USE OF SILSESQUIOXANES FOR THE REMOVAL OF MICROPLASTIC PARTICLES FROM WATER AND / OR A BODY OF WATER

Description

FIELD OF APPLICATION AND STATE OF THE ART

[0001] The invention relates to the use of silsesquioxanes for removing microplastic particles from water and / or a body of water, a method for removing microplastic particles from water and / or a body of water, an inclusion compound and the use of a kit for removing microplastic particles from water and / or a body of water.

[0002] The problem of microplastic contamination is gaining increasing attention in society.

[0003] The sources and pathways for plastics entering the environment are diverse. For example, microparticles from cosmetics or washing machine abrasion from synthetic fibers enter wastewater through direct entry (so-called primary entry). In addition, microparticles are potential carriers for pollutants and bacteria, which can also have pathogenic properties.

[0004] Particle removal in wastewater treatment plants varies depending on the particle diameter. Particles with a diameter or size > 5 mm are typically removed using screens and grit traps. The situation is different for particles present in low concentrations and in a size range < 5 mm, especially in the size range from 0.01 µm to 1 µm, as these are generally uncharged and therefore do not tend to interact ionically.

[0005] Due to their small size, these inert microparticles pass through the treatment stages of a wastewater treatment plant more easily and sometimes unhindered, as they can neither be separated by precipitation reagents nor converted into macroflocs by flocculants. In the case of microplastic particles, the problem is further complicated by the fact that they generally have a lower density than water and therefore are not prone to sedimentation. As a result, these particles leave the wastewater treatment plant together with the treated wastewater and thus enter the water cycle.

[0006] This is how they are distributed throughout the ecosystem, potentially with far-reaching effects (e.g. bioaccumulation) on animals and humans.

[0007] Currently, there are numerous options for performing solid-liquid separation to eliminate particles from water. However, the corresponding processes have limiting factors. Either the effectiveness is too low, as in the case of sedimentation and flocculation, or the process is too inflexible. Or, as in the case of depth filtration, microfiltration, and ultrafiltration, additional chemicals must be introduced into the wastewater, which have a proven impact on the environment or prevent efficient secondary material utilization or material recovery. Furthermore, these processes are characterized by high acquisition and operating costs and require additional infrastructure.

[0008] US 2016 / 0263552 A1 discloses an article containing silsesquioxane for absorbing liquids.

[0009] US 2003 / 0159997 A1 discloses arylene-bridged polysilsesquioxanes for the removal of phenol compounds from wastewater.

[0010] The subject of DE 10 2015 207 061 A1 is a hybrid silica material for the removal and / or detection of anthropogenic contaminants from water.

[0011] Furthermore, the use of alkoxysilyl-functionalized precursor biomolecules for the inclusion of plastic particles is known (Herbort Adrian Frank et al.: "A concept for the removal of microplastics from the marine environment with innovative host-guest relationships", Environ Sci Pollut Res (2017) 24:11061-11065). TASK AND SOLUTION

[0012] The invention therefore aims to provide compounds that enable the removal of microplastic particles from water and / or bodies of water, thus enabling the purification of water and / or bodies of water. Furthermore, the invention aims to provide a corresponding method, an inclusion compound, and a kit.

[0013] These objects are achieved according to the invention by a use according to the features of independent claim 1, by a method according to claim 12, by an inclusion compound having the features of claim 14, and by the use of a kit having the features of claim 15. Preferred embodiments of the invention are described in the dependent claims and in the description. The wording of all claims is hereby expressly incorporated into the present description.

[0014] The invention relates, according to a first aspect, to the use of a silsesquioxane, preferably a cage-shaped silsesquioxane, of the following formula II [RSiO 3 / 2 ] n (formula II), wherein R is an alkyl group, Si is a silicon atom, O is an oxygen atom and n is an integer, for removing microplastic particles from water, in particular wastewater and / or process water and / or leachate and / or drinking water, and / or a body of water.

[0015] The term "a silsesquioxane" in the context of the present invention may mean one silsesquioxane (singular) or a plurality, in particular a mixture, of different silsesquioxanes.

[0016] For the purposes of the present invention, the term "microplastic particles" is to be understood as meaning plastic particles or plastic particles which comprise a plastic or a combination, in particular a mixture (blend), of plastics or consist of a plastic or a combination, in particular a mixture (blend), of plastics and have a diameter, in particular an average diameter, of 100 nm to 5 mm.

[0017] For the purposes of the present invention, the term "large microplastic particles" refers to plastic particles or plastic particles with a diameter, in particular an average diameter, of greater than 1 mm to 5 mm.

[0018] For the purposes of the present invention, the term "small microplastic particles" refers to plastic particles or plastic particles with a diameter, in particular an average diameter, of 100 nm to 1 mm.

[0019] For the purposes of the present invention, the term "water" refers to any form of water, generally liquid water, and / or any form of an aqueous liquid, i.e., a liquid containing water. In particular, the water within the meaning of the present invention can, as already mentioned above, be wastewater, process water, leachate, and / or drinking water.

[0020] For the purposes of the present invention, the term "wastewater" refers to water that is contaminated through use or has undergone changes in its properties or composition. According to the invention, this particularly includes greywater, rainwater, blackwater, yellowwater, brownwater, precipitation water, and / or extraneous water that enters the sewer system, for example, due to structural damage.

[0021] For the purposes of the present invention (and in accordance with European Standard 12056-1), the term "grey water" is understood to mean faeces-free, slightly polluted wastewater, such as that generated during showering, bathing or hand washing, but also from washing machines, and which can be used for treatment into domestic or process water.

[0022] For the purposes of the present invention, the term "rainwater" is understood to mean previously evaporated water from precipitation in liquid form, i.e., rain.

[0023] The term "blackwater" should be understood (in accordance with ISO 6107-7:1997) as domestic wastewater excluding greywater containing faecal solids.

[0024] For the purposes of the present invention, the term "yellow water" refers to urine and urine with rinse water.

[0025] For the purposes of the present invention, the term "brown water" is understood to mean wastewater that contains only feces, flushing water and toilet paper.

[0026] For the purposes of this invention, the term "process water" refers to water that serves a specific technical, commercial, agricultural, or domestic application. Unlike drinking water, process water is not intended for human consumption, but should meet a certain minimum hygiene standard. In any case, it must meet the technological requirements of the respective process.

[0027] For the purposes of the present invention, the term "seepage water" is understood to mean subterranean water which moves downwards under the influence of gravity (so-called seepage flow).

[0028] For the purposes of the present invention, the term "drinking water" is understood to mean any water intended for drinking, cooking, preparing food and beverages, and in particular for domestic purposes, such as personal care and cleaning, cleaning of objects intended to come into contact with food (such as glasses, dishes, cutlery), and cleaning of objects intended to come into contact with the human body for more than a temporary period (such as clothing and laundry).

[0029] For the purposes of the present invention, the term "body of water" refers to naturally flowing or standing water, in particular freshwater and / or saltwater and / or brackish water. Depending on the location of the body of water, this can be an open body of water, i.e., a body of water lying above ground, or a closed body of water, i.e., a subterranean body of water, such as groundwater. Furthermore, the body of water can be an inland body of water or the sea.Inland waters can be, in particular, a flowing water body, such as a stream (a very large body of water flowing into the sea), a river (a large body of water flowing into the sea), a brook (a small body of water flowing into the sea), a canal (a watercourse with an artificially created water bed), a cave river (a watercourse in a water cave), fissure water, aqueducts (artificial bodies of water) or large-scale water supply and / or disposal structures (artificial bodies of water), or a body of still water, such as a lake (a larger body of water), a reservoir (artificial body of water), a pond (a small and moderately deep body of water without inflow or outflow), a pond (a small and moderately deep body of water with inflow and outflow (artificial body of water), a pool (a body of water that regularly dries out), a puddle (short-term standing water), a cave lake, or a cistern (artificial body of water).

[0030] For the purposes of the present invention, the term "fresh water" is to be understood as water which, regardless of its state of aggregation, contains no salts or has a salt content (so-called salinity) < (spoken: less than) 0.1% (mass fraction).

[0031] For the purposes of the present invention, the term "salt water" is understood to mean water with a salt content (salinity) of at least 1% (mass fraction).

[0032] For the purposes of the present invention, the term "seawater" is understood to mean water with a salt content (salinity), in particular an average salt content, of 3.5% (mass fraction).

[0033] For the purposes of the present invention, the term "brackish water" is understood to mean sea or ocean water with a salt content (salinity) of 0.1% to < 1% (mass fraction).

[0034] For the purposes of this document, the term "sea" refers to the Earth's interconnected bodies of water surrounding the continents, including so-called marginal seas, which are more or less separated from the open seas. Examples of marginal seas are the marginal sea (separated by island chains or sea swells), the Mediterranean Sea (separated by island chains, mainland, or sea swells), and the inland sea (connected by a strait).

[0035] For the purposes of the present invention, the term "hybrid silica gel" refers to a gel, in particular a macromolecular gel, with silicon-oxygen bonds and silicon-carbon bonds. Due to the presence of "inorganic" silicon bonds (silicon-oxygen bonds and / or silicon-oxygen-silicon bonds) and "organic" silicon bonds (silicon-carbon bonds), such a hybrid silica gel can also be referred to as an inorganic-organic hybrid silica gel.

