Dielectric properties of sulfonated poly(ether ether ketone) (SPEEK) electrolytes with 1-ethyl-3-methylimidazolium tetrafluoroborate salt: Ionic liquid-based conduction pathways

Constructing the synergistic effects of chitosan and ionic liquid on SPEEK polymer for efficient adsorption of crystal violet dye

In the study, a novel chitosan biopolymer and 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid (IL)-incorporated sulfonated poly (ether ether ketone) (SPEEK) composite (Ch-IL@SPEEK) was prepared for adsorption of cationic crystal violet (CV) dye. The proposed composite was well characterized by several techniques. CV adsorption performance was examined via batch studies by varying various variables involving adsorbent dosage, contact time pH and temperature. The isotherm results were demonstrated the adsorption characters of the processes were Langmuirian. The maximum adsorption capacity was determined as 77.66 mg g-1 for the composite which was significantly higher than SPEEK (qmax = 45.36 mg g-1). The determined equilibrium time of the operated system was 360 min and the kinetic model was assessed as Elovich. At low pHs the protonated surface groups repelled the positively charged CV and the adsorption rate increased with increasing pH. The process is spontaneous and favorable as it proceeds via endothermic interactions. Furthermore, even at the end of 5 successful adsorption cycles, 77.86 % CV removal was obtained. Remarkable efficiencies were also achieved in the removal performance of different organic pollutants. Based on the reported results, Ch-IL@SPEEK composite were exhibited as an impressive adsorbent material for adsorption processes.

Synthesis and characterization of sulfonated poly(eugenol-co-allyleugenol) membranes for proton exchange membrane fuel cells

The research of sulfonated eugenol-allyleugenol copolymer (SPEAE) based membrane for fuel cell from eugenol derivate had been conducted. First, eugenol was reacted with various weights of allyl eugenol to form eugenol-allyleugenol copolymer (PEAE). Determination of the optimum composition of PEAE was done by testing the swelling properties. Then, PEAE was sulfonated using concentrated sulfuric acid with time variations of 1, 2, 3, 4, and 5 h to form SPEAE. The SPEAE produced was tested for the degree of sulfonation, water uptake, cation exchange capacity, and membrane proton conductivity. In addition, the characteristics of the PEAE and SPEAE copolymer membranes were also analyzed using FTIR spectrophotometers, 1H-NMR, TGA, and DSC. The results showed that the copolymerization of eugenol:allyleugenol (EG:AEG) with a ratio of 10:1 gave the lowest swelling degree. The best SPEAE copolymer was obtained from sulfonation for 2 h with yield, degree of sulfonation, water absorption value, proton conductivity, and cation exchange capacity of 90.6%, 12.87%, 50.7%, 1.83 × 10^-5 S cm^-1 and 0.356 meq/g, respectively. FTIR analysis shows the formation of PEAE with the loss of the vinyl eugenol groups used to form the polymer and shows the formation of SPEAE in the presence of sulfonate groups from the sulfonation reaction. ¹H-NMR also confirmed the presence of the PEAE and SPEAE copolymers. In addition, analysis of thermal properties with TGA and DSC also showed that sulfonate treatment could improve membrane stability.

Review on Comparison of Different Energy Storage Technologies Used in Micro-Energy Harvesting, WSNs, Low-Cost Microelectronic Devices: Challenges and Recommendations

This paper reviews energy storage systems, in general, and for specific applications in low-cost micro-energy harvesting (MEH) systems, low-cost microelectronic devices, and wireless sensor networks (WSNs). With the development of electronic gadgets, low-cost microelectronic devices and WSNs, the need for an efficient, light and reliable energy storage device is increased. The current energy storage systems (ESS) have the disadvantages of self-discharging, energy density, life cycles, and cost. The ambient energy resources are the best option as an energy source, but the main challenge in harvesting energy from ambient sources is the instability of the source of energy. Due to the explosion of lithium batteries in many cases, and the pros associated with them, the design of an efficient device, which is more reliable and efficient than conventional batteries, is important. This review paper focused on the issues of the reliability and performance of electrical ESS, and, especially, discussed the technical challenges and suggested solutions for ESS (batteries, supercapacitors, and for a hybrid combination of supercapacitors and batteries) in detail. Nowadays, the main market of batteries is WSNs, but in the last decade, the world's attention has turned toward supercapacitors as a good alternative of batteries. The main advantages of supercapacitors are their light weight, volume, greater life cycle, turbo charging/discharging, high energy density and power density, low cost, easy maintenance, and no pollution. This study reviews supercapacitors as a better alternative of batteries in low-cost electronic devices, WSNs, and MEH systems.