The mechanistic aspects of supramolecular ordering of synthetic β-amino acid based peptides in different organic solvents and fuel oils are reported. The peptide Boc-cis-ACHC-Aib-Phe-OMe (Boc=tert-butyloxycarbonyl, cis-ACHC=cis-2-aminocyclohexanecarboxylic acid, Aib=α-amino isobutyric acid, Phe=phenylalanine; 1) is able to entrap various organic solvents and oils, leading to the formation of self-supporting gels. Spectroscopic studies confirm the turn-type β-sheet arrangement of peptide 1 in the gel phase. A morphology study shows that a bundle of nanofibers form from self-assembled peptide 1. Peptide 1 is capable of entrapping organic or oil layers selectively over the aqueous layer. Furthermore, the phase-selective gelation behavior of peptide 1 is effectively used as a model study for oil spill recovery from a biphasic mixture of oil and water.