While polyoxyethylene-based nonionic surfactants have A series of nonionic saccharide surfactants with an amide group been studied extensively (1-2), studies on saccharide-based linking hydrophilic saccharide segment to hydrophobic alkyl segnonionic surfactants are relatively few (10-30). The disparment were synthesized and their surface active properties were ity is mainly attributable to the rather tedious and expensive determined. We examine the effects of hydrophobic and hydroprotection/deprotection procedures that have been used to philic chain lengths on the surface active properties and correlate prepare structurally well-defined saccharide surfactants such our results to structural differences in the saccharide surfactants.
as alkyl glucosides (10-11), glucosyl alkanes (12-13), N-Alkylmaltonamides were synthesized with hexyl, octyl, decyl, mono-O-alkyl glucose ( 14), glucose monoesters (15), and dodecyl, and octadecyl alkyl segments and N-dodecyl aldonamides sucrose monoesters ( 16). However, by utilizing the reducing were synthesized with glucose, maltose, and dextran (DP ร
9) saccharide segments. Increasing the alkyl chain length in N-alkyl-end group of saccharides, nonionic saccharide surfactants maltonamides decreases the critical micelle concentration, and incan be prepared without protecting the hydroxyl groups (17creases the efficiency of reducing water surface tension and emulsi-27). Generally, the aldehyde end group of an oligosacchafication ability, but the effectiveness in reducing water surface ride can be modified by two methods. The first method is tension is about the same. Increasing the saccharide size in Ncalled reductive amination, in which the aldehyde group is dodecyl aldonamides from glucose to maltose to dextran increases reacted with alkylamine to form a Schiff base, which is then the critical micelle concentration, decreases the efficiency and efreduced to amine (17-18, 27). In the second approach, the fectiveness of reducing water surface tension, but has little effect aldehyde group is oxidized to carboxylic acid, cyclized to on emulsification properties. We show that the size of the sacchalactone, and then reacted with alkylamine to form amide ride segment is important in determining the interfacial surface (19)(20)(21)(22)(23)(24)(25)(26)(27). Recently, we successfully synthesized two maltarea occupied by the surfactant molecules. An octyl, decyl, or ose-and dextran-based nonionic surfactants with diblock dodecyl maltonamide occupies about 40 A ห2 at the air/water interface, but this increases to 60 A ห2 when maltose is replaced by the (AB type) and triblock (ABA type) structures and a hylarger dextran.