Quaternized poly(1-vinylimidazole) hydrogel for anion adsorption

Abstract

Poly(1-vinylimidazole) (PVIm) hydrogels were synthesized through free radical polymerization/crosslinking of 1-vinylimidazole (VIm) in aqueous solutions with azobisisobutyronitrile (AIBN) used as the initiator and N,N 0 -methylenebisacrylamide (MBAAm) as the crosslinking agent. To quaternize PVIm, dimethylsulfate was used as the methylating agent. Pristine and quaternized PVIm hydrogels were characterized by spectroscopic techniques. Finally, ground hydrogels were used in anion adsorption. The amount of anion adsorbed (in m-eq. anion/g polymer) and adsorption% was determined for fluoride, bromide, nitrite, nitrate, phosphate and sulfate anions using ion chromatography techniques. The amount of phosphate adsorbed on QPVIm hydrogel was the highest and the amount of fluoride adsorbed on QPVIm hydrogel was the lowest. Ion chromatographic study showed that when 1/1 mol ratio of anion to polymer (on a repeating unit basis) was used, 24.7 % of fluoride, 60.6 % of nitrite, 61.6 % of bromide, 63.0 % of nitrate, 99.3 % of phosphate and 98.2 % of sulfate were removed from the medium.

Preparation and properties of polybenzimidazole/quaternized poly(1-vinylimidazole) cross-linked blend membranes for vanadium redox flow battery applications

“…It can be seen that the intensities of the absorption bands around 2958 and 2853 cm À1 (C-H stretching) significantly increased and the characteristic absorption bands of imidazolium rings around 1571 and 1552 cm À1 appeared after the quaternization reaction indicating that the quaternization indeed occurred. 37,42,43 The 1 H NMR spectra of the PVI and the QPVI are shown in Figure 3. For the PVI, the broad peak at 1.98 ppm is assigned to the protons of the methylene groups (CH 2 ) of the main chain.…”

Removal of Orange II from Aqueous Solutions Using N-Vinyl Imidazole-based Hydrogels as Adsorbents

“…It was found that p-VIm showed a remarkable affinity to Hg(II) cations and also completely removal of mercury cations was achieved at pH 2.0. In another work by Genç et al (2016), a quaternized p-VIm hydrogel was employed in adsorption of fluoride, bromide, nitrite, nitrate, phosphate and sulfate anions. They demonstrated that the anion adsorption by p-VIm was negligible compared to that quaternized p-VIm.…”

Removal of Acid Dyes from Wastewater using poly(Acrylamide-Vinylimidazole) Hydrogel

“…Son yıllarda, vinil imidazol (VI) bazlı hidrojeller, imidazol halkası üzerindeki elektron sağlayıcı azot atomu tarafından farklı moleküler parçalara güçlü bir bağlanma eğilimi göstermesi ve zayıf baz karakterine sahip imidazol grupları kolayca protonlanarak pH'a bağlı hacim değişim davranışı sergilemesi nedeniyle büyük ilgi haline gelmiştir [19], [20]. VI içeren hidrojellerde, bulundukları ortamın asitlik derecesinin artmasıyla polimer zincirleri arasında meydana gelen elektrostatik itmenin artışına bağlı olarak su moleküllerinin ağ yapı içerisine difüzyonu kolaylaşır ve hidrojelin şişme kapasitesinde artış meydana gelir.…”