System and method for measuring the degradation of polymer films by polymer-degrading reagents

Abstract

The invention relates to a system comprising a first and a second housing part with a first and a second reaction chamber which form a reaction space, wherein the first and second housing parts are configured to accommodate a polymer film in such a way that the polymer film is arranged between the first and second reaction chambers, wherein at least one internal angle between the polymer film and one of the two reaction chambers of a reaction space lies in the range from 10° to 80°. The invention also relates to use of said system and to a method for time-resolved continuous measurement of the degradation of polymer films by polymer-degrading reagents.

Description

[0001] System and method for measuring the degradation of polymer films by polymer-degrading reagents

[0002] The invention relates to a system comprising a first and a second housing part with a first and a second reaction chamber which form a reaction space, wherein the first and the second housing part are designed to receive a polymer film such that the polymer film is arranged between the first and second reaction chamber, wherein at least one interior angle between the polymer film and one of the two reaction chambers of a reaction space is in the range of 10° to 80°, its use and a method for the time-resolved, contact-free and continuous measurement of the degradation of polymer films by polymer-degrading reagents.

[0003] Plastic waste represents an ever-growing environmental and climate problem. One way to reduce the ecological and economic impacts associated with the accumulation of plastics is recycling, which involves mechanically reprocessing plastic material to create new products. The resulting post-consumer plastic waste amounts to six megatons per year in Germany, of which only approximately 30% is recycled. Globally, plastic waste amounts to approximately 360 megatons per year, of which only 9% is recycled.

[0004] Europe-wide, approximately 2.6 million tons of polyethylene terephthalate (PET) processing capacity already exists, with Germany having the largest capacity. The current PET market has a recycling capacity of over 2.2 million tons, resulting in a total of approximately 1.3 million tons of recycled material (EU Recycling Magazine 03 / 2021, page 43, Servicebetrieb Bau & Stadtgrün, City of Schweinfurt).

[0005] However, current recycling technology can barely deliver high-purity recyclates to produce food-grade packaging from used plastic. Currently, recycling, especially mechanical recycling, is almost exclusively downcycling, meaning the polymer backbone can only be reused for less demanding applications. Only 1% is recovered in truly high-quality, i.e., as pure as new material. These chemical processes involve extremely high energy costs, making long-term economic use unlikely. The remaining 99% are sooner or later incinerated or landfilled, thereby generating carbon dioxide emissions and causing environmental pollution.Therefore, polymer-degrading biocatalysts such as enzymes are currently being investigated for plastics degradation. These offer five advantages over previously described chemical recycling processes: 1) They operate in an aqueous environment, meaning the use of organic solvents is minimal or non-existent, 2) Enzymes operate at significantly lower temperatures (50 to 80°C) compared to chemical processes (>180°C to 1600°C), 3) They can be operated at atmospheric conditions without the need for a pressure vessel, which significantly reduces the reactor expenditure in industrial plants, 4) They can be produced and degraded biologically and do not require rare earths, and 5) They are fundamentally suitable for the selective degradation of plastics. However, the number of known polymer-degrading biocatalysts, particularly polymer-degrading enzymes, with potential for industrial use is small.

[0006] A major technical problem is the fact that quantification methods for investigating the degradation activity of polymer-degrading biocatalysts have to be developed individually and in a complex manner for the multitude of different plastic types.

[0007] WO 2022 / 090290 A1 describes a novel esterase for polyester degradation with increased activity and stability. The enzyme is tested on agar plates with PET or in a reactor in a buffered solution with amorphous PET by determining the weight of the unreacted PET or by determining the resulting terephthalic acid. Testing on agar plates provides semi-quantitative information on enzyme activity and is not very suitable for evaluating enzyme performance. Described measurement methods for weight and terephthalic acid determination determine enzyme activity based on the resulting degradation products, i.e., measurements are performed before and after incubation with the enzyme. They primarily provide endpoint values, do not serve for continuous and high-resolution temporal analysis, and are not suitable for high-throughput screening.

[0008] Frank et al. describe a high-throughput microtiter plate-based system and method for enzyme characterization, particularly of cytochrome P450 BM3, through product quantification (Frank et al. 2020). The document describes a microtiter plate format comprising a two-chamber system consisting of a bottom and cover plate. The chambers in the bottom and cover plates are connected by a conductive bridge to determine enzyme activity using fluorescence measurement.

[0009] Another alternative for determining enzyme activity is impedance measurement. US 10018581 B2 and WO 0075360 A2 describe impedance measurement, where one electrode is coated with the substrate or target molecule, or the other is coated with an enzymatically degradable plastic film. Both methods require direct contact between the electrode and the plastic and are not suitable for parallelization in the sense of high-throughput processes.

[0010] EP 1 699 101 A1 describes a system for parallelized electrochemical impedance spectroscopy in polymer electrolyte fuel cells comprising a sandwich with an electrode layer, an ion-conducting membrane, and another electrode layer. Impedance measurement requires direct contact between the electrode and the polymer.

[0011] Frank et al. describe a method for analyzing PET degradation by polyester hydrolases using impedance measurement (Frank et al. 2022). This method is based on additively manufactured single-use, disposable samples and is not suitable for parallelized, time-resolved, and continuous high-throughput analysis.

[0012] Frank and Zimmermann describe the characterization of plastic-degrading enzymes using impedance spectroscopy in a two-chamber system, with two electrodes separated by a plastic film acting as a water- and ion-impermeable layer (Frank and Zimmermann 2022). They particularly emphasize the parallel analysis and high-throughput of the system and method. The first and second reaction chambers are arranged one above the other and separated by a plastic film. It remains unclear how the reaction chambers are filled with an enzymatic solution and / or how the film is used to enable continuous long-term measurements of the dielectric properties of the plastic film.

[0013] JP 2009 / 281 918 A describes a method for determining the degradation of a polymer film comprising adjusting the temperature of the polymer film and measuring electrical properties of the polymer film, in particular the dielectric loss factor or the insulation resistance, along the thickness of the film, from which the glass transition temperature and, on the basis of which the degradation of the polymer film is determined.

[0014] The object is therefore to provide a system and method for degradation analysis of polymer films using polymer-degrading reagents, in particular biocatalysts such as enzymes, which overcomes the deficiencies known from the prior art and, in particular, provides a time-resolved, contact-free, and continuous screening method. According to the invention, this object is achieved by the system, use, and method according to the independent claims. Advantageous embodiments of the invention are specified in the dependent claims.

[0015] A first aspect of the invention relates to a system for measuring the degradation of polymer films by polymer-degrading reagents, comprising i. at least two housing parts comprising at least one reaction space consisting of a first and a second reaction chamber, wherein the first reaction chamber is arranged in a first housing part and the second reaction chamber is arranged in a second housing part, wherein the first and the second housing part are designed to accommodate a polymer film in such a way that the polymer film is arranged between the first and second reaction chambers of the reaction space, wherein at least one interior angle between the polymer film and one of the two reaction chambers of the reaction space is in the range from 10° to 80°, wherein at least one reaction chamber of the reaction space has at least one inlet, ii.at least a first and a second electrode, wherein the first electrode is in functional communication with the first reaction chamber and the second electrode is in functional communication with the second reaction chamber.

[0016] Advantageously, the system according to the invention can be used to measure in real time the degradation of polymer films by polymer-degrading reagents, preferably the degrading activity of polymer-degrading enzymes.

[0017] The continuous measurement of the polymer film, which is located between the first and second reaction chambers throughout the entire measurement period, offers the possibility of monitoring the kinetics of the reagents and the degradation process, as well as changing the process parameters (temperature, additives) and investigating their influence. Thus, the invention offers the potential to replace multiple individual reactions with a single reaction approach, which were previously required for temporal resolution in endpoint measurements. The term "contactless" means that the polymer film to be tested and the at least one first and second electrode are not in contact, so that no polymer coating of the electrodes is required for the test, or conversely, the polymer film does not need to be coated with an electrical conductor.

