Abstract
Coalescence of oil droplets in an oil-in-water (O/W) emulsion was achieved with heating and optical trapping. Three types of O/W emulsions were prepared by adding a mixture of butanol and n-decane to an aqueous solution containing a cationic surfactant (cetyltrimethylammonium bromide, CTAB), an anionic surfactant (sodium dodecyl sulfate, SDS), or a neutral hydrophilic polymer (polyethylene glycol, PEG) as an emulsifier. Two oil droplets in the emulsions were randomly trapped in a square capillary tube by two laser beams in order to induce coalescence. Coalescence of the droplets could not be achieved at room temperature (25°C) regardless of the type of emulsifier. Conversely, the droplets prepared with PEG coalesced at a temperature higher than 30°C, although the droplets with ionic surfactants CTAB and SDS did not coalesce even at the elevated temperature due to their electrostatic repulsion. The size of the resultant coalesced droplet was consistent with that calculated from the size of the two droplets of oil, which indicated successful coalescence of the two droplets. We also found that the time required for the coalescence could be correlated with the temperature using an Arrhenius plot.
| Original language | English |
|---|---|
| Pages (from-to) | 709-713 |
| Number of pages | 5 |
| Journal | Analytical Sciences |
| Volume | 33 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 2017 |
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Keywords
- Coalescence
- Droplet
- Emulsion
- Laser
- Optical trapping
ASJC Scopus subject areas
- Analytical Chemistry
Cite this
Temperature-induced coalescence of droplets manipulated by optical trapping in an oil-in-water emulsion. / Mitsunobu, Manami; Kobayashi, Sakurako; Takeyasu, Nobuyuki; Kaneta, Takashi.
In: Analytical Sciences, Vol. 33, No. 6, 2017, p. 709-713.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Temperature-induced coalescence of droplets manipulated by optical trapping in an oil-in-water emulsion
AU - Mitsunobu, Manami
AU - Kobayashi, Sakurako
AU - Takeyasu, Nobuyuki
AU - Kaneta, Takashi
PY - 2017
Y1 - 2017
N2 - Coalescence of oil droplets in an oil-in-water (O/W) emulsion was achieved with heating and optical trapping. Three types of O/W emulsions were prepared by adding a mixture of butanol and n-decane to an aqueous solution containing a cationic surfactant (cetyltrimethylammonium bromide, CTAB), an anionic surfactant (sodium dodecyl sulfate, SDS), or a neutral hydrophilic polymer (polyethylene glycol, PEG) as an emulsifier. Two oil droplets in the emulsions were randomly trapped in a square capillary tube by two laser beams in order to induce coalescence. Coalescence of the droplets could not be achieved at room temperature (25°C) regardless of the type of emulsifier. Conversely, the droplets prepared with PEG coalesced at a temperature higher than 30°C, although the droplets with ionic surfactants CTAB and SDS did not coalesce even at the elevated temperature due to their electrostatic repulsion. The size of the resultant coalesced droplet was consistent with that calculated from the size of the two droplets of oil, which indicated successful coalescence of the two droplets. We also found that the time required for the coalescence could be correlated with the temperature using an Arrhenius plot.
AB - Coalescence of oil droplets in an oil-in-water (O/W) emulsion was achieved with heating and optical trapping. Three types of O/W emulsions were prepared by adding a mixture of butanol and n-decane to an aqueous solution containing a cationic surfactant (cetyltrimethylammonium bromide, CTAB), an anionic surfactant (sodium dodecyl sulfate, SDS), or a neutral hydrophilic polymer (polyethylene glycol, PEG) as an emulsifier. Two oil droplets in the emulsions were randomly trapped in a square capillary tube by two laser beams in order to induce coalescence. Coalescence of the droplets could not be achieved at room temperature (25°C) regardless of the type of emulsifier. Conversely, the droplets prepared with PEG coalesced at a temperature higher than 30°C, although the droplets with ionic surfactants CTAB and SDS did not coalesce even at the elevated temperature due to their electrostatic repulsion. The size of the resultant coalesced droplet was consistent with that calculated from the size of the two droplets of oil, which indicated successful coalescence of the two droplets. We also found that the time required for the coalescence could be correlated with the temperature using an Arrhenius plot.
KW - Coalescence
KW - Droplet
KW - Emulsion
KW - Laser
KW - Optical trapping
UR - http://www.scopus.com/inward/record.url?scp=85020443878&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85020443878&partnerID=8YFLogxK
U2 - 10.2116/analsci.33.709
DO - 10.2116/analsci.33.709
M3 - Article
VL - 33
SP - 709
EP - 713
JO - Analytical Sciences
JF - Analytical Sciences
SN - 0910-6340
IS - 6
ER -