Stimulus-responsive emulsifiers based on nanocomposite microgel particles

Advanced Materials

Volumn 17, Issue 8, 2005, Pages 1014-1018

  Fujii, Svuji ^a   Read, Elizabeth S ^a   Binks, Bernard P ^b   Armes, Steven P ^a  

^a UNIVERSITY OF SHEFFIELD   (United Kingdom)

^b UNIVERSITY OF HULL   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

CROSSLINKING; DISPERSIONS; EMULSIFICATION; HYDROCHLORIC ACID; NANOSTRUCTURED MATERIALS; POLYETHYLENE GLYCOLS; SOLUTIONS; SURFACE ACTIVE AGENTS; SYNTHESIS (CHEMICAL); TRANSMISSION ELECTRON MICROSCOPY;

HIGH-RESOLUTION TRANSMISSION ELECTRON MICROSCOPY; NANOCOMPOSITE MICROGELS; PROTONATION; STIMULUS-RESPONSIVE EMULSIFIERS;

SILICA GEL;

EID: 17844373528     PISSN: 09359648     EISSN: None     Source Type: Journal    
DOI: 10.1002/adma.200401641     Document Type: Article

References (17)

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14. a of around pH 4.5 for the poly(4-vinylpyridine) homopolymer.
15. 2 nanocomposite particles as an emulsifier. Dissolution at low pH causes a significant increase in solution viscosity, which is detrimental to efficient macroscopic phase separation. Thus a low degree of crosslinking leads to a significant enhancement in demulsification efficiency.
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17. In the work of Amalvy et al. [6,7] and Read et al. [8], the sterically stabilized polystyrene latex actually only acts as a pH-dependent, rather than a pH-responsive paniculate emulsifier. The pH of the initial solution dictates whether or not a stable emulsion is obtained. However, once the latex particles are actually adsorbed at the oil-water interface, desorption cannot be achieved by simply switching the solution pH. This is contrary to some of the discussion in these earlier papers and the true situation has only become clear to us very recently. We have published a correction to previous work [8] in Langmuir to clarify this important distinction (E. S. Read, S. Fujii, J. I. Almavy, D. P. Randall, S. P. Armes, Langmuir 2005, 21, 1662). Thus these nanocomposite microgels are the first example of a genuinely pH-responsive particulate emulsifier.