[0036] The term "inclusion and / or incalation compound" is to be understood in the context of the present invention as a compound or a system which comprises a hybrid silica gel and microplastic particles, in particular agglomerated microplastic particles, wherein the hybrid silica gel is formed or produced by reacting an alkyltrichlorosilane and / or silsesquioxane, in particular an alkyltrichlorosilane and / or silsesquioxane provided according to the invention, in water or a body of water and wherein the hybrid silica gel encloses or surrounds the microplastic particles, in particular the agglomerated microplastic particles, at least partially, in particular only partially or completely.Such an inclusion and / or incalation compound can also be referred to as an agglomeration compound or system in the sense of the present invention, since the inclusion and / or incalation compound ultimately includes an agglomeration of microplastic particles, which will be discussed in more detail below.

[0037] The microplastic particles are preferably inert, i.e., unreactive, and / or hydrophobic, i.e., water-insoluble, microplastic particles.

[0038] The microplastic particles can generally have a diameter, in particular an average diameter, of > (pronounced: larger) 1 mm to 5 mm (so-called large microplastic particles) and / or a diameter, in particular an average diameter, of 100 nm to 1 mm (so-called small microplastic particles).

[0039] The diameter, especially the mean diameter, of microplastic particles can be determined, for example, microscopically or by scanning electron microscopy, in particular using ESEM (Environmental Scanning Electron Microscope).

[0040] The invention is based on the surprising finding that silsesquioxanes can be used to remove or eliminate microplastic particles from water and / or a body of water. The alkyl groups of the silsesquioxanes particularly advantageously localize microplastic particles distributed in water and / or a body of water in a first step, and agglomerate the localized microplastic particles in a second step.

[0041] The localization step is based on inert-inert (and thus "adhesive") interactions, particularly van der Waals interactions and / or hydrophobic interactions, between the alkyl group of the silsesquioxane and the microplastic particles, especially the surface of the microplastic particles. During the localization step, silsesquioxane molecules accumulate / adsorb on the surface of the microplastic particles, creating the conditions for subsequent agglomeration of the localized microplastic particles. Inert-inert interactions, particularly van der Waals interactions and / or hydrophobic interactions, between the silsesquioxane molecules of localized microplastic particles induce and, in particular, promote their agglomeration.The microplastic particles localized and, in particular, agglomerated in this way are then at least partially, in particular only partially or completely, enclosed by the formation of a hybrid silica gel, thereby preventing dismigration and / or deagglomeration and / or leaching of the microplastic particles. The enclosure of the microplastic particles can advantageously be accompanied by further agglomeration of the microplastic particles.

[0042] The formation of the hybrid silica gel is based on a hydrolysis of the silsesquioxane in water and / or a body of water and a subsequent condensation reaction, in particular in the manner of a sol-gel process.

[0043] The reaction product ultimately formed in water and / or a body of water can be referred to as an inclusion and / or incalation compound, whereby the hybrid silica gel at least partially, in particular only partially or completely, encloses or surrounds the microplastic particles, in particular the agglomerated microplastic particles. The resulting inclusion compounds and thus the microplastic particles enclosed therein, in particular agglomerated microplastic particles, can subsequently be removed cost-effectively and efficiently from the water and / or the body of water, for example, using simple filtration methods such as screens and / or grit traps in a wastewater treatment plant.Depending on the reactivity of the silsesquioxane and / or the reaction or contact time, the inclusion compounds can have variable particle diameters, in particular variable average particle diameters, for example, in a range of 1 cm to 6 cm. After their removal from the water and / or the body of water, the inclusion compounds can, if desired, be broken down and analyzed qualitatively and / or quantitatively, and / or the microplastic particles they contain, in particular agglomerated microplastic particles, can be recycled, for example, through thermal decomposition (pyrolysis) and / or use as filler material. A further advantage of the inclusion compounds is their ecotoxicological safety.

[0044] With regard to the processes described in the previous paragraphs which underlie the removal of microplastic particles from water and / or a body of water, it has further been found to be particularly surprising that the silsesquioxanes provided according to the invention, on the one hand, have sufficient initial stability in water and / or a body of water (in particular due to a positive effect induced by the alkyl group, so-called +I effect) so that the localization and / or agglomeration steps necessary for successful inclusion of the microplastic particles can take place, and on the other hand, have sufficient reactivity in water and / or a body of water so that inclusion of the microplastic particles can take place due to the formation of a hybrid silica gel, which ultimately prevents dismigration and / or deagglomeration and / or leaching of the microplastic particles.

[0045] The silsesquioxane according to formula II can be used in particular for the treatment, preferably purification, of municipal wastewater.

[0046] In addition, the silsesquioxane according to formula II can also be used, in particular, for the treatment, preferably purification, of industrial wastewater. Such wastewater is often characterized by an extreme pH value. However, since the process responsible for the formation of a (macromolecular) hybrid silica structure, in particular the sol-gel process, can be catalyzed under both acidic and alkaline pH conditions, this is irrelevant for the separation of microplastic particles from industrial wastewater.

[0047] As already mentioned, the silsesquioxane provided according to the invention is preferably a cage-shaped silsesquioxane, i.e., a silsesquioxane with a cage structure. A cage structure can further promote the localization of microplastic particles in water and / or a body of water, and thus their removal from water and / or a body of water.

[0048] A further advantage of using a silsesquioxane according to the invention is that, due to their slower reaction kinetics, silsesquioxanes are less reactive in water compared to alkyltrichlorosilanes, which allows for better reactivity control and thus even better containment of microplastic particles. Furthermore, the silsesquioxanes according to the invention have an improved shelf life compared to alkyltrichlorosilanes, allowing for the use of larger quantities of silsesquioxanes.

[0049] Another advantage is that the silsesquioxanes provided according to the invention are classified as ecotoxicologically safe. This means that no increased safety standards are required, especially when used in a wastewater treatment plant.

[0050] Another general advantage of using a silsesquioxane is that water content does not have a disruptive effect in potential applications. Partial hydrolysis or prepolymerization of the silsesquioxane to form a hybrid silica gel can even be beneficial with regard to the inclusion behavior of microplastic particles. If partial hydrolysis or prepolymerization is not desired, the silsesquioxane can be packaged in anhydrous or essentially anhydrous form and used accordingly.

[0051] Furthermore, the silsesquioxane can basically be a homofunctionalized silsesquioxane, ie a silsesquioxane in which the silicon atoms are each covalently linked to an identical alkyl group, or a heterofunctionalized silsesquioxane, ie a silsesquioxane with at least two different alkyl groups.

[0052] In one embodiment of the invention, the silsesquioxane is an unsupported silsesquioxane, i.e., a silsesquioxane that is not bound to a carrier material, such as activated carbon or a polyurethane sponge, or, in other words, that is free of a carrier material, such as activated carbon or a polyurethane sponge. In particular, the silsesquioxane can be a silsesquioxane that is not bound to the surface of a carrier material, in particular neither to an outer surface nor to an inner surface of a carrier material.

[0053] In a further embodiment of the invention, R, ie the alkyl group R in the formula II, is an alkyl group having 1 carbon atom to 16 carbon atoms, in particular 3 carbon atoms to 14 carbon atoms, preferably 4 carbon atoms to 8 carbon atoms.

[0054] Particularly preferably, R, i.e., the alkyl group R in formula II, is an alkyl group having at least 4 carbon atoms. In this respect, it has been shown that a positive inductive effect (+I effect) generated by such an alkyl radical is particularly capable of imparting a corresponding silsesquioxane sufficient initial stability in water and / or a body of water so that the localization and / or agglomeration processes that occur prior to the inclusion of microplastic particles can take place to a sufficient extent.

[0055] Preferably, R, ie the alkyl group R in formula II, is a linear alkyl group, especially having at least 4 carbon atoms. The advantage mentioned in the previous paragraph applies accordingly.

[0056] Alternatively, it may be preferred that R, i.e. the alkyl group R in formula II, is a branched alkyl group, in particular a mono-branched or multiply branched alkyl group. The branched alkyl group preferably has at least 4 carbon atoms. A branched alkyl group has the additional advantage over a linear alkyl group that, due to stronger steric shielding of the silicon atom and a stronger positive inductive effect due to the branching of the alkyl group, the initial stability of a corresponding silsesquioxane in water and / or a body of water can be further increased, whereby the processes of localization and / or agglomeration of microplastic particles required for the inclusion of microplastic particles can proceed particularly well.

[0057] In a further embodiment of the invention, R, ie the alkyl group R in the formula II, is selected from the group consisting of n-butyl group, isobutyl group (2-methylpropyl group), hexyl group, isohexyl group (4-methylpentyl group), 2,4,4-trimethylpentyl group, n-octyl group, 6-methylheptyl group, nonyl group, decyl group, dodecyl group, tetradecyl group and hexadecyl group.

[0058] In particular, R, ie the alkyl group R in formula II, can be selected from the group consisting of hexyl group, isohexyl group (4-methylpentyl group), 2,4,4-trimethylpentyl group, n-octyl group, 6-methylheptyl group, nonyl group, decyl group, dodecyl group, tetradecyl group, hexadecyl group, isomers thereof and isomer mixtures thereof.

