IN SITUPREPARED TIO₂NANOPARTICLES CROSS-LINKED SULFONATED PVA MEMBRANES WITH HIGH PROTON CONDUCTIVITY FOR DMFC

Abstract

Organic/inorganic membranes based on sulfonated poly(vinyl alcohol) (SPVA) and in situ prepared TiO 2 nanoparticles nanocomposite membranes with various compositions were prepared to use as proton exchange membranes in direct membrane fuel cells. Poly(vinyl alcohol) (PVA) was sulfonated and cross-linked separately by 4-formylbenzene-1,3-disulfonic acid disodium salt hydrate and glutaraldehyde. The ion exchange capacity and proton conductivity of the membranes increased with increasing amount of TiO 2 nanoparticles. The composite membranes with 15 wt% TiO 2 exhibited excellent proton conductivity of 0.0822 S cm -1 , as well as remarkably low methanol permeability of 1.11×10 −9 cm 2 s -1. The thermal stability and durability were also superior and performance in methanol fuel cell was also reasonably good.

Enhancement in hydrolytic stability and proton conductivity of optimised chitosan/sulfonated poly(vinyl alcohol) composite membrane with inorganic fillers

“…On the basis of Table 8, the water management of CS/SPVA15 composite membrane was improved, where the water uptake and swelling degree were suppressed with the addition of inorganic filler (with the exception of CS/SPVA15‐TiO 2 ). Such phenomenon was abnormal because the inorganic filler addition aimed to effectively improve the water uptake due to its hygroscopic nature, thereby allowing the absorption and retention of water molecules 26,87 . The suppression in water sorption can be attributed to the strong interaction between the inorganic filler and polymer matrix.…”

“…White and dark spots are observed in Figure 4. According to Solanki et al 26 and Gohel et al's 61 work with the impression of TiO 2 ‐modified PVA membrane, the white spots indicate the presence of TiO 2 particles, and the dark dots are the ionic clusters. Similar results are presented by Yang et al 62 and Gahlot et al 63 with the inorganic fillers of SiO 2 and SGO, respectively.…”

“…Such phenomenon was abnormal because the inorganic filler addition aimed to effectively improve the water uptake due to its hygroscopic nature, thereby allowing the absorption and retention of water molecules. 26,87 The suppression in water sorption can be attributed to the strong interaction between the inorganic filler and polymer matrix. According to Beydaghi et al's 88 work, the incorporation of SGO in the PVA membrane demonstrated a decrease in water uptake compared with the PVA membrane.…”

“…Such technique highlights the advantage between inorganic material and organic polymer by filling the void between the polymer matrix, whilst causing an intensive increase in interfacial interaction that is responsible for superior mechanical and physical properties 24,25 . Solanki et al 26 reported that the addition of hygroscopic nature inorganic filler, such as titanium oxide (TiO 2 ), can improve the proton transfer due to its high specific area of protonated sites and good water retention. Dupuis et al 27 reported that the addition of up to 10 wt% of inorganic filler to the Nafion polymer matrix could promote the membrane's proton conductivity.…”