Uncategorized – Page 23 – Pine Research Instrumentation Store

Chronopotentiometry (CP)

This article is part of the AfterMath Data Organizer Electrochemistry Guide

This is a galvanostatic method in which the current at the working electrode is held at a constant level for a given period of time. The working electrode potential and current are recorded as a function of time.

Synonyms: constant current electrolysis

Detailed Description

Like most other electrochemical techniques, this experiment begins with an induction period. During the induction period, a set of initial conditions which you specify is applied to the electrochemical cell and the cell is allowed to equilibrate to these conditions. Data are not collected during the induction period.

After the induction period, the current applied to the electrode is stepped to the value you specified for the duration of the experiment. The instrument's galvanostat circuit maintains the current at a steady level while measuring the potential of the working electrode. Throughout the electrolysis period, the potential and current at the working electrode are recorded at regular intervals based on the number of intervals you choose.

The experiment concludes with a relaxation period. During the relaxation period, a set of final conditions which you specify is applied to the electrochemical cell and the cell is allowed to equilibrate to these conditions. Data is not collected during the relaxation period.

At the end of the relaxation period, the post-experiment idle conditions are applied to the cell, and the instrument returns to the idle state.

Potential is plotted as a function of time.

Parameter Setup

The parameters for this method are arranged on two tabs on the setup panel. The Basic tab contains the parameters relating to the electrolysis. An additional tab for Post Experiment Idle Conditions is common to all of the electrochemical techniques supported by the AfterMath software.

Basic Tab

You can click on the “I Feel Lucky” button (located at the top of the setup) to fill in all the parameters with typical default values (see Figure 1). You will no doubt need to change the Current and Duration in the Electrolysis period box to values which are appropriate for the electrochemical system being studied. You may also want to change the Number of intervals in the Sampling Control box.

Figure 1: Basic Chronopotentiometry Setup

The Electrode Range on the Basic tab is used to specify the expected range of potentials. The potential of the electrode is dictated according to the Nernst equation, assuming a fully reversible system (see Theory section below), and will change to the value necessary to maintain the specified current. Therefore, if the choice of potential range is too small, actual potential may go off scale and the results will be truncated. If the potential range is too large, the potentiogram may have a noisy, choppy, or quantized appearance. Please see the ugly duckling webpage for an analogous situation in a voltammogram.

Some Pine potentiostats (such as the WaveNow and WaveNano portable USB potentiostats) have potential autoranging capability. To take advantage of this feature, set the electrode range parameter to “Auto”. This allows the potentiostat to choose the potential range “on-the-fly” while the chonopotentiogram is being acquired.

The waveform that is applied to the electrode is a simple pulse to the Current listed in the Electrolysis period box (see Figure 2). Note that the flat portions before and after the current pulse are the induction and relaxation periods, respectively.

Figure 2 : Waveform

Post Experiment Conditions Tab

After the Relaxation Period, the Post Experiment Conditions are applied to the cell. Typically, the cell is disconnected but you may also specify the conditions applied to the cell. Please see the separate discussion on post experiment conditions for more information.

Typical Results

The typical chronopotentiogram for a $2.5 \; mM$ solution of Ferrocene in $0.1 \; M \; Bu_4NClO_4/MeCN$ shows a plot similar to a titration (see Figure 3). Initially, the potential is slightly rising until nearly all of the ferrocene at the electrode is consumed, at which point the potential rises rapidly through an inflection point, followed by a trailing off of the potential after the inflection point.

Figure 3: Typical Results

The addition of a Baseline Tool (Tangent type) can be added to find the inflection point, the point at which the slope of the plot is greatest (see Figure 4). The potential at $1/2$ of the inflection point is approximately the $E^0$ for the species of interest ( $0.532 \; V \; vs. \; Ag/AgCl_{(aq)}$ ). Two additional Crosshair tools have been added to the plot to show the time at the inflection point and the time of $1/2$ of the inflection point.

Figure 4 : Worked up Results

In the second example, chronopotentiometry has been used to reduce $Ag^+$ onto a Pt electrode, as you might do in calibrating an Electrochemical Quartz Crystal Microbalance. The application of a cathodic current for a specified period of time reduces $Ag^+$ on the surface of the electrode as $Ag^0$ (see Figure 5, parameters were: $400 \;\frac{\mu A}{cm^2}$ cathodic current, $2 \; mm$ Pt WE, $0.05 \; M \; AgNO_3, \; 0.5 \; M \; HNO_3$ ). The current can be integrated to obtain a charge which can be correlated to the mass deposited on the electrode on the face of the quartz crystal (see Figure 6, parameters were the same as Figure 5). Note that since the potential is plotted against a $Ag^0$ quasireference electrode, the entire face of the platinum electrode is covered once the measured potential drops to roughly zero.

Figure 5: Silver Ion Deposition

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Figure 6 : Silver Ion Deposition Applied Electrolysis Current

Theory

The section presented here is common to both CP and CRP and is only a brief introduction to the theory of chronopotentiometry. If you use CP for electrolysis, please see the theory section of BE for a detailed discussion.

Please see Bard and Faulker¹ for a more detailed description of CP. CP is a technique that, like CV, can be utilized to calculate a concentration or a diffusion coefficient. Consider a reaction $O + e^- \rightarrow R$ with a formal potential $E^{0'}$ . As a current is applied to the working electrode, $O$ begins getting reduced at the electrode surface, producing $R$ . The potential of the electrode, $E$ , moves to values characteristic of the $O/R$ couple, based on a time-based Nernstian relation. As the concentration of $O$ drops to zero at the electrode surface the potential starts to rapidly increase to more negative values. The resulting $E-t$ curve is much like a potentiometric titration with a transition time (analogous to an equivalence point), $\tau$ . The potential at one half $\tau$ is $E^{0'}$ . The transition time is related to the concentration and diffusion coefficient of $O$ through the expression

$\tau^{3/2} = {\frac{2C_0^*nFAD_0^{1/2}}{3\beta}}$

where $C_0^*$ is the concentration of $O$ ( $mol/cm^3$ ), $n$ is the number of electrons, $F$ is Faraday's Constant ( $96485 \; C/mol$ ), $A$ is the electrode area ( $cm^2$ ), $D$ is the diffusion coefficient ( $cm^2/s$ ) and $\beta$ is the sweep rate ( $A/s$ ).

For rapid electrode kinetics, the time-based Nernstian equation is

$E = E_{\tau/4}+\frac{RT}{nF} \; ln\left({\frac{\tau^{1/2}-t^{1/2}}{t^{1/2}}}\right)$

where $E_{\tau/4}$ is equal to

$E_{\tau/4} = E^{0'} - \frac{RT}{2nF} ln \frac{D_O}{D_R}$

Finally, plotting $E \; vs \; ln\left({\frac{\tau^{1/2}-t^{1/2}}{t^{1/2}}}\right)$ should give a straight line with slope of $RT/nF$ for a reversible $E-t$ curve.

Application

The first example shows how CP is used to measure diffusion coefficients. Le et al.² applied a current to a membrane to generating concentration polarizations between bulk solutions and anion exchange membranes. The potential drop across the membrane is monitored as a function of time. By determining the transition time (point of inflection) they were able to calculate diffusion coefficients for several chloride salts in $0.1 \; M$ solutions. An exquisite example, considering the authors were able to determine diffusion coefficients of non-redox active species.

