Ee. Meyer et al., Complexation kinetics of cyclodextrin with hydrophobic molecules confined in an isolated droplet in water, LANGMUIR, 16(13), 2000, pp. 5519-5522
Inclusion complexation kinetics of methyl-beta-cyclodextrin (m-beta-CD) to
hydrophobic molecules confined in an isolated droplet was investigated with
optical tweezers. The radius of the droplet shrank over time as m-beta-CD
was introduced into the sample chamber due to complexation between the hydr
ophobic molecules and the m-beta-CD molecules. The short time behavior of t
he droplet shrinkage can be described by a model based on Brownian kinetics
. The probability of complexation was greater for a branched 2-hexadecanol
than for hexadecane. The probability decreased with increasing chain length
for short alkanes. The long time behavior of the droplet shrinkage is surp
rising because the droplets stopped shrinking even when the uncomplexed m-b
eta-CD concentration was still high. We speculate that surface activities o
f m-beta-CD might have slowed the reaction.