The Role of Functional Groups in Tuning the Self‐Assembly Modes and Physical Properties of Multicomponent Gels

Abstract

We have analyzed the nature and role of functional groups on the self‐assembly modes and the physical properties of multicomponent gels with structurally similar individual components. The gelation properties of individual and mixed enantiomeric compounds of biphenyl bis‐(amides) of alanine (BPA) or phenylalanine (BPP) methyl ester were analyzed in various solvent/solvent mixtures. Multicomponent gels were formed by mixing the enantiomeric BPP compounds at a lower concentration, but a higher concentration was required for mixed alanine‐based BPA gels. The comparison of the mechanical strength of the individual and mixed BPP compounds indicated that the mixed BPP gels displayed enhanced mechanical strength (∼2‐fold increase) in p‐xylene, but a weaker gel was observed in DMSO/water. However, a reverse trend was observed for BPA gels, indicating the role of functional groups in the gel network formation. X‐ray diffraction analysis of the gelator and the xerogels in the solid state confirmed the formation of co‐assembled networks in mixed enantiomeric gels. The stability of the gels towards anions was evaluated by analyzing the anion induced stimuli‐responsive properties. These results indicate the effective modeling of the functional groups of the individual components could lead to multicomponent gels with tunable properties.

Supramolecular Gels Based on C3-Symmetric Amides: Application in Anion-Sensing and Removal of Dyes from Water

“…A positive interaction has the potential to start or enhance the process of gelation, whereas a negative interaction might result in the dissolution or collapse of the gel network [15][16][17][18][19]. LMWGs based on amide moieties are promising candidates for anions sensing [15][16][17][18][19]54], and we have reported the anion-sensing capabilities of amidebased gelators [55,56]. The presence of amide moieties in the gelators prompted us to evaluate the anion-sensing abilities of the N-BTA gelator.…”