[0018] Advantageously, the system allows for easy dissipation of air bubbles formed between the polymer film and the first or second reaction chamber by tilting the polymer film or the reaction chambers, allowing air bubbles to dissipate upwards. At the same time, the system according to the invention ensures that the polymer film is constantly sufficiently wetted with liquid, resulting in complete electrical insulation between the first and second reaction chambers. In some embodiments, the film's inclination to the horizontal is not 0°, as otherwise, air bubbles formed during the measurement cannot dissipate and would falsify the measurement results.

[0019] The term "degradation" refers to the breakdown or degradation of a chemical compound into smaller molecules or ions due to physical, chemical, or biological influences. For practical purposes, the term "degradation" also includes structural changes to the polymer film, in particular perforation and / or erosion of the polymer film.

[0020] The term "housing part" refers to a component of a housing, i.e., a solid shell for the other components (reagents, polymer film) of the system according to the invention. The at least two housing parts together expediently form the housing. Advantageously, the housing, which is created by mechanically pressing the first and second housing parts together, is designed to be reusable, i.e., the housing parts can be used for a multitude of measurement runs, in which the polymer film is not glued but reversibly inserted via a locking mechanism.

[0021] In some embodiments, the housing, consisting of a first and second housing part, is designed as a disposable system, meaning that the housing parts are used for one measurement run. In some embodiments, the polymer film is bonded to at least one housing part, the first housing part and / or the second housing part.

[0022] The term "reaction space" refers to a compartment in which the reaction, in particular degradation, of the polymer film by the polymer-degrading reagent takes place. The polymer film expediently serves as a separator between the two reaction chambers of a reaction space. In preferred embodiments, the polymer film completely isolates the two reaction chambers of a reaction space from each other. The phrase "complete isolation from each other" refers to the formation of an electrical resistance barrier and a liquid barrier by the polymer film.

[0023] The term "internal angle" refers to an angle in a reaction chamber formed between the polymer film and an adjacent wall of a reaction chamber. According to the invention, at least one internal angle between the polymer film and one of the two reaction chambers of the reaction space is in the range of 10° to 80°, preferably in the range of 30° to 50°.

[0024] The term “functional connection” is understood to mean an arrangement in which, in the operating state (function: measurement of the degradation of polymer films by polymer-degrading reagents) of the system according to the invention, the first electrode is located in the first reaction chamber and the second electrode is located in the second reaction chamber, in particular in the solution comprising the polymer-degrading reagent, so that the function can be fulfilled.

[0025] In preferred embodiments, the housing has at least two reaction chambers, each consisting of a first and a second reaction chamber, wherein the two first reaction chambers are arranged in the first housing part and the two second reaction chambers are arranged in the second housing part. Each reaction chamber consists of a first and a second reaction chamber, which are collectively referred to as partner chambers (of a reaction chamber). A partition wall is located between a first and a further first reaction chamber, which are collectively referred to as adjacent chambers.

[0026] In preferred embodiments, the first and second housing parts each have a microtiter plate format with 6, 12, 24, 48, 96 or 384 reaction chambers, i.e., the first and second housing parts each comprise 6, 12, 24, 28, 96 or 384 first and second reaction chambers, respectively. Advantageously, through the use of standardized microtiter plate formats, the system for the first time provides a parallelized measurement method for high-throughput investigations for the degradation analysis of polymer-degrading reagents, preferably on macroscopic polymer samples. By placing the polymer film as a material barrier between the first and second housing parts, depending on the microtiter plate format used, up to 384 reaction mixtures are created, in which up to 384 different reagents can be investigated simultaneously in a one-step process.Due to the reversible introduction of the polymer film, the system can be used for a wide range of high-throughput screenings, significantly reducing resource requirements and labor compared to disposable systems or endpoint measurements.

[0027] In embodiments, the first and second housing parts each have ANSI / SLAS-4 compliant spacing between adjacent reaction chambers, with spacings of 19.5 mm (24-microtiter plate format), 13 mm (48-microtiter plate format), 9 mm (96-microtiter plate format), or 4.5 mm (384-microtiter plate format) between the center of the first reaction chamber and the center of the adjacent reaction chamber. Advantageously, the use of ANSI / SLAS-4 compliant formats enables the use of commercially available adjustable-distance and fixed-distance multi-channel pipettes to fill the reaction chambers, thus enabling an increased degree of automation.

[0028] In embodiments, the two housing parts and the reaction chambers of a housing part are arranged such that the polymer film is arranged vertically between the first and the second reaction chamber of a reaction space.

[0029] In embodiments, the at least two housing parts each comprise at least two reaction chambers, wherein the reaction chambers of one housing part are arranged vertically one above the other and the two housing parts are arranged mirror-symmetrically to the polymer film, wherein the reaction chambers have an upward inclination or an inclination angle in the range of 10° to 80°, starting from a horizontal axis and the intersection point with the polymer film. The inclination of the reaction chambers leads to the formation of an interior angle in the range of 10° to 80° between the polymer film and the first and second reaction chambers of a reaction space. The interior angles between the polymer film and the two reaction chambers of a reaction space are preferably mirror-symmetrical.Advantageously, it has been found that an inclination of the reaction chambers in the range of 10° to 80°, particularly preferably 30° to 50°, starting from the horizontal axis, leads to easy migration of air bubbles and is easily implemented structurally, creating an interior angle in the range of 10° to 80°, preferably 40° to 60°, between the polymer film and a reaction chamber. In embodiments, the sum of the opposing acute interior angles of the two reaction chambers of a reaction space is in the range of 20° to 160°, preferably 80° to 120°. Furthermore, the inclination of the reaction chambers advantageously facilitates filling with a polymer-degrading reagent in solution, while simultaneously minimizing the risk of leakage from the reaction chambers, which arises due to the vertical orientation of the reaction chambers.

[0030] The inventors have recognized that by preferentially inclining the reaction chambers in the range of 10° to 80°, in particular in the range of 30° to 50°, the distance between two adjacent reaction chambers in a housing part is sufficient to minimize the risk of overlapping measurement results.

[0031] Outside these ranges, the risk of inaccurate measurements due to crosstalk effects could significantly increase if the reaction chamber walls are thin. The term "crosstalk" refers to the unwanted, mutual influence of the otherwise independent measurement signals from two adjacent reaction chambers within a housing section.

[0032] In embodiments, the first and second reaction chambers each have at least one inlet for filling the reaction chamber with a solution, preferably on the outside of the reaction chamber (side of the reaction chamber opposite the side formed with the polymer) and at the upper end of the outside of the reaction chamber.

[0033] In preferred embodiments, a guide channel for filling a reaction chamber with a solution connects the inlet with the reaction chamber. The diameter of the inlet and the diameter of the inlet opening of the guide channel are expediently identical. A guide channel is understood to be an elongated passage within the outer wall of a housing part, which leads from the inlet to the reaction chamber. In embodiments, the guide channel is almost cylindrical or funnel-shaped. In a particularly preferred embodiment, the guide channel is a (funnel-shaped) guide channel that tapers towards the reaction chamber, preferably with an incline of approximately 45%, a diameter of the inlet opening in the range of 4 mm to 5 mm, a diameter of the outlet opening to the reaction chamber in the range of 2 mm to 3 mm and a length of 3 mm to 5 mm.Advantageously, such a guide channel allows standardized pipettes, in particular multi-channel pipettes and pipetting robots, to be used for parallel and / or automated filling of all reaction chambers of a housing part despite the vertical orientation of the reaction chambers.

