Preparation of Pickering emulsions and colloidosomes using either a glycerol-functionalised silica sol or core–shell polymer/silica nanocomposite particles

Abstract

Article:Fielding, L.A. and Armes, S.P. (2012) Preparation of Pickering emulsions and colloidosomes using either a glycerol-functionalised silica sol or core-shell polymer/silica nanocomposite particles. Journal of Materials Chemistry,22 (22). 11235 -11244. ISSN 0959-9428 https://doi.org/10.1039/c2jm31433a eprints@whiterose.ac.uk https://eprints.whiterose.ac.uk/ Reuse Unless indicated otherwise, fulltext items are protected by copyright with all rights reserved. The copyright exception in section 29 of the Copyright, Designs and Patents Act 1988 allows the making of a single copy solely for the purpose of non-commercial research or private study within the limits of fair dealing. The publisher or other rights-holder may allow further reproduction and re-use of this version -refer to the White Rose Research Online record for this item. Where records identify the publisher as the copyright holder, users can verify any specific terms of use on the publisher's website. TakedownIf you consider content in White Rose Research Online to be in breach of UK law, please notify us by emailing eprints@whiterose.ac.uk including the URL of the record and the reason for the withdrawal request. form stable Pickering emulsions and also covalently cross-linked colloidosomes. Colloidal core-shell polymer/silica nanocomposite particles produced using this glycerol-functionalised silica were also used to produce both Pickering emulsions and colloidosomes containing hybrid shells comprising both inorganic and organic components. The formation of stable oil-in-water Pickering emulsions required either low pH or the addition of electrolyte: this is rationalised in terms of the highly anionic surface 10 character of the silica particles. Colloidosomes are readily obtained on addition of a polymeric diisocyanate, which reacts with the surface glycerol groups on the silica particles. This oil-soluble crosslinker is confined to the interior of the emulsion droplets, thus avoiding inter-colloidosome aggregation. The oil phase can be removed from the colloidosomes by washing with excess alcohol, resulting in microcapsules comprising either a 19 nm particulate silica shell or a 240 nm polymer/silica shell. These 15 microcapsules can be imaged by optical microscopy in solution and by scanning electron microscopy in the dry state. The permeability of these colloidosomes with respect to small molecule release was also examined by incorporating an oil-soluble fluorescent dye during homogenisation that becomes watersoluble on raising the solution pH of the aqueous continuous phase. Finally, control experiments performed with a non-functionalised silica sol confirmed that Pickering emulsions cannot be converted 20 into colloidosomes due to the absence of surface glycerol groups.

Photoresponsive Hybrid Raspberry‐Like Colloids Based on Cucurbit[8]uril Host–Guest Interactions

“…[1][2][3][4] In particular, hybrid raspberry-like colloids (HRCs), which contain both organic and inorganic components and exhibit an hierarchical structure of a larger core particle decorated with smaller corona particles, have attracted great attention. [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] On account of their hybrid composition and unique morphology, HRCs have potential applications in many areas such as superhydrophobic surfaces, [7,8] optics, [9] and compartmentalized catalysis. [10] Generally, HRCs are prepared by coagulating corona particles onto the in situ prepared core particles.…”

Chapter 8. Multiple Pickering Emulsions for Functional Materials

“…[108][109][110][111][112][113][114][115][116][117][118][119][120][121][122][123][124] A hallmark of colloidosomes is their robust structure, as their building blocks are solid particles, which endow them with enhanced mechanical strength against coalescence. Another advantage associated with colloidosomes is that the permeability can be adjusted by changing the size of the particles.…”

Electrostatic Assembly/Disassembly of Nanoscaled Colloidosomes for Light‐Triggered Cargo Release

“…[9,28,29] First, the synthesis of stable colloidosomes requires the additional crosslinking or "irreversible locking" of the NP building blocks forming the shell to ensure the stability of the structure during solvent transfer and drying steps,a sw ell as further applications. [34] Layered polyelectrolytes were also prepared to stabilize the nanobuilding blocks. [12,17] Silica NPs were crosslinked by additional condensation of as ilica layer to stabilize the colloidosomes.…”

“…[24,32,33] AG lycerol functionalization was used to covalently crosslink silica colloidosomes. [34] Layered polyelectrolytes were also prepared to stabilize the nanobuilding blocks. [1,35,36] Subsequently to silica crosslinking, ap H-responsive copolymer polyelectrolyte was covalently linked to hundred micrometer-large silica colloidosomes to vary the extent of the permeation of dye cargos.…”