Composite polymer particles, porous carbon particles, and method for independently controlling particle size and pore size of porous carbon particles

Abstract

The present invention relates to composite polymer particles having tailored intergranular and intragranular properties and porous carbon particles derived therefrom. Furthermore, the present invention describes a hard template process involving the polymerization and self-assembly of monomers / oligomers / polymers around inorganic template particles to independently control the composite polymer particle size for a given template particle size, thereby independently controlling the pore size and particle size of porous carbon nanoparticles. Thus, the particle size of the porous carbon particles may be produced independently of the pore size via a hard template process.

Description

[0001] The present invention relates to composite polymer particles with tailored inter- and intra-particle properties and porous carbon particles derived therefrom. Furthermore, the present invention describes a hard-template approach involving polymerization and self-assembly of monomers / oligomers / polymer around inorganic template particles to independently control composite polymer particle size for a given template particle size, and thus the pore size and particle size of porous carbon nanoparticles. Thus, the particle size of porous carbon particles can be generated independently of the pore size via a hard-template process. BACKGROUND

[0002] Mesoporous carbons can be widely used in various fields such as catalysis, sensing, energy conversion and storage, and purification and drug delivery due to their large specific surface area, good electrical conductivity, and chemical stability. Controlled particle morphology (shape and size) and well-defined architecture within the particle are required, with suitable pore channels containing accessible and interconnected micropores, mesopores, and (where appropriate) macropores uniformly distributed throughout the carbon particle volume to ensure large specific surface area and full accessibility of the entire volume of the material to any species (e.g. electrolyte medium, adsorbate, analyte, molecules / ions involved in the reaction).

[0003] Rational design of electrode active materials plays an important role in improving the electrochemical properties of both energy storage and energy conversion devices. For most applications, not only well-defined porous structure, but also control over morphology and particle size are required.

[0004] Based on the structure of functional electrodes, it can be demonstrated that not only the porous architecture within the particle volume, but also well-defined architecture between the particles (in the electrode volume) significantly influences the functionality. The porous structure between the particles is controlled by the morphological properties of the powder material (e.g. shape, size, and uniformity of the sample) and determines the packing of the nanoparticles. Polydisperse nanoparticles affect the coating reproducibility on the one hand, but also lead to higher tortuosity, non-uniform pore distribution, and denser packing, creating inaccessible “dead” electrode volume and hindering electrolyte infiltration / permeation, thus limiting mass transfer. If commercial applications are targeted, high current densities are required, which necessitates high loading and thick electrodes with efficient infiltration. This highlights the need for 3D structure engineering to control the nanoparticle properties within the particle (e.g. intra-particle properties such as pore size, pore connectivity, surface area, pore volume, surface functionality, graphitization, and electrical conductivity) and between the particles within the electrode (e.g. infiltration, 3D volume porosity, etc.) built therefrom. However, simultaneous and independent control of all nanoparticle properties is far from trivial and has not been reported to date.

[0005] Similarly, the control of all the previously mentioned intra- and inter-particle properties and low polydispersity of particle size is a great advantage for applications in the fields of adsorption, separation, catalysis, drug delivery, etc. as it allows ensuring uniform and controlled physico-chemical properties of the entire porous carbon powder sample and of all its 3D processed derivatives.

[0006] Current nanocasting strategies, including soft- and hard-templating, represent the main approaches for the synthesis of mesoporous carbon nanoparticles. In this case, a carbon precursor of choice (e.g. a polymerizable carbon source or a polymer) and a nanosized template with suitable properties self-assemble to form a (ordered or disordered) composite (also known as hybrid), which after carbonization (calcination under inert atmosphere) and removal of the template material yields a (meso)porous carbon material, where the ()pores reflect the size geometry and possible surface structure of the template material used.

[0007] In soft-templating methods, structure directing agents used as templates such as surfactant molecules / copolymers self-assemble into micelles, which interact with the matrix of the material to be structured. The micelles are removed by washing steps and / or thermal treatment, forming the porous structure. The pore structure is controlled by the size, chemical composition, thermal properties and concentration of the copolymer / surfactant molecules used. However, controlling the pore size is rather difficult and can only be adjusted within a limited range (<30 nm) as the process relies on the formation of micelles and is usually based on thermal treatment / calcination, which can lead to pore closure considering the low thermal stability of the copolymers. At the same time, soft-templating often requires the use of expensive surfactants and block copolymers, which is disadvantageous for large-scale production.

[0008] Hard-templating methods are based on the polymerization or thermal condensation of a carbon precursor around a thermally stable inorganic template, followed by carbonization. The porous structure is formed by removal of the template, which is usually carried out by etching. The pore size and shape usually correspond to the properties of the template. Therefore, the use of predefined templates with specific structural features allows tailoring the pore structure within a wide range (from micropores to mesopores and to macropores). Moreover, the surface composition and heteroatom doping can be adjusted when different carbon sources are used. Due to the diversity of templates and their good thermal stability, hard-templating has proven to be a reliable method with excellent reproducibility and scalability, contributing to the control of the porous structure.

