Hydrogen Bonding in Colloidal Polymer Materials 5 4 10 3 5 µm 2 0 nm -5 1-10 0 0 1 2 µm 3 4 5 Nicholas Ballard Bon Polymer Colloids Group UK PharmSci 2012
Background chemistry Outline Synthesis of monodisperse colloidal particles containing quardruple hydrogen bonding functionality Supracolloidal polymer film formation Pickering high internal phase emulsions (HIPEs) stabilized by colloidal particles Non covalently crosslinked microgels Summary
Hydrogen bonding in polymers Self-healing Rubber Nylon 66 Cordier, P. et al. Nature 2008, 451, 977
2-ureido-4[1H]-pyridiminone (UPy) Association constant K a = 6 10 7 M -1 AADD DDAA Liquid Poly(ethylene/butylene) Solid rubber product Non-covalent reversible crosslinked network Folmer, B. J. B et al. Adv. Mater. 2000, 12, 874-878 De Greef, T. F. A. et al. Nature 2008, 453, 171-173
Monodisperse colloidal particles containing quardruple hydrogen bonding functionality Hydrophilic Hydrophobic Chen, Y.; Jones, S. T.; Hancox, I.; Beanland, R.; Tunnah, E. J.; Bon, S. A. F. ACS Macro Letters 2012, 1, 603-608.
Emulsion polymerisation PEGMA-UPy Macromonomer (1.5 mol%) + MMA (44wt%) BA(56wt%) PMMA-PBA-PUPy particles D: 330 nm, PDI: 0.007 PMMA-PBA particles D: 378 nm, PDI: 0.02
Colloidal polymer film formation Water evaporation Substrate 1 Substrate 2 Particle deformation Polymer film Substrate 3 Polymer interdiffusion Substrate
Supracolloidal polymer film formation
Upy at 1.5mol% causes increase in Tg of 30 C
AFM Indentation Interaction between UPy reinforced polymer film and atomic force microscope (AFM) tip to measure the Young s modulus. (a) schematic representation of an AFM tip indenting into the top layer of polymer film; (b) indentation locations on the polymer film top surface region by AFM tip(red dots); (c) indention depth curves against the deflection of AFM tip; (d) indention depth curves for reference PMMA-PBA film.
Polymer films comparison
Supracolloidal Polymer film in acetone
Supracolloidal polymer film Pattern Chen, Y.; Jones, S. T.; Hancox, I.; Beanland, R.; Tunnah, E. J.; Bon, S. A. F. ACS Macro Letters 2012, 1, 603-608.
Supracolloidal polymer film after acetone treatment
PMMA-PBA polymer film without hydrogen bonding groups
Background chemistry Outline Synthesis of monodisperse colloidal particles containing quardruple hydrogen bonding functionality Supracolloidal polymer film formation Pickering high internal phase emulsions (HIPEs) stabilized by colloidal particles Non covalently crosslinked microgels Summary
Pickering Emulsion droplet Water Polymerise the continuous phase Oil Particles Purified and drying Porous Polymer Materials
Pickering high internal phase emulsions (HIPEs) Chen, Y.; Ballard, N.; Gayet, F.; Bon, S. A. F. Chem. Comm. 2012, 48, 1117-1119.
HIPE Organo-gels Water-in-Oil
Particles Water droplets
SEM images of HIPE gels with internal phase volume fraction (80%) at different colloidal particle concentrations, (a) 0.1%, (b) 0.5%, (c) 1%, all scale bars: 20μm, and (d) 5%, scale bars: 2μm.
Release from HIPE organogels Chen, Y.; Ballard, N.; Gayet, F.; Bon, S. A. F. Chem. Comm. 2012, 48, 1117-1119.
Background chemistry Outline Synthesis of monodisperse colloidal particles containing quardruple hydrogen bonding functionality Supracolloidal polymer film formation Pickering high internal phase emulsions (HIPEs) stabilized by colloidal particles Non covalently crosslinked microgels Summary
Hydrogen bond crosslinked microgel Chen, Y.; Ballard, N.; Bon, S. A. F. Polymer Chemistry 2012, accepted
Incorporation of UPy into pnipam microgels NMR and UV/vis signal increases upon increasing PEG-Upy monomer content (3.3,6.4,9.4,12.3mol%) Chen, Y.; Ballard, N.; Bon, S. A. F. Polymer Chemistry 2012, accepted
Thermoresponsive behaviour of microgel particles Chen, Y.; Ballard, N.; Bon, S. A. F. Polymer Chemistry 2012, accepted
Disruption of H bonding with DMSO to induce microgel dissolution. UV-Vis spectra of (a) NGP4 nanogel aqueous dispersions in the presence of various amounts of DMSO, (b) dissolved NGP4 nanogel and UPy macromonomer 1 in DMSO; particle size distributions of (c) methylenebisacrylamide covalently crosslinked PNIPAm nanogels in water and water/dmso mixture, and (d) NGP4 nanogels in water and water/dmso mixture. Chen, Y.; Ballard, N.; Bon, S. A. F. Polymer Chemistry 2012, accepted
Core shell polystyrenepolynipam particles P(MEO 2 MA-OEGMA) microgels Chen, Y.; Ballard, N.; Bon, S. A. F. Polymer Chemistry 2012, accepted
Summary UPy quadruple hydrogen bonding group can be introduced into colloidal particles by emulsion polymerization Improved mechanical properties of polymer film Organic solvents resistance Bragg diffraction in solvents, especially in acetone Pickering HIPE-gel can be prepared Hydrogen bond crosslinked microgels can be synthesized
Acknowledgements Supervisor Dr. Stefan Bon Yunhua Chen Unilever Bon Group