CZ296797A3 - Field-controlled polarization or recovery of electrodes or phase interfaces and arrangement for making the same - Google Patents

Abstract

Field-controlled polarization or refresh electrodes or phase-to-phase interfaces This electrode interface is controlled electromagnetic field and physical-chemical fields measurements technical or technological processes in depending on the characteristics mentioned fields. Arrangement for said controlled field polarization or refreshing basically monitored interface interface / 3 / located in the field of measurement electrode system pour and also under the influence of independent interphase polarization interfaces using a referential system a of auxiliary electrodes (7), wherein they are all functional units are controlled by a block of meters device / 9 / that can mediate Measurement measurements and / or other technical or technological measurements utilizing said field-controlled polarization or electrode renewal.

Description

Technical field

The invention provides a method of field-controlled polarization or renewal of electrodes or phase interfaces and arrangements for performing them, for example, for electrochemical, electroanalytical, chromatographic, polarographic, voltammetric and other related measurements, for various technological and technical applications, and the like.

BACKGROUND OF THE INVENTION

The term electrode polarization, especially known in the field of electrochemistry, in particular polarography, voltammetry and related methods, is intended to induce or influence various events on or near the electrode due to the application of electrical potential or current between the electrode and the electrode. its interior and the interior of the solution in which it is immersed. Various types of mercury electrodes are used (J. Heyrovsky, J. Kut: Principles of Polarography, Publishing House Acad.Sci, Prague 1965; L. Novotny in K. Stulik, R. Kalvoda (Eds.) „Electrochemistries for Environmental Protection ”, UNESCO ROSTE, Venice 1996), so solid (F. Vydra, K. Štulík, E.Juláková: Electrochemical Stripping Analysis, J. Wiley, New York 1976; Z. Galus: Fundamentals of Electrochemical Analysis, PWN» » 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9 9999 9999 9999 999 9999 999 9999 φ * *

Warszawa 1994), pasty (Kal. Kalcher: Electroanalysis 2 (1990) 419-33;

I. Svancara, K. Vytrans et al .: Electroanalysis, 8 (1996) 61), based on two immiscible liquids (V. Marecek, Z, Male: J. Electroanal. Chem. 185 (1985) 263; Anal. Lett. 14 (B15) (1981) 1241), variously modified, etc. (R. Kalvoda: Fresenius J. Anal. Chem. 349 (1994) 565; E. Palecek. Bioelectrochem. Bioenerg. 20 (1988) 171; J. Churacek (Ed.): Advanced Institutional Methods of Chemical Analysis, Academia, Prague 1993. K. Stulik: Electroanalysis 4 (1992) 829-834, S. Mesaros, D. Bustin et al .: Anal Chim Acta 339 (1997) J. Wang: Analytical Electrochemistry, VCH, New York 1994). The design of these and other types of electrodes is a permanent part of the continuous development of polarographic and voltammetric methodology and instrumentation.

However, new approaches, principles, phenomena and procedures are highly valued and sought in the pursuit of further generational progress in the development of electrochemical and interphase techniques, followed by appropriate ongoing developments. The present invention also seeks to contribute in this respect. It is directed, in particular, to solving the following and related problems: The accompanying polarization of the above-mentioned electrodes in the above-mentioned (practically the only) way is inter alia the essential role of sufficient conductivity of both involved phases; from the specific electrode interface, uniform (isotropic, homogeneous) polarization of the whole surface of the interface and limited (essentially limited by construction) reproducibility of the flat and often also the quality of the electrode interface. The latter factors, for example, result in a limited measurement reproducibility, a limited detection limit and selectivity, and a relatively high noise level. Other effective ways of polarization would open up new possibilities of development of the described electrochemical methodology and instrumentation, as well as possibilities of acquiring new knowledge about properties and behavior of studied systems.