In the second example, Nagaraju and Lakshminarayanan³ used CP to grow mesoporous Au films for use for electro-oxidation of alcohols in alkaline media. The researchers showed that varying the current density and deposition times gave different surface areas. These films were then used to electro-oxidize methanol or ethanol, indicating that they could be used in direct alcohol alkaline fuel cells.

References

1. Faulkner, L. R.; Bard, A. J. Controlled-Current Techniques, Electrochemical Methods: Fundamentals and Applications, 2^nd ed.; Wiley: New Jersey, 2000; 305-330.

2. Le, X. T.; Viel, P.; Tran, D. P.; Grisotto, F.; Palacin, S. J. Phys. Chem. B, 2009, 113, 5829–5836

3. Nagaraju D. H.; Lakshminarayanan, V. J. Phys. Chem. C, 2009, 113, 14922–14926.

Additional Resources

Links: Electrochemist's Guide, AfterMath User's Guide, AfterMath Main Support Page

Related Techniques: Current Ramp Chronopotentiometry (CRP), Cyclic Current Ramp Chronopotentiometry (CCP), Constant Potential Electrolysis (BE)

Posted 1/4/2016 in Uncategorized
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Rotating Disk Bulk Electrolysis (BE-RDE)

This article is part of the AfterMath Data Organizer Electrochemistry Guide

Rotating disk bulk electrolysis (BE-RDE) is very similar to bulk electrolysis (BE) in that a constant current or constant potential is applied to a two or three compartment electrochemical cell in order to effect a large change in the oxidation state of an analyte. The amount of charge passed during the electrolysis can be calculated by integrating the current with respect to time. In almost any bulk electrolysis experiment, the solution is stirred in some way. The unique aspect of the method discussed here (BE-RDE) is that a rotating electrode is used both to stir the electrode and to convey the analyte towards the electrode surface.

Detailed Description

Like most of the other electrochemical techniques offered by the AfterMath software, this experiment begins with an induction period. During the induction period, a set of initial conditions is applied to the electrochemical cell and the cell is allowed to equilibrate to these conditions. The default initial condition involves holding the working electrode potential at the Initial Potential for a brief period of time (i.e., 3 seconds). If the potentiostat is being used to control the rotator speed, the rotator is also spun at the desired speed during this time. The WaveNow and WaveNano are capable of outputting a potential proportional to the desired rotator speed. This output can then be coupled to the input on an MSR rotator for fully automated control of the rotation speed.

Bulk electrolysis can be used to impart a large electrochemical change on a system. This can be complete oxidation or reduction or a species, the complete production of a product through electrochemical synthesis or just a partial oxidation or reduction of a compound to change the ratio of oxidized and reduced species.

Bulk electrolysis typically consists of a three chamber electrochemical cell with the chambers separated by glass frits. One chamber has the working electrode, which is the rotating electrode in this case. The second chamber usually has the reference electrode and the third chamber houses the auxiliary electrode.

After the induction period, a potential is applied to the cell for the specified period of time. After electrolysis the conditions specified in the relaxation period are applied to the cell.

Finally, the Post Experiment Conditions are applied to the cell.

The results of an electrolysis are usually presented as a plot of current versus time. Integrating the current versus time data produces a plot of charge versus time.

Parameter Setup

The parameters for this method are arranged on various tabs on the setup panel. The most commonly used parameters are on the Basic tab, and less commonly used parameters are on the Advanced tab. Additional tabs for Ranges and post experiment idle conditions are common to all of the electrochemical techniques supported by the AfterMath software.

Basic Tab

The Basic Tab (see Figure 1) contains parameters related to the Induction period, Electrolysis period, Relaxation period, Electrode range and Sampling control.

Some Pine potentiostats (such as the WaveNow and WaveNano portable USB potentiostats) have current and voltage autoranging capabilities. To take advantage of this feature, set the Electrode range parameter to “Auto”. This allows the potentiostat to choose the current and voltage ranges “on-the-fly” while the electrolysis is conducted. Please see the wiki regarding Electrode Range for a more detailed description and example of how the integrity of the data is affected by the choice of the range.

Typically, the Induction period, Relaxation period, and Sampling control parameters are filled in. You must enter a Potential and Duration for the electrolysis.

The Number of intervals in the Sampling control box is the number of data points taken during the experiment. A larger number of intervals means that the number of data points acquired will be more and data files will therefore be larger. Likewise, a smaller intervals means that fewer points will be acquired and data files will be smaller.

Figure 1: Basic setup for rotating disk controlled potential bulk electrolysis.

The waveform that is applied to the electrode first starts with the potential entered in the Induction period, followed by the potential entered in the Electrolysis period, and finally followed by the potential entered in the Relaxation period (see Figure 2).

Figure 2 : Waveform applied to electrode throughout experiment

The Electrode Range on the Basic tab is used to specify the expected range of current. If the choice of electrode range is too small, actual current may go off scale and be truncated. If the electrode range is too large, the current-time curve may have a noisy, choppy, or quantized appearance. Please see the ugly duckling webpage for an example of what happens when an improper range is selected.

Finally, the Rotation Parameters box contains the Speed parameter. Even if the potentiostat is not being used to control the rotator, you must enter a rotation speed.

Post Experiment Conditions Tab

After the Relaxation Period, the Post Experiment Conditions are applied to the cell. Typically, the cell is disconnected but you may also specify the conditions applied to the cell. Please see the separate discussion on post experiment conditions for more information.

Typical Results

In the typical result discussed below, the starting material, $K_4Fe(CN)_6$ , is partially oxidized to $K_3Fe(CN)_6$ by applying a sufficiently positive potential ( $+500 mV$ ) to drive the oxidation. The end result of the experiment is a mixture of $K_4Fe(CN)_6$ and $K_3Fe(CN)_6$ .

Prior to performing the electrolysis, the observed value of the open circuit potential ( $~50 mV$ ) was consistent with a solution containing primarily the reduced form of the analyte, $K_4Fe(CN)_6$ . In addition, a preliminary cyclic voltammogram (see Figure 3, experimental parameters: $K_4Fe(CN)_6$ in $0.1 \; M \; Na_2SO_4$ , $2 \; mm$ Pt disc working electrode, Pt counter electrode, sweep rate $100 \; mV/s$ ) confirms that a significant oxidation current is observed if the working electrode potential is at or above $500 \; mV$ .

Figure 3: Cyclic voltammogram of a Potassium Ferrocyanide Solution

The principle result from a bulk electrolysis is a plot of current versus time (see Figure 4, experimental parameters: $K_4Fe(CN)_6$ in $0.1 \; M \; Na_2SO_4$ , $5 \; mm$ Pt Disk, $2800 \; rpm$ , Pt mesh counter electrode, Electrolysis Potential = $0.5 V$ ). Integrating the current with respect to time will yield total charge ( $Q$ ) passed during the experiment. One way to accomplish this integration is to use the Area Tool. This tool can be added to a trace with a right-click on the trace followed by choosing Add Tool » Area from the menu. Once the tool is placed on the trace, you can manipulate the control points to choose the limits of the integration (see Figure 5). In this example, the total charge ( $Q$ ) passed during the electrolysis is $26.96 \; mC$ .

