The interaction between ammonia and poly(pyrrole)

Gustafsson, G.; Lundström, Ingemar; Liedberg, Bo; Wu, Claudia; Inganäs, Olle; Wennerström, Olof

doi:10.1016/0379-6779(89)90812-6

Cited by 187 publications

(98 citation statements)

References 19 publications

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“…The interactions of conducting polymer with ammonia are also documented in the literature [14,15], which offers strong evidence that reversible deprotonation of the polymer structure takes place, while a concomitant increase in the pH of the medium can be detected electrochemically.…”

Section: Preparation Of Pt/popda/urease Biosensormentioning

confidence: 92%

Urea Amperometric Biosensors Based on Nanostructured Polypyrrole and Poly Ortho-Phenylenediamine

Ivanova¹,

Ivanov²,

Godjevargova³

2013

OJAB

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Urea Amperometric biosensor was obtained on the base of nanostructured polypyrrole (PPy) and poly orthophenylenediamine (POPDA). The optimal conditions for monomer electropolymerization were determined. The effect of supporting electrolyte and number of deposition cycles on the OPDA and Py electropolymerization were studied. It was proved that POPDA and PPy were affected by pH changes and responded to the ammonium, product of urease catalyzed reaction. SEM images of the modified Pt/PPy electrode were presented. The cycle voltammograms and chrono amperometric curves of Pt/POPDA/urease and Pt/PPy/urease electrodes were studied. A good linear relationship was observed for Pt/POPDA/urease electrode in a concentration range from 6.7 to 54 mM urea. For Pt/PPy/urease electrode the linear relation in the range from 0.02 to 0.16 mM urea was determined. The entrapped carbon nanotubes (CNT) in PPy film and the bipolymer layers were prepared for construction of Pt/PPy/CNT/urease, Pt/POPDA/PPy/urease and Pt/PPy/POPDA/urease biosensors. Obviously, the addition of POPDA to the composition of the two biosensors (Pt/PPy/POPDA/urease and Pt/POPDA/PPy/urease) reduced their sensitivity to urea. Pt/РPy/CNT/urease and Pt/РPy/ urease biosensors were 173 and 138 times more sensitive to urea than biosensor without PPy (Pt/POPDA/urease biosensor). It was found, that the performance of Pt/PPy/CNT/urease electrode was the best from the five obtained biosensors: linear range of urea concentrations-from 0.02 to 0.16 mM; sensitivity-15.22 µA/mM and detection limit-0.005 mM urea.

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Section: Preparation Of Pt/popda/urease Biosensormentioning

confidence: 92%

Urea Amperometric Biosensors Based on Nanostructured Polypyrrole and Poly Ortho-Phenylenediamine

Ivanova¹,

Ivanov²,

Godjevargova³

2013

OJAB

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“…Gustafsson e colaboradores LUNDSTRÖM, 1987;GUSTAFSSON et al, 1989) demonstraram que, em baixas concentrações de amônia, o aumento provocado na resistência é reversível, enquanto concentrações acima de 1 atm, ou na presença de água leva a um aumento irreversível da resistência. O aumento da resistência foi atribuído ao ataque nucleofílico da amônia ou hidróxido no polímero provocando a uma perda na conjugação e ainda uma abertura do anel.…”

Section: Sensores Amperométricos De Amônia Baseados Em Polipirrois E unclassified

“…Um mecanismo proposto por Gustafson e colaboradores LUNDSTRÖM, 1987;GUSTAFSSON et al, 1989), explicou o mecanismo por meio de uma reação reversível da desprotonação do polímero com amônia nucleofílica, de acordo com a equação 1.…”

Section: Sensores Amperométricos De Amônia Baseados Em Polipirrois E unclassified

“…Alguns pesquisadores atribuem essa ineficiência ao ataque nucleofílico da amônia ou hidróxido no polímero, esse provoca uma perda na conjugação e ainda uma abertura do anel LUNDSTRÖM, 1987;GUSTAFSSON et al, 1989;TROJANOWICZ et al, 1996;LÄHDESMÄKI et al, 2000). Entretanto, foi demonstrado que mesmo após uma exposição por longo período de tempo, o filme polimérico ainda pode ser regenerado pela ciclagem do mesmo em uma solução fortemente ácida (HEIDUSCHKA et al, 1997), o que, de certa forma, invalida os mecanismo de ruptura do anel prevendo uma perda irrecuperável do eletrodo.…”

Section: Sensores Amperométricos De Amônia Baseados Em Polipirrois E unclassified

“…O mecanismo de detecção da amônia por filmes poliméricos de PPy pode ser verificado por meio de espectroscopia Raman, no qual a diminuição da banda referente a deformação no plano N-H, é um indicio do mecanismo para a detecção de amônia no estado gasoso, equação 1, proposto por Gustafsson e colaboradores LUNDSTRÖM, 1987;GUSTAFSSON et al, 1989). Porém nenhuma evidência de que uma destruição da cadeia polimérica, com consequente ruptura do anel pirrólico, pode ser observado por espectroscopia Raman, de modo que para filmes expostos há uma elevada concentração de amônia .…”

Section: Sensores Amperométricos De Amônia Baseados Em Polipirrois E unclassified

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Determinação de íons amônio em eletrodos modificados com polipirrol

Mendes

Dall’Antônia

2007

Semina: Tech. Ex.

