Polyaniline modified magnetic nanoparticles coated with dicationic ionic liquid for effective removal of rhodamine B (RB) from aqueous solution

Polyaniline (PANI) modified magnetic nanoparticle (MNP) nanocomposites coated with newly synthesized dicationic ionic liquid (DICAT) forming MNP-PANI-DICAT were successfully synthesized as a potential material for the removal of Rhodamine B (RB) from water samples. The synthesized material was successfully characterized using a few techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), thermo gravimetric analysis (TGA), Brunauer–Emmett–Teller (BET), and transmission electron microscopy (TEM) analysis. Several parameters have been optimized to enhance the efficiency of the removal process. The adsorption kinetics were investigated and the results showed that MNP-PANI-DICAT was best fitted to a pseudo-second order model for the adsorption of RB. As for the isotherm studies, Temkin's model was found to fit well with the adsorption isotherm of RB on MNP-PANI-DICAT. Other than that, thermodynamics results showed negative values of DG� for the adsorption of RB, which indicated that the process is thermodynamically feasible, spontaneous and chemically controlled at lower temperature. The negative value of enthalpy DH� (40.41) indicated that the adsorption was an exothermic process. The percentage removal of RB was found to be 94.7% by MNP-PANI-DICAT under optimized conditions

Synthesis of dicationic ionic liquids and their application as co-catalyst for fructose conversion / Suhaila Mohd Yaman

In this study, six new imidazolium based dicationic ionic liquids (ILs) were successfully synthesized with one step process. These ILs were designated with three different positions of substituent of benzyl-imidazolium at ortho, meta and para on cationic site while tuning the counter anion with chloride and hydrogen sulphate anion. As a result, this unique combination between cation and anion dramatically impact towards the properties of ILs. The characterizations of all ILs were elucidated using 1HNMR, 13C-NMR, FT-IR and CHN elemental analyses. The thermal analysis of these ILs reveals the information of phase transition of glass transition (Tg), melting temperature (Tm), decomposition temperature (Td) and their high thermal stability. Further, the acidity properties were quantified by Hammet acidity function (Ho) that gives the information on the acidity strength of each ILs. These ILs also meet the criteria as catalyst as they were hydrophilic, high stability, acidic and can be recycled. The investigation was started with the screening process by using each IL as a catalyst in separate reaction. Each parameter such as time, temperature, catalyst loading was optimized and the transformation mechanism of fructose to HMF was rationalized. Besides, the reusability study had also been conducted. In addition, in–situ study by using 1H-NMR provides information on the selectivity of the ILs at a given time and temperature. The intrinsic properties of dipole moment and polarity that existed in the structural ILs were also discussed. The difference in position of ortho, meta and para substituent was proven to give a significant contribution and affecting the fructose dehydration process

Polyaniline-dicationic ionic liquid coated with magnetic nanoparticles composite for magnetic solid phase extraction of polycyclic aromatic hydrocarbons in environmental samples

In this present study, magnetic nanoparticles (MNPs) nanocomposites modified with polyaniline (PANI) coated newly synthesised dicationic ionic liquid (DICAT) forming MNP-PANI-DICAT were successfully synthesised as new generation material for magnetic solid phase extraction (MSPE). MNP-PANI-DICAT was characterised by FT-IR NMR, CHN, BET, SEM, TEM, and VSM techniques and the results were compared with MNP-PANI and native MNP. This new material was applied as a magnetic adsorbent for the pre-concentration and separation of polycyclic aromatic hydrocarbons (PAHs) due to the π–π interaction between polyaniline shell and dicationic ionic liquid (DICAT) with PAHs compounds. Under the optimal conditions, the proposed method was evaluated and applied for the analysis of PAHs in environmental samples using gas chromatography-mass spectrometry (GC-MS). The validation method showed good linearity (0.005–500 µg L−1) with the coefficient of determination (R2) > 0.999. The limits of detection (LOD) and quantification (LOQ) of the developed method (MNP-PANI-DICAT-MSPE) were in the range of 0.0008–0.2086 µg L−1 and 0.0024–0.6320 µg L−1, respectively. The enrichment factor (EF) of PAHs on MNP-PANI-DICAT-MSPE were in the range of 7.546–29.632. The extraction recoveries of natural water, sludge, and soil samples were ranged from 80.2% to 111.9% with relative standard deviation (RSD) less than 5.6%. The newly synthesised MNP-PANI-DICAT possess good sensitivity, reusability, and fast extraction of PAHs under the MSPE procedure in various environmental samples