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SUMMARY OF THE INVENTION

The present invention is based on field-controlled polarization or renewal of electrodes or phase interfaces, wherein a metering electrode metering system is placed in a first immiscible phase within the system to be measured, and at a selected location, at least partially between these electrodes or in their field. phase, and a second immiscible phase of a predetermined shape, the electrical or electromagnetic potential or current signal of a specified time course, currencies is controlled in a controlled manner, selected physicochemical or electrochemical quantities, their changes, or selected quantities that are their functions, separately or / and in relation to each other or depending on the determined parameters of the inserted electric or electromagnetic potential or current signal, on the composition or determined by physicochemical the properties of the first and / or second immiscible phase or interfacial interface and the properties, parameters, and / or composition of the first immiscible phase, second immiscible phase or interfacial interface, and then the first immiscible phase, second immiscible phase or interfacial the metering electrode system is restored and / or restored at specified intervals, and the whole process is repeated starting from the controlled insertion of the electrical or electromagnetic potential or current signal. Furthermore, the interface will at least partially position or bring into contact with the independent interface the independent phase of the shape and the process starts from the controlled insertion of the electric or electromagnetic potential or current signal and the signals and / or dependencies obtained also it concludes on the composition or physico-chemical properties of the independent interfacial interface or independent phase. In this case, a system of independent reference and / or auxiliary electrodes is placed in the first immiscible phase, the second immiscible phase and, if necessary, the independent phase, and an independent electric or electromagnetic potential or current is inserted between these electrodes in a controlled manner. a signal of a predetermined time course, the insertion program of this independent signal is combined with the insertion program of the electrical or electromagnetic potential or current signal between the measuring electrodes, after which the process starts from the insertion of the electrical or electromagnetic potential or current signal. on the composition or physicochemical properties of the phases and / or interfaces present. Further, depending on the process selected, at least a portion of the first immiscible phase, the second immiscible phase, the interface between the first immiscible phase and the second immiscible phase, the independent interfacial interface or the independent phase are treated with a selected independent energy log or a specified temperature regime; they act by an array of particles or objects introduced into the first immiscible phase, the second immiscible phase, the independent phase or the interface between the first immiscible phase and the second immiscible phase, or the independent interphase interface, or expands, keeps constant or shrinks and / or the measured system is placed in program-controlled external energy fields of specified parameters, these programs are combined with the program of insertion of electric or electromagnetic potentials him or current signal to the measuring electrode after the loading process starting from electrical or electromagnetic bonding or current signal and repeats identified from the obtained signals and / or dependency is considered on the composition and physico-chemical properties of the present phases and / or interfacial boundaries.

Another object of the present invention is to provide an apparatus comprising a block of a measured system comprising a system of measuring electrodes between or in a field of which there is at least partially an interface of a predetermined shape between the first immiscible phase and the second immiscible phase. a measuring device block to which the program and control block and the evaluation block are also connected in parallel and, if necessary, interconnected and where the evaluation block is connected to the recording block and the second immiscible phase is connected to the second immiscible phase also connected to the measuring device block and / or the program and control block, and where the leads of the independent reference and / or auxiliary electrodes and the independent phase are also connected to the measuring device block. Further, the interface is at least partially located in or adjacent to the independent interface of the independent phase of the shape, or is connected to the independent interface, wherein the independent phase is connected to an independent phase of introduction or generation, interconnected with the measuring device block and / or program block; management. A system of independent reference and / or auxiliary electrodes connected to the metering unit is also placed in the first immiscible phase, the second immiscible phase and, if necessary, the independent phase, and the system to be measured is at least partially located in an external energy field or thermostat with measuring device block and / or program and control block as required. In this case, the interfacial interface also has the character of a liquid / beep, liquid / liquid or liquid / solid interface, as required, with arrangements within the system to be measured where a porous coating separates the independent phase from the second immiscible phase with the interphase interface. or / and the electrically nonconductive independent phase is provided with an interphase interface in the form of a bubble, drop, meniscus or at least partially curved surface, or / and a solid second immiscible phase is formed on the independent phase with interphase interface between the measuring electrodes and at least the measuring electrode system; the interphase interface, the second immiscible phase, and the independent reference and auxiliary electrodes have a determined geometric shape and a spatial arrangement corresponding to the system in which it is located, with the movable or stationary first immiscible phase.