[0059] Preferably, R, ie the alkyl group R in the formula II, is selected from the group consisting of n-butyl group, isobutyl group (2-methylpropyl group), n-hexyl group, 2-methylpentyl group, 3-methylpentyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, n-octyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 2,2-dimethylhexyl group, 2,3-dimethylhexyl group, 2,4-dimethylhexyl group, 2,5-dimethylhexyl group, 3,3-dimethylhexyl group, 3,4-dimethylhexyl group, 3-ethylhexyl group, 2,2,3-trimethylpentyl group, 2,2,4-trimethylpentyl group, 2,4,4-trimethylpentyl group, 2,3,3-trimethylpentyl group, 2,3,4-trimethylpentyl group, 3-ethyl-2-methylpentyl group, 3-ethyl-3-methylpentyl group and 2,2,3,3-tetramethylbutyl group.

[0060] In a further embodiment of the invention, R, ie the alkyl group R in the formula II, is selected from the group consisting of n-butyl group, isobutyl group, n-octyl group and 2,4,4-trimethylpentyl group.

[0061] In particular, R, ie the alkyl group R in formula II, can be selected from the group consisting of n-butyl group, isobutyl group, n-octyl group, 2,4,4-trimethylpentyl group, isomers thereof and isomer mixtures thereof.

[0062] Preferably, R, ie the alkyl group R in the formula II, is selected from the group consisting of n-butyl group, isobutyl group, n-octyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 2,2-dimethylhexyl group, 2,3-dimethylhexyl group, 2,4-dimethylhexyl group, 2,5-dimethylhexyl group, 3,3-dimethylhexyl group, 3,4-dimethylhexyl group, 3-ethylhexyl group, 2,2,3-trimethylpentyl group, 2,2,4-trimethylpentyl group, 2,4,4-trimethylpentyl group, 2,3,3-trimethylpentyl group, 2,3,4-trimethylpentyl group, 3-ethyl-2-methylpentyl group, 3-ethyl-3-methylpentyl group and 2,2,3,3-Tetramethylbutyl group.

[0063] Particularly preferably, R, ie the alkyl group R in formula II, is an n-butyl group. In other words, it is particularly preferred according to the invention if the silsesquioxane according to formula II is a silsesquioxane functionalized with n-butyl groups.

[0064] Furthermore, it is particularly preferred if R, ie the alkyl group R in formula II, is an isobutyl group. In other words, it is further particularly preferred according to the invention if the silsesquioxane according to formula II is a silsesquioxane functionalized with isobutyl groups (2-methylpropyl groups).

[0065] Furthermore, it is particularly preferred if R, ie the alkyl group R in formula II, is an n-octyl group. In other words, it is further particularly preferred according to the invention if the silsesquioxane according to formula II is a silsesquioxane functionalized with n-octyl groups.

[0066] Furthermore, it is particularly preferred if R, ie the alkyl group R in formula II, is a 2,4,4-trimethylpentyl group. In other words, it is further particularly preferred according to the invention if the silsesquioxane according to formula II is a silsesquioxane functionalized with 2,4,4-trimethylpentyl groups.

[0067] In a further embodiment of the invention, n in formula II is an integer from 4 to 16, in particular 6 to 14, preferably 6 to 12. This allows particularly good inert-inert interactions, in particular van der Waals interactions and / or hydrophobic interactions, to be formed into microplastic particles.

[0068] In a further embodiment of the invention, n in formula II is the integer 6, 8, 10, or 12. In other words, it is preferred if the silsesquioxane according to formula II is a hexasilsesquioxane, octasilsesquioxane, decasilsesquioxane, or dodecasilsesquioxane. This allows particularly good inert-inert interactions, in particular van der Waals interactions and / or hydrophobic interactions, to be formed to form microplastic particles.

[0069] In a further embodiment of the invention, the silsesquioxane has the following formula III where R represents an alkyl group, Si represents a silicon atom and O represents an oxygen atom.

[0070] Preferably, the alkyl group R (in formula III) is an alkyl group having 1 carbon atom to 16 carbon atoms, in particular 3 carbon atoms to 14 carbon atoms, preferably 4 carbon atoms to 8 carbon atoms.

[0071] Furthermore, it is preferred if the alkyl group R (in formula III) is an alkyl group, in particular a linear or branched, in particular mono-branched or multiply branched, alkyl group, preferably having at least 4 carbon atoms.

[0072] Furthermore, it is preferred if the alkyl group R (in formula III) is selected from the group consisting of n-butyl group, isobutyl group (2-methylpropyl group), hexyl group, isohexyl group (4-methylpentyl group), 2,4,4-trimethylpentyl group, n-octyl group, 6-methylheptyl group, nonyl group, decyl group, dodecyl group, tetradecyl group and hexadecyl group.

[0073] Furthermore, it is preferred if the alkyl group R (in formula III) is selected from the group consisting of n-butyl group, isobutyl group, n-octyl group, and 2,4,4-trimethylpentyl group. In other words, it is preferred if the silsesquioxane of the present invention is an octa-n-butylsilsesquioxane, octa-isobutylsilsesquioxane (octa-2-methylpropylsilsesquioxane), octa-n-octylsilsesquioxane, or octa-2,4,4-trimethylpentylsilsesquioxane.

[0074] With regard to further features and advantages, in particular with regard to the alkyl group R (in formula III), reference is made in full to the previous description. The statements made therein, particularly with regard to the alkyl group R, apply mutatis mutandis to the silsesquioxane according to formula III.

[0075] In a further embodiment of the invention, the alkyl group in formula II and / or in formula III comprises at least two different alkyl groups, in particular selected from the group consisting of n-butyl group, isobutyl group (2-methylpropyl group), hexyl group, isohexyl group (4-methylpentyl group), 2,4,4-trimethylpentyl group, n-octyl group, 6-methylheptyl group, nonyl group, decyl group, dodecyl group, tetradecyl group and hexadecyl group.In other words, it may further be preferred according to the invention if the silsesquioxane according to formula II and / or formula III is a silsesquioxane having at least two different alkyl groups (so-called heterofunctionalized silsesquioxane), wherein the alkyl groups are in particular selected from the group consisting of n-butyl group, isobutyl group (2-methylpropyl group), hexyl group, isohexyl group (4-methylpentyl group), 2,4,4-trimethylpentyl group, n-octyl group, 6-methylheptyl group, nonyl group, decyl group, dodecyl group, tetradecyl group and hexadecyl group.

[0076] In a further embodiment of the invention, the silsesquioxane is a pure substance, i.e. a single type of silsesquioxane, or a mixture, i.e. a mixture, of different silsesquioxanes. The silsesquioxane can in particular be a mixture of isomeric silsesquioxanes, preferably a mixture of branched isomeric silsesquioxanes. This makes it particularly advantageous to dispense with time-consuming and costly purification measures. In particular, the silsesquioxane can be a mixture or a mixture of at least two different silsesquioxanes, which are preferably selected from the group consisting of octa-n-butyl-silsesquioxane, octa-isobutyl-silsesquioxane (octa-2-methylpropyl-silsesquioxane), octa-n-octyl-silsesquioxane and octa-2,4,4-trimethylpentyl-silsesquioxane. With regard to further suitable silsesquioxanes, reference is made in full to the previous description.

[0077] In a further embodiment of the invention, the microplastic particles comprise or consist of a plastic which is selected from the group consisting of polyethylene (PE) such as low-density polyethylene (LDPE) and / or high-density polyethylene (HDPE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyurethane (PU), polyamide (PA), polycarbonate (PC), polytetrafluoroethylene (PTFE), polyoxymethylene (PMO), acrylonitrile-butadiene-styrene copolymer (ABS), polyethylene terephthalate (PET), polymethyl methacrylate (PMMA), polyacrylonitrile (PAN), copolymers of at least two of the plastics mentioned and combinations, in particular mixtures (blends), of at least two of the plastics mentioned.

[0078] In a further embodiment of the invention, the microplastic particles have a diameter, in particular an average diameter, of 100 nm to 5 mm, in particular 10 µm to 5 mm, preferably 100 µm to 1 mm.

[0079] According to a second aspect, the invention relates to a method for removing microplastic particles from water, in particular wastewater and / or process water and / or leachate and / or drinking water, and / or a body of water.

[0080] The procedure comprises the following steps: a) Dosing or adding a silsesquioxane of the following formula II [RSiO 3 / 2 ] n (formula II), where R is an alkyl group, Si is a silicon atom, O is an oxygen atom and n is an integer, to a water containing microplastic particles, ie a water which contains microplastic particles, in particular inert and / or hydrophobic microplastic particles, and / or a body of water containing microplastic particles, iea body of water which contains microplastic particles, in particular inert and / or hydrophobic microplastic particles, and b) removing inclusion compounds formed after addition of the silsesquioxane from the water and / or the body of water, wherein the inclusion compounds each comprise a hybrid silica gel and microplastic particles, in particular agglomerated microplastic particles, wherein the hybrid silica gel is formed or produced by reacting the silsesquioxane in the water and / or body of water and the hybrid silica gel encloses or surrounds the microplastic particles, in particular the agglomerated microplastic particles, at least partially, in particular only partially or completely.