[0034] In embodiments, the two housing parts and the reaction chambers of a reaction space are arranged vertically one above the other, wherein the polymer film is arranged with an inclination in the range of 10° to 80°, starting from the horizontal axis, between the first and the second reaction chamber of a reaction space, thereby forming an upper (first) and a lower (second) reaction chamber.

[0035] The sum of the opposing interior angles between the first and second reaction chambers, formed by the separation of a reaction space by the polymer film, is expediently 180°. Inclining the polymer film in the range of 10° to 80° creates a corresponding acute angle and an obtuse angle. In one example, the polymer film is arranged at an inclination of 50° between the first and second reaction chambers, forming an acute angle of 50° and an obtuse angle of 130°.

[0036] In embodiments, the outer side of the upper (first) reaction chamber has a first inlet for filling the upper reaction chamber and a second inlet for filling the lower (second) reaction chamber. The outer side lies opposite the inner side of the first reaction chamber, which is formed by the polymer film and the first reaction chamber. Conveniently, the first inlet is connected to the upper (first) reaction chamber, and the second inlet is connected to the lower (second) reaction chamber.

[0037] In preferred embodiments, the second inlet has a filling channel that extends into the lower reaction chamber. This advantageously enables independent filling of the first and second reaction chambers with different reagents.

[0038] In embodiments, the reaction space between the upper (first) and lower (second) reaction chambers has an opening for filling the lower reaction chamber. The polymer film is expediently perforated at the location of the opening for filling the lower reaction chamber.

[0039] The term "perforated" refers to a film that has holes in it. A polymer film is typically perforated by punching, piercing, drilling, melting, cutting, or during production.

[0040] In embodiments, the housing, consisting of two housing parts, has at least two reaction spaces, each consisting of a first and a second reaction chamber, wherein the first reaction chambers and the second reaction chambers are arranged offset in height, in particular in a stepped manner. In embodiments, the two housing parts are arranged such that a first housing part is arranged above a second housing part, thereby forming an upper (first) and a lower (second) housing part.

[0041] In embodiments, the system according to the invention further comprises at least one cover plate for closing the reaction chambers.

[0042] In embodiments, the at least one cover plate is suitable for closing at least one reaction chamber, preferably all reaction chambers, of a housing part. The at least one cover plate expediently enables the closure of the reaction chambers and thus protection against leakage, evaporation, the ingress of pollutants and / or oxygen, and / or the contacting of an electrode arranged in the reaction chamber.

[0043] In embodiments, the at least one cover plate is designed such that the cover plate completely closes the reaction chambers of an upper housing part, so that a lower and an upper housing part form a closed component with the cover plate.

[0044] In embodiments, the system according to the invention comprises at least two cover plates for closing the reaction chambers, wherein the first reaction chamber can be closed with at least one first cover plate and the second reaction chamber with at least one second cover plate. In preferred embodiments, the at least one first cover plate closes the reaction chambers of a first housing part, and the at least one second cover plate closes the reaction chambers of a second housing part, so that the two housing parts and the two cover plates form a closed component.

[0045] In embodiments, the at least one first electrode is located in the first cover plate or in the first reaction chamber. In embodiments, the at least one second electrode is located in the first or second cover plate or in the second reaction chamber.

[0046] In preferred embodiments, the first electrode is arranged in the first reaction chamber of the first housing part, and the second electrode is arranged in the second reaction chamber of the second housing part. In embodiments, the arrangement in the first and second housing parts is effected via a printed circuit board (PCB) each comprising the at least one first or the at least one second electrode. In embodiments, the at least one first housing part comprises further reaction chambers and / or the at least one second housing part comprises further reaction chambers.

[0047] According to the invention, each reaction chamber has a functional connection to at least one electrode. In embodiments, each reaction chamber has a functional connection to one electrode, i.e., the number of reaction chambers corresponds to the number of electrodes. If the first housing part comprises, for example, 96 first reaction chambers, 96 electrodes are located either in the respective reaction chambers or are arranged in the cover plate.

[0048] In further embodiments, the first electrode is arranged in the cover plate and the second electrode is arranged in the second reaction chamber. In further embodiments, the second electrode is arranged in the cover plate and the first electrode is arranged in the first reaction chamber.

[0049] If the system comprises more than one reaction chamber in the at least one first and at least one second housing part and thus the corresponding number of electrodes, all electrodes of a housing part are arranged either in the cover plate or in the respective reaction chambers.

[0050] In embodiments, the first electrode is arranged in the first cover plate and the second electrode is arranged in the second cover plate.

[0051] In further embodiments, the first and second electrodes are arranged in a cover plate. Preferably, the at least one second electrode is guided into the second (lower) reaction chamber via the filling channel.

[0052] In embodiments, an electrode located in a reaction chamber can be electrically contacted via a contact arranged in the cover plate.

[0053] In embodiments, the at least one first and second electrode are each soldered to a plug, preferably a pin, in the housing part, and the cover plate each comprises at least one contact, preferably a socket (counterpart of the plug), wherein the plug and the contact are arranged such that when the housing part is closed with the at least one cover plate, the plug is electrically contacted by the contact. The term "pin" refers to a thin pin made of an electrically conductive material. The term "socket" refers to a sleeve surrounded by insulation for receiving a plug, preferably a pin, which serves as a contact.

[0054] In embodiments, the at least one first and second electrode are each soldered to a contact, preferably a flat metal surface, in the housing part and the cover plate each comprises at least one plug, preferably a spring contact pin, wherein the contact and the plug are arranged such that when the housing part is closed with the at least one cover plate, the contact is electrically conductively contacted by the plug.

[0055] In embodiments, the at least one first and second electrode is each designed as a plug, preferably as a pin, and the cover plate comprises at least one contact, preferably a socket (counterpart of the plug), wherein the plug and the contact are arranged such that when the housing part is closed with the at least one cover plate, the plug is electrically conductively contacted by the contact.

[0056] In embodiments, the electrodes are made of a precious metal, preferably platinum or gold; stainless steel or graphite.

[0057] In embodiments, the electrodes have a thickness in the range of 0.3 mm to 1 mm, preferably in the range of 0.7 mm to 0.85 mm.

[0058] In embodiments, the at least one reaction chamber is connected by an air duct between the first and second reaction chambers. This advantageously enables continuous pressure equalization between the first and second reaction chambers of a reaction chamber, which is particularly relevant for stable long-term measurements in a sealed system, especially for periods longer than 1 hour, at temperatures above room temperature, and / or with gases generated during the degradation process. Without pressure equalization, deformation of the polymer film arranged between the reaction chambers occurs, which distorts the degradation process and the measurement results.

[0059] In embodiments, an air channel is a rectangular, oval or round channel in which air is transported between the first and second reaction chambers.

[0060] In embodiments, an air duct is located in each of the first and second reaction chambers, with an air duct system being created by joining the first and second housing parts. In this embodiment, a polymer film with openings is expediently provided, with the openings being provided at the position of the air ducts, in particular by punching, piercing, drilling, melting, cutting, or during production.

[0061] In further embodiments, an air duct is located in the upper (first) reaction chamber, wherein the air duct connects the unfilled space of the filling duct to the second (lower) reaction chamber with the unfilled space of the upper (first) reaction chamber. When the upper (first) reaction chamber is closed with the cover plate, pressure equalization occurs between the upper (first) and lower (second) reaction chambers via the air duct.

[0062] In embodiments, the system according to the invention comprises at least one seal for sealing the reaction chamber with the polymer film. In embodiments, the reaction chamber has at least one seal at the contact point with the polymer film, in particular at the edge of the reaction chamber.

[0063] In embodiments, the system according to the invention comprises at least one seal for closing the at least one inlet of a reaction chamber with the cover plate. In embodiments, the inlet and the cover plate comprise complementary components of a seal, which form a complete seal when the reaction chamber is closed with the cover plate and, if appropriate, with additional sealing materials.

