Permselective Films of Sulfonic Acid-Functionalized N-Vinylcarbazole Block Copolymers: Optoelectronic Studies and Electrochemical Sensing of Dopamine

This study focused on incorporating block copolymers of poly(N-vinylcarbazole) [PNVCz] with three distinct sulfonic acid polymer derivatives. The synthesis of the polymers involved utilizing the xanthate reversible addition-fragmentation chain transfer (RAFT) polymerization technique. Nanomicelle block copolymers, including poly(N-vinylcarbazole)-b-poly(2-methyl-2-propene-1-sulfonic acid) [PNVCz-b-PMPSA], poly(N-vinylcarbazole)-b-poly(2-acrylamido-2-methyl-1-propanesulfonic acid) [PNVCz-b-PAMPS], and poly(N-vinylcarbazole)-b-poly(styrenesulfonic acid) [PNVCz-b-PSSA], were synthesized using a xanthate RAFT agent, (2-ethyl isobutyrate)-(O-ethyl xanthate) [EIX]. The linear relationship between molar mass and conversion suggests pseudo-first-order kinetics. The molar mass distribution of the copolymers ranged from 1.17 to 1.30. Characterization of the block copolymers and homopolymers included techniques such as ¹H NMR, X-ray diffraction [XRD], Fourier transform infrared spectroscopy [FTIR], scanning electron microscopy (SEM), gel permeation chromatography (GPC), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The block copolymer’s aqueous solution at a concentration of 1 mg/mL demonstrated self-assembly within the 50-150 nm range, as evidenced by dynamic light scattering [DLS] and transmission electron microscopy [TEM]. The permselective properties exhibited by the polymer films were advantageously utilized for the electrochemical sensing of dopamine in the presence of ascorbic acid. The optical characteristics of the block copolymers were also assessed using UV-vis absorption and photoluminescence techniques. These block copolymers display captivating self-organization tendencies and exhibit ion-exchange properties facilitating the detection of dopamine.