[0081] The silsesquioxane is preferably an unsupported silsesquioxane, i.e., a silsesquioxane that is not bound to a carrier material, such as activated carbon or a polyurethane sponge, or, in other words, that is free of a carrier material, such as activated carbon or a polyurethane sponge. In particular, the silsesquioxane may be a silsesquioxane that is not bound to the surface of a carrier material, in particular neither to an outer surface nor to an inner surface of a carrier material.

[0082] Furthermore, it is preferred if R, ie the alkyl group R in the formula II, is an alkyl group having 1 carbon atom to 16 carbon atoms, in particular 3 carbon atoms to 14 carbon atoms, preferably 4 carbon atoms to 8 carbon atoms.

[0083] Furthermore, it is preferred if R, ie the alkyl group R in the formula II, is an alkyl group having at least 4 carbon atoms.

[0084] Furthermore, it is preferred if R, ie the alkyl group R in the formula II, is a linear alkyl group, in particular having at least 4 carbon atoms.

[0085] Furthermore, it is preferred if R, ie the alkyl group R in formula II, is a branched alkyl group, in particular a mono-branched or multiply branched alkyl group. The branched alkyl group preferably has at least 4 carbon atoms.

[0086] Furthermore, it is preferred if R, ie the alkyl group R in the formula II, is selected from the group consisting of n-butyl group, isobutyl group (2-methylpropyl group), hexyl group, isohexyl group (4-methylpentyl group), 2,4,4-trimethylpentyl group, n-octyl group, 6-methylheptyl group, nonyl group, decyl group, dodecyl group, tetradecyl group and hexadecyl group.

[0087] In particular, R, ie the alkyl group R in formula II, can be selected from the group consisting of hexyl group, isohexyl group (4-methylpentyl group), 2,4,4-trimethylpentyl group, n-octyl group, 6-methylheptyl group, nonyl group, decyl group, dodecyl group, tetradecyl group, hexadecyl group, isomers thereof and isomer mixtures thereof.

[0088] Preferably, R, ie the alkyl group R in the formula II, is selected from the group consisting of n-butyl group, isobutyl group (2-methylpropyl group), n-hexyl group, 2-methylpentyl group, 3-methylpentyl group, 2,2-dimethylbutyl group, 2,3-dimethylbutyl group, n-octyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 2,2-dimethylhexyl group, 2,3-dimethylhexyl group, 2,4-dimethylhexyl group, 2,5-dimethylhexyl group, 3,3-dimethylhexyl group, 3,4-dimethylhexyl group, 3-ethylhexyl group, 2,2,3-trimethylpentyl group, 2,2,4-trimethylpentyl group, 2,4,4-trimethylpentyl group, 2,3,3-trimethylpentyl group, 2,3,4-trimethylpentyl group, 3-ethyl-2-methylpentyl group, 3-ethyl-3-methylpentyl group and 2,2,3,3-tetramethylbutyl group.

[0089] Furthermore, it is preferred if R, ie the alkyl group R in the formula II, is selected from the group consisting of n-butyl group, isobutyl group, n-octyl group and 2,4,4-trimethylpentyl group.

[0090] In particular, R, ie the alkyl group R in formula II, can be selected from the group consisting of n-butyl group, isobutyl group, n-octyl group, 2,4,4-trimethylpentyl group, isomers thereof and isomer mixtures thereof.

[0091] Preferably, R, ie the alkyl group R in the formula II, is selected from the group consisting of n-butyl group, isobutyl group, n-octyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 2,2-dimethylhexyl group, 2,3-dimethylhexyl group, 2,4-dimethylhexyl group, 2,5-dimethylhexyl group, 3,3-dimethylhexyl group, 3,4-dimethylhexyl group, 3-ethylhexyl group, 2,2,3-trimethylpentyl group, 2,2,4-trimethylpentyl group, 2,4,4-trimethylpentyl group, 2,3,3-trimethylpentyl group, 2,3,4-trimethylpentyl group, 3-ethyl-2-methylpentyl group, 3-ethyl-3-methylpentyl group and 2,2,3,3-Tetramethylbutyl group.

[0092] Furthermore, it is preferred if n in the formula II is an integer from 4 to 16, in particular 6 to 14, preferably 6 to 12.

[0093] In particular, it is preferred if n in formula II is the integer 6, 8, 10 or 12.

[0094] Step a) can generally be performed manually, semi-automatically, or (fully) automatically. Preferably, step a) is performed semi-automatically or (fully) automatically.

[0095] Furthermore, it is preferred if step b) is carried out by means of filtration, in particular by means of a screen or sand trap.

[0096] Furthermore, it is preferred if step a) and / or step b) are / is carried out in a sewage treatment plant, ie a wastewater treatment plant, in particular in an aeration tank and / or a secondary clarifier thereof.

[0097] The sewage treatment plant or wastewater treatment plant can basically be a central, i.e. stationary, sewage treatment plant or wastewater treatment plant or a decentralized, i.e. mobile, sewage treatment plant or wastewater treatment plant, such as a container.

[0098] For the purposes of the present invention, the term "secondary clarifier" is to be understood as meaning a purification stage of a sewage treatment plant or wastewater treatment plant, which usually forms a process unit together with an aeration tank in which a so-called activated sludge is separated from the wastewater by settling.

[0099] For the purposes of the present invention, the term "aeration tank" is to be understood as a purification stage of a sewage treatment plant or wastewater treatment plant in which wastewater constituents (of a fresh wastewater) are biotically oxidatively degraded by aeration of a wastewater mixed with activated sludge.

[0100] For the purposes of this invention, the term "activated sludge" refers to a collection of microorganisms that degrade organic matter during aerobic biological wastewater treatment. Activated sludge consists primarily of bacteria, fungi, and protozoa.

[0101] Furthermore, it may be preferred if step a) and / or step b) are / is carried out before or after a reverse osmosis step.

[0102] Furthermore, it may be preferred if step a) and / or step b) are / is carried out before or after a sea salt extraction step.

[0103] Furthermore, it is preferred if, before performing step a) and / or during the performance of step a), the water and / or the body of water, in particular at least in sections, preferably only in sections, is / are set in a rotational motion. This can particularly advantageously promote the localization and / or aggregation of the microplastic particles, which is essential for their successful inclusion.

[0104] Furthermore, it is preferred if, before performing step a) and / or during the performance of step a), a vortex is created in the water and / or the body of water, in particular at least in sections, preferably only in sections, and the silsesquioxane is added into a suction funnel of the vortex. In this way, the localization and / or aggregation of the microplastic particles required for successful inclusion of the microplastic particles can be achieved particularly effectively.

[0105] With regard to further features and advantages of the process, in particular the silsesquioxane, reference is made in full to the statements made in the context of the first aspect of the invention. The statements made there also apply mutatis mutandis to the process according to the second aspect of the invention.

[0106] According to a third aspect, the invention relates to an inclusion compound which comprises a hybrid silica gel and microplastic particles, in particular agglomerated microplastic particles, wherein the hybrid silica gel is obtained by reacting a silsesquioxane of the following formula II [RSiO 3 / 2 ] n (formula II), wherein R is an alkyl group, Si is a silicon atom, O is an oxygen atom and n is an integer, is formed or produced in water and / or a body of water and the hybrid silica gel encloses or surrounds the microplastic particles, in particular the agglomerated microplastic particles, at least partially, in particular only partially or completely.

[0107] Furthermore, it is preferred if R, ie the alkyl group R in the formula II, is an alkyl group having 1 carbon atom to 16 carbon atoms, in particular 3 carbon atoms to 14 carbon atoms, preferably 4 carbon atoms to 8 carbon atoms.

[0108] Furthermore, it is preferred if R, ie the alkyl group R in the formula II, is an alkyl group having at least 4 carbon atoms.

[0109] Furthermore, it is preferred if R, ie the alkyl group R in the formula II, is a linear alkyl group, in particular having at least 4 carbon atoms.

[0110] Furthermore, it is preferred if R, ie the alkyl group R in formula II, is a branched alkyl group, in particular a mono-branched or multiply branched alkyl group. The branched alkyl group preferably has at least 4 carbon atoms.

[0111] Furthermore, it is preferred if R, ie the alkyl group R in the formula II, is selected from the group consisting of n-butyl group, isobutyl group (2-methylpropyl group), hexyl group, isohexyl group (4-methylpentyl group), 2,4,4-trimethylpentyl group, n-octyl group, 6-methylheptyl group, nonyl group, decyl group, dodecyl group, tetradecyl group and hexadecyl group.

[0112] Furthermore, it is preferred if R, ie the alkyl group R in the formula II, is selected from the group consisting of n-butyl group, isobutyl group, n-octyl group and 2,4,4-trimethylpentyl group.

[0113] Furthermore, it is preferred if n in the formula II is an integer from 4 to 16, in particular 6 to 14, preferably 6 to 12.

[0114] In particular, it is preferred if n in formula II is the integer 6, 8, 10 or 12.

[0115] The inclusion compound can have variable particle diameters, in particular variable average particle diameters, depending on the reactivity of the silsesquioxane and / or the reaction or contact time. For example, the inclusion compound can have a particle diameter, in particular an average particle diameter, of 1 cm to 6 cm.

[0116] With regard to further features and advantages of the inclusion compound, reference is also made to the previous description, in particular to the statements made in the context of the first aspect of the invention. The statements made therein also apply mutatis mutandis to the inclusion compound according to the third aspect of the invention.

