Membrane and method of manufacture

• US 10,436,738 B2
• Filed: 12/20/2016
• Issued: 10/08/2019
• Est. Priority Date: 12/21/2015
• Status: Active Grant

• Current Assignee: Endress+Hauser Conducta Gesellschaft FUER Mess- und Regeltechnik mbH+Company KG
• Original Assignee: Endress+Hauser Conducta GmbH+Company KG
• Inventors: Lobbert, Andreas, Horig, Alexander
• Primary Examiner(s): White, Dennis
• Application Number:
  US15/384,799
• Publication Number:
  US 20170176375A1
• Time in Patent Office: 1,022 Days
• CPC Class Codes: B05D 3/065 After-treatment
• CPC Class Codes: B05D 3/148 affecting the surface properties of the coating
• CPC Class Codes: G01N 2021/6432 Quenching
• CPC Class Codes: G01N 2021/775 Indicator and selective membrane
• CPC Class Codes: G01N 2021/7786 Fluorescence
• CPC Class Codes: G01N 21/77 by observing the effect on a chemical indicator
• CPC Class Codes: G01N 27/40 Semi-permeable membranes or partitions

Abstract

The present disclosure concerns a membrane for a sensor, such as an opto-chemical or electrochemical sensor, including a polymer layer, for example, one featuring pores or openings, that is permeable to a measuring fluid and/or an analyte contained in the measuring fluid, with a surface designed to be in contact with a measuring fluid, wherein the surface is designed such that, at least in a moist condition of the polymer layer obtained by moistening the surface, a contact angle of a water drop applied to the surface is less than 50°, including less than 30°, and including less than 10°.

Claims

1. A membrane for an opto-chemical sensor, comprising:

a polymer layer having pores or openings and a surface embodied to contact a measuring fluid, the polymer layer permeable to the measuring fluid and/or an analyte contained in the measuring fluid, wherein the surface is further embodied such that, at least in a moist condition of the polymer layer, upon moistening the surface a contact angle of a water drop in contact with the surface is less than 50°

;

a silicon matrix layer arranged on a side of the polymer layer opposite the surface; and

at least one function layer disposed on a side of the polymer layer opposite the surface embodied to contact the measuring medium, wherein said function layer comprises a sensor-specific substance.

2. The membrane according to claim 1, wherein the surface in a dry condition is less hydrophilic than in the moist condition such that the contact angle of a water drop in contact with the surface in the dry condition is greater than the contact angle of a water drop in contact with the surface in the moist condition.

3. The membrane according to claim 2, wherein the decrease of the contact angle in the moist condition relative to the dry condition is reversible and remains functional after repeated drying and wetting of the surface.

4. The membrane according to claim 3, wherein the surface becomes super-hydrophilic, such that the contact angle of a water drop in contact with the surface is approximately 0°

, after being moistened by introducing the membrane into water over a period of less than 5 minutes.

5. The membrane according to claim 1, wherein the sensor-specific substance is a fluorophore.

6. The membrane according to claim 1, wherein the silicon matrix layer is arranged between the at least one function layer and the polymer layer.

7. The membrane according to claim 1, wherein the polymer layer in the dry condition at least transmits visible light to a lesser degree than in the moist condition, such that a layer disposed on a side of the polymer layer opposite the surface embodied to contact the measuring medium becomes visible through the polymer layer once the surface is moistened.

8. The membrane according to claim 1, wherein the surface embodied to contact the measuring medium is treated by energy input and/or a chemical reaction.

9. The membrane according to claim 1, wherein the polymer layer comprises a silicon, a polymer with photo-reactive groups, a polymer with high temperature stability at least up to a temperature of 140°

C., or a derivate of such a polymer.

10. The membrane according to claim 1, wherein the polymer layer comprises a polymer, a co-polymer, a ter-polymer, or a polymer blend with adjacent or alternating electron withdrawing groups and electron pushing groups.

11. The membrane according to claim 10, wherein the electron withdrawing groups include halogenated groups and the electron pushing groups include carbon-hydrogen groups.

12. The membrane according to claim 1, wherein the polymer layer comprises a metalloid oxide from a group consisting titanium oxide, zinc oxide, and silicon oxide, and/or metal nanoparticles of a metal from a group consisting of silver, gold, and platinum.

13. The membrane according to claim 1, wherein contact angle of a water drop in contact with the surface is less than 10°

or less than 30°

.

14. A method for production of a membrane for an opto-chemical or electrochemical sensor, comprising:

providing the membrane including at least one polymer layer with a surface embodied to contact a measuring fluid, the polymer layer being permeable to the measuring fluid and/or an analyte contained in the measuring fluid;

providing a function layer arranged on a side of the polymer layer opposite the surface and including a sensor-specific substance;

providing a silicon matrix layer between the polymer layer and the function layer; and

treating the surface by means of energy input and/or by means of a chemical reaction such that, at least in a moist condition of the polymer layer, upon moistening the surface a contact angle of a water drop in contact with the surface is less than 50°

.

15. The method of claim 14, wherein the treating includes etching by a plasma, etching by an oxygen plasma, or irradiation with UV radiation.

16. The method according to claim 14, the method further comprising applying at least one second layer to a side of the membrane opposite the treated surface, wherein the second layer is optically unchangeable by the treating of the surface of the polymer layer.

17. The method according to claim 16, wherein the at least one second layer includes a fluorophore substance having at least one optical property that changes depending upon a concentration of an analyte in a measuring fluid interacting with the substance.

18. An opto-chemical sensor, comprising:

a membrane including;

a polymer layer having pores or openings and a surface embodied to contact a measuring fluid;

a function layer including a fluorophore, the function layer arranged on a side of the polymer layer opposite the surface; and

a silicon matrix layer arranged between the polymer layer and the function layer, at least one of the polymer layer and the function layer being embedded into the silicon matrix layer;

wherein the polymer is permeable to the measuring fluid and/or an analyte contained in the measuring fluid, wherein the surface is embodied such that, at least in a moist condition of the polymer layer upon moistening the surface, a contact angle of a water drop in contact with the surface is less than 50°

;

wherein, during use of the opto-chemical sensor, an optical property of the fluorophore changes based on a concentration of an analyte in the measuring fluid interacting with the fluorophore.