Nanoparticle stabilized oil in water emulsions: A critical review

Novel Oil‐in‐Water Emulsions Stabilised by Ionic Surfactant and Similarly Charged Nanoparticles at Very Low Concentrations

“…[19] Although the monolayer of ionic surfactant at the oil-water interface is far from saturated at such low concentrations,i te ndows droplets with charge resulting in electrostatic repulsion between droplets and between droplets and particles preventing drop flocculation. [19] Although the monolayer of ionic surfactant at the oil-water interface is far from saturated at such low concentrations,i te ndows droplets with charge resulting in electrostatic repulsion between droplets and between droplets and particles preventing drop flocculation.…”

“…[18] Some of these particle types are switchable between being surfaceactive and surface-inactive using stimuli such as pH, temperature and CO 2 /N 2 addition. Arab et al have just given areview on this topic, [19] and up to now systems involving ionic surfactants and oppositely charged inorganic particles have been widely studied, [19][20][21][22][23][24][25][26][27][28] in which hydrophilic particles like silica, [19,21,23,24] laponite, [20] or calcium carbonate [15,22] can be made surface-active by adsorbing oppositely charged ionic surfactant so as to stabilize aP ickering emulsion. Arab et al have just given areview on this topic, [19] and up to now systems involving ionic surfactants and oppositely charged inorganic particles have been widely studied, [19][20][21][22][23][24][25][26][27][28] in which hydrophilic particles like silica, [19,21,23,24] laponite, [20] or calcium carbonate [15,22] can be made surface-active by adsorbing oppositely charged ionic surfactant so as to stabilize aP ickering emulsion.…”

“…Depending on the type and adsorbed amount of surfactant, the Pickering emulsions can undergo as ingle or double phase inversion [15,22,23] and even be made switchable [25] or stimuli-responsive. [19,[30][31][32] Herein we report for the first time novel O/W emulsions which can be stabilised by ac ationic surfactant (cetyltrimethyl ammonium bromide,C TAB) in combination with positively charged alumina nanoparticles at extremely low concentration (ca. [19,[30][31][32] Herein we report for the first time novel O/W emulsions which can be stabilised by ac ationic surfactant (cetyltrimethyl ammonium bromide,C TAB) in combination with positively charged alumina nanoparticles at extremely low concentration (ca.…”

“…[18] Aq uestion which arises is what will happen when surfactant molecules meet particles in an emulsion system? Arab et al have just given areview on this topic, [19] and up to now systems involving ionic surfactants and oppositely charged inorganic particles have been widely studied, [19][20][21][22][23][24][25][26][27][28] in which hydrophilic particles like silica, [19,21,23,24] laponite, [20] or calcium carbonate [15,22] can be made surface-active by adsorbing oppositely charged ionic surfactant so as to stabilize aP ickering emulsion. Depending on the type and adsorbed amount of surfactant, the Pickering emulsions can undergo as ingle or double phase inversion [15,22,23] and even be made switchable [25] or stimuli-responsive.…”

“…[26][27][28][29] On the other hand, emulsion systems involving similarly charged ionic surfactant and particles are much less studied. [19,[30][31][32] Herein we report for the first time novel O/W emulsions which can be stabilised by ac ationic surfactant (cetyltrimethyl ammonium bromide,C TAB) in combination with positively charged alumina nanoparticles at extremely low concentration (ca. 0.001 cmc and 0.0001 wt %, respectively).…”