[0117] According to a fourth aspect, the invention relates to the use of a kit for removing microplastic particles from water, in particular wastewater and / or process water and / or leachate and / or drinking water, and / or a body of water.

[0118] The kit includes: a silsesquioxane of the following formula II [RSiO 3 / 2 ] n (formula II) , where R is an alkyl group, Si is a silicon atom, O is an oxygen atom and n is an integer.

[0119] In addition, the kit comprises at least one further component, particularly spatially separated from the silsesquioxane according to formula II. The further component is preferably an adsorbent, particularly selected from the group consisting of activated carbon, calcium silica hydrates, polonite, rocks, and combinations of at least two of the aforementioned adsorbents.

[0120] It is preferred if R, ie the alkyl group R in the formula II, is an alkyl group having 1 carbon atom to 16 carbon atoms, in particular 3 carbon atoms to 14 carbon atoms, preferably 4 carbon atoms to 8 carbon atoms.

[0121] Furthermore, it is preferred if R, ie the alkyl group R in the formula II, is an alkyl group having at least 4 carbon atoms.

[0122] Furthermore, it is preferred if R, ie the alkyl group R in the formula II, is a linear alkyl group, in particular having at least 4 carbon atoms.

[0123] Furthermore, it is preferred if R, ie the alkyl group R in formula II, is a branched alkyl group, in particular a mono-branched or multiply branched alkyl group. The branched alkyl group preferably has at least 4 carbon atoms.

[0124] Furthermore, it is preferred if R, ie the alkyl group R in the formula II, is selected from the group consisting of n-butyl group, isobutyl group (2-methylpropyl group), hexyl group, isohexyl group (4-methylpentyl group), 2,4,4-trimethylpentyl group, n-octyl group, 6-methylheptyl group, nonyl group, decyl group, dodecyl group, tetradecyl group and hexadecyl group.

[0125] Furthermore, it is preferred if R, ie the alkyl group R in the formula II, is selected from the group consisting of n-butyl group, isobutyl group, n-octyl group and 2,4,4-trimethylpentyl group.

[0126] Furthermore, it is preferred if n in the formula II is an integer from 4 to 16, in particular 6 to 14, preferably 6 to 12.

[0127] In particular, it is preferred if n in formula II is the integer 6, 8, 10 or 12.

[0128] With regard to further features and advantages of the kit, reference is also made in full to the previous description, in particular to the statements made in the context of the first aspect of the invention. The remaining statements made there also apply mutatis mutandis to the kit according to the fourth aspect of the invention.

[0129] Further features and advantages of the invention will become apparent from the following description of preferred embodiments in the form of figures and examples. Individual features can be implemented individually or in combination with one another. The examples described below serve merely to further explain the invention without limiting the invention to the disclosure content of the examples. SHORT DESCRIPTION OF THE FIGURES

[0130] The following is shown schematically in the figures: Fig. 1: the reaction scheme for the preparation of a hybrid silica gel starting from an alkyltrichlorosilane and water, which is not part of the invention; and Fig. 2a-d: the structural formulas of some alkyltrichlorosilanes, which are not part of the invention.

[0131] Fig. 1 shows schematically the basic reaction scheme underlying the conversion of an alkyltrichlorosilane 1 to a hybrid silica gel 3, in particular macromolecular hybrid silica gel 3, which is suitable for the inclusion of microplastic particles and / or agglomerated microplastic particles.

[0132] Upon contact with water, the silicon-chlorine bonds of the alkyltrichlorosilane 1 are hydrolyzed to silanol compounds 2, forming hydrochloric acid. Due to the catalytic effect of the released hydrochloric acid, the intermediate silanol compounds 2 rapidly undergo condensation reactions, forming the hybrid silica gel 3.

[0133] The alkyl group of alkyltrichlorosilane 1 makes it possible to localize and aggregate microplastic particles distributed in water and / or a body of water. For this purpose, a certain initial stability of the alkyltrichlorosilane is advantageous, allowing sufficient localization and aggregation of microplastic particles before the microplastic particles / aggregated microplastic particles are entrapped by forming the hybrid silica, particularly through a sol-gel process.

[0134] The alkyltrichlorosilane can in particular be n-butyltrichlorosilane, isobutyltrichlorosilane, n-octyltrichlorosilane or 2,4,4-trimethylpentyltrichlorosilane.

[0135] Fig. 2a shows the structural formula of n-butyltrichlorosilane. Fig. 2b shows the structural formula of isobutyltrichlorosilane. Fig. 2c shows the structural formula of n-octyltrichlorosilane. Fig. 2d shows the structural formula of 2,4,4-trimethylpentyltrichlorosilane. The use of these alkyltrichlorosilanes for removing microplastic particles from water and / or a body of water is particularly preferred. EXAMPLE PART 1. General test procedure for the formation of agglomeration compounds 1.1 Laboratory scale

[0136] 100 mg of microplastic powder (PE, PP, or mixtures) (150 µm - 300 µm) and 1 L of distilled water were placed in a 2 L round-bottom flask and stirred vigorously (24 h swelling process). A small amount (approximately 50-100 µmol) of agglomeration reagent was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. After 20 min, the mixture was filtered, and the white solid was dried at 105 °C for 24 h. The silane initially formed small droplets that circulated in the vessel (localization). The droplets accumulated the microplastic particles within 3-4 min. After 2 min, gel formation began, and a large agglomerate was formed, which floated on the water surface (fixation). After 10 min, no free PE, PP, or mixtures of both were left unbound in the reaction vessel. The pH of the water was 6-7. 1.2 Pilot plant scale

[0137] 100 g of microplastic powder (PP, PE / PP(1 / 1) (150 µm - 300 µm) and 2000 L of process water (secondary clarifier) ​​were filled into a discontinuous 2000 L batch reactor. The mixture was then stirred at room temperature for 24 h at 250 rpm (swelling process). The agglomeration process was initiated by adding agglomeration reagent (approx. 50-100 mmol) and stirring the mixture for 24 h at room temperature and 250 rpm. The mixture was filtered, and the agglomerated white solids were dried at 105 °C for 24 h. The agglomerated solids had a diameter of 2-6 cm. 2. General information

[0138] GUR 4150 UHMW-PE particles were purchased from Celanese. Additional PE (LDPE, HDPE) and PP microplastic particles were purchased from LyondellBasell.

[0139] The alkyltrichlorosilanes (which are not part of the invention) and silsesquioxanes listed in Table 1 below were used in the experiments described below. Table 1: Alkyltrichlorosilanes and silsesquioxanes used Name CAS.no. n-Butyltrichlorsilan 7521-80-4 Isobutyltrichlorsilan 18169-57-8 n-Octyltrichlorsilan 5283-66-9 Isooctyltrichlorsilan 18379-25-4 Isooctyl POSS Cage Mixture 1472635-27-0

[0140] Environmental scanning electron microscope (ESEM) images of hybrid silica gels (sample size up to 3 mm) were acquired using an FEI Quanta 250 ESEM (FEI Company, Hillsboro, USA) with low vacuum (60 and 80 Pa). To generate high-quality images, a large-field detector (LFD) with an accelerating voltage between 7 and 20 kV was used. IR spectra were measured with FTIR Nicolet iS10 (Thermo, Dreieich, Germany) and FTIR Nicolet iS5 (Thermo, Dreieich, Germany). Additionally, IR spectra were recorded on a VARIAN FT-IR 630 with ATR Hecht (4000–400 cm-1). 3. General test procedure for the formation of agglomeration compounds

[0141] 100 mg of microplastic powder (PE, PP, or mixtures) (150 µm - 300 µm) and 1 L of distilled water were placed in a 2 L round-bottom flask and stirred vigorously. A small amount (1*10 -3 < mol) of agglomeration reagent (experiments 1-6) was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. After 20 min, the mixture was filtered, and the white solid was dried at 60 °C for 24 h. 4. Experiments; the experiments 4.1-4.4.4 do not form part of the invention. 4.1 Synthesis of a microplastic inclusion compound using n-octyltrichlorosilane (not according to the invention) 4.1.1 Synthesis of a hybrid silica gel based on n-octyltrichlorosilane

[0142] 1 L of distilled water was placed in a 2 L round-bottom flask and stirred vigorously. 43.2 µmol of n-octyltrichlorosilane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. Gel formation began immediately upon contact with water, and several agglomerates were formed. After 20 min, the mixture was filtered, washed with water, and the white, very voluminous solid was dried at 60 °C for 24 h. A transparent solid was formed.

[0143] EA: C 77.93, H 14.44, N 0 IR: n-octyl at v (CH 2 ) 2951 cm -1 < , 2905 cm -1 < , δ (CH) 1430-1485 cm -1 < , v (Si-O-Si) 1106 cm -1< . 4.1.2 Synthesis of an LDPE / HDPE microplastic inclusion compound

[0144] 100 mg of microplastic powder (LDPE / HDPE) (50 µm - 300 µm) and 1 L of distilled water were placed in a 2 L round-bottom flask and stirred vigorously (24 h swelling process). 43.2 µmol of n-octyltrichlorosilane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane initially formed small droplets that circulated in the vessel (localization). The droplets partially accumulated the microplastic particles (approximately 50%) within 3-4 minutes. Gel formation began immediately upon contact with water, and several agglomerates were formed, which floated on the water surface (fixation). After 10 minutes, 50% (mass balance) of PE was bound and 50% unbound in the reaction vessel. The pH of the water was 6-7. The mixture was stirred for a further 10 minutes, then filtered, washed with water, and dried for 24 hours at 60 °C. A transparent solid with embedded white microplastic particles was formed.

