Preparation of non-aqueous Pickering emulsions using anisotropic block copolymer nanoparticles

Article English OPEN
Rizzelli, S.L. ; Jones, E.R. ; Thompson, K.L. ; Armes, S.P. (2015)
  • Publisher: Springer Verlag

In this work, we show that amphiphilic diblock copolymer worms prepared via alcoholic RAFT dispersion polymerization can be used to stabilize non-aqueous Pickering emulsions. A previously reported synthesis protocol based on polymerization-induced self-assembly (PISA) was modified to enable the preparation of poly(2-(dimethylamino)ethyl methacrylate)-poly(benzyl methacrylate) (PDMA-PBzMA) worm-like particles directly in methanol at relatively high solids. A dilute dispersion of these highly anisotropic nanoparticles was then homogenized with sunflower oil to produce sunflower oil-in-methanol emulsions. The mean droplet diameter ranged from 9 to 104 μm, depending on the nanoparticle concentration and the stirring rate used for homogenization. The sunflower oil content was increased systematically, with stable emulsions being obtained up to a volume fraction of 0.60. In all cases, the sunflower oil droplets gradually increase in size on ageing for up to 4 days. However, stable emulsions were obtained after this time period, with no further change in the mean droplet diameter for at least 2 months on standing at ambient temperature. Turbidimetry studies of the continuous phase after sedimentation of the relatively dense emulsion droplets indicated that the initial adsorption efficiency of the PDMA-PBzMA worms is very high, but this is reduced significantly as the droplet diameter gradually increases during ageing. There is a concomitant increase in fractional surface coverage over the same time period, suggesting that the increase in droplet diameter is the result of limited coalescence, rather than an Ostwald ripening mechanism.
  • References (109)
    109 references, page 1 of 11

    2. Pickering SU (1907) Emulsions. J Chem Soc 91:2001-2021.

    doi:10.1039/ct9079102001 4. Binks BP, Lumsdon SO (1999) Stability of oil-in-water emulsions stabilised by silica particles. PCCP 1 (12):3007-3016.

    35 doi:10.1039/a902209k

    5. Binks BP, Lumsdon SO (2000) Effects of oil type and aqueous phase

    hydrophobicity. PCCP 2 (13):2959-2967. doi:10.1039/b002582h 6. Binks BP, Whitby CP (2004) Silica particle-stabilized emulsions of

    40 silicone oil and water: Aspects of emulsification. Langmuir 20 (4):1130- 1137. doi:10.1021/la0303557 7. Gautier F, Destribats M, Perrier-Cornet R, Dechezelles JF, Giermanska J, Heroguez V, Ravaine S, Leal-Calderon F, Schmitt V (2007) Pickering emulsions with stimulable particles: from highly- to weakly-covered

    45 interfaces. PCCP 9 (48):6455-6462. doi:10.1039/b710226g

    8. Lagaly G, Reese M, Abend S (1999) Smectites as colloidal stabilizers

    and nonionic surfactants. Appl Clay Sci 14 (1-3):83-103.


  • Metrics
    views in OpenAIRE
    views in local repository
    downloads in local repository

    The information is available from the following content providers:

    From Number Of Views Number Of Downloads
    White Rose Research Online - IRUS-UK 0 124
Share - Bookmark