To characterize the microstructure and mechanism of gelation, microscopy and x-ray scattering techniques were employed. To elucidate the nanoscale structure of the TR-CP and what prompts it to form a porous network, we performed cryogenic transmission electron microscopy (cryo-EM) (SI Section 3.4). The samples were vitrified at two different temperatures, 25 °C and 45 °C, and two different concentrations, 1.8 wt% (no gelation observed, Fig. ) and 3.6 wt% (gelation observed; Fig. ). For samples vitrified below the LCST (Fig. , Fig. ), the TR-CP at both concentrations exhibited structures with two different length scales: small spherical/ovoid particles with a radius of 4.7 ± 0.6 nm, sometimes assembled in a flexible chain-reminiscent of filomicelles-over 20 nm, and rod-like lamellar fringes predominantly outside these nanoparticles with close to 1.6 nm spacing (Fig. , S11a, S11b). These lamellar fringes are likely associated with a semi-crystalline PEDOT phase. The small size of these particles in solution likely explains the excellent colloidal stability of the dispersion and their ability to be lyophilized and redispersed.