[0145] EA: C 79.23, H 14.00, N 0 IR: PE v (CH 2 ) 2920 2870 cm -1< (R= n-octyl is superimposed v (CH 2 ) 2951 cm -1< ,2905 cm -1< ), δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< . 4.1.3 Synthesis of a PP microplastic inclusion compound

[0146] 100 mg of microplastic powder (PP) (50 µm - 300 µm) and 1 L of distilled water were placed in a 2 L round-bottom flask and stirred vigorously (24 h swelling process). 43.2 µmol of n-octyltrichlorosilane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane initially formed small droplets that circulated in the vessel (localization). The droplets partially accumulated the microplastic particles (approximately 50%) within 3-4 minutes. Gel formation began immediately upon contact with water, and several agglomerates were formed, which floated on the water surface (fixation). After 10 minutes, 50% (mass balance) of PE was bound and 50% unbound in the reaction vessel. The pH of the water was 6-7. The mixture was stirred for a further 10 minutes, then filtered, washed with water, and dried for 24 hours at 60 °C. A transparent solid with embedded white microplastic particles was formed.

[0147] EA: C 76.80, H 14.05, N 0 IR: PP v (CH 2 ) 2920 2870 cm -1< (R= n-octyl is superimposed v (CH 2 ) 2951 cm -1< , 2905 cm -1< , δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< . 4.1.4 Synthesis of a PE / PP microplastic inclusion compound

[0148] 100 mg of microplastic powder (LDPE / HDPE / PP 0.5 / 0.5 / 1) (50 µm - 300 µm) and 1 L of distilled water were placed in a 2 L round-bottom flask and stirred vigorously (24 h swelling process). 43.2 µmol of n-octyltrichlorosilane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane initially formed small droplets that circulated in the vessel (localization). The droplets partially accumulated the microplastic particles (approximately 50%) within 3-4 minutes. Gel formation began immediately upon contact with water, and several agglomerates were formed, which floated on the water surface (fixation). After 10 minutes, 50% (mass balance) of the microplastic mixture was bound and 50% unbound in the reaction vessel. The pH of the water was 6-7. The mixture was stirred for a further 10 minutes, then filtered, washed with water, and dried for 24 hours at 60 °C. A transparent solid with embedded white microplastic particles was formed.

[0149] IR: PE / PP v (CH 2 ) 2920 2870 cm -1< (R= n-octyl is superimposed v (CH 2 ) 2951 cm -1< , 2905 cm -1< , δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< . 4.2 Synthesis of a microplastic inclusion compound using n-butyltrichlorosilane 4.2.1 Synthesis of a hybrid silica gel based on n-butyltrichlorosilane (not according to the invention)

[0150] 1 L of distilled water was placed in a 2 L round-bottom flask and stirred vigorously. 60.5 µmol of n-butyltrichlorosilane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane formed small droplets that settled to the bottom. Gel formation began after 2 min, and a large agglomerate was formed. After 20 min, the mixture was filtered, washed with water, and the white solid was dried at 60 °C for 24 h. A white gel-like solid was formed.

[0151] EA: C 41.16, H 07.93, N 0 IR: n-Butyl v (CH 2 ) 2950 cm -1< -2870 cm -1< , δ (CH) 1465-1407 cm -1< , v (Si-O-Si) 1202 cm -1< , (vSi-O) 874-688 cm -1< . 4.2.2 Synthesis of a PE microplastic inclusion compound

[0152] 100 mg of microplastic powder (LDPE / HDPE) (50 µm - 300 µm) and 1 L of distilled water were placed in a 2 L round-bottom flask and stirred vigorously (24 h swelling process). 60.5 µmol of n-butyltrichlorosilane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane initially formed small droplets that circulated in the vessel (localization). The droplets completely accumulated the microplastic particles (approximately 75%) within 2-4 minutes. Gel formation began after 2 minutes, and a large agglomerate was formed, which floated on the water surface (fixation). After 10 minutes, 75% (mass balance) of PE was bound. The pH of the water was 6-7. The mixture was stirred for a further 10 minutes, then filtered, washed with water, and dried for 24 hours at 60 °C. A transparent solid with embedded white microplastic particles was formed.

[0153] EA: C 75.04, H 12.74, N 0 IR: PE v (CH 2 ) 2920 2870 cm -1< (R= n-butyl is superimposed v (CH 2 ) 2951 cm -1< , 2905 cm -1< , δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< . 4.2.3 Synthesis of a PP microplastic inclusion compound

[0154] 100 mg of microplastic powder (PP) (50 µm - 300 µm) and 1 L of distilled water were placed in a 2 L round-bottom flask and vigorously stirred (24 h swelling process). 60.5 µmol of n-butyltrichlorosilane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane initially formed small droplets that circulated in the vessel (localization). The droplets completely accumulated the microplastic particles (approximately 75%) within 2-4 min. Gel formation began after 2 min, and a large agglomerate was formed, which floated on the water surface (fixation). After 10 min, 100% (mass balance) of PP was bound. The pH of the water was 6-7. The mixture was stirred for another 10 min, then filtered, washed with water, and dried for 24 h at 60 °C. A transparent solid with embedded white microplastic particles was created.

[0155] EA: C 80.30, H 13.76, N 0

[0156] IR: PP v (CH 2 ) 2920 2870 cm -1< (R= n-butyl is superimposed v (CH 2 ) 2951 cm -1< , 2905 cm -1< , δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< . 4.2.4 Synthesis of a PE / PP microplastic inclusion compound

[0157] 100 mg of microplastic powder (LDPE / HDPE / PP; 0.5 / 0.5 / 1) (50 µm - 300 µm) and 1 L of distilled water were placed in a 2 L round-bottom flask and stirred vigorously (24 h swelling process). 60.5 µmol of n-butyltrichlorosilane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane initially formed small droplets that circulated in the vessel (localization). The droplets completely accumulated the microplastic particles (approximately 75%) within 2-4 min. Gel formation began after 2 min, and a large agglomerate was formed, which floated on the water surface (fixation). After 10 min, 100% (mass balance) of the microplastic mixture was bound. The pH of the water was 6-7. The mixture was stirred for a further 10 minutes, then filtered, washed with water, and dried for 24 hours at 60 °C. A transparent solid with embedded white microplastic particles was formed.

[0158] EA: C 69.67, H 11.55, N 0 IR: PE / PP v (CH 2 ) 2920 2870 cm -1< (R= n-butyl is superimposed v (CH 2 ) 2951 cm -1< , 2905 cm -1< , δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< . 4.3 Synthesis of a microplastic inclusion compound using isobutyltrichlorosilane (not according to the invention) 4.3.1 Synthesis of a hybrid silica gel based on isobutyltrichlorosilane

[0159] 1 L of distilled water was placed in a 2 L round-bottom flask and stirred vigorously. 60 µmol of isobutyltrichlorosilane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane formed small droplets and initially did not mix with water. Gel formation began after 6 min. After 10 min, the trichlorosilane had completely converted to the hybrid silica gel, and small aggregates were visible. After 20 minutes, the aggregates increased in size. The aggregates were 1-3 mm in size. The mixture was filtered, washed with water, and the white solid was dried at 60 °C for 24 h. A white solid was formed.

[0160] EA (found): C 40.64, H 08.17, N 0 REM EDX: C 47.92, O 37.734, Si 14.35.

[0161] IR: v (CH 2 ) 2953 cm -1 < , 2869 cm -1 < , δ (CH) 1465-1401 cm -1 < , v (Si-O-Si) 1128 cm -1 < -997, v (Si-O) 835-737 cm -1< . 4.3.2 Synthesis of a PE microplastic inclusion compound

[0162] 100 mg of microplastic powder (LDPE / HDPE) (50 µm - 300 µm) and 1 L of distilled water were placed in a 2 L round-bottom flask and vigorously stirred (24 h swelling process). 60 µmol of isobutyltrichlorosilane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane initially formed small droplets that circulated in the vessel (localization). The droplets completely accumulated the microplastic particles (approximately 100%) within 2-4 minutes. Gel formation began after 6 minutes, and a large agglomerate was formed. After 10 minutes, the trichlorosilane had completely converted to the hybrid silica gel, and small aggregates with the bound PE (100% mass balance) were visible. After 20 minutes, the aggregates increased in size (2-3 mm), floating on the water surface (fixation). The pH of the water was 6-7. It was then filtered, washed with water, and dried at 60 °C for 24 hours.A white solid with embedded white microplastic particles was formed.

[0163] EA (found): C 76.36, H 14.15, N 0 REM EDX (found): C 47.92, O 37.734, Si 14.35.

