Natural montmorillonite was modified with a quaternary ammonium compound, hexadecyltrimethylammonium (HDTMA). The sedimentation capabilities of unmodified and modified montmorillonites were then investigated. The sedimentation velocity of modified montmorillonites increased if the amounts of adsorbed HDTMA were from 0.3 to 1.0 times the cation exchange capacitity (CEC). It also emerged that the...

Eight quaternary ammonium compounds were tested for their ability to induce contact dermatitis in guinea pigs by using a modified Freund's complete adjuvant test together with the guinea pig maximization test. Only two quaternary ammonium salts of the eight tested could be designated as strong allergens. These two active substances were shown to be capable of stable association with membrane li...

In the crystals of the title N-halo-methyl-ated quaternary ammonium salts, C19H23IN(+)·I(-), (I) [systematic name: N-(4,4-di-phenyl-but-3-en-1-yl)-N-iodo-methyl-N,N-di-methyl-ammonium iodide], C20H25IN(+)·I(-), (II) [systematic name: N-(5,5-di-phenyl-pent-4-en-1-yl)-N-iodo-methyl-N,N-di-methyl-ammonium iodide], and C21H27IN(+)·I(-), (III) [systematic name: N-(6,6-di-phenyl-hex-5-en-1-yl)-N-iodo...