Figure 4: Bulk electrolysis of a Potassium Ferrocyanide Solution

Figure 5 : Using the control points to manipulate the area tool

Finally, the open circuit potential measured after the electrolysis period is $0.275 \; V$ . The ratio of oxidized to reduced species can then be calculated using the Nernst equation shown below

$E = E^{0'} + \frac{RT}{nF} ln \left(\frac{[K_3Fe(CN)_6]}{[K_4Fe(CN)_6]}\right)$

where $E$ is the open circuit potential, $E^{0'}$ is the formal potential ( $0.230 \; V$ in this instance), $R$ is the Universal Gas Constant, $T$ is the absolute temperature, $n$ is the number of electrons and $F$ is the Faraday Constant ( $96485 \; C/mol$ ). The ratio of oxidized to reduced species in this example is $5.77:1$ , meaning that the solution contains approximately $85\% \; K_3Fe(CN)_6$ and $15\% \; K_4Fe(CN)_6$ .

For a complete electrolysis example, consult the basic discussion of bulk electrolysis (BE).

Theory

The theory of bulk electrolysis is really quite simple. However, for a more thorough description of the technique and general considerations, you are directed to the literature.¹

Consider a reaction $O + e^- \rightarrow R$ , where $O$ is reduced to $R$ in a one electron reaction. A solution of $m$ moles of $O$ would require $m$ moles of electrons to completely reduce $O$ to $R$ . Upon applying a sufficient reducing potential, a large amount of $O$ is converted to $R$ and subsequently swept away from the electrode by stirring. As more $O$ is converted to $R$ the current falls off exponentially until it reaches background level. It is at this point, the electrolysis can be stopped. The charge ( $Q$ ) passed during the experiment can be obtained by integrating the current with respect to time.

$Q = {\int}i(t) \; dt$

The charge can then be converted to the number of moles of $O$ using the equation

$m = \frac{Q}{Fn}$

where $F$ is Faraday's constant, and $n$ is the number of electrons transferred during the reaction.

Application

The first instance of BE-RDE reduced $Cu(II)$ onto a copper disk electrode. Puglisi and Bard² utilized BE-RDE to remove most of the stirring noise associated with traditional electrolysis. Also, the authors were able to calculate a diffusion coefficient from the coulometric current-time curve that matched well with a value obtained using RDE.

One recent application highlights the usefulness of BE using RDE. Chardon-Noblat et al.³ synthesized a the macromolecule $[Ru(bpy)(MeCN)_2Cl_2]$ in a one-electron reduction of a $Ru(III)$ precursor. Previously, this molecule was only obtained in mixtures with the corresponding tris(acetonitrile) derivative, $[Ru(bpy)(MeCN)_3Cl]$ . The authors also chemically synthesize the $[Ru(bpy)(MeCN)_2Cl_2]$ using a one-electron reducing reagent, sodium diethyldithiocarbamate. Correlating the amount of charge passed during electrolysis with the amount of liberated chloride ion confirmed that the electrochemical synthesis of the desired complex proceeded with no side reactions. This application highlights the usefulness of bulk electrolysis for synthesis.

For more typical applications, please see the Application section of regular BE.

References

1. Faulkner, L. R.; Bard, A. J. Bulk Electrolysis Methods, Electrochemical Methods: Fundamentals and Applications, 2^nd ed.; Wiley: New Jersey, 2000; 417-470.

2. Puglisi, V. J.; Bard, A. J. Anal. Lett. 1970, 3, 443-448.

3. Chardon-Noblat, S.; Renfrew, A.; Lafolet, F.; Deronzier, A.; Jakonen, M.; Laurila E.; Haukka, M. Dalton Trans. 2008, 5891-5896.

Additional Resources

Links: Electrochemist's Guide, AfterMath User's Guide, AfterMath Main Support Page

Related Techniques: Bulk Electrolysis, Dual Electrode Bulk Electrolysis

Posted 1/4/2016 in Uncategorized

Controlled Potential Bulk Electrolysis (BE)

This article is part of the AfterMath Data Organizer Electrochemistry Guide

Bulk Electrolysis is a technique where either a constant current or constant potential is applied to an two or three comparment electrochemical cell in order to effect a large change in the oxidation state of a species of interest. The amount of charge passed during the electrolysis can be calculated by integrating the current with respect to time.

Synonyms: Controlled Potential Electrolysis, Potentiostatic Coulometry, Controlled Potential Coulometry,

Detailed Description

The basic setup for Controlled Potential Bulk Electrolysis is shown in Figure 1. Bulk electrolysis can be used to impart a large electrochemical change on a system. This can be complete oxidation or reduction or a species, the complete production of a product through electrochemical synthesis or just a partial oxidation or reduction of a compound to change the ratio of oxidized and reduced species.

Bulk electrolysis typically consists of a three chamber electrochemical cell with the chambers separated by glass frits. One chamber has the working electrode. This chamber should be stirred to provide maximum mass transport to the electrode during electrolysis. The second chamber usually has the reference electrode and the third chamber houses the auxiliary electrode. Note that both the working and auxiliary electrodes should have a large surface area (typically platinum meshes or vitrious carbon).

After the induction period, a potential is applied to the cell for the specified period of time. After electrolysis the conditions specified in the relaxation period are applied to the cell.

Finally, the Post Experiment Conditions are applied to the cell.

Current is plotted as a function of time which can be integrated to yield total charge passed during electrolysis.

Parameter Setup

The parameters for this method are arranged on the two tabs of the setup panel. The parameters relating to bulk electrolysis are on the Basic tab and the post experimental parameters are on the Post experiment conditions tab.

Basic Tab

The Basic Tab (see Figure 1) contains parameters related to the Induction period, Electrolysis period, Relaxation period, Electrode range and Sampling control.

Typically, the Induction period, Relaxation period, and Sampling control parameters are filled in. You must enter a Potential and Duration for the electrolysis.

Figure 1: Basic setup for controlled potential bulk electrolysis.

Figure 2 : Waveform applied to electrode throughout experiment

Post Experiment Conditions

Typical Results

In the typical result discussed below, $K_4Fe(CN)_6$ was oxidized to $K_3Fe(CN)_6$ by the application of a potential of $0.57 \;V$ . The purpose of the experiment was to convert $Fe^{2+}$ in the complex to $Fe^{3+}$ . A cyclic voltammogram of the solution is shown below to show that the potential of $0.57 \; V$ will oxidize completely $K_4Fe(CN)_6$ (see Figure 3, a $2 \; mm$ Pt disc working electrode and Pt counter electrode were used with a sweep rate of $100 \; mV/s$ ).

Figure 3 : Cyclic Voltammogram of a Potassium Ferrocyanide Solution

The principle result from a bulk electrolysis is a plot of current versus time (see Figure 4, experimental conditions were: $5 \; mL$ of $K_4Fe(CN)_6$ in $0.1 \; M \; KCl$ , Pt mesh working electrode, Pt mesh counter electrode, Electrolysis Potential $= 0.57 V$ ). Integration of current with respect to time will yield total charged ( $Q$ ) passed during the experiment.

Figure 4 : Bulk Electrolysis of a Potassium Ferrocyanide Solution.

Right-click on the trace to bring up a dialog box and choose Add Tool » Area in order to integrate the area under the curve (see Figure 5).

Figure 5 : Add Area Tool to electrolysis results

You can manipulate the control points of the tool in order to obtain a proper area under the curve (see Figure 6).

Figure 6 : Drawing the proper baseline

The total charge ( $Q$ ) passed during electrolysis was $459.0 \; mC$ or $0.459 C$ . This charge can then be used to calculate the number of moles of species in solution through the use of Faraday's Constant ( $F, \; 96485 \; C/mol$ ) using the equation below:

$m = \frac{Q}{Fn}$

where $n$ is the number of electrons for the redox process. $F$ and $Q$ are defined above. The number of moles of
$K_4Fe(CN)_6$ in solution was $4.76$ x $10^{-6}$ . Dividing this by the volume of solution ( $4 \; mL$ in this instance) in the cell, yields a concentration of $1.19$ x $10^{-3} \; M$ .

