The Stokes-Einstein equation and the diffusion of ferrocene in imidazolium-based ionic liquids studied by cyclic voltammetry: Effects of cation ion symmetry and alkyl chain length

Thakurathi, Mahesh; Gurung, Eshan; Cetin, M. Mustafa; Thalangamaarachchige, Vidura D.; Mayer, M.; Korzeniewski, Carol; Quitevis, Edward L.

doi:10.1016/j.electacta.2017.10.149

Cited by 34 publications

(13 citation statements)

References 39 publications

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“…The validity of the SE relationships for the ILs under consideration can be tested using the calculated values of diffusivity and viscosity. Because these values are at different temperatures, we have plotted 1/ D versus η/ T , which provides an even more stringent test of the SE equation for the ILs (Figure a,b). The data in these figures were successfully fitted to a power-law relationship (1/ D ∼ (η/ T ) a , where a is the fit parameter).…”

Section: Results and Discussionmentioning

confidence: 99%

Temperature Dependence of Volumetric and Dynamic Properties of Imidazolium-Based Ionic Liquids

Khabaz¹,

Zhang

Xue³

et al. 2018

J. Phys. Chem. B

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Atomistically detailed molecular dynamics simulations were used to investigate the temperature dependence of the specific volume, dynamic properties, and viscosity of linear alkyl chain ([CCIm][NTf], n = 3-7) and branched alkyl chain ([(n - 2)mCCIm][NTf]) ionic liquids (ILs). The trend of the glass transition temperature (T) values obtained in the simulations as a function of the alkyl chain length of cations was similar to the trend seen in experiments. In addition, the system relaxation behavior as determined from the temperature dependence of the diffusion coefficient, rotational relaxation time, and viscosity close to T was observed to follow the Vogel-Fulcher-Tammann expression. Furthermore, the reciprocal of the diffusion coefficient of the anion and cation in both linear and branched IL systems showed a linear correlation with viscosity, thus confirming the validity of the Stokes-Einstein relationship for these systems. Similarly, the average rotational relaxation time of the ions was also found to correlate linearly with the viscosity of the ILs over a wide range of temperatures, thereby validating the Debye-Stokes-Einstein relationship for the ILs. These simulation findings suggest that the temperature dependence of the relaxation time of ILs is very similar to that of other glass-forming liquids.

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Section: Results and Discussionmentioning

confidence: 99%

Temperature Dependence of Volumetric and Dynamic Properties of Imidazolium-Based Ionic Liquids

Khabaz¹,

Zhang

Xue³

et al. 2018

J. Phys. Chem. B

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“…For all electrodes, it can be seen that there is a linear dependence between the current of the anodic peak and the square root of the scan rate ( Figure 1 b,d,f), which proves that the electrochemical process is controlled by the diffusion of the electroactive species [ 51 ]. To calculate the active area of the electrodes, the Randles–Ševčík equation was used [ 52 ].

where: I pa is the anodic current (A), n is the number of electrons transferred in the redox process, A is the area of the active surface of the electrode (cm 2 ), D is the diffusion coefficient (cm 2 ·s −1 ), C is the concentration (mol·cm −3 ) and v is the scan rate (V·s −1 ).…”

Section: Resultsmentioning

confidence: 99%

Development of a Novel Electrochemical Biosensor Based on Carbon Nanofibers–Gold Nanoparticles–Tyrosinase for the Detection of Ferulic Acid in Cosmetics

