A series of peptide-based triblock copolymers consisting of poly(gamma-benzyl-L-glutamate)-b-poly(dimethylsiloxane)-b-poly(gamma-benzyl-L-glutamate) [PBLG-b-PDMS-b-PBLG] were synthesized using ring-opening polymerization (ROP). The chemical structure and degree of polymerizations were evaluated by H-1 NMR. These triblock copolymers form thermoreversible gels in toluene with critical gel concentration as low as 1.5 wt % and following trends which correlate directly with the secondary structure of the peptidic block. Fourier transform infrared spectroscopy (FTIR) studies indicate that the alpha-helical content is increased while beta-sheets and random coil contents are systematically decreased with increasing volume fraction of the PBLG blocks. The gel solution transition behavior of the triblock copolymers was examined using modulated dynamic light scattering (MDLS). It was observed that all the gels undergo gel solution transition around 50 degrees C and revert back to its original state when cooling down to room temperature. Dye diffusion and diffusing wave spectroscopy (DWS) experiments showed a reduced mobility of both the dye molecules and tracer particles in the gels compared to that in solution state. The rheological studies on the organogels indicate that increasing molecular weight of the PBLG blocks or concentration of the triblock copolymers increase the gel strength considerably. Using transmission electron microscopy (TEM), the morphology of the organogels was shown to be prevalently formed by nanofibrils, with an average thickness in the range of 6-12 nm.