Abstract
The simple structural modification of replacing a terminal carboxylic acid with a primary amide group was found to lower the minimum gelation concentration (MGC), by at least an order of magnitude, for a series of N-lauroyl-l-amino acid phase-selective organogelators in decane. The amide-functionalized analogue N-lauroyl-l-alanine-CONH2 was demonstrated to gel a broad range of solvents from diesel to THF at MGCs of 2.5% w/v or less, as well as to produce gels with a higher thermal stability (ca. 30 °C) and enhanced mechanical properties (5 times increase in complex modulus), compared to the carboxylic acid analogue, N-lauroyl-l-alanine-COOH. These improved properties may be due to the additional hydrogen bonding in the primary amide analogue as revealed by SCXRD. Most significantly for this study, the introduction of the primary amide functionality enabled N-lauroyl-l-alanine-CONH2 to form a self-assembled fibrillar network in water. The aqueous network could then actively uptake and rapidly gel decane, diesel, and diluted bitumen (“dilbit”) with MGCs of 2.5% w/v or less. This aqueous delivery method is advantageous for oil-remediation applications as no harmful carrier solvents are required and the gel can be easily separated from the water, allowing the oil to be recovered and the gelator recycled.
Highlights
Low-molecular-weight organogelators (LMOGs) are compounds that can form supramolecular gels in an organic solvent
We modified the enantiopurity of the amino acids as it had been previously reported that the enantiopurity of LMOGs can influence their gelling behavior.[30,31]
All compounds were recrystallized from methanol/water (9:1) to yield the pure material and characterized using nuclear magnetic resonance (NMR), elemental analysis (EA), and high-resolution mass spectrometry
Summary
Low-molecular-weight organogelators (LMOGs) are compounds that can form supramolecular gels in an organic solvent. In these systems, the LMOGs self-assemble to form long fibrillar structures (i.e., fibers, rods, and ribbons), when an external trigger is applied, such as heat, increased concentration, or solvent.[1] The fibers entangle to form a selfassembled fibrillar network (SAFiN), which has a high void volume that can trap organic solvents (Figure 1) at relatively low concentrations of LMOGs (i.e.,
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