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Novelty that the field-controlled electrode polarization of the present invention provides include, for example, the possibility of both controlled homogeneous as well as non-homogeneous (amzotropic, mosaic) polarization of the electrode surface, as needed in combination with previously used polarization methods;

• the possibility of alternating mosaic polarization of the electrode at different frequency and intensity;

• Possibility of faster changes of the interfacial interface state, with limited influence of slow diffusion processes;

• applicability of the described polarization method even in low conductive environments;

• a type of controlled polarizability of an interfacial interface such as a solution / gas interfacial;

• Under appropriate experimental conditions (eg under alternating field polarization), electrode / solution interface renewability.

These and other factors make it possible to obtain and use new knowledge about interfacial and electrochemical processes with the experimental conditions used up to now.

Pictures

1 to 4 show an example of the arrangement, FIG. 2 shows a polarized interfacial interface in the form of blobs inside the membrane, FIG. 3 shows an example of four-pole polarization of the interfaces and FIG. in which the electrode interface of the fixed electrode is polarized.

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The arrangement in Fig. 1 represents a system which consists of a block of a measured system 8 comprising a system of measuring electrodes 2, between or in which there is at least partially an interface of a predetermined shape between the first immiscible phase 1 and the second immiscible phase 4, the electrodes 2 are connected to the measuring device block 9, to which the program and control block 10 and the evaluation block 11 are also connected in parallel, if necessary also interconnected and where the evaluation block 11 is connected to the record block 12 and the second immiscible phase 4 connected to the block the introduction or generation of a second immiscible phase 13, which is also connected to the measuring device block 9 and / or the program and control block 10, and wherein the leads of the independent reference and / or auxiliary electrodes 7a of the independent phase 6 are also connected to the measuring device block 9; where the interphase ro The interface 3 is at least partially placed in the proximity of the independent interface 5 of the independent phase 6 of the shape or is in contact with the independent interface 5, the independent phase 6 being connected to the independent phase introduction or generation block 14, connected further to the measuring device block 9 or and a program block and control block 10. Furthermore, a system of independent reference and / or auxiliary electrodes 7 connected to the block of the measuring device 9 is located in the first immiscible phase I, the second immiscible phase 4 and, if necessary, the independent phase 6, connected to the measuring device block 9. partly placed in a block of external energy fields or a thermostat 15, connected as necessary to the meter block 9 and / or the program and control block 10.

In the arrangement of FIG. 2, the interface 3 has the character of a liquid / gas, liquid / liquid or liquid / solid interface, as required, with arrangements within the measured system 8 where a porous coating separating the independent phase is formed on the electrically conductive independent phase 6. 6 from the second immiscible phase 4 with the interfaces 3.

Giant. 3 illustrates an example in which an electrically non-conducting independent phase 6 is provided with an interface 3 in the form of a bubble, drop, meniscus or 4 4 • 444 4444

4 to 4 at least partially curved surfaces, the scheme of measurement electrodes 2, the second immiscible phase 4 and the system of independent and / or auxiliary electrodes 7 are also indicated in the diagram for clarity.

Fig. 4 shows an arrangement in which a solid second immiscible phase 4 is formed on an independent phase 6 with an interfacial interface 3 between the measuring electrodes 2 and a system of independent reference and / or auxiliary electrodes 7 is also present. or stepwise with the movable or stationary first immiscible phase i, as the figure shows.