[0064] The term "seal" refers to an element designed to reduce or prevent unwanted mass transfer. In some embodiments, the seal is a contact, static seal, i.e., a seal that allows for a reduction in the movement of the contacting parts to be sealed. Advantageously, a seal enables a hermetic and reversible closure and serves to protect the liquids in the reaction chambers from leakage and evaporation.

[0065] The inventors recognized that a particularly secure closure can be achieved by a seal whose thickness is in the range from 0.2 mm to 2 mm, preferably in the range from 0.5 mm to 1.5 mm, particularly preferably in the range from 0.75 mm to 1 mm, and whose strength is in the range from 40 Shore A to 80 Shore A, preferably in the range from 50 to 70 Shore A. The unit “Shore A” is understood to be the unit of Shore hardness A, which is determined when determining the hardness of soft elastomers by determining the penetration depth of a test pin type A (flat tip with a diameter of 0.79 mm and an opening angle of 35°) made of hardened steel, whereby a test weight of 1 kg presses onto the material for 15 s at a temperature of 23°C ± 2 K (standard DIN ISO 7619-1).

[0066] In embodiments, the seal consists of ethylene propylene diene rubber (EPDM), acrylonitrile butadiene rubber (NBR), perfluorocarbon elastomers (perfluorocarbon rubber, FFKM), fluorocarbon elastomers (fluorocarbon rubber, FKM), polyurethane elastomer, silicone rubber, in particular vinyl methyl silicone (VMQ) or fluorosilicone (FVMQ). In preferred embodiments, the seal consists of silicone rubber.

[0067] In embodiments, the seal has a density in the range of 1.0 g / cm 3 up to 2.0 g / cm 3 , preferably in the range of 1.1 g / cm 3 up to 1.3 g / cm 3 , on.

[0068] Such seals advantageously enable reliable and long-term stable sealing, especially when using saline and / or detergent-containing solutions.

[0069] In some embodiments, the seal consists of a sealing ring with a flat or round cross-section, which is arranged at the contact point between the reaction chamber and the polymer film. In other embodiments, the seal is realized via a smooth, elastic flat seal at the contact point of the reaction chamber, which serves to form-fit the edge of a reaction chamber with the polymer film when the polymer film is inserted.

[0070] In embodiments, the seal consists of a sealing ring, a recess for a sealing ring at the edge of the reaction chamber inlet, and / or a complementary contact position for the sealing ring in the cover plate. In embodiments, the contact position takes the form of a smooth surface or a sealing ring additionally attached thereto, which, due to its size, is able to engage the sealing ring at the reaction chamber inlet by the sealing ring on the cover plate being slightly smaller or larger than the sealing ring at the inlet. Advantageously, the combination of the sealing ring with the recess and the contact position enables a water- and water vapor-tight seal.

[0071] In embodiments, the first and second housing parts and / or the at least one cover plate are made of glass-filled, glass-fiber- or carbon-fiber-reinforced synthetic resins or thermosets, such as a polyacrylate or polycarbonate, a polyetheretherketone, a polyetherketoneketone, a polyphenylene sulfide, a polyethersulfone, a polyamide, a polyolefin, preferably polypropylene, acrylonitrile-butadiene-styrene copolymer, polyoxymethylene, or fluorinated polyolefins, particularly preferably polytetrafluoroethylene, or mixtures thereof. Advantages of the materials mentioned are their high strength and chemical inertness, in particular corrosion resistance and dimensional stability at temperatures up to 80°C.

[0072] In embodiments, the first and second housing parts and / or the at least one cover plate have a hydrophobic and optionally lipophobic coating, in particular with polypropylene, silicone resins, silicones, or fluorocarbon polymers. Advantageously, the coating enables the system to be resistant to any polymer-degrading reagents selected from whole cells, preferably bacterial cells or fungal cells; catalytic ribonucleic acids; chemical reagents, preferably organic solvents, acids and / or bases; and / or biocatalysts.

[0073] In embodiments, the first and second housing parts and the at least one cover plate are connected by mechanical means selected from clamping means, preferably clamps or clamping containers; screws, preferably screw connections with restoring forces (coil springs, spring washers, rubber rings); levers and / or springs. In further embodiments, the first cover plate and the first housing part and / or the second cover plate and the second housing part are connected by mechanical means selected from clamping means, preferably clamps or clamping containers; screws, preferably screw connections with restoring forces (coil springs, spring washers, rubber rings); levers and / or springs.

[0074] The mechanical fasteners allow the housing parts and lids to be opened and closed repeatedly.

[0075] In embodiments, the first and / or second housing part comprises guide points or guide lines for positioning the polymer film.

[0076] In embodiments, the first and second housing parts and the at least one cover plate form a common component.

[0077] In embodiments, the first cover plate and the first housing part form a common component with the second cover plate and the second housing part.

[0078] A further aspect of the invention relates to the use of the system according to the invention for measuring the degradation of polymer films by polymer-degrading reagents. The term "reagent" refers to a substance that exhibits a specific reaction when in contact with other substances, in particular the polymer film.

[0079] In embodiments, the polymer-degrading reagent is selected from the group comprising whole cells, preferably bacterial cells or fungal cells; catalytic ribonucleic acids; chemical reagents, preferably organic solvents, acids and / or bases; and / or biocatalysts.

[0080] In embodiments, chemical reagents are selected from organic solvents, in particular ethylene glycol or toluene; ionic liquids; acids, in particular hydrochloric acid, sulfuric acid, or phosphoric acid; and / or bases, in particular potassium hydroxide, sodium hydroxide, or ammonia. The term "ionic liquids" refers to salts that melt below 100°C. In embodiments, the ionic liquid comprises an imidazolium, pyridinium, pyrrolidinium, sulfonium, ammonium, or phosphonium as a cation. In embodiments, the ionic liquid comprises a halide, a weakly coordinating ion, in particular a tetrafluoroborate, hexafluorophosphate, trifluoroacetate, triflate, or tosylate as an anion.

[0081] In embodiments, biocatalysts are enzymes, preferably from the class of oxidoreductases, transferases, lyases or hydrolases.

[0082] In preferred embodiments, the system according to the invention is used to measure enzyme activities during the degradation of polymer films.

[0083] In embodiments, hydrolases are selected from cutinases, esterases, preferably carboxylesterases; proteases, peptidases, amidases, lipases, or cellulases. In embodiments, the hydrolase is Polyester Hydrolase Leipzig No. 7 (PHL-7, Sonnendecker et al. 2022) or a variant thereof, or Leaf Compost Cutinase (LCC, Sulaiman et al. 2012, Sonnendecker et al. 2022).

[0084] In embodiments, enzymes are further preferably selected from the group comprising peroxidases, monooxygenases, dioxygenases, cytochrome P450 oxygenases, laccases, alkane hydroxylases, dehalogenases, and tryptophanases. A further aspect of the invention relates to a method for measuring the degradation of polymer films by polymer-degrading reagents, comprising the steps of a) providing a system according to the invention, b) inserting a polymer film between the first and second housing parts, wherein each reaction chamber comes into contact with the polymer film, c) filling at least one of the reaction chambers of a reaction space with at least one solution comprising a polymer-degrading reagent, and d) determining the dielectric properties of the polymer film to measure the degradation of polymer films by the polymer-degrading reagent.

[0085] In embodiments, the method for measuring the degradation of polymer films by polymer-degrading reagents further comprises, between steps c) and d), closing at least one housing with at least one cover plate, wherein the first and second housing parts form a component with the at least one cover plate, and / or inclining the component such that the polymer film is arranged vertically.

