Fabrication of Polypyrrole Nanoparticles Using Microemulsion Polymerization for Diferent Py/APS/SDS Molar Ratios

Abstract

Polypyrrole nanoparticles (PPy) were synthesized by the chemical oxidative microemulsion of pyrrole (Py) monomer using ammonium persulfate (APS) as an oxidant agent and sodium dodecylsulfate (SDS) as a surfactant at 28°C and 0°C. Different Py:APS:SDS molar ratios were used, and the properties of the resulting material were examined by four-probe DC electrical conductivity, ultraviolet-visible-near infrared (UV-vis-Nir), and Fourier-transform infrared (FTIR) spectroscopies as well as field-emission scanning electron microscopy (FESEM). UV-vis-Nir and FTIR spectra show the formation of a polaron band owing to the doping of PPy by SDS. The electrical conductivity and morphology of PPy nanoparticles depend on the synthesis conditions. Electrical conductivity of ~95.3×10-3 S/cm was achieved for PPy synthesized at 0°C. For the same Py:APS:SDS molar ratio, the nanoparticle shape changed from cylindrical to spherical upon simply lowering the synthesis temperature.

Synthesis and factor affecting on the conductivity of polypyrrole: a short review

“…PPy nanoparticles have been synthesized using different Py/APS/SDS ratios and processing temperatures through microemulsion polymerization by Santim et al 112 . The increase in SDS and APS molar ratio does not significantly affect PPy nanoparticle conductivity.…”

“…Microemulsion polymerization is extensively used because of its low interfacial tension, high thermodynamic stability, and ability to solubilize otherwise immiscible liquids 112 . However, in microemulsion polymerization method, a large amount of surfactant or cosurfactant is needed to achieve effective stabilization.…”

“…Results demonstrate that with increased FeCl 3 /Py molar ratio from 1 to 4, PPy nanoparticle conductivity increases to 10.98 × 10 −2 , 13.89 × 10 −2 S/cm, 21.74 × 10 −2 , and 10 S/cm, respectively. In a similar work, Santim et al 112 studied the effect of O/M (APS/Py) on PPy nanoparticle conductivity. Results show that PPy nanoparticle conductivity increases from 0.6 × 10 −3 to 20.4 × 10 −3 S/cm with increased O/M from 0.5 to 1.…”

“…Another factor affecting the electrical conductivity of PPy is reaction temperature 43,112 . Based on Sasso et al, 43 the polymerization kinetics is slowed down at low temperature, and a relatively linear PPy is subsequently formed.…”

“…For example, Santim et al 112 that with decreased synthesis temperature from 28°C to 0°C, PPy nanoparticle conductivity increases from 5.8 × 10 −3 S/cm to 21.2 × 10 −3 S/cm. Meanwhile, Minisy et al 80 examined PPy nanotube conductivity under the influence of reaction temperatures.…”