Theory

The theory of bulk electrolysis is really quite simple. However, for a more thorough description of the technique and general considerations, please see the literature.¹

$Q = \int i(t) dt$

The charge can then be converted to the number of moles of $O$ using the equation

$m = \frac{Q}{Fn}$

where $F$ is Faraday's constant, and $n$ is the number of electrons transferred during the reaction.

Application

Four examples of the usefulness of bulk electrolysis are shown below.

The first example shows has bulk electrolysis can be used to quantify the amount of a species in solution. Wolfe and coworkers² electrolyzed solutions of gold nanoparticles passivated with a layer of 6-(ferrocenyl) hexanethiol. Typically, quantitation of the number of ligands protecting a nanoparticle is accopmlished through the use of thermogravimetric analysis (TGA). However, since ferrocene sublimes easily, TGA was inconclusive. The researchers were able to quantitate the number of ligands by using solutions of known nanoparticle concentration and oxidizing ferrocene to ferrocenium. By determining the charge passed during the experiment, they were able to calculate the number of ligands per nanoparticle. This first example is useful because it shows that an electrochemical technique such as bulk electrolysis can be used in places whether traditional techniques might fail.

The second example uses bulk electrolysis to deposit a film of cobalt-based water oxidation catalysts. Surendranath and coworkers³ oxidized $Co^{2+}$ to $Co^{3+}$ in the presence of various electrolyte solutions. $Co^{3+}$ reacts with the electrolytes, forming a thin film of particles on an ITO electrode. Complete electrolysis of the solution was not necessary to form the films that were later used as water oxidation catalysts. This second example is useful since it illustrates that bulk electrolysis need not be solely used to completely oxidize or reduce a species in solution. Rather, the partial electrolysis was enough for the researchers to make their thin films.

The third example shows how bulk electrolysis can be used in a chemical synthesis. Blattes and coworkers⁴ used bulk electrolysis to simultaneously generate cycloaddition partners for inverse-electron demand Diels-Alder reactions. Inverse-electron demand Diels-Alder reactions have not been used as extensively as the normal Diels-Alder reaction due to the limited availability of readily accessible simple electron-deficient dienes. Using bulk electrolysis, the researchers were able to access, in situ, two unstable entities for use in cycloaddition reactions. The researchers were even able to show regiospecificity and diastereospecificity in the case of heterocyclic annulations.

Finally, the fourth example shows how bulk electrolysis can be used to teach electrochemisty to first-year undergraduate students. Chyan and Chyan⁵ used screen-printed electrodes to examine the metal-deposition process through bulk electrolysis. Normally, electrochemistry is introduced at a later time in the undergraduate curriculum when students have had more time to develop essential lab skills. Since the electrodes are screen printed the usually labor-intensive step of electrode preparation is removed. Using a variety of deposition solutions, students are able to generate films of different, visually-attractive films in one lab period. Along with the introduction of Faraday's Law, the researchers are also able to introduce electrodeposition efficiency since these electrodes can be weighed after the deposition process. This great example shows a wonderful way to get students hooked on the fascinating world of electrochemistry.

References

1. Faulkner, L. R.; Bard, A. J. Bulk Electrolysis Methods, Electrochemical Methods: Fundamentals and Applications, 2^nd ed.; Wiley: New Jersey, 2000; 417-470.

2. Wolfe, R. L.; Balasubramanian, R.; Tracey, J. B.; Murray, R. W. Langmuir, 2007, 23, 2247–2254.

3. Surendranath, Y.; Dinca, M.; Nocera, D. G. J. Am. Chem. Soc., 2009, 131, 2615–2620.

4. Blattes, E.; Fleury, M.-B.; Largeron, M. J. Org. Chem., 2004, 69, 882-890.

5. Chyan, Y.; Chyan, O. J. Chem. Educ. 2008, 85, 565.

Additional Resources

Links: Electrochemist's Guide, AfterMath User's Guide, AfterMath Main Support Page

Posted 1/4/2016 in Uncategorized

CBP Bipotentiostat: Upgrade Options

Owners of the Pine CBP Bipotentiostat system who are presently using our classic PineChem software may wish to upgrade to our new AfterMath software package. Such an upgrade is likely to involve both a software upgrade and a corresponding hardware upgrade. This article discusses some of the issues to consider when contemplating an upgrade.

What can I get for free?

All users of our classic PineChem software may take advantage of the FREE AfterMath Viewer download option. If you are only looking for the ability to analyze data and prepare plots from your bipotentiostat data, then you can download a free copy of our AfterMath Viewer software package. The viewer permits you to import PineChem data files directly into the AfterMath viewer software, and then you can prepare plots and analyze data using AfterMath.

AfterMath Download

What if I want to control the CBP Bipotentiostat using AfterMath?

If you wish to to control your CBP Bipotentiostat using AfterMath, then you need to consider upgrades to all five of the following components in your existing CBP system:

Interface Board Upgrade. The interface board (which is installed inside the computer) must be a 16-bit interface board. Older bipotentiostat systems are likely to have an earlier 12-bit interface board rather than a 16-bit interface board. Because AfterMath uses the interface board to digitally generate the waveform applied to the working electrode, it is essential to use a higher resolution 16-bit interface board when working with AfterMath. If you have purchased your CBP bipotentiostat system recently, you may already have a 16-bit interface board. If not, you will need to purchase a 16-bit board (click here for details)
Filter Board Upgrade. When using the interface board to send digital waveforms to the bipotentiostat and to record the response from the potentiostat, it is very likely that noise will be introduced as signals travel between the computer and the bipotentiostat. For this reason, Pine strongly recommends that a signal filter board be installed in the bipotentiostat. This easily installed add-on board provides various levels of signal filtering for both the excitation signals and the response signals travelling in the interface cable. (click here for details)
Software License Upgrade. The software license for AfterMath is tied to the particular interface board installed in the computer. For this reason, it is important to first settle the issue of the 16-bit interface board upgrade (discussed above) before ordering AfterMath from Pine. You will need to report the serial number of your interface board to Pine at the time you purchase the AfterMath upgrade (click here for details)
Operating System Upgrade. AfterMath works with Windows 8, Windows 7, Windows Vista, and Windows XP (32 bit). If you are using a computer with an earlier version of Windows, then you will need to upgrade the operating system. (click here for minimum system requirements)
Device Driver Upgrade. If you upgrade the interface board and/or the operating system, then you will very likely need to upgrade the device driver for the interface board. (click here for device driver information)

How much does it cost to upgrade?

Pine is happy to provide you with a quotation for an upgrade package. Contact Pine at (919) 782-8320 or using our online contact form (click here). We will be happy to help you evaluate exactly what you need to successfully upgrade your system.

In general, most customers choose to purchase the filter board together with the software license directly from Pine. In the event that an interface board upgrade is also required, Pine can also supply the interface board, but it is generally less expensive to purchase the interface board directly from National Instruments.

What features does AfterMath offer?

AfterMath software has many advantageous features. In each of the tabs below, the functions of the software are displayed.

