System for determining the zeta potential for characterizing a solid/liquid interface with controlled profile pressure loading

Patent metadata

Field	Value
Publication number	US-9933377-B2
Application number	US-201514711006-A
Country	US
Kind code	B2
Filing date	May 13, 2015
Priority date	May 13, 2014
Publication date	Apr 3, 2018
Grant date	Apr 3, 2018

Abstract

A device determines information indicative for a zeta potential at the interface between a solid phase and a liquid phase. The device includes a pressure vessel, in which the liquid phase can be accommodated and a measuring cell, downstream of the pressure vessel and such that it can be brought into fluid communication with the pressure vessel and in which the solid phase can be accommodated. A storage vessel is downstream of and in fluid communication with the measuring cell. A pressure loading apparatus, loads the pressure vessel with a pressure profile with a temporally continuous pressure change so a liquid phase can be conveyed out of the pressure vessel through the measuring cell into the storage vessel. A detection apparatus detects the information indicative for the zeta potential at the measuring cell during the loading of the pressure vessel with the pressure profile.

First claim

What is claimed is:

1. A method for determining information being indicative for a zeta potential for characterising an interface between a solid phase and a liquid phase, wherein the method comprises:
accommodating the liquid phase in a pressure vessel;
accommodating the solid phase in a measuring cell, which is arranged downstream of and such that it can be brought into fluid communication with the pressure vessel;
arranging a storage vessel downstream of and in fluid communication with the measuring cell;
loading the pressure vessel with a pressure profile with a temporally continuous pressure change in such a manner that as a result liquid phase can be conveyed out of the pressure vessel through the measuring cell into the storage vessel, wherein the interior of the pressure vessel is pressure-decoupled from the environment when the liquid phase flows out of the pressure vessel, and wherein the pressure drops continuously when the liquid phase flows out of the pressure vessel; and
determining the information being indicative for the zeta potential at the measuring cell during the loading of the pressure vessel with the pressure profile.

2. The method as set forth in claim 1 , wherein determining the information being indicative for the zeta potential is carried out at high ionic strength, and/or during an adsorption process or during a desorption process, and/or at a metallic material surface, and/or in the direct vicinity of the isoelectric point.

3. The method as set forth in claim 1 , wherein the measuring cell is provided with a pressure profile with a pulsation-free pressure change.

4. The method as set forth in claim 1 , wherein the information being indicative for the zeta potential is determined whilst carrying out a baseline correction which changes over time.

5. The method as set forth in claim 1 , wherein a base signal, which is independent of the solid phase and the liquid phase is determined during the loading of the pressure vessel with the pressure profile; and/or wherein during the pressure change, there is changed in an alternating manner between an operating mode permitting a fluid connection between the pressure vessel and the measuring cell and an operating mode preventing a fluid connection between the pressure vessel and the measuring cell, in order to detect, in the operating mode preventing the fluid connection, a baseline signal and thereby to correct a measurement signal detected in the operating mode permitting the fluid connection.

6. A device for determining information indicative for a zeta potential, for characterising an interface between a solid phase and a liquid phase, wherein the device comprises:
a pressure vessel, in which the liquid phase can be accommodated;
a measuring cell, which is arranged downstream of the pressure vessel and such that it can be brought into fluid communication with the pressure vessel and in which the solid phase can be accommodated;
a storage vessel which is arranged downstream of and in fluid communication with the measuring cell;
a pressure loading apparatus, which is configured for loading the pressure vessel with a pressure profile with a temporally continuous pressure change in such a manner that as a result, liquid phase can be conveyed out of the pressure vessel through the measuring cell into the storage vessel, wherein the interior of the pressure vessel is pressure-decoupled from the environment when the liquid phase flows out of the pressure vessel, and wherein the pressure drops continuously when the liquid phase flows out of the pressure vessel; and
a detection apparatus for detecting the information being indicative for the zeta potential at the measuring cell during the loading of the pressure vessel with the pressure profile.

7. The device as set forth in claim 6 , wherein the pressure loading apparatus is configured to provide a pressure profile with a pulsation-free pressure change to the measuring cell.

8. The device as set forth in claim 6 , wherein the pressure loading apparatus is configured to load a gas chamber above the liquid phase in the pressure vessel with a compressed gas cushion in order to, as a consequence, generate the pressure profile with the continuous drop of the pressure.

9. The device as set forth in claim 6 , wherein the pressure loading apparatus comprises a pressure generation unit for generating pressure in the pressure vessel and a switching element, said switching element fluidly coupling the pressure vessel with the measuring cell, the measuring cell receiving the liquid phase in accordance with the pressure profile.

10. The device as set forth in claim 9 , wherein the switching element is arranged between the pressure vessel and the measuring cell.

11. The device as set forth in claim 9 , comprising a pressure measuring unit for detecting a pressure.

12. The device as set forth in claim 11 , wherein the switching element can be switched in such a manner that it activates the fluid connection between the pressure vessel and the measuring cell in the event of a determined exceedance of a predeterminable pressure threshold value, which exceedance is determined by means of the pressure measuring unit.

13. The device as set forth in claim 6 , wherein the storage vessel is configured to be free from overpressure.

14. The device as set forth in claim 6 , wherein the detection apparatus is configured for detecting the information being indicative for the zeta potential on the basis of an electric current measurement and/or on the basis of an electric voltage measurement at the measuring cell.

15. The device as set forth in claim 6 , comprising an input electrode at an input of the measuring cell and an output electrode at an output of the measuring cell, wherein the detection apparatus for detecting the information being indicative for the zeta potential is formed between the input electrode and the output electrode.

16. The device as set forth in claim 15 , wherein the detection apparatus is configured to detect information being indicative for an electrical resistance of the solid phase and the liquid phase in the measuring cell with the input electrode and the output electrode.

17. The device as set forth in claim 6 , comprising a liquid-phase return mechanism for returning liquid phase from the storage vessel into the pressure vessel.

18. The device as set forth in claim 6 , further comprising:
a further pressure vessel, in which further liquid phase can be accommodated;
a further measuring cell, which is arranged downstream of the further pressure vessel and such that it can be brought into fluid communication with the further pressure vessel and in which the solid phase can be accommodated;
wherein the pressure loading apparatus is configured for loading the further pressure vessel with a pressure profile with a temporally continuous pressure change in such a manner that, as a result, further liquid phase can be conveyed out of the further pressure vessel through the further measuring cell;
wherein the detection apparatus is configured for detecting information being indicative for the zeta potential at the further measuring cell during the loading of the further pressure vessel with the pressure profile.

19. The device as set forth in claim 6 , wherein the detection apparatus is configured for detecting the information being indicative for the zeta potential whilst carrying out a baseline correction which changes over time.

20. The device as set forth in claim 6 , wherein the detection apparatus is co

Assignees

• Anton Paar Gmbh

Inventors

• Luxbacher Thomas

Classifications

• G01N27/60 Primary

  by investigating electrostatic variables {, e.g. electrographic flaw testing (G01N27/007 takes precedence)} · CPC title

• G01N27/00 Primary

  Investigating or analysing materials by the use of electric, electrochemical, or magnetic means (G01N3/00 – G01N25/00 take precedence; measurement or testing of electric or magnetic variables or of electric or magnetic properties of materials G01R) · CPC title

• G01N27/44752

  Controlling the zeta potential, e.g. by wall coatings · CPC title

• G01N27/26 Primary

  by investigating electrochemical variables; by using electrolysis or electrophoresis · CPC title

• G01N33/1893

  using flow cells · CPC title