Physical gelation of organic liquids by achiral amino acid based amphiphilic gelators: Effect of chirality

We report gelation behavior of a series of N-acyl-beta-alanine (C-n-beta-Ala) gelators in a variety of organic liquids. The effect of alkyl chain length was studied to elucidate gelation mechanism. The gelation behavior of the C-n-beta-Ala gelators was compared with that of corresponding N-acyl-L-alanine (C-n-L-Ala) derivatives. Unlike C-n-L-Ala the C-n-beta-Ala gelators failed to gel aliphatic hydrocarbons and exhibit phase-selective gelation in the presence of water. The gelation ability of C-n-beta-Ala was observed to be poorer than C-n-L-Ala gelators. Also C-n-beta-Ala organogels are thermally less stable, but they are observed to have higher mechanical strength than C-n-L-Ala organogels. (C) 2012 Elsevier B. V. All rights reserved.