Classic PineChem

Data Analysis and Plotting Features
Multi-Trace Overlay Plotting
Peak Area, Height & Baseline Tools
Trace Data Transform Functions
Drag-n-Drop Traces on to Plots
Full Support for SI Units
Select Traces, Segments, and Points
International Unicode Font Support
Superscripts, Subscripts, Symbols
Publication Quality Printing
Queueing Multiple Experiments
Control of Multiple Potentiostats
Cell Control while Idle

System Clipboard Support
Copy Trace Data to Clipboard
Copy Trace Data from Clipboard
Copy Plot Image to Clipboard

Original PineChem Methods:
Cyclic Voltammetry (CV)
Bulk Electrolysis (BE)
– Constant Potential
Dual Electrode Cyclic Voltammetry (DECV)
– Collection, Shielding, and Window variants
Dual Electrode Bulk Electrolysis (DEBE)
– Controlled Potential

Additional Single Step Methods:
Open Circuit Potential vs time (OCP)
Bulk Electrolysis (BE)
– Constant Current
Dual Electrode Bulk Electrolysis (DEBE)
– Mixed Mode Constant Current and/or Potential
Single-Step Chronoamperometry (CA)

Staircase, Pulse, and Multistep Methods:
Double-Step Chronoamperometry (DPSCA)
Linear Staircase Voltammetry (LSCV)
Differential Pulse Voltammetry (DPV)
Square Wave Voltammetry (SWV)
Normal Pulse Voltammetry (NPV)
– including Reverse Normal Pulse Voltammetry

Cyclic Staircase & Pulse Methods:
Cyclic Staircase Voltammetry (CSCV)
Cyclic Differential Pulse Voltammetry (CDPV)
Cyclic Square Wave Voltammetry (CSWV)
Cyclic Normal Pulse Voltammetry (CNPV)
– including Cyclic Reverse Normal Pulse Voltammetry

Galvanostatic Methods:
Chronopotentiometry (CP)
Current Ramp Chronopotentiometry (CRP)
Cyclic Current Ramp Potentiometry (CCP)

Stripping Voltammetry (anodic and cathodic):
Stripping Voltammetry (ASV)
Differential Pulse Stripping Voltammetry (DPSV)
Square Wave Stripping Voltammetry (SWSV)

Data Storage Formats
PineChem Setup File (.stp)
PineChem Results File (.exp)
AfterMath Data Archive (.paax)

Limited
Limited
Limited
No
No
No
No
No
No
No
No
Yes

No
No
No

Yes
Yes
Yes
Yes
Yes
Yes
Yes

No
No
No
No
No
No

No
No
No
No
No
No

No
No
No
No
No

No
No
No

No
No
No

Yes
Yes
No

AfterMath – Viewer Only Version

System Clipboard Support
Copy Trace Data to Clipboard
Copy Trace Data from Clipboard
Copy Plot Image to Clipboard

Galvanostatic Methods:
Chronopotentiometry (CP)
Current Ramp Chronopotentiometry (CRP)
Cyclic Current Ramp Potentiometry (CCP)

Stripping Voltammetry (anodic and cathodic):
Stripping Voltammetry (ASV)
Differential Pulse Stripping Voltammetry (DPSV)
Square Wave Stripping Voltammetry (SWSV)

Data Storage Formats
PineChem Setup File (.stp)
PineChem Results File (.exp)
AfterMath Data Archive (.paax)

Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes

Yes
Yes
Yes

No
No
No
No
No
No
No

No
No
No
No
No
No

No
No
No
No
No
No

No
No
No
No
No

No
No
No

No
No
No

Import Only
Import Only
Yes

AfterMath – Full Version

System Clipboard Support
Copy Trace Data to Clipboard
Copy Trace Data from Clipboard
Copy Plot Image to Clipboard

Galvanostatic Methods:
Chronopotentiometry (CP)
Current Ramp Chronopotentiometry (CRP)
Cyclic Current Ramp Potentiometry (CCP)

Stripping Voltammetry (anodic and cathodic):
Stripping Voltammetry (ASV)
Differential Pulse Stripping Voltammetry (DPSV)
Square Wave Stripping Voltammetry (SWSV)

Data Storage Formats
PineChem Setup File (.stp)
PineChem Results File (.exp)
AfterMath Data Archive (.paax)

Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes

Yes
Yes
Yes

Yes
Yes
Yes
Yes
Yes
Yes
Yes

Yes
Yes
Yes
Yes
Yes
Yes

Yes
Yes
Yes
Yes
Yes
Yes

Yes
Yes
Yes
Yes
Yes

Yes
Yes
Yes

Yes
Yes
Yes

Import Only
Import Only
Yes

Download Options

PineChem owners can purchase the full version of AfterMath.

Purchase AfterMath Upgrade

Alternatively, PineChem owners can download the AfterMath Viewer for free.

Free AfterMath Viewer

Posted 1/4/2016 in Uncategorized

Autoranging

This article is part of the AfterMath Data Organizer Electrochemistry Guide

The choice of measurement sensitivity is very important when performing an electrochemical technique. If the instrument sensitivity is set too low, then small signals may be lost in the noise. If the instrument sensitivity is adjusted too high, then even relatively small signals may overwhelm the measurement circuitry, causing large features in the signal to be “clipped” or truncated.

In almost every electrochemical technique, the software is able to automatically choose the proper sensitivity for the excitation signal. For example, before a cyclic voltammetry experiment even begins, the software is well aware that the potential excitation waveform is a simple triangle wave that will alternate between a few known setpoints. Because the magnitude of these setpoints is known ahead of time, the software can automatically match the proper potential measurement sensitivity to these known setpoint levels. Such “software autoranging” is always possible for whichever signal (potential or current) is the excitation signal.

Choosing the proper range for measuring response signals is a bit trickier. the autoranging feature for response signals, when available, is generally done in “real time” by the instrument itself. During an experiment, the instrument actively monitors the response signal levels and makes “on the fly” adjustments to the range settings. For example, in a cyclic voltammetry experiment, the current generally starts off at some small level. Then, as the potential is swept toward the formal potential for an electroactive substance in the cell, the current begins to increase quickly. The instrument senses this increase in current and automatically switches to a less sensitive current range to prevent the ever-growing current signal from being “clipped”.

The advantage to having an instrument capable of autoranging response signals is that you don't need to specify the signal sensitivity ahead of time. The instrument determines the proper range while the experiment is occurring. The disadvantage of such instrument-based autoranging is that small glitches may be introduced into your results whenever the instrument switches from one measurement range to another. These glitches are caused by a momentary loss of cell control during the circuit switching event.

In the worst case, the proper choice of current or potential measurement sensitivity must be determined by a trial-and-error process. By repeating the same experiment once or twice, you are able to determine the anticipated signal levels and adjust the instrument sensitivity accordingly.

The choice to use autoranging for the potential and current signals is made on the Ranges Tab (see above). By default, both of these range settings are set to “Auto”, meaning that the software and/or instrument will attempt to choose an appropriate signal sensitivity automatically.

Not all instruments support the autoranging feature for response signals. For instruments which do not support this feature, choosing the “Auto” range setting usually causes the least sensitive range setting to be selected.

Links: Electrochemist's Guide, AfterMath User's Guide, AfterMath Main Support Page

Related Topics: specifying ranges

Posted 1/4/2016 in Uncategorized
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CBP Bipotentiostat: System Requirements

In general, the personal computer used with the CBP bipotentiostat system must be a desktop or tower system (not a laptop). There must be one full size PCI slot available to accomodate the interface board. The operating system must be one of the versions of Microsoft Windows listed below.