Bounegru

Apetrei

2020

Sensors

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The present paper deals with the electrochemical behavior of three types of sensors based on modified screen-printed electrodes (SPEs): a sensor based on carbon nanofibers (CNF/SPE), a sensor based on nanofibers of carbon modified with gold nanoparticles (CNF-GNP/SPE) and a biosensor based on nanofibers of carbon modified with gold nanoparticles and tyrosinase (CNF-GNP-Ty/SPE). To prepare the biosensor, the tyrosinase (Ty) was immobilized on the surface of the electrode already modified with carbon nanofibers and gold nanoparticles, by the drop-and-dry technique. The electrochemical properties of the three electrodes were studied by cyclic voltammetry in electroactive solutions, and the position and shape of the active redox peaks are according to the nature of the materials modifying the electrodes. In the case of ferulic acid, a series of characteristic peaks were observed, the processes being more intense for the biosensor, with the higher sensitivity and selectivity being due to the immobilization of tyrosinase, a specific enzyme for phenolic compounds. The calibration curve was subsequently created using CNF-GNP-Ty/SPE in ferulic acid solutions of various concentrations in the range 0.1–129.6 μM. This new biosensor allowed low values of the detection threshold and quantification limit, 2.89 × 10−9 mol·L−1 and 9.64 × 10−9 mol·L−1, respectively, which shows that the electroanalytical method is feasible for quantifying ferulic acid in real samples. The ferulic acid was quantitatively determined in three cosmetic products by means of the CNF-GNP-Ty/SPE biosensor. The results obtained were validated by means of the spectrometric method in the infrared range, the differences between the values of the ferulic acid concentrations obtained by the two methods being under 5%.

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Section: Preliminary Studies For Electrode Characterizationmentioning

confidence: 98%

“…For all three electrodes, there is a linear dependence between the anodic peak current and the square root of the scan rate, which demonstrates that the electrochemical process is controlled by the diffusion of electroactive species [54]. The Randles-Sevcik equation was used to calculate the active area of the electrodes [55]. Using the linear regression equation Ipa vs. v 1/2 and the diffusion coefficient of the ferrocyanide ion D = 7.26 × 10 −6 cm 2 /s, [56] the value of the area of the active surface for the three electrodes was calculated.…”

Section: Preliminary Studies For Electrode Characterizationmentioning

confidence: 99%

Development of a Novel Electrochemical Biosensor Based on Carbon Nanofibers–Cobalt Phthalocyanine–Laccase for the Detection of p-Coumaric Acid in Phytoproducts

Bounegru

Apetrei

2021

IJMS

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The present paper developed a new enzymatic biosensor whose support is a screen-printed electrode based on carbon nanofibers modified with cobalt phthalocyanine and laccase (CNF-CoPc-Lac/SPE) to determine the p-coumaric acid (PCA) content by cyclic voltammetry and square wave voltammetry. Sensor modification was achieved by the casting and cross-linking technique, using glutaraldehyde as a reticulation agent. The biosensor’s response showed the PCA redox processes in a very stable and sensitive manner. The calibration curve was developed for the concentration range of p-coumaric acid of 0.1–202.5 μM, using cyclic voltammetry and chronoamperometry. The biosensor yielded optimal results for the linearity range 0.4–6.4 μM and stood out by low LOD and LOQ values, i.e., 4.83 × 10−7 M and 1.61 × 10−6 M, respectively. PCA was successfully determined in three phytoproducts of complex composition. The results obtained by the voltammetric method were compared to the ones obtained by the FTIR method. The amount of p-coumaric acid determined by means of CNF-CoPc-Lac/SPE was close to the one obtained by the standard spectrometric method.

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The Stokes-Einstein equation and the diffusion of ferrocene in imidazolium-based ionic liquids studied by cyclic voltammetry: Effects of cation ion symmetry and alkyl chain length

Cited by 34 publications

References 39 publications

Temperature Dependence of Volumetric and Dynamic Properties of Imidazolium-Based Ionic Liquids

Temperature Dependence of Volumetric and Dynamic Properties of Imidazolium-Based Ionic Liquids

Development of a Novel Electrochemical Biosensor Based on Carbon Nanofibers–Gold Nanoparticles–Tyrosinase for the Detection of Ferulic Acid in Cosmetics

Development of a Novel Electrochemical Biosensor Based on Carbon Nanofibers–Cobalt Phthalocyanine–Laccase for the Detection of p-Coumaric Acid in Phytoproducts

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