Giant. 5 shows a typical example of the waveforms of the repeated polarization curve i-U obtained in the arrangement according to FIG. 2 as a function of the electric current i between the reference and auxiliary electrodes 7 between which the time-varying polarization voltage U is comprised. exceeding the threshold voltage U _o and further reducing the value of U _o with the number of polarization cycles.

An exemplary embodiment of the method and arrangement of the present invention

An exemplary embodiment of the method of the present invention is a process wherein a metering electrode metering system is placed in the first immiscible phase even within the measured system 8. 2 and at the selected location, at least partially between or in the field of these electrodes, an interfacial interface 3 is formed between the first immiscible phase I and the second immiscible phase 4 of a predetermined shape, then an electrical or electromagnetic potential or current signal selected physicochemical or electrochemical quantities, their changes, or selected quantities that are their function, separately or / and in relation to each other or depending on the specified parameters of the inserted electromagnetic * · 9 k k ** ·.... ** ** ** ** ** ** **

the potential or current signal, the composition or the determined physicochemical properties of the first and / or second immiscible phase or interfacial interface 3, and the properties, parameters, and / or composition of the first immiscible phase i, second immiscible phase 4 or interfacial interface 3, or (a) the described process is used in a specified manner for selected technical or technological purposes, after which the first immiscible phase 1, the second immiscible phase 4 or the interfacial interface 3 are restored as intended, or / and the metering electrode system 2 and the whole process starting with the controlled insertion of an electrical or electromagnetic potential or current signal. In this case, the interfacial interface 3 is at least partially placed in proximity or brought into contact with the independent interfacial interface 5 of the independent phase 6 of a given shape and the whole process is repeated starting from the controlled insertion of the electric or electromagnetic potential or current signal. where appropriate, the composition or physico-chemical properties of the independent interfacial interface 5 or the independent phase 6 are also considered, and / or the described process is used, at least in part, for the technical or technological purposes selected. Furthermore, a system of independent reference and / or auxiliary electrodes 7 is placed in the first immiscible phase I, the second immiscible phase 4 and, if necessary, the independent phase 6, as appropriate, a controlled electrical or electromagnetic potential or current signal of a predetermined time , the insertion program of this independent signal is combined with the insertion program of the electrical or electromagnetic potential or current signal between the measuring electrodes 2, after which the process starts from the insertion of the electrical or electromagnetic potential or current signal and determined from the obtained signals and / physico-chemical properties of the phases and / or interfaces present, * »· · •

Or, and / or the procedure described above is used, at least in part, for the selected technical or technological process. purposes. Depending on the choice of process, at least a portion of the first immiscible phase, the second immiscible phase, the interface between the first immiscible phase and the second immiscible phase, the independent interfacial interface or the independent phase are treated with, or acts by an array of particles or objects introduced into the first immiscible phase, the second immiscible phase, the independent phase or the interface between the first immiscible phase and the second immiscible phase, or the independent interphase interface, and / or expands, keeps constant or shrinks and / or the measured system 8 is placed in program-controlled external energy fields of specified parameters, these programs are combined with an electric or electromagnetic potential input program or the current signal on the measuring electrodes, then the process starts with the insertion of the electric or electromagnetic potential or current signal and from the determined signals and / or dependencies is judged on the composition or physico-chemical properties of the phases and / or interfaces present; using the described process for at least partially determined method for chosen technical or technological purposes.

