Quartz crystal microbalance study of volume changes and modulus shift in electrochemically switched polypyrrole

Bahrami-Samani, Mehrdad; Cook, Christopher David; Madden, John D. W.; Spinks, Geoffrey M.; Whitten, Philip G.

doi:10.1016/j.tsf.2007.04.139

Cited by 22 publications

(20 citation statements)

References 34 publications

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Section: Introductionmentioning

confidence: 99%

“…Equation 2 can be solved for the polymer shear modulus and layer thickness simultaneously when the imaginary part of shear moduli are set to zero at 5 MHz, which is a reasonable assumption according to Dynamical Mechanical Analysis of polypyrrole previously reported. 25 Several studies, 26,4 have shown that polypyrrole films with large-and medium size dopants swell upon electrochemical cycling. The volumetric changes and surface roughnesses have been measured by contact mode AFM or ellipsometry and mass changes by EQCM.…”

Section: Introductionmentioning

confidence: 99%

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Electroactivity and biocompatibility of polypyrrole‐hyaluronic acid multi‐walled carbon nanotube composite

Pelto

Haimi

Puukilainen

et al. 2009

J Biomedical Materials Res

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Electroactivity of polypyrrole hyaluronic acid, electropolymerized in the presence of oxidized carbon nanotubes (PPyHA-CNT) was studied in situ by electrochemical atomic force microscopy (EC-AFM) in physiological electrolyte solution. In situ Raman spectroscopic and quartz crystal microbalance (QCM) studies were conducted on layers of the polymer grown on AT-cut 5 MHz quartz crystals. Human adipose stem cell (ASC) attachment and viability were studied by Live/Dead staining, and the proliferation was evaluated by WST-1 Cell proliferation assay for polypyrrole samples electropolymerized on titanium. According to cyclic voltammetry, the measured specific capacitance of the material on gold is roughly 20% of the reference polypyrrole dodecylbenzene sulfonate (PPyDBS). Electrochemical-QCM (EC-QCM) analysis of a 210-nm thick film reveals that the material is very soft G' approximately 100 kPa and swells upon reduction. EC-AFM of samples polymerized on microelectrodes show that there are areas of varying electroactivity, especially for samples without a hydrophopic backing PPyDBS layer. AFM line scans show typically 20-25% thickness change during electrochemical reduction. Raman spectroscopic analysis suggests that the material supports noticeable polaron conduction. Biocompatibility study of the PPyHA-CNT on titanium with adipose stem cells showed equal or better cell attachment, viability, and proliferation compared with the reference polylactide.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Electroactivity and biocompatibility of polypyrrole‐hyaluronic acid multi‐walled carbon nanotube composite

Pelto

Haimi

Puukilainen

et al. 2009

J Biomedical Materials Res

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“…There has recently been some investigation of the dependence of the mechanical Young's modulus on oxidation state (15)(16)(17)(18)(19)(20). According to these studies, Young's modulus of the polymer changes when its oxidation state is changed.…”

Section: Model Derivationmentioning

confidence: 99%

A Model for Mechanical Force Sensing in Conducting Polymers

Mirfakhrai¹,

Shoa²,

Fekri³

et al. 2010

ECS Trans.

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Conducting polymers have been shown to work as force sensors in an electrolyte by generating a voltage or current when the force applied to them is changed. One possible sensing mechanism is the change in the polymer capacitance as a result of an induced tension. This change in capacitance can be related to perturbation of Donnan equilibrium potential by external load. In this paper we present a model using this proposition to predict conducting polymer sensing behaviour. The model also takes the dependence of the sensing voltage on the polymer oxidation state into account. The predicted model results are compared with experimental measurements on a free-standing film of polypyrrole in an aqueous electrolyte of NaPF6. Sensing voltages ranging from ~ 80-110 μV were detected in response to 1.72 MPa change in the polymer stress, when the polymer was at oxidation states of -0.2 V to 0.4 V vs. Ag/AgCl reference electrode. The load-dependent capacitance necessary to induce the observed sensing currents and voltages is determined. The cycle life of the polypyrrole mechanical sensor was also studied and it was shown that after an initial transient period, the sensing current amplitude stays constant for at least 5400 cycles.

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“…The EQCM technique is used to study ionic and molecular transport during oxidation and reduction processes in conductive polymers and allows for sensitive monitoring of the simultaneous mass changes [31][32][33][34]. Two PPy systems with increased porosity over traditional PPy films were examined: a PPy LbL construction utilizing multiwalled carbon nanotubes (MWCNTs) and a polystyrene (PS) NT PPy.…”

Section: Introductionmentioning

confidence: 99%

Electrochemically controlled swelling properties of nanoporous templated polypyrrole and layer by layer polypyrrole

Aygun

Buthker

Stephenson

et al. 2012

Journal of Electroanalytical Chemistry

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Quartz crystal microbalance study of volume changes and modulus shift in electrochemically switched polypyrrole

Cited by 22 publications

References 34 publications

Electroactivity and biocompatibility of polypyrrole‐hyaluronic acid multi‐walled carbon nanotube composite

Electroactivity and biocompatibility of polypyrrole‐hyaluronic acid multi‐walled carbon nanotube composite

A Model for Mechanical Force Sensing in Conducting Polymers

Electrochemically controlled swelling properties of nanoporous templated polypyrrole and layer by layer polypyrrole

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