Poly N-(2-cyanoethyl)pyrrole as a selective film for the thickness-shear-mode acoustic wave sensor

Abstract

Poly N-(2-cyanoethy1)pyrrole films have been synthesized by electrochemical polymerization and characterized by cyclic voltammetry, scanning electron microscopy, and X-ray photoelectron spectroscopy. Polymeric coatings prepared on the surface of a thickness-shear-mode acoustic wave sensor have been used to examine response selectivity to a number of gas-phase probe molecules. The responses of the poly N-(2-cyanoethy1)pyrrole based sensor are compared with the parent polypyrrole device and rationalized in terms of the molecular interactions between probes and polymer films. The polar cyano functionality enhances interactions with analytes such as acetonitrile.Key words: gas sensor, thickness-shear-mode acoustic wave sensor, poly N-(2-cyanoethy1)pyrrole film, polypyrrole film, conducting polymer.RCsumC : On a synthCtisC des films de poly N-(2-cyanoCthy1)pyrrole par polymCrisation Clectrochimique et on les a caractCrisCs par voltampCromCtrie cyclique, microscopie tlectronique A balayage et par spectroscopic photoClectronique des rayons X. On a utilisC les rev&tements polymtriques prCparCs sur la surface d'un senseur d'onde acoustique dans le mode de cisaillement de 1'Cpaisseur pour examiner la stlectivitC de la rCponse A un certain nombre de molCcules sondes en phase gazeuse. On a compare les rkponses du senseur base sur le poly-N-(2-cyanoCthy1)pyrrole avec celles de 1'Cquivalent ne portant que le polypyrrole parent et on a rationalis6 les diffkrences en fonction d'interactions moltculaires entre les sondes et les films de polymbre. Une fonction polaire cyano augmente les interactions avec les produits A analyser, comme acetonitrile.Mots clks : senseur de gaz, senseur d'onde acoustique dans le mode cisaillement de l'Cpaisseur, film de poly-N-(2-cyanoCthyl)pyrrole, film de polypyrrole, polymbre conducteur.

Raman and resonance-Raman spectra of polypyrrole with application to sensor – gas probe interactions

“…However, the oxidized form is mainly composed of neutral segments so their contribution to the ultimate behavior of apolypyrrole sensor needs to be considered also and this is possible using this spectroscopic technique. These results are put in context with complementary mass-based results from acoustic wave sensor work that we report in a companion paper (25). Here frequency decreases indicate the relative degrees of interaction between the analytes and polypyrrole.…”

“…The reason for employing gold-coated piezoelectric crystals as the polymer substrate was to maintain our previous experimental conditions (25). Although we are not reporting any new microgravimetric results, this ensures the most relevant comparisons to previous results and also allows us to work with well-characterized samples.…”

Applications and Advances in Electronic-Nose Technologies

“…Acoustic wave sensor sensitivity to VOCs is determined by the types of sorptive coatings used on the sensors. Different materials have been used for this purpose: monolayer films [ 92 ], surface-attached molecules [ 93 ], and layers of a wide variety of polymeric films [ 94 – 96 ].…”

Characterization and Properties of Poly[N‐(2‐cyanoethyl)pyrrole]

“…On the other hand, in an early study the cyano functionality was used to improve the abilities of PPy derivatives as selective gas sensors by incorporating it at the N position of pyrrole repeating units. [31][32][33] Specifically, poly[N-(2-cyanoethyl)pyrrole] (PNCPy; Scheme 1) films were prepared by electrochemical polymerization and preliminary characterized by cyclic voltammetry (CV) and scanning electron microscopy (SEM), even though the investigations reported in such studies were mainly focused on the utility of PNCPy to detect organic vapors, [31][32][33] to develop impedimetric immunosensors, [34] and to prepare membranes for ion separation. [35] However, in spite of its potential applicability as selective sensor, the knowledge about the chemical, and physical properties of PNCPy is very scarce.…”