happens in the presence of Stöber silica latex number L -1 at maximal conversion experimental [styrene] = 100 g/l [NP30] = 20*CMC [Na 2 S 2 O 8 ] = 0.5 g/l T = 70 C [bare silica] = 5 g/l nm 127 nm 50 nm silica diameter nm time : 120 min conversion ~20 % scale bar : 200 nm

11 Styrene seeded-emulsion polymerization Macromonomer pre-adsorption onto Stöber silica O H O 3 C O CH 2 CH 2 CH 3 n ~ 23 CH 2 n experimental [styrene] = 100 g/l [NP30] = 20*CMC [Na 2 S 2 O 8 ] = 0.5 g/l T = 70 C 500-nm silica [silica] = 10 g/l [macrom.] = 0.1 g/l conversion ~30 % + free latex 500 nm SEM 500 nm TEM raspberry-like silica/ps particles Duguet and coll, Chem. Mater , 2354

Styrene seeded-emulsion polymerization Influence of

1 g/l 30 min 60 min 120 min scale bar : 100 nm N Si /N

12 Styrene seeded-emulsion polymerization Influence of silica concentration N Si /N PS = 1 silica 64 nm [silica] = 4.6 g/l experimental [styrene] = 100 g/l [NP30] = 20*CMC [Na 2 S 2 O 8 ] = 0.5 g/l T = 70 C [macrom.] = 0.1 g/l 30 min 60 min 120 min scale bar : 100 nm N Si /N PS = 1/2 silica 93 nm [silica] = 7.5 g/l 120 min scale bar : 200 nm N Si /N PS = 1/6 silica 127 nm [silica] = 4.8 g/l 30 min 60 min scale bar : 500 nm

13 Styrene seeded-emulsion polymerization experimental idem Influence of silica size (N Si < N PS ) silica 42 nm [silica] = 0.2 g/l 120 min silica 64 nm [silica] = 0.5 g/l 120 min 3 silica 85 nm [silica] = 1.2 g/l 90 min 4 silica 127 nm [silica] = 3.2 g/l 60 min 6

14 Styrene seeded-emulsion polymerization experimental idem Influence of silica size (N Si < N PS ) silica 127 nm [silica] = 3.2 g/l 60 min 6 silica 170 nm [silica] = 4.7 g/l 25 min 8 silica 212 nm [silica] = 4.7 g/l 20 min 10

2 g/l 60 min 6 silica 170 nm [silica] = 4.

15 Styrene seeded-emulsion polymerization experimental idem Influence of conversion (N Si < N PS ) 120 min silica 127 nm [silica] = 3.2 g/l 60 min 6 silica 170 nm [silica] = 4.7 g/l 25 min 8 silica 212 nm [silica] = 4.7 g/l 20 min 10 Are our colloids really planar?

16 Styrene seeded-emulsion polymerization Electronic tomography in dried state 120 min silica 170 nm [silica] = 4.7 g/l 25 min 8 3D-reconstruction

17 Styrene seeded-emulsion polymerization Electronic tomography in dried state 120 min silica 170 nm [silica] = 4.7 g/l 25 min 8 Falling-in mechanism TEM grid

Styrene seeded-emulsion polymerization Silane surface

methacryloxymethyltriethoxysilane (MMS) CH 2 OC 2 H 5

[styrene] = 100 g/l [NP30] = 20*CMC [Na 2 S 2 O 8 ] = 0.

18 Styrene seeded-emulsion polymerization Silane surface treatment of Stöber silica OC 2 H 5 O C H 3 O CH 2 Si OC 2 H 5 methacryloxymethyltriethoxysilane (MMS) CH 2 OC 2 H 5 Silane-saturated surface 50 nm 127 nm 450 nm experimental [styrene] = 100 g/l [NP30] = 20*CMC [Na 2 S 2 O 8 ] = 0.5 g/l T = 70 C [silica] = 10 g/l [silane] = 16.6 µmol/m 2 conversion ~20 % scale bar : 200 nm

19 Styrene seeded-emulsion polymerization Silane unsaturated surface experimental [styrene] = 100 g/l [NP30] = 20*CMC [Na 2 S 2 O 8 ] = 0.5 g/l T = 70 C 85 nm 1.2 g/l 106 nm 2.0 g/l 127 nm 3.2 g/l 170 nm 4.7 g/l 255 nm 4.7 g/l [silica] = 10 g/l [silane] = 1.66 µmol/m 2 conversion ~20 % 120 min scale bar : 200 nm

20 Styrene seeded-emulsion polymerization Cryo-TEM / tomography experiments 127 nm 3.2 g/l 120 min Regular polyhedron

21 Summary H H H H F B F F Cl Be Cl H F H O H Currently in progress High yields of regular morphologies Large scale production of planar morphologies Complete bestiary of molecules made of a single central atom Study of interactions and packing

22 Acknowledgements Adeline Perro, Stéphane Reculusa and David Nguyen Serge Ravaine (CRPP/Bordeaux) Elodie Bourgeat-Lami (LCPP/Villeurbanne) Olivier Lambert and Jean-Christophe Taveau (IECB/Bordeaux) Elisabeth Sellier and Michel Martineau (CREMEN/Bordeaux)

24 Styrene seeded-emulsion polymerization Electronic tomography background acquisition of tilt series from -60 to +60 every 2 3D-reconstruction from these projections Cartoon J.C. Taveau

Self-Assembly of Polyhedral Hybrid Colloidal Particles

Mater. Res. Soc. Symp. Proc. Vol. 1135 2009 Materials Research Society 1135-CC06-08 Self-Assembly of Polyhedral Hybrid Colloidal Particles Adeline Perro 1, Etienne Duguet 3, Serge Ravaine 4 and Vinothan