[0086] In embodiments, the reaction chambers of a reaction space are arranged vertically one above the other, wherein the polymer film is arranged between the first and the second reaction chamber of a reaction space at an inclination in the range of 10° to 80°, starting from the horizontal axis, thereby forming an upper and a lower reaction chamber. The method for measuring the degradation of polymer films by polymer-degrading reagents further comprises, between steps c) and d), closing the at least one upper reaction chamber of the first housing part with a cover plate, wherein the first (upper) and second (lower) housing parts form a component with the cover plate. In embodiments, the first and second reaction chambers of the first and second housing parts are closed with at least one cover plate.The component is then tilted until the polymer film, which is immobile within the component, is positioned vertically relative to the horizontal axis. In one example, the polymer film is arranged at an inclination of 40° between the first and second reaction chambers. After the upper housing section is closed, the entire component is tilted by 50° so that the polymer film is positioned vertically. Tilting the component is understood to mean an inclination from the horizontal plane to the point where the polymer film is positioned vertically to the horizontal.

[0087] In one embodiment, the upper reaction chambers are sealed with a cover plate, with the first and second housing parts forming a single component with the cover plate. In one embodiment, the activity of polymer-degrading enzymes is determined when measuring the degradation of polymer films by polymer-degrading reagents.

[0088] In embodiments, the method according to the invention is a method for measuring enzyme activities in the degradation of polymer films, comprising a) providing a system according to the invention, b) inserting a polymer film between the first and the second housing part, wherein each reaction chamber comes into contact with the polymer film, c) filling at least one of the reaction chambers of a reaction space with at least one solution comprising an enzyme, and d) determining the dielectric properties of the polymer film for measuring the enzyme activities in the degradation of polymer films.

[0089] The term "polymer" refers to a macromolecular compound comprising at least one type of monomer unit (structural unit). The term "polymer" expediently also includes polycondensates. In embodiments, the polymer is a natural or synthetic polymer.

[0090] In embodiments, the polymer is a homopolymer, a copolymer, and / or a polymer blend. The term "homopolymer" refers to a polymer consisting of one type of monomer. The term "copolymer" refers to a polymer consisting of at least two different types of monomer. The term "polymer blend" refers to a mixture of at least two different polymers, in particular homopolymers and / or copolymers.

[0091] In embodiments, the polymer film consists of polyester selected from polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), polyethylene isosorbide terephthalate (PEIT), polylactic acid (PLA), in particular poly(L-lactic acid) (PLLA), poly(D-lactic acid) (PDLA), poly(D,L-lactic acid) (PDLLA);PLA- Stereokomplex (scPLA), Polyhydroxyalkanoat (PHA), Poly(3-Hydroxybutyrat) (P(3HB) / PHB), Poly(3-Hydroxyvalerat) (P(3HV) / PHV), Poly(3-Hydroxyhexanoat) (P(3HHx)), Poly(3- hydroxyoctanoat) (P(3HO)), Poly(3-hydroxydecanoat) (P(3HD)), Poly(3-hydroxybutyrat-co-3- hydroxyvalerat) (P(3HB-co-3HV) / PHBV), Poly(3-hydroxybutyrat-co-3- hydroxyhexanoat) (P(3HB- co-3HHx) / (PHBHHx)), Poly(3-hydroxybutyrat-co-5-hydroxyvalerat) (PHB5HV), Poly(3- hydroxybutyrat-co-3-hydroxypropionat) (PHB3HP), Polyhydroxybutyrat-co-hydroxyoctonoat (PHBO), Polyhydroxybutyrat-co-hydroxyoctadecanoat (PHBOd), Poly(3-hydroxybutyrat-co-3- hydroxyvalerat-co-4-hydroxybutyrat) (P(3HB-co-3HV-co-4HB)), Polybutylensuccinat (PBS), Polybutylensuccinatadipat (PBSA), Polybutylensuccinat-Terephthalat (PBAT), Polyethylenfuranoat (PEF), Polycaprolacton (PCL), Poly(ethylenadipat) (PEA) oder Mischungen dieser.;

[0092] In embodiments, the polymer film consists of polyamide selected from polyamide-6 (polycaprolactam, polycaproamide, PA6), polyamide-6,6 (poly(hexamethylene adipamide, PA6,6), poly(11-aminoundecanoamide) (PA11), polydodecanolactam (PA12), poly(tetramethylene adipamide) (PA4,6), poly(pentamethylene sebacamide) (PA5,10), poly(hexamethylene azelamide) (PA6,9), poly(hexamethylene sebacamide) (PA6,10), poly(hexamethylene dodecanoamide) (PA6,12), poly(m-xylylene adipamide) (PAMXD6), polyhexamethylene adipamide / polyhexamethylene terephthalamide copolymer (PA66 / 6T), polyhexamethylene adipamide / polyhexamethylene isophthalamide copolymer (PA66 / 6I) and mixtures thereof.

[0093] In further embodiments, the polymer film is a polyester or a polyesteramide produced by polycondensation from one or more different diols, diamines, and / or dicarboxylic acids, in particular with a monomer chain length of C2, C4, C6, C8, C10, C12, C14, C16, C18, or C20. In further embodiments, the polymer film is a polyester or a polyesteramide produced by polycondensation from one or more different dicarboxylic acids, in particular with a monomer chain length of C14, C16, or C18.

[0094] In some embodiments, the polymer film is selected from polyethylene terephthalate (PET), polybutylene succinate (PBS), polycaprolactone, polylactide (PLA), or mixtures thereof. In some embodiments, the polymer film consists of polyethylene terephthalate (PET) or polybutylene succinate (PBS), in particular amorphous PET.

[0095] In further embodiments, the film further comprises at least one material, in particular selected from the group comprising mineral fillers, talc, quartz, calcium carbonate, glass particles, glass or carbon fibers, ceramic fillers such as boron nitrite, aluminum oxide, zirconium oxide, silicates, and / or chemical additives such as antiblocking agents, antioxidants, antistatic agents, dyes, light stabilizers, flame retardant additives (e.g., chlorinated paraffins, bromine compounds), blowing agents, release agents, heat stabilizers, plasticizers, and, in the case of polymer mixtures, adhesion promoters. The term "film" is understood to mean a flat structure. The term "film" expediently also includes membranes, such as semipermeable membranes, including those made of cellulose acetate, polysulfone, polyethersulfone, polyamide, or polyvinylidene fluoride; ion exchange membranes, among others.made of perfluorosulfonic acid, perfluorocarboxylic acid, polystyrene resins, quaternary ammonium resins, or modified polyvinyl alcohols; or barrier layers for gases such as oxygen, vapors, or migration barriers for plasticizers, monomers, and dyes, including polyethylene, polyamides, and ethylene-vinyl alcohol copolymers. In embodiments, the film has a thickness in the range of 1 μm to 1 mm, preferably in the range of 50 μm to 250 μm.

[0096] In embodiments, the insertion of a polymer film between the first and second housing parts, with each reaction chamber coming into contact with the polymer film, is carried out by opening a mechanical connecting means selected from clamping means, preferably clamps or clamping containers; screws, preferably screw connections with restoring forces (coil springs, spring washers, rubber rings); levers and / or springs. Advantageously, the system according to the invention is reusable.

[0097] In embodiments, a polymer film is inserted between the first and second housing parts, with each reaction chamber coming into contact with the polymer film, by gluing. Advisably, a disposable system is obtained by gluing the polymer film.

[0098] In some embodiments, the polymer film is inserted freehand, i.e., without any tools. In some embodiments, the polymer film is inserted by positioning the polymer film using guide points or guide lines on at least one of the two housing parts.

[0099] According to the invention, a polymer film is inserted such that the polymer film is arranged between all reaction chambers of the two housing parts. The polymer film is expediently inserted with an orientation of the polymer film such that the thinnest dimension (film thickness) is arranged between the first and second reaction chambers or between the first and second housing parts.

