Dioxyethene fragment
(−(OCH2CH2)2−) was
introduced into traditional alkyl β-d-glucopyranosides
to ameliorate the water solubility, and eight
nonionic surfactants, that is, alkoxy ethoxyethyl β-d-glucopyranosides with alkyl chain lengths (n =
6–16), were synthesized and characterized. Their hydrophilic
and lipophilic balance number, water solubility, critical micelle
concentration (cmc), γcmc, Γmax,
and hygroscopic rate decreased with an increase in the alkyl chain
length. Hexadecoxy ethoxyethyl β-d-glucopyranoside
had no water solubility at 25 °C. Decoxy ethoxyethyl β-d-glucopyranoside had the best emulsifying property in the toluene/water
and n-octane/water systems and the strongest foaming
property, whereas dodecoxy ethoxyethyl β-d-glucopyranoside
had the best emulsifying property in the rapeseed oil/water system.
Such β-d-glucopyranosides (n = 6–12)
exhibited excellent surface activity. In addition, for the binary
mixture of alkoxy ethoxyethyl β-d-glucopyranosides
(n = 8, 10, 12) and sodium dodecyl sulfate or cetyl
trimethyl ammonium chloride, their cmc values were lower than the
pure β-d-glucopyranosides, indicating that they had
synergistic interactions. The fan focal conic textures of alkoxy ethoxyethyl
β-d-glucopyranosides (n = 7–16)
were observed during the cooling process under a polarizing optical
microscope. Alkoxy ethoxyethyl β-d-glucopyranosides
(n = 14, 16) had the related melting points and the
clear points with differential scanning calorimetry. With β-d-glucopyranosides (n = 6–16) and n-butanol as the surfactant and cosurfactant, respectively,
and with cyclohexane as the oil phase, the related microemulsion areas
in their pseudoternary phase diagram system were investigated with
the visual observation at 25 °C. Along with the slashing requirements
of petroleum consumption, environmental protection, and green and
sustainable development, nonionic sugar-based alkoxy ethoxyethyl β-d-glucopyranosides should be expected to have their potential
practical application because of their strengthened hydrophilicity,
improved water solubility, and enhanced surface activity.