Nafion

About: Nafion is a research topic. Over the lifetime, 9110 publications have been published within this topic receiving 320865 citations.

A glucose oxidase immobilization platform for glucose biosensor using ZnO hollow nanospheres

Abstract: A good route (template-directed synthetic route) for the fabrication of ZnO hollow nanospheres (ZnO-HNSPs) was proposed. ZnO hollow nanosphere is a wonderful platform to immobilize glucose oxidase for glucose biosensor owing to the high specific surface area and high isoelectric point (IEP). Along with nafion and glucose oxidase (GOD), a glucose sensor was designed. Nafion/ZnO-HNSPs/GOD/GCE displays higher catalytic activity toward the glucose oxidation than Nafion/ZnO nano-Flowers/GOD/GCE. Linear response was obtained over a concentration range from 5.0 × 10 −3 mM to 13.15 mM with a detection limit of 1.0 μM (S/N = 3), and the sensitivity was 65.82 μA/(mM cm 2 ). Satisfyingly, the Nafion/ZnO-HNSPs/GOD/GCE could effectively avoid the interferences from the common interfering species such as uric acid (UA), ascorbic acid (AA), dopamine (DA) and fructose. The Nafion/ZnO-HNSPs/GOD modified electrode allows high sensitivity, excellently selective, stable, and fast amperometric sensing of glucose and thus is promising for the future development of glucose sensors.

Phosphonic acid functionalized aminopropyl triethoxysilane–PVA composite material: organic–inorganic hybrid proton-exchange membranes in aqueous media

Abstract: Poly(vinyl alcohol)–silica composite proton-exchange membranes were prepared by a sol–gel process in acidic conditions using aminopropyltriethoxysilane as an inorganic precursor and functionalized with phosphonic acid. Phosphorylation of the membranes was confirmed by Fourier transform infrared (FTIR) spectroscopy and ion-exchange capacity (IEC) studies. These membranes were extensively characterized for their thermal and mechanical stabilities, physicochemical and electrochemical properties using thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), water uptake studies, proton conductivity and methanol permeability measurements. The silica content in the membrane matrix and the time allowed for the phosphorylation were optimized as functions of the membrane properties. It was observed that the PVA–silica composite acts as an excellent methanol barrier possessing good hydrophilicity and proton conductivity. Moreover, from estimation of the selectivity parameter among all the synthesized membranes, 50% silica composition and 3 h of phosphorylation resulted in the best proton-exchange membrane, which exhibited about 20% more suitability in comparison to Nafion 117 membrane for direct methanol fuel cell applications.

Microstructural evolution of a silicon oxide phase in a perfluorosulfonic acid ionomer by an in situ sol-gel reaction. 3. Thermal analysis studies

Abstract: Microcomposite membranes were produced via the in situ diffusion-controlled, acid-catalyzed sol-gel reaction for tetraethoxysilane in prehydrated and methanol-swollen Nafion perfluorosulfonic acid films. The thermal behavior of these microcomposites was investigated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). It was found by TGA that significant