Preparation and properties of chitosan/organic‐modified attapulgite composite proton exchange membranes for fuel cell applications

Abstract

The chitosan (CS) matrix‐based composite proton exchange membranes (CS/QATP) were prepared by the incorporation of organic‐modified attapulgite (QATP) into CS, through an organic‐inorganic composite synthesis method. The QATP was obtained by the modification with silane coupling agent (octadecyldimethyl [3‐trimethoxysilylpropyl] ammonium chloride). The morphology, crystallinity, thermal and mechanical property, dimensional stability, and proton conductivity of CS/QATP composite membranes were investigated. The compatibility and dispersibility of QATP in CS matrix were significantly improved with enhanced interfacial interaction. The dimensional and thermal stability of the CS/QATP composite membranes were improved compared with pure CS film, owing to good dispersion and lower water uptake. Especially, the composite membrane with 2 wt% QATP (CS/QATP‐2) exhibits the highest mechanical strength and proton conductivity, which is much higher than pure CS film. These results indicated that CS/QATP composite membranes have a great potential for proton exchange membranes applications.

The Construction and Application of Dual‐Modified Carbon Nanotubes in Proton Exchange Membranes with Enhanced Performances

“…The pristine CS membrane shows the T g value of 204 °C, which is close to other reported values of CS. [36,37] In comparison of pure CS, the T g values of composite membranes increased gradually with the increasing of SSiO 2 @CNTs from 1 to 7 wt%, and the CS/SSiO 2 @CNTs-7 shows the highest T g value of 215 °C. This enhancement is mainly due to the hydrogen bonding and electrostatic attractions between -SO 3 H in SSiO 2 @CNTs and -OH, -NH 2 groups in CS matrix, which can restrict the mobility of CS molecular chains and lead to the formation of more compact polymer matrix.…”

“…Besides, the influence of nanosheet may become more obvious with the increasing of SSiO 2 @CNTs content and thus leads to gradually decreasing intensities of these characteristic peaks, such ob-servation are also confirmed by our previous reports about other fillers incorporated CS membranes. [36,38] In the FTIR spectrum of Figure 4b, the CS characteristic absorption peaks display clearly. The broad band located at 3342 cm −1 is attributed to the hydroxyl group of CS, and the bands of amide I and amide II located at 1637 and 1524 cm −1 , respectively, are formed by the crosslinking of sulfonic acid during the preparation of films.…”

“…On the other hand, the SSiO 2 @CNTs fillers are fine dispersion in the CS matrix, this is conducive to the formation of abundant physics crosslinking points in CS, thereby the mobility of CS chains would be further interfered and leads to increase of tensile strength. [36,42] The decreasing of tensile strength with increasing of SSiO 2 @CNTs content from 7 to 10 wt% is mainly due to the aggregation, which results in poor dispersion and decreased interface interaction. The enhanced mechanical properties imply promising application potential in proton exchange membranes fuel cells.…”

Application of biowaste and nature-inspired (nano)materials in fuel cells

“…Natural ATP was modified using a silane coupling agent (DC5700) and incorporated in CS as a biopolymer matrix to synthesize a PEM membrane. 146 The mixed solution of CS and organic chains of QATP was cast on the surface of a glass plate and dried in a vacuum oven at 35 °C for 24 h. Subsequently, the membrane was immersed in NaOH solution (5 wt%) for 2 h to remove acetic acid, followed by rinsing with DW. The cross-linked CS/QATP PEM was prepared by immersion in 2 M H 2 SO 4 for 24 h, followed by washing with DW.…”

Ultralong hydroxyapatite nanofibers/organics composite film for improving its mechanical property: Effect of proportions

“…Its hydrophilic surface is conducive to cell adhesion, proliferation, and differentiation. [ 16 ] At the same time, the calculation results show that the molecular polarity and high viscosity [ 17 ] of chitosan contribute to the formation of the composite. On the other hand, gelatin (GA) is obtained from partial hydrolysis of collagen and also be considered the base material for composites.…”