Evaluation of solvent property of air-water interface based on the fluorescence spectra of 1,2'-dinaphthylamine in the aqueous solution of ultrafine bubbles.

Solvent property of air-water interface was evaluated based on the fluorescence spectra of 1,2'-dinaphthylamine in water containing ultrafine bubbles (average diameter: 103 nm, standard deviation: 38 nm). Among naphthylamine derivatives whose fluorescence spectra were responsive to microscopic hydrophobicity, 1,2'-dinaphthylamine (DN) was selected because its wavelength of the maximum emission (λ) was significantly dependent on the concentration and microenvironment of the ultrafine bubble. The λ value of DN in water was 486 nm, while it shifted to shorter wavelength (408 nm) in the presence of 1.

Effect of air bubbles on the membrane filtration of rhodamine B.

Effect of air bubbles on the membrane filtration of a basic dye, rhodamine B (RB), using a hydrophilic PTFE membrane filter (pore size: 0.20 μm) was studied. The air bubbles were generated by vigorously mixing the aqueous solution containing 0.

Surfactant-free air bubble flotation-coagulation for the rapid purification of chloroquine.

A simple and rapid separation method based on surfactant-free air bubble flotation and coagulation was designed for the purification of chloroquine (CQ) from its crude product. An open glass column having a sintered glass filter (for column chromatography) was used as a flotation vessel. The flotation was conducted by pouring the crude CQ into the aqueous solution containing 0.