ChemInform Abstract: A New Type of Phase‐Transfer Catalysts (PTC). Reaction of Substrates in the Inner Organic Phase with the Outer Aqueous Anions Catalyzed by PTC Grafted on the Capsule Membrane.

Phase transfer catalysis: Chemistry and engineering

“…No induction time was required, as is needed while using polymer supports. Comparison of reactivities of the capsule membrane system to that observed by using soluble PTC in a stirred reactor showed that the capsule membrane showed the higher reactivity (Okahata and Ariga, 1986), possibly due to free movement of the onium salts attached to long graft polymer chains at the interface of the ultrathin (low diffusional limitations) membrane capsule. It is speculated that these spacer chains can even .form a micellar like structure at the organic/water interface.…”

“…In a modification of triphase catalysis, hydrophobic onium salts or poly(ethy1ene oxide) were grafted onto the surface of a porous ultrathin nylon capsule membrane (Okahata and Ariga, 1986). Typical dimensions of the capsule membrane were 25 mm diameter and a thickness of 5 microns.…”

Modeling and kinetics of allylation of phenol in a triphase‐catalytic membrane reactor

“…Yadav and Mehta13 presented the theoretical and experimental analysis of capsule membrane phase‐transfer catalysis for alkaline hydrolysis of benzyl chloride to benzyl alcohol. Okahata and Ariga14 reported the reaction of sodium azide with benzyl bromide in the presence of a capsule membrane with pendant quaternary ammonium groups and polyethylene glycol groups on the outside. However, the capsule membrane is not suitable for direct scale‐up to the industrial level because of the inconveniences of working with capsules.…”

Kinetics of allylation of phenol using quaternary ammonium membranes in a membrane reactor

“…Yadav and Mehta (1993) presented theoretical and experimental analyses of capsule membrane phase-transfer catalysis for alkaline hydrolysis of benzyl chloride to benzyl alcohol. Okahata and Ariga (1986) reported the reaction of sodium azide with benzyl bromide in the presence of a capsule membrane with pendant quaternary ammonium groups and polyethylene glycol groups on the outside. The capsule membrane is not suitable, however, for direct scale up to an industrial level, due to the inconvenience of working with capsules.…”