[0100] In embodiments, if an air duct system or filling duct is present for filling the lower reaction chamber, a polymer film comprising openings is inserted, wherein the openings in the polymer film are provided at the position of the air duct system or the filling duct, in particular by punching, piercing, drilling, melting, cutting or during production.

[0101] In embodiments, the solution is an electrolyte solution with a concentration in the range of 0 M to 4 M, preferably in the range of 0.1 M to 1 M, comprising a polymer-degrading reagent. The term "electrolyte solution" refers to a solution comprising at least partially dissociated acids, bases, and / or salts.

[0102] In embodiments, one of the two reaction chambers of a reaction space is filled in step c) with at least one solution comprising a polymer-degrading reagent. In embodiments, the other reaction chamber of a reaction space is filled with a solution without a polymer-degrading reagent, in particular a salt-containing buffer solution. By filling only one reaction chamber of a reaction space, the required amount of reagent is advantageously reduced, which leads to cost advantages, especially with expensive reagents.

[0103] In further embodiments, the two reaction chambers of a reaction space in step c) are each filled with an identical solution comprising a polymer-degrading reagent. By filling the two reaction chambers of a reaction space with the same solution, the degradation of the polymer film on both sides is expediently measured. Measuring the degradation on both sides advantageously increases the process speed and thus reduces the analysis time.

[0104] In further embodiments, the two reaction chambers of a reaction space are filled in step c) with different solutions, each containing a polymer-degrading reagent. This advantageously results in a pooling of polymer-degrading reagents, whereby the two reagents cannot influence each other due to the spatial separation in the first and second reaction chambers.

[0105] In further embodiments, pooling is carried out with at least two different polymer-degrading reagents, which are present in a common solution and applied to at least one of the reaction chambers. In a second step, a subselection of the tested polymer-degrading reagents is made in order to perform depooling with them, which allows a clear statement about a single polymer-degrading reagent. The advantage of this two-stage pooling process is that, in principle, a larger number of polymer-degrading reagents can be tested. Using multi-stage pooling processes, up to 768 enzymes can be directly investigated without the enzymes influencing each other by dividing two enzymes into up to 384 reaction chambers and differentiating hits in a second reaction run. Furthermore, pooling with more than two enzymes per reaction chamber is also feasible.

[0106] In some embodiments, step d) is performed using impedance spectroscopy. The term "impedance spectroscopy" refers to the measurement of the alternating current resistance (impedance) between two electrodes as a function of the frequency of the alternating current. Continuous electronic measurements are performed between the reaction chambers of a reaction space. The impedance data are used to determine a measure of the change in the film's layer thickness during degradation. Advantageously, impedance spectroscopy enables the degradation of the polymer film to be investigated continuously and with high precision in a time-resolved manner.

[0107] In embodiments, the determination of the dielectric properties in step d) is carried out at a measurement frequency in the range of 1 Hz to 100 MHz, preferably in the range of 1 kHz to 100 kHz.

[0108] In embodiments, the determination of the dielectric properties in step d) is carried out with a sinusoidal excitation amplitude in the range of 10 mV to 200 mV, preferably with a sinusoidal excitation amplitude of 100 mV.

[0109] In embodiments, the determination of the dielectric properties in step d) is carried out by means of a multiplexer circuit and an impedance analyzer for controlling parallelized reaction spaces.

[0110] In embodiments, the dielectric capacitance is determined in step d) from the impedimetric raw data using a suitable equivalent circuit model.

[0111] In embodiments, the change in the dielectric capacitance of the polymer film is determined in step d). An ohmic resistance (R-system) in series with a parallel element consisting of a capacitance and another ohmic resistance is preferably used as an equivalent circuit. Impedance spectroscopy can be used to determine the temporal change in the capacitance of the polymer acting as a dielectric. The measured capacitance change depends on the degradation process, which affects both the layer thickness and the topography of the film surface. Long-term studies (measurement periods greater than 1 hour) are preferably conducted using the dielectric capacitance change, since the sensitivity of the measurement data increases proportionally with the measurement duration.

[0112] In embodiments, one micropore per reaction space with a pore diameter in the range of 1 pm to 100 pm, preferably in the range of 5 pm to 50 pm, is introduced into the polymer film before step b).

[0113] In embodiments, the micropores have a length to diameter ratio (aspect ratio) in the range of 1 to 100, preferably in the range of 10 to 30.

[0114] In embodiments, the micropores are introduced by means of laser microdrilling (laser ablation), preferably with a pulsed femtosecond laser; mechanical-abrasive microdrilling, preferably with ultrasound assistance; or electron beam microdrilling.

[0115] In embodiments, the electrochemical resistance of the micropores and thus the change in the micropore diameter are recorded in step d). Advantageously, measuring the electrochemical resistance of the micropores allows the reaction rate to be determined after just seconds to a few minutes, depending on the initial diameter of the pore. The thickness of the film is selected such that changes in this resistance can be neglected in relation to the change in the pore diameter.

[0116] Advantageously, the system according to the invention enables a parallelized, time-resolved, contact-free and continuous measurement and thus a high-throughput measurement of the enzymatic and chemical degradation of polymer films, in particular for the screening of enzymes for the tertiary (molecular, material) recycling of polymers.

[0117] For the realization of the invention, it is also expedient to combine the above-described inventive embodiments, embodiments and features of the claims.

[0118] The invention will be explained in more detail below using exemplary embodiments. These exemplary embodiments are intended to describe the invention without limiting it.

[0119] Fig. 1: System according to the invention in a preferred embodiment with vertically arranged reaction chambers in a housing part. Fig. 2: Partial cross-section of the system according to the invention. Fig. 1.

[0120] Fig. 3: Cross-section of the system according to the invention, as in Fig. 1, comprising two covers.

[0121] Fig. 4: A) Section from Fig. 3 including guide channel and inlet. B) Section from Fig. 3 showing a seal.

[0122] Fig. 5: Partial cross-section of a system according to the invention in a further preferred embodiment.

[0123] Fig. 6: Partial cross-section of a system according to the invention in a further embodiment.

[0124] Fig. 1 shows a preferred embodiment of a system according to the invention with two housing parts 1, 2, each with 96 reaction chambers 4, which together form 96 reaction spaces. The second housing part is only shown as a detail and shows a section of the interior. Both the reaction chambers 4 of a housing part 1, 2 and the housing parts 1, 2 are arranged vertically, i.e. perpendicular to the plane. The system according to the invention further comprises the polymer film 3, which is arranged vertically between the first and second housing parts 1, 2. The reaction chambers 4 are inclined mirror-symmetrically in the direction of the polymer film 3, starting from the horizontal axis. The housing parts 1 and 2 together form the housing 13. The system further comprises air ducts 5 for pressure equalization within a reaction space.The polymer film 3 contains openings 8 in the area of ​​the air channels to enable the transport of air between the first and second air channels and consequently the first and second reaction chambers. The system further comprises an inlet 14, a guide channel 10 for filling the reaction chamber with solution, and a plug 9 for connecting the electrodes. Recesses 11 are located on the inlet 14, into which a sealing ring 15a can be inserted when closing the housing part. The sealing ring 15a then serves as a seal between the outer contact surface of a housing part and a lid. 15b shows a seal between the polymer film and the housing part, which is implemented as a flat gasket.

[0125] Fig. 2 shows a partial cross-section of the system according to the invention from Fig. 1. In addition to the two housing parts 1, 2 with three reaction chambers, two cover plates 7 are shown. The housing parts each have three reaction chambers 4 with air ducts 5 and electrodes 6, arranged on the cover plates 7. The air ducts 5 form the air duct system 5a after the mechanical closure of the housing parts 1 and 2. The polymer film 3 contains openings 8 in the region of the air ducts in order to enable the transport of air between the first and second air ducts and consequently the first and second reaction chambers. The reaction chambers are inclined by 40° mirror-symmetrically to the polymer film (angle α), resulting in an interior angle between the reaction chamber and the polymer film of 50° (angle β). The polymer film 3 is vertical, i.e. at a right angle (angle γ), to the horizontal. The sum of the interior angles β is 100°.