[0164] IR: PE v (CH 2 ) 2920 2870 cm -1< (R= isobutyl is superimposed on v (CH 2 ) 2951 cm -1< , 2905 cm -1< , δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< . 4.3.3 Synthesis of a PP microplastic inclusion compound

[0165] 100 mg of microplastic powder (PP) (50 µm - 300 µm) and 1 L of distilled water were placed in a 2 L round-bottom flask and stirred vigorously (24 h swelling process). 60 µmol of isobutyltrichlorosilane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane initially formed small droplets that circulated in the vessel (localization). The droplets completely accumulated the microplastic particles (approximately 100%) within 2-4 min. Gel formation began after 6 min, and a large agglomerate was formed. After 10 min, the trichlorosilane had completely converted to the hybrid silica gel, and small aggregates with the bound PP (100% mass balance) were visible. After 20 minutes, the aggregates increased in size (2-3 mm), floating on the water surface (fixation). The pH of the water was 6-7. It was then filtered, washed with water, and dried at 60 °C for 24 hours.A white solid with embedded white microplastic particles was formed.

[0166] EA (found): C 73.72, H 13.46, N 0 REM EDX (found): C 72.2, O 24.27, Si 3.53.

[0167] IR: PP v (CH 2 ) 2920 2870 cm -1< (R= isobutyl is superimposed v (CH 2 ) 2951 cm -1< , 2905 cm -1< , δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< . 4.3.4: Synthesis of a PE / PP microplastic inclusion compound

[0168] 100 mg of microplastic powder (LDPE / HDPE / PP, 0.5 / 0.5 / 1) (50 µm - 300 µm) and 1 L of distilled water were placed in a 2 L round-bottom flask and stirred vigorously (24 h swelling process). 60 µmol of isobutyltrichlorosilane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane initially formed small droplets that circulated in the vessel (localization). The droplets completely accumulated the microplastic particles (approximately 100%) within 2-4 min. Gel formation began after 6 min, and a large agglomerate was formed. After 10 min, the trichlorosilane was completely converted to the hybrid silica gel, and small aggregates with the bound microplastic mixture (100% mass balance) were visible. After 20 minutes, the aggregates increased in size (2-3 mm) and floated on the water surface (fixation). The pH of the water was 6-7. The sample was then filtered, washed with water, and dried for 24 hours at 60 °C.A white solid with embedded white microplastic particles was formed.

[0169] EA (found): C 75.54, H 13.63, N 0 REM EDX (found): C 46.04, O 40.51, Si 13.452.

[0170] IR: PE / PP v (CH 2 ) 2920 2870 cm -1< (R= isobutyl is superimposed v (CH 2 ) 2951 cm -1< , 2905 cm -1< , δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< . 4.4 Synthesis of a microplastic inclusion compound using isooctyltrichlorosilane 4.4.1 Synthesis of a hybrid silica gel based on isooctyltrichlorosilane

[0171] 1 L of distilled water was placed in a 2 L round-bottom flask and stirred vigorously. 43 µmol of isooctyltrichlorosilane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane formed small droplets and initially did not mix with water, sinking to the bottom. After 5-10 s, gel formation began, and a large aggregate became visible, floating on the water surface. After 10 min, the trichlorosilane had completely converted to the hybrid silica gel, and small aggregates were visible. A white gel formed. After 20 minutes, the aggregates increased in size. The size of the aggregates was 1-3 mm. The mixture was filtered, washed with water, and the white solid was dried at 60 °C for 24 h. A white solid was formed.

[0172] EA (found): C 40.85, H 08.30, N 0 REM EDX (found): C 49.43, O 40.16, Si 10.41.

[0173] IR: Isooctyl v (CH 2 ) 2951 cm -1 < , 2905 cm -1 < , δ (CH) 1430-1485 cm -1 < , v (Si-O-Si) 1106 cm -1 < . 4.4.2 Synthesis of a PE microplastic inclusion compound

[0174] 100 mg of microplastic powder (LDPE / HDPE) (50 µm - 300 µm) and 1 L of distilled water were placed in a 2 L round-bottom flask and stirred vigorously (24 h swelling process). 43 µmol of isooctyltrichlorosilane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane initially formed small droplets that circulated in the vessel (localization). The droplets completely accumulated the microplastic particles (approximately 100%) within 2-4 min. Gel formation began after 5-10 s, and a large agglomerate was formed. After 10 min, the trichlorosilane was completely converted to the hybrid silica gel, and small aggregates with the bound PE (100% mass balance) were visible. After 20 minutes, the aggregates increased in size (2-3 mm) and floated on the water surface (fixation). The pH of the water was 6-7. The sample was then filtered, washed with water, and dried for 24 hours at 60 °C.A white solid with embedded white microplastic particles was formed.

[0175] EA (found): C 70.96, H 14.57, N 0 REM EDX (found): C 79.55, O 15.79, Si 4.65.

[0176] IR: PE v (CH 2 ) 2920 2870 cm -1< (R= isooctyl is superimposed v (CH 2 ) 2951 cm -1< ,2905 cm -1< ), δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< . 4.4.3 Synthesis of a PP microplastic inclusion compound

[0177] 100 mg of microplastic powder (PP) (50 µm - 300 µm) and 1 L of distilled water were placed in a 2 L round-bottom flask and vigorously stirred (24 h swelling process). 43 µmol of isooctyltrichlorosilane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane initially formed small droplets that circulated in the vessel (localization). The droplets completely accumulated the microplastic particles (approximately 100%) within 2-4 min. Gel formation began after 5-10 s, and a large agglomerate was formed. After 10 min, the trichlorosilane was completely converted to the hybrid silica gel, and small aggregates with the bound PE (100% mass balance) were visible. After 20 minutes, the aggregates increased in size (2-3 mm), which floated on the water surface (fixation). The pH of the water was 6-7. It was then filtered, washed with water, and dried at 60 °C for 24 hours.A white solid with embedded white microplastic particles was formed.

[0178] EA (found): C 74.95, H 13.59, N 0 REM EDX (found): C 67.56, O 26.6, Si 5.84.

[0179] IR: PP v (CH 2 ) 2920 2870 cm -1< (R= isooctyl is superimposed v (CH 2 ) 2951 cm -1< , 2905 cm -1< , δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< . 4.4.4 Synthesis of a PE / PP microplastic inclusion compound

[0180] 100 mg of microplastic powder (LDPE / HDPE / PP, 0.5 / 0.5 / 1) (50 µm - 300 µm) and 1 L of distilled water were placed in a 2 L round-bottom flask and stirred vigorously (24 h swelling process). 43 µmol of isooctyltrichlorosilane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane initially formed small droplets that circulated in the vessel (localization). The droplets completely accumulated the microplastic particles (approximately 100%) within 2-4 min. Gel formation began after 5-10 s, and a large agglomerate was formed. After 10 min, the trichlorosilane was completely converted to the hybrid silica gel, and small aggregates with the bound microplastic mixture (100% mass balance) were visible. After 20 minutes, the aggregates increased in size (2-3 mm) and floated on the water surface (fixation). The pH of the water was 6-7. The sample was then filtered, washed with water, and dried for 24 hours at 60 °C.A white solid with embedded white microplastic particles was formed.

[0181] EA (found): C 78.21, H 14.31, N 0 REM EDX (found): C 62.66, O 29.85, Si 7.485.

[0182] IR: PE / PP v (CH 2 ) 2920 2870 cm -1< (R= isooctyl is superimposed v (CH 2 ) 2951 cm -1< , 2905 cm -1< , δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< .

[0183] 4.5 Synthesis of a microplastic inclusion compound using isooctyl-T 8 polyoctahedral silsesquioxane; all of the following experiments are in accordance with the invention. 4.5.1 Synthesis of a hybrid silica gel based on isooctyl-T 8 -polyoctahedral silsesquioxane

[0184] 1 L of distilled water was placed in a 2 L round-bottom flask and vigorously stirred. 7.64 µmol of isooctyl-T8-polyoctahedral silsesquioxane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The highly viscous silane formed small droplets and did not mix with water, resulting in a floating mass. Upon contact with water, no visible hybrid silica gel initially formed. A color change was observed upon vigorous mixing. The material changed from a slightly yellowish color to a whitish-transparent, highly viscous liquid. The gel was filtered, washed with water, and dried at 60 °C for 24 h. A whitish-transparent, highly viscous liquid was formed.

[0185] EA (found): C 57.02, H 10.41 IR: Isooctyl v (CH 2 ) 2951 cm -1 < , 2905 cm -1 < , δ (CH) 1430-1485 cm -1 < , v (Si-O-Si) 1106 cm -1 < . 4.5.2 Synthesis of a PE microplastic inclusion compound

[0186] 100 mg of microplastic powder (LDPE / HDPE) (50 µm - 300 µm) and 1 L of distilled water were placed in a 2 L round-bottom flask and stirred vigorously (24 h swelling process). 7.64 µmol of isooctyl-T 8 -polyoctahedral silsesquioxane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane initially formed small droplets that circulated in the vessel (localization). The droplets completely accumulated the microplastic particles (approximately 100%) within 2-4 min. Gel formation began after 5-6 min, with the color of the liquid changing from slightly yellowish to white. After 5-6 min, a large agglomerate containing the bound PE (100% mass balance) was visible. The pH of the water was 6-7. The agglomerate was then filtered, washed with water, and dried for 24 hours at 60 °C. A white, highly viscous liquid containing embedded white microplastic particles was obtained.

