Polysulfone Nanocomposite Membranes with improved hydrophilicity

Electrochemical application of cobalt nanoparticles-polypyrrole composite modified electrode for the determination of phoxim

In this study, cobalt nanoparticles (CoNPs) were synthesized and cobalt nanoparticles modified glassy carbon electrode (CoNPs/GCE) was prepared by drop coating the nanoparticles on glassy carbon electrode. After preparing polypyrrole modified glassy carbon electrode (PPy/GCE) using electropolymerization of pyrrole in LiClO4 solution, cobalt nanoparticles-polypyrrole composite modified glassy carbon electrode (CoNPs/PPy/GCE) was fabricated by drop coating the CoNPs on the PPy/GCE. Different characterization techniques such as scanning electron microscopy, transmission electron microscopy, energy dispersive spectroscopy, FTIR spectroscopy, electrochemical impedance spectroscopy and cyclic voltammetry were used to study the morphological structure and electrochemical behavior of the sensors. The results demonstrated that PPy chains interacted with CoNPs through donor-acceptor bonds. Among all the electrodes, CoNPs/PPy/GCE exhibited highest electroactive surface area and lowest electron transfer resistance towards phoxim. Under the optimal conditions, the sensor showed linear relationship between the reduction peak current and the concentration of phoxim in the range of 0.025 μM-12 μM with the detection limit as 4.5 nM. Besides, the composite electrode demonstrated excellent reproducibility, good stability and selectivity towards the possible interfering substances. All of these properties made CoNPs/PPy/GCE a suitable electrochemical sensor for the electrochemical determination of phoxim in water samples using square wave voltammetry.

Dye Separation and Antibacterial Activities of Polyaniline Thin Film-Coated Poly(phenyl sulfone) Membranes

We fabricated a nanofiltration membrane consisting of a polyaniline (PANI) film on a polyphenylsulfone (PPSU) substrate membrane. The PANI film acted as a potent separation enhancer and antimicrobial coating. The membrane was analyzed via scanning electron microscopy and atomic force microscopy to examine its morphology, topography, contact angle, and zeta potential. We aimed to investigate the impact of the PANI film on the surface properties of the membrane. Membrane performance was then evaluated in terms of water permeation and rejection of methylene blue (MB), an organic dye. Coating the PPSU membrane with a PANI film imparted significant advantages, including finely tuned nanometer-scale membrane pores and tailored surface properties, including increased hydrophilicity and zeta potential. The PANI film also significantly enhanced separation of the MB dye. The PANI-coated membrane rejected over 90% of MB with little compromise in membrane permeability. The PANI film also enhanced the antimicrobial activity of the membrane. The bacteriostasis (B R) values of PANI-coated PPSU membranes after six and sixteen hours of incubation with Escherichia coli were 63.5% and 95.2%, respectively. The B R values of PANI-coated PPSU membranes after six and sixteen hours of incubation with Staphylococcus aureus were 70.6% and 88.0%, respectively.

Polysulfone metal-activated carbon magnetic nanocomposites with enhanced CO2 capture

In the present study, polysulfone (PSF)-activated carbon nanocomposites were synthesized by a melt mixing technique. Here, 2 wt% activated carbon (CA, CA-Ni, and CA-Co) was used as filler, and effects on thermal, mechanical, magnetic, morphological, and carbon dioxide capture properties were studied. The pyrolysis of wood sawdust produced carbon materials activated by Co and/or Ni salt. The thermal degradation and the amount of metal in the carbon materials were investigated by thermogravimetric analysis. The maximum degradation temperature showed an improvement of up to 3 °C, while the initial degradation temperature decreased up to 4 °C with the addition of metal-activated carbons. The values of T g estimated by differential scanning calorimetry appear to be practically identical for pure PSF and its nanocomposites. The elasticity modulus of the nanocomposite shows an enhancement of 17% concerning the neat PSF. The water contact angle showed a decrease with the incorporation of the fillers, indicating the hydrophilic nature of the composite. The carbon dioxide sorption capacity of the nanocomposite showed an enhancement of almost 10% in contrast to neat PSF. Ferromagnetic behavior of the thermoplastic nanocomposite was observed with the introduction of 2.0 wt% metal-carbonized filler. The exceptional magnetic properties, for a thermoplastic material such as polysulfone, make it promising for various industrial applications.