[0126] The air channel 5 between two adjacent reaction chambers also serves as part of the partition wall and provides sufficient distance to avoid crosstalk signals.

[0127] The black, solid line in the middle, right-hand reaction chamber indicates the minimum height for complete liquid wetting of the polymer film, while the dashed line indicates the maximum height. It is clear that even at maximum filling level, there is sufficient space for air bubbles to escape. During measurement, housing sections 1 and 2 are each hermetically sealed by a cover 7.

[0128] Fig. 3 shows the housing parts 1, 2, which are mirror-symmetrical to the polymer film 3, and two cover plates 7 with three cross sections A, B and C of the system according to the invention from Fig. 1. Part A shows the cross section comprising inlet 14 and guide channel 10 as well as the electrode 6, the plug 9 and the contact 12 for the plug 9. In the embodiment, the electrodes 6 are located in the reaction chambers 4. The electrode 6 is soldered to a plug 9, e.g. a pin, in the housing part and can be electrically contacted via the contact 12, e.g. a socket for the pin, located in the cover plate 7. Section B shows (black arrows) how the electrodes are electrically contacted during operation, ie when the housing parts are closed by the cover plates 7 (right-hand graphic). In section C, air channels 5 between two adjacent reaction chambers and openings 8 in the polymer film 3 in the area of ​​the air channels 5 are shown.

[0129] Fig. 4A shows a section of Fig. 3, including the guide channel 10 and inlet 14. The guide channel tapers funnel-shaped toward the inlet of the reaction chamber 4, allowing standard pipette systems to be used for filling despite the vertical orientation of the housing parts. The electrode 6 is soldered to a connector 9, e.g., a pin, in the housing part 1.

[0130] Fig. 4B shows a section of Fig. 3 and depicts a seal 15a between the outer contact surface of a housing part and a cover in the form of a sealing ring. Recesses 11 are located on the inlet 14, into which a sealing ring is inserted when the housing part is closed. A complementary contact position 16 for the sealing ring is located on the cover plate 7. In use, the sealing rings are permanently inserted into the recess 11, e.g., by adhesive bonding. 15b shows a seal between the polymer film and the housing part, which is implemented as a flat gasket.

[0131] Fig. 5 shows a partial cross-section of another preferred embodiment of the system according to the invention with two housing parts 1, 2 and three reaction chambers 4 each, forming three reaction spaces. A) shows the orientation of the system for filling and measuring, and B) shows another positioning for measuring.

[0132] The reaction chambers 4 of a reaction space are arranged vertically one above the other, with the polymer film 3 arranged between them at an inclination of 40° starting from the horizontal axis. This creates an upper (first) 4a and a lower (second) 4b reaction chamber. The reaction space is separated by the polymer film 3, resulting in a correspondingly acute interior angle of 40° (angle α) and an obtuse interior angle of 140° (β). The sum of the interior angles is 180°. The housing parts 1 and 2 together form the housing 13, with the upper housing part 1 being arranged on the lower housing part 2. The reaction chambers 4 are arranged offset in height, in particular in a stepped manner.

[0133] The upper reaction chamber 4a comprises a (first) inlet 14a for filling the upper reaction chamber and a second inlet 14b for filling the lower reaction chamber 4b. For filling the lower reaction chamber, the upper reaction chamber 4a further contains a filling channel 17. In the area of ​​the filling channel, the polymer film 3 contains openings 8 to enable the filling of the lower reaction chamber after the polymer film has been inserted. Furthermore, the upper reaction chamber comprises an air channel 5, which is used for pressure equalization between the upper and lower reaction chambers. The black dashed lines show the maximum fill level at which, on the one hand, complete liquid wetting of the polymer film 3 is ensured, and, on the other hand, mixing of the reagents from the upper and lower reaction chambers is excluded. The pressure equalization, ieThe transport of air between the upper and lower reaction chambers takes place above the maximum fill level in the area of ​​the air channel 5. The electrodes 6 of the lower housing part are located in the reaction chambers, while the electrodes of the upper housing part are located in the lid 7. After the housing is filled with the polymer-degrading reagents, the lid 7 is placed on the upper housing part 1 and, together with the upper housing part 1 and the housing part 2, forms the closed component 18.

[0134] After the housing has been closed with the lid, the dielectric properties can be recorded using electrodes 6 for degradation analysis of polymer-degrading reagents. However, the inventors have found that it may be preferable to tilt component 18, as shown in B), to such an extent that polymer film 3 is arranged at a right angle (angle y) to the plane for carrying out the test. Any air bubbles that may form between the contact surfaces of the reaction chambers and the polymer film can, in a corresponding structure, migrate even more effectively upwards into the area of ​​the air channel (i.e., into the area without reagents). The interior angles α and β formed between the polymer film and the reaction chambers remain unchanged.

[0135] Fig. 6 shows a cross-section of another embodiment of a system according to the invention with two housing parts 1, 2 and three reaction chambers 4 each, forming three reaction spaces. The system according to the invention comprises the first and second housing parts 1, 2 with a polymer film 3 and a cover plate 7. The housing parts each have three reaction chambers 4 with electrodes 6 arranged in the reaction chambers 4 and on the cover plate 7.

[0136] Method for measuring the degradation of polymer films

[0137] An amorphous PET film (Goodfellow, thickness 225 pm) with a size of 45 mm 2is placed in a two-chamber system. Both chambers are filled with approximately 300-600 pL of a 1 M hydrogen phosphate buffer (pH 7.8) so that the PET film is completely covered. The buffer also contains 500 nM of a polymer-degrading hydrolase enzyme such as Polyester Hydrolase Leipzig No. 7 (PHL7) or Leaf Compost Cutinase (LOG). The two-chamber system is closed with a lid that provides a platinum spiral electrode for each chamber, which is immersed in the buffer, and the entire unit is transferred to a heating cabinet. The unit is heated from room temperature to, for example, 70°C and maintained there for the entire measurement time. The platinum electrodes are connected to an impedance analyzer (e.g., Agilent 4294A High-Precision Impedance Analyzer) and, if necessary, a multiplexer circuit for PC control. For example,Every two minutes, impedance spectra for a frequency range from 50 Hz to 5 MHz with 61 logarithmically distributed frequency points at a sine amplitude of 100 mV were recorded and stored.

[0138] Determination of the change in dielectric capacitance

[0139] The impedance spectra are modeled using an equivalent circuit consisting of a fixed series resistance R system, corresponding primarily to the multiplexer resistance, and a parallel element connected in series with it, comprising a second ohmic resistance R2 and a capacitance C, for example, but not exclusively, using the Nelder-Mead fitting method. It is assumed, for example, that changes in capacitance C during the degradation process are, to a first approximation, caused exclusively by the aforementioned degradation process on the PET film. The measuring system was designed in such a way that no other materials, such as the chamber walls or the electrode, can be considered for measurement. The change in capacitance is a measure of the degradation, such as erosion, of the PET film by the polymer-degrading hydrolase enzyme.The capacitance value is influenced by the layer thickness of the PET film, the surface roughness, and material-intrinsic and partly temperature-dependent properties such as relative permittivity and crystallinity. The significance of the capacitance in determining degradation ends as soon as a perforation occurs in the PET film. This point in time also serves as a measure of the degradation of the PET film by the polymer-degrading enzyme.

