Poly(4-vinyl pyridine) radiografted PVDF track etched membranes as sensors for monitoring trace mercury in water

Abstract

International audiencePoly-4-vinyl pyridine chains were radiografted inside the etched-tracks of PVDF nanoporous membrane. P4VP grafting was found to be localized on the solid PVDF surface. Coating of these PVDF-g-P4VP membranes with a very thin layer of gold results in an ASV electrochemical sensor. Functionalized ion track-etched PVDF-g-P4VP sensors were found very selective and highly sensitive for mercury LOD 5 ng/L. a b s t r a c t By a radiation-induced grafting technique, we have functionalized track-etched nanoporous polymer membranes with mercury sensitive poly-4-vinyl pyridine (P4VP). Coating of these membranes with a very thin layer of gold results in an electrochemical sensor that is very selective and highly sensitive for mercury LOD 5 ng/L – well below the norms for water (0.015 mg/L potable water and 0.5 mg/L residual waters-French water norms of 27 October 2011). E-beam irradiation permitted optimization of the radiografting synthesis on PVDF thin films prior to ion-track grafting. Synthesis and characterization by EPR, FESEM and FTIR are described in detail. A comparison between FTIR in ATR and transmission modes enabled us to localize the grafting on the surface of the e-beam irradiated PVDF films allowing us to extrapolate what happens on the etched tracks. Using Square Wave Anodic Stripping Voltammetry (SW-ASV), mercury concentrations of 1 mg/L are detected in 2 h and low ng/L concentrations are detected after 24 h of adsorption. The adsorption is passive so sensors do not require instrumentation and the analysis takes only 3–4 min. Also, the P4VP functionalized sensor appears insensitive to pH variations (pHs 3–9), high salt concentrations (up to 1 g/ L) and the presence of other heavy metals in the same solution.

Poly(vinylidene fluoride-co-chlorotrifluoro ethylene) Nanohybrid Membrane for Fuel Cell

“…The physical and chemical changes (e.g., chain scission, cross-linking, electric, and dielectric properties) of different polymers have been reviewed depending on LET. 9,10 As a general rule, the bombardment of SHI on polymers creates damage zones along its path and forms a latent track due to its large electronic energy deposition. 11,12 The track diameter depends on the mass and energy of the ions.…”

Track‐Etched Nanopore/Membrane: From Fundamental to Applications

“…Later, the same group polymerized poly(4‐vinyl pyridine) (P4VP) in PVDF membrane by radiation‐induced RAFT. [ 119 ] The P4VP functionalization makes the membrane a good sensor for monitoring trace of mercury in water. In this strategy, it is essential to preserve the free radical generated by the track.…”

Functionalization of PET Track-Etched Membranes by UV-Induced Graft (co)Polymerization for Detection of Heavy Metal Ions in Water

“…For such purpose, materials based on carbon nanotubes [9], carbon thin film [10], graphene and graphene oxide [11], metal nanoparticles [11,12,13,14], and polymers and membranes [15,16,17] are used as WE. Moreover, the number of publications has been growing on the use of track-etched membranes (TeMs) based on polyvinylidene fluoride (PVDF) as a dual-electrode [18,19,20,21,22,23]. TeMs are thin (5–24 µm), light, and flexible polymeric films with pores with narrow pore-size distribution.…”

“…Such grafted membranes were transformed into membrane electrode by deposition of gold layer (50 nm) and found to be sensitive to sub-ppb Pb 2+ concentration. Poly(4-vinyl pyridine) (P4VPy) grafted into PVDF was found to be effective in detection of mercury [19,26] with concentrations ng/L after 24 h of absorption and µg/L after 2 h of absorption. Penaeva et al [18] reported the electron-beam-induced graft polymerization of bis[2-(methacryloyloxy)ethyl] phosphate onto PVDF membrane for the detection of uranium (VI) in ppb concentrations from 20 to 100 ppb using square wave cathodic stripping voltammetry.…”

“…Such polymers can be PAA and P4VPy. PAA [20,30] and P4VPy [19,31] were found to be effective modifier of electrodes for the detection of lead, cadmium, cobalt, and others. Their copolymers can form more stable complexes with heavy metal ions [32,33].…”