Processor Class: Pentium IV or equivalent

Operating System: Windows XP (32 bit only), Windows Vista (32 or 64 bit), or Windows 7 (32 or 64 bit)

Processor Speed: 1 GHz or faster

Physical Memory: 512 MB or higher

GUI Platform: Microsoft .NET 2.0 (what's this?)

Screen Resolution: 1280 x 1024 pixels recommended

PCI Port: One full size PCI slot must be available for the interface board

Device Driver: The interface board uses device driver software developed by National Instruments, Inc. (www.ni.com)

Optical Drive: Required if you wish to install AfterMath from a CDROM shipped to you by Pine

Related Links: CBP Bipotentiostat Support Page

Posted 1/4/2016 in Uncategorized
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CBP Bipotentiostat: NIDAQ Permissions

Security Issues

The Legacy NIDAQ device drivers used with the Pine AFCBP1 Bipotentiostat typically work without any problems when they are installed from an account which has administrative privileges and when the AfterMath or PineChem software applications are run from an account which has administrative privileges.

Problems are encountered, however, when normal user accounts are used to install NIDAQ or to run the AfterMath or PineChem software applications. Typically, customers at large organizations with central control of computing resources are the first to encounter these problems (because such customers do not have access to the administrative accounts on their laboratory computers).

There are ways to overcome these problems if a person with an administrative account is available to assist with the initial installation of the NIDAQ device driver. This article describes Pine's recommendations about how to install AfterMath and NIDAQ in an environment where everyday users will not have access to an administrative account.

Installation

Installation of AfterMath, PineChem and/or the NIDAQ device drivers should ALWAYS be performed using an account with administrative privileges.

Installation is generally a simple matter of downloading the appropriate software (or using an installation CD-ROM), and then running the “setup.exe” file in the installation package. See the AfterMath Installation Guide or NIDAQ Installation Guide for more information.

Instructions for downloading NIDAQ are provided at the end of this article.

Post-Installation NIDAQ Tuning

NOTE: The information in this section is based on National Instruments KnowledgeBase article 3CQGAFHS which has the title ”How Do I Give Non-Administrators Full Control Over National Instruments Products?”.

After the main installation using an administrative account has been completed successfully, the next step is to make sure that all users (both administrators and non-administrators) have access to the folders in which the National Instruments applications were installed. These folders are all typically located within the parent folder “C:Program FilesNational Instruments” (see below).

Note that the following steps should be performed while you are still logged into an administrative account.

Locate the parent National Instruments folder (see below):

Go to the Properties dialog box associated with the parent folder (see below):

Select the “Security” tab, click on the group called “Users”, and then check the box to allow “Full Control” over the folder (see below):

Click the “OK” button after making the changes described above.

At this point, log out of the administrator account and then log into one of the normal user accounts. Launch AfterMath from the normal user account. After a few seconds, AfterMath should detect the presence of the AFCBP1 bipotentiostat connected to the system.

Download

The required NIDAQ device driver (for the interface board) may be downloaded directly from the National Instruments web site.

Device Driver Download

Posted 1/4/2016 in Uncategorized
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CBP Bipotentiostat: Signal Filters

A complete CBP bipotentiostat system is a combination of the bipotentiostat itself, an interface board and cable (manufactured by National Instruments), and a Windows-based desktop computer (usually provided by the customer). With any system made up of components from a variety of manufacturers, it is important to assure that all of the components are working together in the best possible configuration. In the specific case of the CBP bipotentiostat, a common issue is making sure that the interconnections between the components are made in such a way that excess signal noise is not introduced into the system. This article describes best practices for electrical connections (to eliminate most signal noise at its source) and for signal filtering (for removing noise as the signals are sampled).

Ground Connections

When working with the CBP bipotentiostat system, it is very important to make certain that all parts of the system are properly grounded. The computer system, the monitor, and the bipotentiostat should all be connected to the same grounded power source (i.e., do not connect the computer and the bipotentiostat to different power circuits).

The metal chassis of the bipotentiostat is connected to the earth ground via the third prong on the power cord. The front panel of the bipotentiostat has a convenient binding post (in the lower right corner) that can be used to make additional earth grounding connections as needed. Typically, any metal object located near the electrochemical cell (such as a rotating disk electrode, a clamp holding the cell, or a Faraday cage around the cell) should be connected to the earth ground.

Cell Cable Shielding

The various cables which connect the bipotentiostat to the electrochemical cell should be of the shielded (coaxial) type whenever possible. These cell cables should be routed well away from any power cords, network cables, or video monitors, all of which are considerable sources of electrical noise.

The cable which connects to the reference electrode must be of the shielded coaxial type. The shield of this cable is driven by the bipotentiostat to the same potential as the reference electrode. Thus, the shield line on the reference electrode cable should never be connected to ground.

Internal Filter Board Settings

There is a signal filter board installed inside the CBP bipotentiostat which filters the signals which travel through the interface cable. Both the excitation signals and the response signals are filtered using this board. Note that this board may not be present in some early model CBP bipotentiostats, but it may be obtained from Pine and installed in an existing CBP system. (click here for installation instructions)

CAUTION:
If an internal filter board is installed inside the CBP bipotentiostat system, and the older PCI-6030E interface board is being used, there are limitations regarding the current and potential measurement ranges that must be taken into consideration. Be sure to read and understand the description of the limitations of this particular interface board (click here for details). In addition, be sure to use AfterMath Version 1.2.4532 (or a more recent version) when working with this combination of boards.

Excitation Signal Filters

The waveforms applied by the interface board to the bipotentiostat are called the excitation signals. There is one excitation signal for each of the two working electrodes (K1 and K2). These excitation signals are generated by the interface board (which is installed in a Windows-based personal computer), and the signals travel through the interface cable to a connector on the back panel of the bipotentiostat. After passing through the back panel, these signals may be filtered to remove any digital noise from the computer that may have traveled through the interface cable.

There are three filtering options available for each excitation signal. One option is to allow the signal to pass through without any filtering. The other two options are low-pass filters with either a 10 Hz or 1 KHz cutoff frequency. The excitation signal filters for each signal (K1 and K2) may be set independently; however, it is common practice to apply the same amount of filtering to both signals.

The boxes below list the jumper settings for the filtering options available for the K1 and K2 excitation signals. The factory default settings use the 1 kHz filters for both K1 and K2.

K1 Electrode Excitation Signal

1 kHz Filter
JP6 – A&B open
JP7 – pins 1&2 closed

10 kHz Filer
JP6 – A&B closed
JP7 – pins 1&2 closed

No Filter
JP7 – pins 2&3 closed

K2 Electrode Excitation Signal

1 kHz Filter
JP8 – A&B open
JP9 – pins 1&2 closed

10 kHz Filer
JP8 – A&B closed
JP9 – pins 1&2 closed

No Filter
JP9 – pins 2&3 closed

The two figures below show the proper configurations for the jumpers which control filtering of the excitation signals.

Example Settings for JP6 and JP8

Example Settings for JP7 and JP9

Response Signal Filters

The current and potential signals measured at both working electrodes are the four principle response signals which travel from the bipotentiostat back to the interface board through the interface cable. All four of these signals (E1, I1, E2, and I2) are filtered using low-pass filters. The cutoff frequency for all four low-pass filters is adjusted using jumpers JP1 and JP2 on the signal filter board. There are four different cutoff frequencies available (1, 10, 100, and 1 kHz). The frequency setting applies to all four signals (i.e., it is not possible to set the frequency individually for each response signal). The factory default settings use the 10 Hz filters for both K1 and K2.

