scholarly journals Ion Mobility in Thick and Thin Poly-3,4 Ethylenedioxythiophene Films—From EQCM to Actuation

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2448
Author(s):  
Rudolf Kiefer ◽  
Daniel Georg Weis ◽  
Bharath Kumar Velmurugan ◽  
Tarmo Tamm ◽  
Gerald Urban
Keyword(s):  
Ion Transport ◽  
Ion Mobility ◽  
Quartz Crystal ◽  
Linear Expansion ◽  
Conductive Polymer ◽  
Electrochemical Quartz Crystal Microbalance ◽  
And Control ◽  
Charge Discharge ◽  
Charge Change

Conductive polymer actuators and sensors rely on controlled ion transport coupled to a potential/charge change. In order to understand and control such devices, it is of paramount importance to understand the factors that determine ion flux at various conditions, including the synthesis potential. In this work, the ion transport in thinner poly-3,4-ethylenedioxythiophene (PEDOT) films during charge/discharge driven by cyclic voltammetry is studied by consideration of the electrochemical quartz crystal microbalance (EQCM) and the results are compared to the actuation responses of thicker films that have been synthesized with the same conditions in the bending and linear expansion modes. The effects of polymerization potentials of 1.0 V, 1.2 V, and 1.5 V are studied to elucidate how polymerization potential contributes to actuation, as well the involvement of the EQCM. In this work, it is revealed that there is a shift from anion-dominated to mixed to cation-dominated activity with increased synthesis potential. Scanning electron microscopy shows a decrease in porosity for the PEDOT structure with increasing synthesis potential. EQCM analysis of processes taking place at various potentials allows the determination of appropriate potential windows for increased control over devices.

Effect of Current Distribution on Quartz Crystal Microbalance Measurements

1997 ◽  
Vol 502 ◽  
Author(s):  
James J. Kelly ◽  
Christopher J. Durning ◽  
Alan C. West
Keyword(s):  
Quartz Crystal Microbalance ◽  
Current Distribution ◽  
Quartz Crystal ◽  
Electrochemical Quartz Crystal Microbalance ◽  
Sensitivity Factor ◽  
A Posteriori ◽  
Frequency Shifts ◽  
Point To Point ◽  
Measured Mass

ABSTRACTSpatially nonuniform electrodeposition can cause discrepancies between predicted and experimentally measured mass loadings on an electrochemical quartz crystal microbalance (EQCM) since the sensitivity of the quartz crystal varies significantly from point to point. These discrepancies can be significant even if the current distribution is nearly uniform. These effects were examined experimentally by varying the conductivity of the electrolyte and the current density during the electrodeposition of copper on an EQCM, effecting changes in the spatial, deposited-mass distribution in a controlled manner. The resulting frequency shifts are in agreement with results predicted by current distribution simulations, validated a posteriori with profilometry measurements. Our results permit determination of the spatial variation of the quartz crystal sensitivity factor or of the current distribution on the EQCM.

scholarly journals A Novel Signal-Amplified Immunoassay for the Detection of C-Reactive Protein Using HRP-Doped Magnetic Nanoparticles as Labels with the Electrochemical Quartz Crystal Microbalance as a Detector

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Ning Gan ◽  
Ping Xiong ◽  
Ji Wang ◽  
Tianhua Li ◽  
Futao Hu ◽  
...  
Keyword(s):  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Microtiter Plate ◽  
Electrochemical Quartz Crystal Microbalance ◽  
Magnetic Core ◽  
Enzyme Linked Immunosorbent Assay ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Insoluble Product

A novel horseradish peroxidase- (HPR-) doped magnetic core-shell Fe3O4@SiO2@Au nanocomposites (Fe-Au MNPs) were employed on immunoassay for the determination of C-reactive protein (CRP) based on a electrochemical quartz crystal microbalance detector (EQCM). Firstly, the secondary CRP antibody and HRP were both immobilized on the Fe-Au MNPs (Fe-Au MNPs-anti-CRP2/HRP) as a signal tag. Secondly, the above tag and the primary antibody (anti-CRP1) in the bottom of 96-well microtiter plate were employed to conjugate with a serial of CRP concentrations to produce a sandwich immunocomplex. Thirdly, the immunocomplex solution was subsequently exposed to3,3′-diaminobenzidine (DAB) in the presence of H2O2, resulting in an insoluble product. When the precipitation solution was dripped on EQCM, it can achieve a decrease of frequency of crystal (Δf). The amount ofΔfwas proportional to (CRP) from 0.003 to 200 ng mL−1with a low detection limit of 1 pg mL−1. Compared with the enzyme-linked immunosorbent assay (ELISA), the immunoassay shows greatly improved sensitivity due to the significant amount of HRP labeled on signal tag. It also has good specificity and low sample consumption, which is expected to be a benefit for the CRP screening in early diagnosis of cardiovascular disease.

Determination of the Boron/Lead Ratio in Ceramic Materials Based on Electrochemical Quartz Crystal Microbalance

2004 ◽  
Vol 16 (21) ◽  
pp. 1814-1822 ◽  
Author(s):  
A. Doménech-Carbó ◽  
S. Sánchez-Ramos ◽  
D. J. Yusá-Marco ◽  
M. Moya-Moreno ◽  
J. V. Gimeno-Adelantado ◽  
...  
Keyword(s):  
Quartz Crystal Microbalance ◽  
Quartz Crystal ◽  
Ceramic Materials ◽  
Electrochemical Quartz Crystal Microbalance

Electrodeposition of Metals on Conductive Polymer Films

1996 ◽  
Vol 451 ◽  
Author(s):  
Maria Hepel ◽  
Laura Adams ◽  
Cynthia Rice-Belrose
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Resonant Frequency ◽  
Electrode Potential ◽  
Quartz Crystal ◽  
Conductive Polymer ◽  
Electrochemical Quartz Crystal Microbalance ◽  
Transmission Electron ◽  
20 Nm ◽  
Electrodeposition Of Metals

ABSTRACTThe electrodeposition of copper on composite conductive polymer polypyrrole/polystyrenesulfonate PPy(PSS) has been studied. The morphology of copper deposits was investigated in the presence of thiourea and other additives. It has been found that in the presence of thiourea in the solution, the rate of copper deposition on a PPy(PSS) substrate is slightly inhibited but the rate of copper stripping is faster than in its absence. The Electrochemical Quartz Crystal Microbalance (EQCM) technique allowed us to simultaneously monitor voltamperometric and resonance frequency vs. potential or time characteristics. The amount of electrodeposited copper was controlled by monitoring the EQCM resonant frequency. Composite PPy(PSS) films functioning as cation-exchange membranes were used as substrate materials for metal deposition. They allowed us to electrodeposit copper not only on the surface of the conductive polymer but also inside the polymer matrix. The size of copper nanocrystals formed inside the polymer was controlled by the applied electrode potential. Copper crystals as small as 20 nm were detected with Transmission Electron Microscopy (TEM).

Sign in / Sign up

Export Citation Format

Share Document