Understanding Thermodynamics and Kinetics of PEDOT:PSS\nUsing ATR-FTIR and Density Functional Theory

This work demonstrates\npoly(3,4-ethylenedioxythiophene) polystyrenesulfonate\n(PEDOT:PSS) and divinyl sulfone (DVS) cross-linking to form insoluble\nand porous PEDOT:PSS-DVS hydrogels. We propose a reaction mechanism\nand demonstrate the kinetics of a PEDOT:PSS modification that prevents\nPEDOT:PSS dispersibility. PSS and DVS undergo a second-order reaction\nbetween the DVS secondary carbocations and PSS oxygen anion to form\na PSS-DVS network. The kinetics, from real-time attenuated total reflectance-Fourier\ntransform infrared spectroscopy and density functional theory, reveal\na temperature-dependent rate expression with a 1.458 1/s pre-exponential\nfactor and a 2.429 kcal/mol activation energy. Cryogelation, phase\nseparation, and phase inversion methods induce porosity in the PEDOT:PSS-DVS\nhydrogels with pore sizes ranging from 12 to 121 μm. Most importantly,\nthe porous PEDOT:PSS-DVS hydrogels do not redisperse in solution.\nThe results provide evidence for the reaction mechanism and kinetics\nof porous nondispersible PEDOT:PSS-DVS hydrogels.