High frequency impedance analysis of quartz crystal microbalances coated with conducting polymers

Topart, P.; Noel, M.; Liess, H.-D.

doi:10.1016/0040-6090(94)90851-6

Cited by 11 publications

(8 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…21 However, f s calculated by eq 2 has been used in order to investigate the R m dependence of f s and f o . 13c, 22 It is known that f r change is associated with mass change of a film whereas f s change and f o change are associated with both its mass change and R t change. In Figure 4b, R t varies during redox cycle, leading to large difference between the f r diagram and the f s diagram.…”

Section: Resultsmentioning

confidence: 99%

Mass Transport Investigated with the Electrochemical and Electrogravimetric Impedance Techniques. 1. Water Transport in PPy/CuPTS Films

Yang

Kwak

1997

J. Phys. Chem. B

View full text Add to dashboard Cite

Water transport in poly(pyrrole/copper phthalocyaninetetrasulfonate) (PPy/CuPTS) films, where cation transport prevails, has been investigated by employing the electrochemical quartz crystal microbalance (EQCM) technique, the electrochemical impedance technique, and the electrogravimetric impedance technique. The approximate numbers of accompanying waters per cation for PPy/CuPTS films have been obtained from both cyclic EQCM experiment and impedance experiment. It is shown that the number of accompanying waters depends on the nature and concentration of an electrolyte solution as well as the redox state of the film. It increases with the hydration number of cation in an aqueous electrolyte solution and exhibits hysteresis behavior during redox cycle. It is found that ionic conductivity of cation in a film depends on the number of accompanying waters and the ion-ion interactions inside the film. It is also found that a substantial amount of water moves with the cation during the break-in process at the first cathodic scan. Moreover, the electromechanical impedance technique has been employed to verify the relation between mass and resonant frequency of an oscillating quartz crystal and to monitor morphology changes (viscoelastic change and volume change) during the redox reaction of PPy/CuPTS films. It is found that mass change can be obtained from resonant frequency without consideration of morphology changes of PPy films. It is also found that morphology changes of PPy/CuPTS films relate to the amount of water moving into or out of the film.

show abstract

Section: Resultsmentioning

confidence: 99%

Mass Transport Investigated with the Electrochemical and Electrogravimetric Impedance Techniques. 1. Water Transport in PPy/CuPTS Films

Yang

Kwak

1997

J. Phys. Chem. B

View full text Add to dashboard Cite

show abstract

“…If certain conditions are met, the change in the resonant frequency can be directly related to the mass of the film which rests on the electrode surface. Unfortunately, many factors can complicate this analysis, including viscoelastic energy dissipation within the thin film, interfacial slippage, or a nonuniform mass distribution. − In these cases additional information can be obtained from the shape of the resonance, although the analysis is not necessarily straightforward. − …”

Section: Introductionmentioning

confidence: 99%

Equilibrium Swelling of Hydrophilic Polyacrylates in Humid Environments

Chen¹,

Shull²,

Papatheodorou³

et al. 1998

Macromolecules

View full text Add to dashboard Cite

The hydrophilicity of polymers, as indicated by their swelling characteristics in water, is an important parameter with regard to their use as coatings which are able to modify the wettability and adhesive properties of a material. We have investigated the swelling behavior of a series of hydrophilic random copolymer coatings in controlled humidity environments and in water. Swelling data were obtained from a quartz crystal microbalance (QCM) and from spectroscopic ellipsometry. The hydrophilic polymers are based on polyacrylates with low molecular weight side chains of poly(ethylene glycol) (PEG). These polymers also contain a random distribution of acrylic acid. Triblock copolymers with these random copolymers as the midblock and poly(methyl methacrylate) (PMMA) as the end blocks have also been investigated. At low and intermediate humidities, the swelling behavior of appropriately chosen block copolymers is similar to the swelling behavior of the corresponding polymers that do not have the PMMA end blocks. Substantial differences between the two types of polymers are observed at very high humidities and in water. The PMMA end blocks stabilize the structure of the copolymer layer so that it does not dissolve in water. Swelling curves obtained from the quartz crystal microbalance and from ellipsometry are in agreement with one another when the shape of the quartz crystal resonance (as determined by impedance spectroscopy) is not affected by humidity. We also find evidence for a reversible, humidity-induced phase transition which is readily detectable by the quartz crystal microbalance.

show abstract

“…The experimental apparatus and the data treatment were described previously . It was shown that the comparison of the mass change obtained from the electrochemical impedance of a quartz crystal with the mass change from the resonance frequency of an oscillating quartz crystal verifies the linear relation between resonant frequency and mass. , In this experiment, there is no significant difference between the mass change from the electromechanical impedance and the mass change from the resonant frequency. Thus, the mass change in the gravimetric experiment was obtained from the resonant frequency without consideration of the morphology change of the film.…”

Section: Methodsmentioning

confidence: 66%

Mass Transport Investigated with the Electrochemical and Electrogravimetric Impedance Techniques. 2. Anion and Water Transport in PMPy and PPy Films

Yang

Kwak

1997

J. Phys. Chem. B

View full text Add to dashboard Cite

Water transport during anion transport in poly(N-methylpyrrole/nitrate) (PMPy/NO 3 ), poly(N-methylpyrrole/ chloride) (PMPy/Cl), and poly(N-methylpyrrole/sulfate) (PMPy/SO 4 ) films, where ion transport is anionspecific, has been investigated by comparing electrical responses with gravimetric responses in the cyclic electrochemical quartz crystal microbalance (EQCM) experiment and the impedance experiment. It is shown that the number of accompanying waters per Clor SO 4 2is considerable, whereas the number per NO 3 -is not large. The number of accompanying waters per anion does not change extensively with the concentration of an electrolyte solution and the applied potential. Moreover, the possibilities of OH -, H + , cation, and water transport in poly(pyrrole/nitrate) (PPy/NO 3 ) and poly(pyrrole/chloride) (PPy/Cl) films, where ion transport is not anion-specific, have also been investigated. It is found that OHmoves competitively with NO 3 -or Clduring their redox reaction.

show abstract

High frequency impedance analysis of quartz crystal microbalances coated with conducting polymers

Cited by 11 publications

References 23 publications

Mass Transport Investigated with the Electrochemical and Electrogravimetric Impedance Techniques. 1. Water Transport in PPy/CuPTS Films

Mass Transport Investigated with the Electrochemical and Electrogravimetric Impedance Techniques. 1. Water Transport in PPy/CuPTS Films

Equilibrium Swelling of Hydrophilic Polyacrylates in Humid Environments

Mass Transport Investigated with the Electrochemical and Electrogravimetric Impedance Techniques. 2. Anion and Water Transport in PMPy and PPy Films

Contact Info

Product

Resources

About