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ResumoO trabalho teve como objetivo a preparação de filmes de polipirrol (PPy) depositado sobre superfícies de carbono vítreo, níquel e ITO (óxido de estanho dopado com Índio) em plástico tipo PET, a fim de estudar suas propriedades em relação à detecção de amônia. Os filmes de polipirrol dopados com dodecilbenzenosulfonato (DBSA) foram formados sobre os eletrodos, a + 0,70 V vs. Ag/AgCl, a partir de uma solução contendo o monômero pirrol e o sal anfifílico sendo que os filmes depositados sobre carbono vitreo apresentaram melhor performance. Voltametrias cíclicas, entre -1,50 até + 0,5 V vs. Ag/ AgCl, foram repetidas acrescentando diferentes concentrações de NH 4 Cl, a fim de observar o comportamento do filme como um possível detector de íons NH 4 + . A corrente do pico de oxidação em função da concentração de amônia para esses filmes varia com a quantidade de NH 4 Cl. Observa-se uma região linear, na faixa de 0 a 80 mM, com uma sensibilidade (S ppy ) aproximadamente igual a 4,2 mA mM -1 cm -2 , demonstrando a eficácia dos eletrodos como sensores de íons amônio. A quantidade de polímero depositada, controlada pelo tempo de crescimento, não influi na sensibilidade do sensor. O eletrodo modificado foi usado para determinar amônio em águas subterrâneas. Palavras-chave: Amônio. Sensor. Polipirrol. AbstractThe present work relates the preparation of polypyrrole films (PPy) deposited on surfaces of glass carbon, nickel and ITO (tin oxide doped with indium) on PET plastic, in order to study the ammonium detection. The popypyrrole films were polymerized with dodecylbenzenesulfonate (DBSA) on the electrodes, at + 0,70 V vs. Ag/AgCl, based on a solution containing the pyrrole monomer and the amphiphilic salt. Films deposited on glass carbon presented better performance. Cyclic voltammetries, between -1,50 to + 0,5 V vs. Ag/AgCl, were repeated adding different concentrations of NH 4 Cl, in order to observe the behavior of the film as a possible detector of ions NH4+. The peak current for oxidation varies with the concentration of ammonium. A linear region can be observed in the band of 0 to 80 mM, with a sensibility (S ppy ) approximately similar to 4,2 mA mM -1 cm -2 , showing the efficacy of the electrodes as sensors of ammonium ions. The amount of deposited polymer, controlled by the time of growth, does not influence on the sensor sensibility. The modified electrode was used to determine ammonium in grounded waters.

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Surface studies of pristine and surface-modified polypyrrole films

Zhang

Kang

Neoh

et al. 1996

J. Appl. Polym. Sci.

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SYNOPSISPolypyrrole (PPY) films having high conductivity were synthesized electrochemically in acetonitrile at low temperature and low current density. Pristine, deprotonated, and ozonepretreated PPY films were subjected to either thermally induced or near-UV-light-induced graft copolymerization with acrylic acid (AAc), or sodium salt of 4-styrenesulfonic acid (NaSS). Surface structures and redox states of the pristine, deprotonated, reprotonated, and surface-modified polypyrrole films were studied by angle-dependent X-ray photoelectron spectroscopy (XPS). The morphology of the PPY surface after modification by graft copolymerization was revealed by atomic force microscopy (AFM). The results showed that the density of surface grafting decreased with ozone pretreatment. Surface grafting of the two polymeric acids also gave rise to a self-protonated surface structure. A substantial proportion of the grafted protonic acid groups at the surface remained free for further surface functionalization. The surface characteristics, in particular the charge-transfer interactions and the changes in the intrinsic redox states of the substrate films, associated with the external protonation and surface self-protonation processes were also discussed.

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The interaction between ammonia and poly(pyrrole)

Cited by 187 publications

References 19 publications

Urea Amperometric Biosensors Based on Nanostructured Polypyrrole and Poly Ortho-Phenylenediamine

Urea Amperometric Biosensors Based on Nanostructured Polypyrrole and Poly Ortho-Phenylenediamine

Determinação de íons amônio em eletrodos modificados com polipirrol

Surface studies of pristine and surface-modified polypyrrole films

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