An example of an arrangement for carrying out this method is a device consisting of a block of a measured system 8 comprising a metering electrode system 2 between or in their field at least partially being an interface of a predetermined shape between the first immiscible phase i and the second immiscible phase 4. 2 connected to the measuring device block 9, to which the program and control block 10 and the evaluation block 11 are also connected in parallel, if necessary also interconnected and where the evaluation block 11 is connected to the record block 12 and the second immiscible phase 4 is connected to the loading block or the generation of the second immiscible phase 13, which is also connected to the measuring device block 9 and / or the program block, and control system 10 and where the supply lines of the independent system are also connected to the measuring device block 9 the reference and / or auxiliary electrodes 7 and the independent phase 6. The interfacial interface 3 is at least partially positioned at least partially in the proximity of the independent interfacial interface 5 of the independent phase 6 of a given shape, or touches the independent interfacial interface 5. the introduction or generation of an independent phase 14, further connected to the metering unit. 9 or / and with the program and control block 10, and further optionally, the first immiscible phase I, the second immiscible phase 4 and, if necessary, the independent phase 6 is provided with a system of independent reference and / or auxiliary electrodes 7 connected to the measuring device block 9. If necessary, the system to be measured is at least partially placed in an external energy field or thermostat block 15, connected as necessary to a measuring device block 9 and / or a program and control block 10, and the interfacial interface 3 having a liquid / gas, liquid / liquid interface liquid / solid, wherein there are arrangements within the measured system 8 wherein a porous coating is formed on the electrically conductive independent phase 6 separating the independent phase 6 from the second immiscible phase 4 with the interfacial interface 3, or / and in the electrically non-conductive independent phase 6 interfacial interface 3 in the form of bu blinks, drops, meniscus or at least partially curved surface, or a solid second immiscible phase 4 is formed on the independent phase 6 with an interfacial interface 3 between the measuring electrodes 2 and at least a specific electrode system 2, an interfacial interface 3, a second immiscible phase 4 and independent The reference and auxiliary electrodes 7 have a defined geometric shape and spatial arrangement corresponding to the system in which they are located, with a movable or stationary first immiscible phase L The described method and apparatus can also serve as the basis of an "electrochemical spectrograph", enabling eg voltammetric • · 9,999 9 9 in • · · · · ♦ · 9 9 ·· 9

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9999 9999 99 99 99 9 signal as it is to date, but register new signals corresponding to the reaction of the system to its field-controlled polarization.

The polarization of the interface 3 can be carried out, for example, in the arrangement in FIG. 2. Here, for example, a polarizing voltage U is inserted between the reference and / or auxiliary electrodes 7 and the electric current i is registered between these electrodes, i.e. polarization curves i-U. is shown in Fig. 5: Increasing the polarizing voltage U leads to a decrease in the surface tension γ at the meniscus-shaped interfaces 3 in the pores of the Teflon membrane; when a certain value of U _o is reached, the magnitude of γ decreases to such an extent that the pores in the Teflon membrane (or at least a part of them) become wettable, the phases present (originally, separated) contact and the value of electric current increases significantly. Decreasing U below U _o may again lead to the rewetting of the pores of the Teflon membrane, to phase separation and thus again to a significant decrease of i. For example, _a decrease in the threshold value of U 0 with the number of cycles was observed, possibly due to electrolytic deposition of metal ions on the electrode during contact of the solution with it and thus reducing the distance of the electrode from the aqueous solution.

Fields of application

The invention is applicable for example in the field of interfacial measurements, analytical chemistry, characteristics and studies of liquids, solutions and surfactants, design of new types of electrodes for accumulators and power sources, study of cell wall processes, possibilities of influencing healing processes, etc. electrochemistry (including bioelectrochemistry and electrolysis), interfacial chemistry, environmental chemistry, medicine, pharmacy, etc. It also enables the design of new electrochemical methods using new methods

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Polarization of the electrodes, increasing the selectivity of the determination of quantities, especially organic substances, elimination or reduction of the influence of transport processes to the electrode surface, work in miniaturized systems and micro-volumes, etc. These and other possibilities are described in other materials.