[0187] EA (found): C 69.51, H 12.18, N 0 REM EDX (found): C 63.13, O 24.26, Si 12.37

[0188] IR: PE v (CH 2 ) 2920 2870 cm -1< (R= isooctyl is superimposed v (CH 2 ) 2951 cm -1< ,2905 cm -1< ), δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< . 4.5.3 Synthesis of a PP microplastic inclusion compound

[0189] 100 mg of microplastic powder (PP) (50 µm - 300 µm) and 1 L of distilled water were placed in a 2 L round-bottom flask and stirred vigorously (24 h swelling process). 7.64 µmol of isooctyl-T 8 -polyoctahedral silsesquioxane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane initially formed small droplets that circulated in the vessel (localization). The droplets completely accumulated the microplastic particles (approximately 100%) within 2-4 min. Gel formation began after 5-6 min, with the color of the liquid changing from slightly yellowish to white. After 5-6 min, a large agglomerate containing the bound PP (100% mass balance) was visible. The pH of the water was 6-7. The agglomerate was then filtered, washed with water, and dried for 24 hours at 60 °C. A white, highly viscous liquid containing embedded white microplastic particles was obtained.

[0190] EA (found): C 75.30, H 13.22, N 0 REM EDX (found): C 63.5, O 20.92, Si 15.58.

[0191] IR: PP v (CH 2 ) 2920 - 2870 cm -1< (R= isooctyl is superimposed on v (CH 2 ) 2951 cm -1< ,2905 cm -1< ), δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< . 4.5.4 Synthesis of a PE / PP microplastic inclusion compound

[0192] 100 mg of microplastic powder (LDPE / HDPE / PP, 0.5 / 0.5 / 1) (50 µm - 300 µm) and 1 L of distilled water were placed in a 2 L round-bottom flask and stirred vigorously (24 h swelling process). 7.64 µmol of isooctyl-T 8 -polyoctahedral silsesquioxane was slowly added. The reaction mixture was stirred at 250 rpm and 25 °C. The silane initially formed small droplets that circulated in the vessel (localization). The droplets completely accumulated the microplastic particles (approximately 100%) within 2-4 min. Gel formation began after 5-6 min, with the color of the liquid changing from slightly yellowish to white. After 5-6 min, a large agglomerate containing the bound microplastic mixture (100% mass balance) was visible. The pH of the water was 6-7. The agglomerate was then filtered, washed with water, and dried for 24 hours at 60 °C. A white, highly viscous liquid / solid containing embedded white microplastic particles was obtained.

[0193] EA (found): C 77.75, H 13.86, N 0 REM EDX (found): C 63.43, O 21.38, Si 15.19.

[0194] IR: PE / PP v (CH 2 ) 2920 - 2870 cm -1< (R= isooctyl is superimposed v (CH 2 ) 2951 cm -1< , 2905 cm -1< , δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< . 4.6 Synthesis of a microplastic inclusion compound using isooctyl-T8 polyoctahedral silsesquioxane on a 2000 L pilot scale 4.6.1 Synthesis of a PE microplastic inclusion compound

[0195] 100 g of microplastic powder (LDPE / HDPE) (150 µm–300 µm) and 2000 L of process water (secondary clarifier) ​​were charged into a discontinuous 2000 L batch reactor. The mixture was then stirred at 250 rpm for 24 h at an external temperature of 15–20 °C (swelling process). The agglomeration process was initiated by adding 7.64 mmol of isooctyl-T 8 polyoctahedral silsesquioxane, and the mixture was stirred at 250 rpm for 24 h at an external temperature of 15–20 °C. The mixture was filtered, and the white agglomerates were dried at 60 °C for 24 h. The white agglomerates had a diameter of 2–6 cm.

[0196] IR: PE v (CH 2 ) 2920 - 2870 cm -1< (R= isooctyl is superimposed on v (CH 2 ) 2951 cm -1< ,2905 cm -1< ), δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< . 4.6.2 Synthesis of a PP microplastic inclusion compound

[0197] 100 g of microplastic powder (PP) (150 µm–300 µm) and 2000 L of process water (secondary clarifier) ​​were charged into a discontinuous 2000 L batch reactor. The mixture was then stirred at 250 rpm for 24 h at an external temperature of 15–20 °C (swelling process). The agglomeration process was initiated by adding 7.64 mmol of isooctyl-T 8 polyoctahedral silsesquioxane, and the mixture was stirred at 250 rpm for 24 h at an external temperature of 15–20 °C. The mixture was filtered, and the white agglomerates were dried at 60 °C for 24 h. The white agglomerates had a diameter of 2–6 cm.

[0198] IR: PE v (CH 2 ) 2920 - 2870 cm -1< (R= isooctyl is superimposed on v (CH 2 ) 2951 cm -1< ,2905 cm -1< ), δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< . 4.6.3 Synthesis of a PE / PP microplastic inclusion compound

[0199] 100 g of microplastic powder (LDPE / HDPE / PP, 0.5 / 0.5 / 1) (150 µm–300 µm) and 2000 L of process water (secondary clarifier) ​​were charged into a discontinuous 2000 L batch reactor. The mixture was then stirred at 250 rpm for 24 h at an external temperature of 15–20 °C (swelling process). The agglomeration process was initiated by adding 7.64 mmol of isooctyl-T8 polyoctahedral silsesquioxane, and the mixture was stirred at 250 rpm for 24 h at an external temperature of 15–20 °C. The mixture was filtered, and the white agglomerates were dried at 60 °C for 24 h. The white agglomerates had a diameter of 2–6 cm.

[0200] IR: PE v (CH 2 ) 2920 - 2870 cm -1< (R= isooctyl is superimposed on v (CH 2 ) 2951 cm -1< ,2905 cm -1< ), δ (CH) 1430-1485 cm -1< , v (Si-O-Si) 1106 cm -1< .

Claims

1. Use of a silsesquioxane of the following formula II         [RSiO3 / 2]n     (formula II), wherein R represents an alkyl group, Si represents a silicon atom, O represents an oxygen atom and n represents an integer for the removal of microplastic particles from water and / or a body of water.

2. Use according to claim 1, characterized in that the silsesquioxane is an unsupported silsesquioxane.

3. Use according to claim 1 or 2, characterized in that R is an alkyl group having 1 carbon atom to 16 carbon atoms, in particular 3 carbon atoms to 14 carbon atoms, preferably 4 carbon atoms to 8 carbon atoms.

4. Use according to one of the preceding claims, characterized in that R is a linear alkyl group.

5. Use according to one of the claims 1 to 3, characterized in that R is a branched alkyl group.

6. Use according to one of the preceding claims, characterized in that R is selected from the group consisting of n-butyl group, isobutyl group, hexyl group, isohexyl group, 2,4,4-trimethylpentyl group, n-octyl group, 6-methylheptyl group, nonyl group, decyl group, dodecyl group, tetradecyl group and hexadecyl group.

7. Use according to one of the preceding claims, characterized in that R is selected from the group consisting of n-butyl group, isobutyl group, n-octyl group and 2,4,4-trimethylpentyl group.

8. Use according to one of the claims 1 to 3, characterized in that the silsesquioxane comprises at least two different alkyl groups, in particular selected from the group consisting of n-butyl group, isobutyl group, hexyl group, isohexyl group, 2,4,4-trimethylpentyl group, n-octyl group, 6-methylheptyl group, nonyl group, decyl group, dodecyl group, tetradecyl group and hexadecyl group.

9. Use according to one of the preceding claims, characterized in that the silsesquioxane is a pure substance or a mixture of different silsesquioxanes.

10. Use according to one of the preceding claims, characterized in that n represents an integer from 4 to 16,in particular 6 to 14, preferably 6 to 12, in particular the integer 6, 8, 10 or 12.

11. Use according to one of the preceding claims, characterized in that the silsesquioxane is a silsesquioxane of the following formula III: wherein R represents an alkyl group, Si represents a silicon atom and O represents an oxygen atom.

12. Method for the removal of microplastic particles from water and / or a body of water, the method having the following steps: a) metering or adding a silsesquioxane of the following formula II         [RSiO3 / 2]n     (formula II), wherein R represents an alkyl group, Si represents a silicon atom, O represents an oxygen atom and n represents an integer, to a microplastic particle-containing water and / or a microplastic particle-containing body of water, and b)removing, from the water and / or the body of water, inclusion compounds formed after addition of the silsesquioxane, wherein the inclusion compounds each comprise a hybrid silica gel and microplastic particles, wherein the hybrid silica gel is formed by reaction of the silsesquioxane in the water and / or body of water and encloses the microplastic particles at least partially.

13. Method as claimed in claim 12, further characterized by the features of the characterizing part of at least one of claims 2 to 11.

14. Inclusion compound, comprising a hybrid silica gel and microplastic particles, wherein the hybrid silica gel is formed by reaction of a silsesquioxane of the following formula II         [RSiO3 / 2]n     (formula II), wherein R represents an alkyl group, Si represents a silicon atom, O represents an oxygen atom and n represents an integer, in water and / or a body of water and at least partially encloses the microplastic particles.

15. Use of a kit for the removal of microplastic particles from water and / or a body of water, said kit having, spatially separated from one another, a silsesquioxane as claimed in one of claims 1 to 11 and at least one further component, wherein the further component is an adsorbent, in particular selected from the group consisting of activated carbon, calcium-silica hydrates, polonite, rocks and combinations of at least two of the specified adsorbents.