Ion Conducting Nanocomposite Membranes Based on PVA-HA-HAP for Fuel Cell Application: II. Effect of Modifier Agent of PVA on Membrane Properties

摘要

This work explores the synthesis and properties alteration of new nanocomposite membrane systembased on polyvinyl alcohol (PVA) blended with hyaluronic acid (HA) and hydroxyapatite (HAP) asnanofiller. The membranes were synthesized by solution-casting method, where PVA was initiallymodified with orthophosphoric acid (OPA) or sulphuric acid and then epichlorohydrin (EPI) wasemployed as chemical crosslinker. Physicochemical properties of composite membranes e.g. gelfraction (%), swelling degree and mechanical stability were estimated, depending on PVA modifieragent alteration. Results revealed that the PVA-modifier agent type influenced sharply on mostmembrane properties. For example, the swelling ability of PVA-HA-HAP composite membranes wasreduced apparently with increasing H2SO4 amount as used for PVA modification, unlike it wasincreased with the used amount of OPA for the same purpose. The mechanical properties wereimproved with increasing the amount of EPI until certain extent, whereas they have deterioratedcontroversially with addition of high incorporated amounts of HAP or using high amounts of OPA orH2SO4 for PVA modification. Meanwhile, electrochemical properties of PVA-HA-HAP compositemembranes showed a big improvement in ionic conductivity with PVA modification and HAPincorporation as well. An oneimensional matlab model is devoloped to study the performance ofDMFC for different new composite membranes. Both experimatl and modeled performance ofdiffernet membranes in DMFC were compared and discussed in details.