Quaternized polysulfone‐based nanocomposite membranes and improved properties by intercalated layered double hydroxide

Abstract

Two anions (dodecylbenzenesulfonate anion and stearate anion) are employed to synthesize intercalated layered double hydroxides (LDH) by co-precipitation method. Then the intercalated LDHs are incorporated in the casting solutions of chloromethylated polysulfone (CMPSF) for fabricating quaternized polysulfone/LDH nanocomposite membranes. Fourier transform infrared, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and mastersizer laser particle size analysis are used to characterize the structure and morphology of LDHs and membranes. The properties of the composite membranes including water uptake, mechanical property, thermal stability, and ionic conductivity are investigated. Compared with other anion exchange membranes, both nanocomposite membranes containing 5% LDH sheets displayed better balanced performance. They exhibit the ionic conductivity of 3.58 3 10 22 S cm 21 and 3.86 3 10 22 S cm 21 at 608C, respectively. POLYM. ENG. SCI.,

Enhancement of Hydroxide Conduction by Incorporation of Metal–Organic Frameworks into a Semi-Interpenetrating Network

“…Thus, the trade-off effect between conductivity and SR still exists as a scientific challenge. − The covalent cross-linking strategies have been frequently employed to sustain an adequate swelling of membranes at high IECs. , However, some of the membranes with cross-linked linkages are slightly brittle in dry states and also hydroxide conductivity declines sharply because of the lack of well-connected ion conducting nanochannels and reduced WU. , Currently, there has been an interest in semi-interpenetrating network (semi-IPN) anion exchange membranes containing both cross-linking networks and linear (flexible) polymer chains that interpenetrate one another. They have exhibited improved mechanical strength and flexibility, but their conductivity and WU need further improvements. , On the other hand, hybrid ion conductive membranes, which merge the advantages of both polymeric and inorganic materials, for instance, SiO 2 , , TiO 2 , , ZrO 2 , graphene oxide, , layered double hydroxide, − and metal–organic frameworks (MOFs), − are effective to improve the ion conductivity and physicochemical stability of membranes. Chen et al synthesized a new class of AEMs based on triple-cationic side-chain poly­(2,6-dimethyl-1,4-phenylene oxide) (TC-QAPPO) membranes by spraying quaternary-ammonium-modified layered double hydroxide (QA-LDH) on the surface of the TC-QAPPO membrane.…”

Quaternized Polysulfone Cross-Linked N,N-Dimethyl Chitosan-Based Anion-Conducting Membranes

“…An AEM with phase-separated morphology analogous to PEMs has been reported to exhibit faster ionic mobility [21,22]. In this regard, composite/nanocomposite material can be suitably used in AEMs, primarily owing to the biphasic nature of the materials [14,16,23,24,25,26,27]. Such materials can form micro-phase separated structures conducive for ion transport.…”

Aqueous Fabrication of Recyclable and Color-Adjustable Superhydrophobic Pigments Based on NiFe-Layered Double Hydroxide Nanostructures for Coating Applications

“…In practical applications, coloring substances may fade and deteriorate due to prolonged UV exposure and high temperatures, which renders the architectural coating useless for decorative purposes. , Therefore, it is necessary to investigate the color stability of SHP pigments under high radiation and high temperature. As shown in Figure S6c, the presence of about 5–10% mass loss of the five types of pigments is due to the weight loss of physically absorbed water and interlayer water below 200 °C. − The larger mass loss occurring between 200 and 400 °C has mainly resulted from the thermal decomposition of interlayer anions and DBSA. , Figure S6d shows the comparison image of synthetic pigments before and after being baked at 120 °C and irradiated under a UV lamp. The pigments’ colors did not significantly change, which illustrates that the synthesized multi-colored SHP pigments have high color stability under high temperature and UV radiation.…”