[0140] Determination of the electrochemical conduction resistance of the micropores

[0141] Analogous to the determination of the change in dielectric capacitance, micropores are characterized using the electrochemical conduction resistance R2 (see Determination of the Change in Dielectric Capacitance). This resistance depends on the length of the micropore, the layer thickness of the PET film at the location of the micropore, and the cross-sectional area of ​​the micropore. The resistance R2 can be calculated from the impedance spectra, similar to the capacitance. It serves as a measure of the degradation of the PET film from the moment a pore is present. It is particularly advantageous when the geometry of the pore and the electrolyte concentration in the reaction solution are known.

[0142] Cited non-patent literature

[0143] Frank R, Prönnecke C, Azendorf R, Jahnke HG, Beck-Sickinger AG, Robitzki AA (2020) Advanced 96-microtiter plate based bioelectrochemical platform reveals molecular short cut of electron flow in cytochrome P450 enzyme. Lab Chip 20, 1449-1460.

[0144] Frank R, Krinke D, Sonnendecker C, Zimmermann W, Jahnke HG (2022) Real-Time Noninvasive Analysis of Biocatalytic PET Degradation. ACS Catal. 12(1), 25-35.

[0145] Frank R, Zimmermann W (2022) How enzymes decompose plastic - Part 2. GIT Laboratory Journal 10 / 2022, 36-38.

[0146] Sonnendecker C, Oeser J, Richter PK, Hille P, Zhao Z, Fischer C, Lippold H, Bläzquez-Sänchez P, Engelberger F, Ramirez-Sarmiento CA, Oeser T, Lihanova Y, Frank R, Jahnke HG, Billig S, Abel B, Sträter N, Matysik J, Zimmermann W (2022) Low Carbon Footprint Recycling of Post- Consumer PET Plastic with a Metagenomic Polyester Hydrolase. ChemSusChem 15, e202101062.

[0147] Sulaiman S, Yamato S, Kanaya E, Kim JJ, Koga Y, Takano K, Kanaya S (2012) Isolation of a Novel Cutinase Homolog with Polyethylene Terephthalate-Degrading Activity from Leaf-Branch Compost by Using a Metagenomic Approach. Applied and Environmental Microbiology 78 (5).

[0148] Reference symbol

[0149] 1 first housing part

[0150] 2 second housing part

[0151] 3 polymer film

[0152] 4 Reaction chamber

[0153] 4a First reaction chamber

[0154] 4b Second reaction chamber

[0155] 5 Air duct

[0156] 5a Air duct system

[0157] 6 Electrode

[0158] 6a First electrode

[0159] 6b Second electrode

[0160] 7 Cover plate

[0161] 8 Opening

[0162] 9 plugs

[0163] 10 guide channel

[0164] 11 Recess

[0165] 12 Contact

[0166] 13 housings

[0167] 14 Entrance

[0168] 14a First entrance

[0169] 14b Second entrance

[0170] 15 Seal

[0171] 15a Seal between housing part and cover

[0172] 15b Seal between housing part and polymer film

[0173] 16 Contact position

[0174] 17 Filling channel

[0175] 18 component

Claims

Patent claims 1. System for measuring the degradation of polymer films (3) by polymer-degrading reagents, comprising i. at least two housing parts (1, 2), comprising at least one reaction space consisting of a first and a second reaction chamber (4), wherein the first reaction chamber (4a) is arranged in a first housing part (1) and the second reaction chamber (4b) is arranged in a second housing part (2), wherein the first and the second housing part (1, 2) are designed to accommodate a polymer film (3) such that the polymer film (3) is arranged between the first and second reaction chambers (4a, 4b) of the reaction space, wherein at least one interior angle between the polymer film (3) and one of the two reaction chambers (4a, 4b) of the reaction space is in the range of 10° to 80°, wherein at least one reaction chamber (4a, 4b) of the reaction space has at least one inlet (14), ii.at least a first and a second electrode (6), wherein the first electrode (6a) is in functional connection with the first reaction chamber (4a) and the second electrode (6b) is in functional connection with the second reaction chamber (4b).

2. System according to claim 1, characterized in that the at least two housing parts (1, 2) each comprise at least two reaction chambers (4), wherein the reaction chambers (4) of one housing part are arranged vertically one above the other and the two housing parts (1, 2) are arranged mirror-symmetrically to the polymer film (3), wherein the reaction chambers (4) have an inclination in the direction of the polymer film in the range of 10° to 80°, preferably 30° to 50°, starting from the horizontal axis.

3. System according to one of the preceding claims, characterized in that the inlet (14) is connected to the reaction chamber (4) by a guide channel (10) for filling a reaction chamber with a solution.

4. System according to claim 1, characterized in that the reaction chambers (4) of a reaction space are arranged vertically one above the other, wherein the polymer film (3) is arranged with an inclination in the range of 10° to 80°, starting from the horizontal axis, between the first and the second reaction chamber (4a, 4b) of a reaction space, whereby an upper and a lower reaction chamber (4) is formed.

5. System according to claim 4, characterized in that the upper reaction chamber (4a) has a first inlet (14a) for filling the upper reaction chamber (4a) and a second inlet (14b) for filling the lower reaction chamber (4b), wherein the reaction space between the first and the second reaction chamber (4a, 4b) has an opening (8) for filling the lower reaction chamber (4b) and the polymer film (3) is perforated in the region of the opening (8) for filling the lower reaction chamber (4b).

6. System according to one of the preceding claims, further comprising at least one cover plate (7) for closing the reaction chambers (4), wherein the at least one cover plate (7) is suitable for closing all reaction chambers (4) of a housing part.

7. System according to claim 6, wherein the first and second electrodes (6a, 6b) are independently integrated in the at least one cover plate (7) or arranged in the reaction chamber (4) of the housing part.

8. System according to one of the preceding claims, characterized in that the at least one reaction chamber is connected by means of an air duct (5) between the first and the second reaction chamber (4a, 4b).

9. Use of the system according to one of claims 1 to 8 for measuring the degradation of polymer films (3) by polymer-degrading reagents.

10. Use of a system according to claim 9, characterized in that polymer-degrading reagents are selected from the group comprising whole cells, catalytic ribonucleic acids, chemical reagents and / or biocatalysts.

11. A method for measuring the degradation of polymer films (3) by polymer-degrading reagents, comprising the steps of a) providing a system according to one of claims 1 to 8, b) inserting a polymer film (3) between the first and the second housing part (1, 2), wherein each reaction chamber (4) comes into contact with the polymer film (3), c) filling at least one of the reaction chambers (4) of a reaction space with at least one solution comprising a polymer-degrading reagent, and d) determining the dielectric properties of the polymer film (3) for measuring the degradation of polymer films (3) by the polymer-degrading reagent.

12. The method according to claim 11, wherein in the system provided in step a), the reaction chambers (4) of a reaction space are arranged vertically one above the other, wherein the polymer film (3) is arranged with an inclination in the range of 10° to 80°, starting from the horizontal axis, between the first and the second reaction chamber (4a, 4b) of a reaction space, thereby forming an upper and a lower reaction chamber (4), wherein the method further comprises between steps c) and d): Closing the upper reaction chambers (4a) with a cover plate (7), wherein the first and second housing parts (1, 2) form a component (18) with the cover plate (7), and Inclination of the component (18) so that the polymer film (3) is arranged vertically.

13. The method according to claim 11 or 12, characterized in that the polymer film (3) is selected from polyethylene terephthalate, polybutylene succinate, polycaprolactone, polylactide or mixtures thereof.

14. Method according to one of claims 11 to 13, characterized in that in step d) the change in the dielectric capacitance of the polymer film (3) is determined.

15. Method according to one of claims 11 to 13, characterized in that micropores with a pore diameter in the range of 1 pm to 100 pm are introduced into the polymer film (3) before step b).

16. The method according to claim 15, characterized in that in step d) the electrochemical conduction resistance of the micropores is determined.

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