Organogels from different self-assembling new dendritic peptides: morphology, rheology, and structural investigations

Abstract

Three new peptide based dendrimers with different generations were synthesized, purified, and characterized. Each of these dendrimers form efficient organogels under suitable conditions and these gels were characterized by field emission scanning electron microscopy (FE-SEM), high resolution transmission electron microscopy (HR-TEM), atomic force microscopy (AFM), Fourier transformed infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) and rheology. It has been observed that gel forming propensity increases from first to second generation dendrimer and it decreases from second to third generation. The hydrogen bonding interaction is the main driving force for the formation of aggregated structure that leads to the formation of a fibrillar network, responsible for gelation. The morphology is network type consisting of taped or twisted fibrils spanning throughout the space. DSC measurements show the thermoreversible first-order phase transition. Rheological studies indicate that flow behavior and segmental motion of these gels are different for different peptidic gels, obtained from various generations of dendritic peptides.