Electrode Response Signal Filters

1 Hz
JP1 – all pins open
JP2 – all pins open

10 Hz
JP1 – all pins open
JP2 – pins 1&2 closed

100 Hz
JP1 – pins 1&2 closed
JP2 – all pins open

1 kHz
JP1 – pins 1&2 closed
JP2 – pins 1&2 closed

External Software Filter Control

The choice of cutoff frequency for the response signals may be placed under external software control (via the interface board) by setting the jumpers as shown in the figure below. This option is only available when using AfterMath (version 1.3 or higher) in conjunction with an M Series interface board (such as the PCI-6251). Contact Pine for further details.

Jumper Settings to Permit External Control of Filter
JP1 – pins 2&3 closed
JP2 – pins 2&3 closed

Ground Reference Selection (Excitation Signals)

The excitation signals generated by the interface board are (by default) referenced with respect to the analog output ground (AOGND) located on the interface board itself. It is possible to use a jumper on the filter board to cause the excitation signals to be referenced with respect to the local ground for the CBP bipotentiostat instead. This latter choice is not recommended at this time. Contact Pine for further details.

Jumper Settings for Excitation Signal Ground Reference

Interface Board Ground (AOGND)
JP3 – pins 2&3 closed

CBP Local Ground (DC Common)
JP3 – pins 1&2 closed

Ground Reference Selection (Response Signals)

It is possible to connect the response signal ground reference from the CBP bipotentiostat (i.e., the DC Common) to any of three different ground references on the interface board. By default, no such connections are made. However, a jumper on the filter board can be used to connect the DC Common to one of three lines on the interface board (AOGND, AISENSE, or AIGND). Such connections are not recommended at this time. Contact Pine for further details.

Jumper Settings for Response Signal Ground Reference

No Connection (default)
JP5 – all pins open

AOGND
JP5 – pins 1&2 closed

AISENSE
JP5 – pins 3&4 closed

AIGND
JP5 – pins 5&6 closed

Feedback Attenuation Knob

An analog bipotentiostat circuit is based on a set of feedback loops built from operational amplifiers. In any such feedback system, there is a tradeoff between the response time of the system and the stability of the system. To increase the stability of the system, the response time of the system can be intentionally attenuated (i.e., slowed or damped). Conversely, adjusting the system to be more responsive may make the system prone to oscillations caused by constructive feedback and amplification of small noise signals.

When a potentiostat system is connected to a particular electrochemical cell, it is often necessary to tune the responsiveness of the instrument to match the cell geometry and type experiment being performed. In general, it is desirable to tune the potentiostat to the minimum amount of feedback attenuation required to guarantee stable operation. Finding the proper amount of attenuation is often a trial-and-error process.

On the back panel of the CBP bipotentiostat, there is a knob that can be used to adjust the amount of attenuation in the analog feedback circuits. This knob has four settings marked 0, 1, 2, and 3. The lowest setting (0) represents the least amount of attenuation (fastest instrument response time) while the highest setting (3) introduces a great deal of attenuation into the circuit (slow instrument response time).

Feedback Attenuation Knob (back panel)

When possible, the instrument should be operated with the feedback attenuation knob in position “0” or “1”. This allows the instrument to remain fairly responsive to sudden changes in signal levels without significant distortion.

In certain slow, steady-state experiments (such as rotating disk voltammetry and rotating ring-disk voltammetry), the attenuation knob can be adjusted to position “2” to provide even greater stability. Because such steady state experiments do not typically generate signals which change rapidly, the extra damping associated with position “2” is not a major concern.

Position “3” is not recommended except for those cases where signals remain constant over very long periods of time (i.e., very long-term electrolysis experiments).

Related Hardware Links: Filter Board Installation, CBP Bipotentiostat, Interface Boards

Related Software Links: AfterMath, PineChem, NIDAQ Device Driver

Posted 1/4/2016 in Uncategorized
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CBP Bipotentiostat: System Installation

This article is meant as a guide to the installation of the CBP Bipotentiostat system and the AfterMath Data Organizer software package which controls this instrument. It includes instructions for the physical installation of the interface board in your computer, the NI-DAQ device driver software, connection of the interface board to the bipotentiostat, and finally, testing of the overall system. Information in this article is generally only needed during the initial installation and setup of the system.

Overview

A successful installation of your CBP bipotentiostat system involves doing the following steps in the order listed below:

Verifying that your computer system meets the minimum requirements.

Installing the software

Installing the AfterMath software package on your computer system.

Installing the NIDAQ interface board device driver on your computer system (includes a reboot of your system).

Installing the hardware

Powering off your system.

Physically installing the interface board inside your computer system.

Connecting the interface board to your potentiostat.

Powering on your system again.

Verifying the installation

Testing to assure that your computer's Windows operating system recognizes the interface board.

Testing to assure that the NIDAQ device driver recognizes the interface board.

Testing to assure that AfterMath recognizes and can communicate with your bipotentiostat.

Host PC Requirements

In general, the personal computer used with the CBP bipotentiostat system must be a desktop or tower system (not a laptop), and it must be running the Windows XP operating system. There must be one full size PCI slot available to accomodate the interface board.

Processor Class: Pentium IV or equivalent

Operating System: Windows XP, Windows Vista, Windows 7

Processor Speed: 1 GHz or faster

Physical Memory: 512 MB or higher

GUI Platform: Microsoft .NET 2.0 (what's this?)

Screen Resolution: 1280 x 1024 pixels recommended

PCI Port: one full size PCI slot must be available

Optical Drive: Required if you wish to install AfterMath from a CDROM shipped to you by Pine

Software Installation

Successful installation of the the CBP Bipotentiostat system requires installing AfterMath and the NIDAQ Device Driver (see below for more information).

AfterMath Installation

If you purchase a CBP Bipotentiostat system and the AfterMath software package at the same time, then the AfterMath software is shipped to you on a CDROM. In most cases, when you insert this CDROM into your computer, the AfterMath installer will start automatically. However, if the installer does not start automatically, you can simply browse to your CDROM drive and double-click on the setup.exe application on the CDROM (see image below).

The first four screens you are likely to see during the installation process are shown below. The most important of these is the fourth screen where you specify the location where the AfterMath software should be installed and also which users (“Everyone” or “Just Me”) have access to AfterMath. We recommend choosing the “Everyone” option.

If you encounter different screens than those shown above when you first start the installation process, it is most likely because one or two Microsoft system components are missing from your computer. If these components are missing, then you may be prompted to download and install two Microsoft system components directly from the Microsoft web site. This task is easier if your computer is directly connected to the Internet. If your computer is not directly connected to the Internet, then you can download these two system components using a different computer and then transfer them using a USB drive.

The latest version of AfterMath and/or the Microsoft system components required by AfterMath are available on another website.

Latest AfterMath Version

More detailed screenshots of the entire AfterMath installation process are also available.

AfterMath Screenshots

After you have installed AfterMath, you may briefly launch the application if you wish. However, AfterMath will not be able to detect or control your bipotentiostat until you have completed the installation of the device driver and the interface board as described in the succeeding sections.

NIDAQ Device Driver Installation

The interface board and device driver software are products of National Instruments Corporation (Austin, TX). An appropriate device driver is usually included on the software disk from National Instruments that comes with the interface board. Drivers may be downloaded from the National Instruments website (see below). This information is also located on the Aftermath install disk in the “drivers” directory.

NIDAQmx 9.x.x for XP (32 bit only), Vista, and Windows 7 – Click Here

NIDAQmx 8.9.5 for XP (32 bit only) and Vista – Click Here

NIDAQ 7.4.1 for XP (32 bit only) – Click Here

NIDAQ drivers may download directly from the National Instruments web site.

