Synthesis of Highly Conductive Poly(3-hexylthiophene) by Chemical Oxidative Polymerization Using Surfactant Templates

• Published in: Polymers 2022-09, Vol.14 (18), p.3860
• Main Authors: Kesornsit, Sanhanut, Direksilp, Chatrawee, Phasuksom, Katesara, Thummarungsan, Natlita, Sakunpongpitiporn, Phimchanok, Rotjanasuworapong, Kornkanok, Sirivat, Anuvat, Niamlang, Sumonman
• Format: Article
• Language: English
• Subjects: Acids; Chemical synthesis; Chloroform; Doping; Electric properties; Electrical conductivity; Electrical resistivity; Emulsion polymerization; Ferric chloride; Micelles; Nanoparticles; Oxidation; Oxidizing agents; Particle shape; Polymerization; Polymers; Radiation; Ratios; Shape effects; Sodium; Sodium dodecyl sulfate; Sodium dodecylbenzenesulfonate; Software; Solvents; Spectrum analysis; Sulfosuccinates; Surface active agents; Surfactants; Technology application; Temperature effects; Thermal analysis
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym14183860

Poly(3-hexylthiophene) (P3HT) was systematically synthesized by chemical oxidative polymerization in chloroform with ferric chloride (FeCl3) as the oxidizing agent and various surfactants of the shape templates. The effects of 3HT: FeCl3 mole ratios, polymerization times, and surfactant types and concentrations on the electrical conductivity, particle shape and size were systematically investigated. Furthermore, dodecylbenzenesulfonic acid (DBSA), p-toluenesulfonic acid (PTSA), sodium dodecyl sulfate (SDS), and sodium dioctyl sulfosuccinate (AOT) were utilized as the surfactant templates. The P3HT synthesized with DBSA at 6 CMC, where CMC stands for the Critical Micelle Concentration of surfactant, provided a higher electrical conductivity than those with PTSA, SDS and AOT. The highest electrical conductivity of P3HT using DBSA was 16.21 ± 1.55 S cm−1 in which the P3HT particle shape was spherical with an average size of 1530 ± 227 nm. The thermal analysis indicated that the P3HT synthesized with the surfactants yielded higher stability and char yields than that of P3HT without. The P3HT_DBSA electrical conductivity was further enhanced by de-doping and doping with HClO4. At the 10:1 doping mole ratio, the electrical conductivity of dP3HT_DBSA increased by one order of magnitude relative to P3HT_DBSA prior to the de-doping. The highest electrical conductivity of dP3HT_DBSA obtained was 172 ± 5.21 S cm−1 which is the highest value relative to previously reported.