Schiff base functionalized chitosan anion exchange membranes with 1,4-dichlorobutane as the crosslinker

In Situ Reduction of Au(I) for Efficient Recovery of Gold from Thiosulfate Solution by the 3D MoS2/Chitosan Aerogel

“…18 Absorption peaks at 1713 and 1650 cm −1 correspond to the stretching vibration of amide I (−NH 2 , primary amide) and amide II (−NH−, secondary amide), respectively. 19 It can be seen that the characteristic peaks of CS at 3426, 2939, and 1650 cm −1 can be easily detected from the FT-IR spectrum of the MoS 2 /CS aerogel, revealing the successful combination of MoS 2 and the CS aerogel.…”

“…In the FT-IR spectrum of CS (Figure b), 3426 cm –1 is attributed to the multiabsorption peak of stretching vibration of NH and OH with hydrogen bonds, and the absorption of 2939 cm –1 is assigned to the stretching vibration of C–H . Absorption peaks at 1713 and 1650 cm –1 correspond to the stretching vibration of amide I (−NH 2 , primary amide) and amide II (−NH–, secondary amide), respectively . It can be seen that the characteristic peaks of CS at 3426, 2939, and 1650 cm –1 can be easily detected from the FT-IR spectrum of the MoS 2 /CS aerogel, revealing the successful combination of MoS 2 and the CS aerogel.…”

Preparation and Property Investigation of Chitosan-Based Anion-Exchange Membranes with Different Cross-Linking Structures

“…Consistent with the value of WR (Table ), this may be attributed to the dense main chain of CS-based AEMs, which increases the resistance to the aggregation of cations and makes it difficult to form ion channels across the dense backbone clusters of the main chain, whereas the introduction of cross-linked structures further restricts the aggregation of cations, which achieves the limitation of excessive swelling while reducing the utilization rate of cations and the degree of hydrophilic and hydrophobic microphase separation of membranes, thus reducing the ionic conductivity. In addition, due to the increased WR providing more ionic transport sites, the CNSiPCS with a hydrophilic cross-linking agent exhibits higher ionic conductivity compared to the CNHePCS with a hydrophobic cross-linking agent, which conforms to the vehicle mechanism and Grotthuss mechanism …”

“…Regarding the variety of AEMs reported, commercialization still faces challenges such as poor conductivity of hydroxides and alkaline instability of cationic groups at high pH and temperatures. − Therefore, it is necessary to develop stable cationic groups that can be used for extended periods of time. Among the large number of cationic groups that have been reported, quaternary ammonium piperidinium cations have received widespread attention due to the ring tension and improved alkali stability over conventional cationic groups. , Olsson et al prepared cyclic quaternary ammonium-functionalized polystyrene based on polystyrene by grafting piperidine onto the polystyrene backbone via Friedel–Crafts organic coupling reaction of 2-(4-piperidinyl)-2-propanol with benzene rings, followed by quaternization with methyl iodomethane, demonstrating that the quaternary ammonium piperidinium cation has excellent alkali resistance . Further studies revealed that the alkali stability of the piperidinium cations is related to its structure, with the β-H of the quaternary ammonium cation being on the piperidinium ring, which confers favorable chemical stability by the site resistance effect of the piperidinium ring …”

Fabrication of cellulose acetate‐based radiation grafted anion exchange membranes for fuel cell application

“…The FTIR spectra of the CA film (Figure 3(a)) showed a broad band at 3476 cm −1 ( ) corresponding to the stretching vibration of OH in the anhydroglucose units of cellulose. 29,30 The broad peak at 2944 cm −1 (⌂) is associated to the stretching vibrations of CH 2 in cellulose 31,32 while the sharp peak at 1735 cm −1 (□) denotes the stretching of the C O bond of the ester carbonyl. 33 The peak at 1367 cm −1 (×) corresponds to the C H deformation vibration in the cellulose groups and symmetric CH 3 stretching in the acetyl group while the C O stretching of the acetyl groups is manifested by the 1213 cm −1 (Δ) signal.…”