Device Driver Download

SECURITY NOTE: The NIDAQ driver should always be installed from a Windows user account which has administrative privileges. If the user who will routinely be using the AFCBP1 Bipotentiostat does not have an account with administrative privileges, then special steps must be taken to assure that the user is granted access to certain installation folders.

Account With No Administrative Privileges

ALWAYS INSTALL THE DEVICE DRIVER BEFORE INSTALLING THE INTERFACE BOARD

Hardware Installation

In order that the hardware is installed correctly, please perform the following ordered steps.

Power Off Your Computer

In preparation for physically installing the interface board in your computer, you should turn off your computer and disconnect the power cord from the power source.

Physical Installation

The interface board is designed to fit into one of the available PCI slots on your computer's motherboard. Installation will involve opening up your computer's case and working with small hand tools.

If you have never installed a PCI card before, you may find the following YouTube videos helpful. Note that these example videos describe how to install network cards, so some of the information in these videos is not applicable to the interface board used with the CBP bipotentiostat system. Nevertheless, these videos will give you a good idea how to install any kind of PCI card.

http://www.youtube.com/watch?v=I2iCxPi1o7E

http://www.youtube.com/watch?v=L50Azbh34sk

If you prefer to look at a series of still photos which describe how to install a PCI card, then take a look at the following links:

http:/compreviews.about.com/od/tutorials/ss/DIYPCICard.htm

http:/lifehacker.com/software/feature/how-to-install-a-pci-card-135479.php

Potentiostat Connection

A two meter long cable with a special adapter is used to connect the potentiostat to the interface board. Be sure to route this cable away from any potential noise sources such as power cords or network communications cables.

Plug one end of the cable into the interface board. Use the two threaded screws on either side of the connector to firmly mount the cable.

Plug the special adapter into the connector on the back of the potentiostat. Then, plug the other end of the cable into the adapter.

A properly installed cable is shown below. Note how the cable is routed away from the power cord.

Powering On Your Computer System

After you have installed the interface board, you should close the computer's case and connect the computer to its power source. Then, turn on the computer. Soon after your computer has rebooted, you should notice a series of one or more messages in the lower-right hand corner of the screen which indicate that Windows has recognized the presence of the new interface board.

Installation Verification

To verify that the installation was successful, the interface board must be detected by Windows, the NIDAQ Device Driver, and AfterMath. The sections below detail how to assess the installation.

Interface Board Recognition by Windows

To confirm that Windows recognizes the presence of the interface board that you have just installed in your computer, use the Windows Device Manager to view a list of the hardware devices attached to your computer.

One of the easiest ways to access the Windows Device Manager is to right-click on the “My Computer” icon on the desktop and choose the “Properties” item from the menu. Then, choose the Hardware tab and click on the Device Manager button.

The main view offered by the Device Manager is a list of all of the hardware components installed in your computer. This list is organized into various catagories, and each computer will have a unique list depending upon which devices are installed. The interface board usually appears under the category called Data Acquisition Devices.

Interface Board Recognition by the NIDAQ Device Driver

Use the National Instruments' Measurement & Automation Explorer to verify that the NIDAQ interface device is functioning properly. To start Measurement & Automation Explorer click Start > Programs > National Instruments > Measurement & Automation Explorer. You should see the device under “Devices and Interfaces” as shown in the image below:

Interface Board Recognition by AfterMath

Finally, start AfterMath. The instrument should appear in the lower-left pane as shown below:

If the instrument description does not end with “idle” as seen in the image:

Stop/exit the AfterMath software.

Verify that the instrument is turned on.

Verify that the “CONTROL SOURCE” is set to “External”.

Re-start the AfterMath software.

Trademarks

Product and company names listed below are trademarks or trade names of their respective companies.

Microsoft Windows™ is a trademark of Microsoft Corporation (Redmond, Washington).

NI-DAQ™ is a trademark of National Instruments Corporation (Austin, Texas).

WinZip™ is a Registered Trademark of WinZip International LLC (Mansfield, CT).

Posted 1/4/2016 in Uncategorized
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CBP Bipotentiostat: Interface Boards

There are a variety of interface boards available for use with the CBP bipotentiostat system. When using our AfterMath software to control the bipotentiostat, Pine generally recommends using a 16-bit interface board because these boards produce higher resolution digital waveforms. This higher resolution is especially important when using sweep voltammetry to study surface-bound electrochemical processes (see reference at end of this article).

When using our older PineChem software to control the bipotentiostat, either a 12-bit or a 16-bit board may be used. PineChem uses the true analog sweep generator within the bipotentiostat to generate waveforms, and the resolution (12 bit vs. 16 bit) of the interface board is less of an issue. It is very important to use the correct version of the NIDAQ device driver software when using these boards with PineChem or AfterMath.

CBP Bipotentiostat owners in need of a new interface board are encouraged to order an interface board directly from National Instruments. A summary page providing details and pricing can be found on the National Instruments website at the following link: https://www.ni.com/en-us/shop/select/multifunction-io-device

National Instruments Interface Boards Compatible with the Pine Research CBP Bipotentiostat

16-bit X-Series (PCIe)
16-bit M-Series (PCI)
16-bit E-Series (PCI)
12-bit E-Series (PCI)

AfterMath* only
AfterMath* only
AfterMath* or PineChem
AfterMath* or PineChem

PCIe-6351
PCI-6251
PCI-6030E
PCI-6040E

PCIe-6361
PCI-6259
PCI-MIO-16XE-10
PCI-MIO-16E-4

* AfterMath version 1.5 or earlier must be used with the CBP Bipotentiostat. Newer versions of AfterMath do not support the CBP Bipotentiostat.
Additional information about obsolete and unofficial interface boards is discussed below.

Obsolete Interface Boards

These boards were used during the era of the ISA slot (1990s) primarily with Pine’s older PineChem software. It is now very rare for any Windows-based computer to have an ISA slot, so it is nearly impossible to make use of these boards now. It is possible (but often very tricky) to use an AT-MIO-16E-10 board with AfterMath if you happen to have a very old computer with an ISA slot that also has Windows XP installed.

Obsolete Interface Boards

ISA Board
ISA Board

AfterMath or PineChem
Early PineChem only

AT-MIO-16E-10
AT-MIO-16H-9

Unofficially Supported Interface Boards

Both the PineChem and AfterMath software unofficially recognize several other boards manufactured by National Instruments. These include the PCI-MIO-16E-1, PCI-6070E, PCI-6052E, AT-MIO-16E-2, AT-MIO-16E-1, and AT-MIO-16XE-10 boards. Pine makes no guarantee with regard to how well AfterMath or PineChem will work with these boards, but if you happen to already own one of these boards, you can give it a try.

Further Reading and Information

The issue of digital waveform resolution in sweep voltammetry and its influence on surface-bound voltammetry experiments is discussed in great detail in the article linked below. If you work with electrochemical systems involving adsorption, oxide films, self-assembled monolayers, etc., you are encouraged to read this article: P. He, Analytical Chemistry 67 (1995) 986–992

*All photos of interface boards on this web page are Copyright © 1999-2008 Artisan Scientific (Champaign IL). Used with Permission.

Related Hardware Links: CBP Bipotentiostat, Interface Boards

Related Software Links: AfterMath, PineChem, NIDAQ Device Driver

Posted 1/4/2016 in Uncategorized
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