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Claims (6)

4 44 » PATENT CLAIMS Array-controlled polarization or renewal of electrodes or phase interfaces and arrangements for carrying out the method, characterized in that a measurement electrode metering system is placed in the first immiscible phase within the measured system and at a selected location, at least partially between or in the field; an interphase interface is formed between the first immiscible phase and the second immiscible phase of a predetermined shape, whereupon an electrical or electromagnetic potential or current signal of a specified time course is inserted in a controlled manner, measured, evaluated and recorded selected physicochemical or electrochemical variables , or selected quantities that are their function, separately or / and in mutual relationship or depending on the determined parameters of the inserted electric or electromagnetic potential or current signal, and / or the composition of the first immiscible phase, the second immiscible phase or the interphase interface, thereafter the first immiscible phase, the second immiscible phase, or the interphase interface is restored as intended, - or / and the metering electrode system is restored at specified intervals, and the whole process is repeated, starting from the controlled insertion of an electrical or electromagnetic potential or current signal. 2. The field-controlled polarization or renewal of electrodes or phase interfaces according to claim 1, characterized in that the interface is at least partially placed in proximity to or brought into contact with the independent phase interface of an independent phase of a given shape and starting from controlled insertion of electrical or electromagnetic. ového '' '' '' '' '' '' ' φφ. φφ φφ · repeats the current signal and from the obtained signals and / or dependencies the composition or physico-chemical properties of the independent interfacial interface or independent phase are also considered as necessary. 3. The field-controlled polarization or restoration of the electrode interface or phase interface according to claims 1 and 2, characterized in that a system of independent reference and / or auxiliary electrodes is placed in a controlled manner in a first immiscible phase, a second immiscible phase and, if necessary, an independent phase. inserting an independent electrical or electromagnetic potential or current signal over a predetermined time course between these electrodes, the program for inserting the independent signal merging with a program for inserting an electric or electromagnetic potential or current signal between the measuring electrodes, then starting the process of inserting the electric or electromagnetic potential or current signal The composition or physico-chemical properties of the phases and / or interphase interfaces present are judged and determined from the signals and / or dependencies obtained. 4. The field-controlled polarization or renewal of the electrodes or phase interfaces of any one of claims 1 to 3, wherein at least a portion of the first immiscible phase, the second immiscible phase, the interfacial interface between the first immiscible phase and the second immiscible phase acting on the selected independent energy logs or on a specified temperature regime, or / and on an array of particles or objects introduced into the first immiscible phase, the second immiscible phase, the independent phase or the interface between the first immiscible phase and the second immiscible phase; and / or that at least a portion of the interfaces formed according to the specified program is expanded, maintained constant or contracted, and / or the measured system is placed in program-controlled external energy fields determined by the program. · • · »1 '· ··· ··· · · • · · · · ·; These programs are combined with a program of inserting an electrical or electromagnetic potential or current signal on the measuring electrodes, after which the process starts with the insertion of the electrical or electromagnetic potential or current signal. The composition or physico-chemical properties of the phases and / or interphase interfaces present are judged and determined from the signals and / or dependencies obtained. Arrangement for conducting field-controlled polarization or restoration of electrodes or phase interfaces according to Claims 1 to 4, characterized in that it consists of a block of a measured system (8) comprising a system of measuring electrodes (2) between which or at least partially placed in them an interfacial interface (3) of a predetermined shape between the immiscible beer phase (1) and the second immiscible phase (4), the measuring electrodes (2) being connected to a measuring device block (9) to which the program block and control unit (10) are further connected in parallel ) and an evaluation block (11), also interconnected as needed, and wherein the evaluation block (11) is connected to the recording block (12) and the second non-quenching phase (4) is associated with a second quenching phase (13) it is also connected to the measuring device block (9) or / and the program and control block (10) and where they are connected to the measuring device block (9). the supply of the independent system - reference and / or auxiliary electrodes (7) and independent phases (6). Arrangement for conducting field-controlled polarization or renewal of electrodes or phase interfaces according to claim 5, characterized in that the interfaces interface (3) is at least partially located in the designated proximity of the independent interfaces interface (5) of the independent phase (6) of said shape, or an independent interface (5) is contacted, the independent phase (6) being connected to a block of introduction or generation of the independent phase (14), further connected to the measuring device block (9) and / or to the program and control block (10).