[0009] One known synthesis strategy is the synthesis of colloidal polyaniline-silica composite nanoparticles, which can be converted into porous carbon nanoparticles in further steps. In this case, for example, various reports have been published:

[0010] Gill et al. (Langmuir 1992, 8, 2178-2182) report colloidal polyaniline-silica composites with a size of about 300 nm. The influence of the synthesis parameters on the particle size is not disclosed.

[0011] Feng et al. (Journal of Applied Polymer Science, 2006, Volume 101, 2088-2094) report colloidal composites of polyaniline and porous silica at a constant ratio of initiator to aniline (1 :1) and a constant particle size.

[0012] Roosz et al. (Journal of Colloid and Interface Science, 2017, 502, 184-192) report polyaniline-silica composites for the production of “raspberry” or “core-shell” structures. Therein, the ratio of initiator to aniline also varies between 1.0 and 1.5, but the influence on the particle size and the dispersity is not described.

[0013] Fischer et al. (Carbon 2019, 146, 44) describe mesoporous N-doped carbon nanospheres (MPNCs) synthesized via oxidative polymerization of aniline in the presence of silica nanoparticles as hard templates. While the pore size of the MPNCs is varied, the customization of the particle size is not addressed.

[0014] Wang et al. (Angew. Chem. Int. Ed. 2015, 54, 15191) disclose composite polymer particles and porous carbon particles, which are described as monodisperse. However, the particle size distribution of the disclosed particles is not particularly limited and the particle size cannot be controlled independently of the pore size.

[0015] However, despite the successful implementation of the hard template approach, the simultaneous control of the intraparticle properties (e.g. pore size, chemical and surface composition, degree of graphitization, (nano)particle size and dispersity) and the interparticle properties (e.g. resulting from (nano)particle size and dispersity) required for the successful processing of the materials into derivative structures and functionally optimized particles in practical applications has not been achieved. Furthermore, for such tailored materials, their synthesis should have a good reproducibility and scalability while being sustainable, inert and non-toxic in order to enable commercial applications.

[0016] In summary, a hard template polymerization process wherein the composite polymer particle size (with controlled dispersity) can be adjusted independently of the inorganic template size has not been described so far.

[0017] Object of the invention

[0018] It is therefore an object of the present invention to provide a method for the synthesis of porous carbon (nano)particles which allows for the simultaneous control of intraparticle properties (e.g. pore size, chemical and surface composition, degree of graphitization) and interparticle properties (e.g. (nano)particle size and dispersity) of the particles. In particular, it should be possible to tailor the particle size of the porous carbon particles via a hard templating method independent of the size of the template used.

[0019] It is a further object of the present invention to control the particle size dispersity of the porous carbon particles.

[0020] It is a further object of the present invention to provide porous carbon particles with predefined properties with respect to pore size, particle size, specific surface area and pore volume, composition and degree of graphitization.

[0021] It is a further object of the present invention to provide a process for large scale implementation without significantly affecting or altering the quality of the porous carbon particles.

[0022] It was surprisingly found that the potential problem of the present invention is solved by the composite polymer particles according to claim 1, wherein the particle size and the particle size dispersity can be adjusted independently from each other and independent of the particle size of the template. Further embodiments of the present invention are outlined in the dependent claims and throughout the specification.

[0023] It is a second object of the present invention the porous carbon particles obtained from the composite polymer particles according to the present invention.

[0024] It is a third object of the present invention a method for controlling the particle size of the composite polymer particles independent of the size of the template.

[0025] It is a fourth object of the present invention also a method for independently controlling the pore size and the particle size of the porous carbon particles.

[0026] It is a fifth object of the present invention also an article comprising the composite polymer particles according to the present invention and / or the porous carbon particles manufactured according to the method of the present invention.

[0027] It is a sixth object of the present invention the use of the molar ratio of initiator to polymerizable carbon source for controlling the particle size and the particle size dispersity of the composite polymer (nano)particles in a hard templating method independent of the particle size of the inorganic nanoparticles used as templates and further controlling the particle size and the particle dispersity of the porous carbon (nano)particles derived therefrom .

[0028] For a better understanding of the present invention, the following explanations of the terms used herein are considered useful. In the meaning of the present invention:

[0029] - "composite polymer particles" means particles comprising a polymer matrix with homogenously distributed inorganic nanoparticles.

[0030] - "Polymer matrix" means the continuous phase of the polymeric material obtained from the one or more precursor monomers forming the composite polymeric particles.

[0031] - "Nanoparticle" means a particle having a particle size in the nanometer range between 1 nm and 1000 nm.

[0032] - "Hard-template method" also called hard templating or hard templating method describes a synthesis method based on the polymerization or thermal condensation of a carbon precursor around an inorganic template followed by carbonization. The porous structure is formed by removing the template, which is usually done by etching.

[0033] - "Particle size" also called particle size, denotes the spatial extent of an individual particle. The particle size is determined by counting the particle size of a sufficient number of particles (at least 200 particles) on electron micrographs obtained by scanning (transmission) electron microscopy. Non-spherical particles (e.g. oblong particles) are described by their smallest and largest diameter.

[0034] - "Particle size dispersity (Dspan) is based on the IUPAC dispersity definition given in Pure Appl. Chem., Vol. 83, Issue 12: 2251-2259, 2011. The particle size dispersity measures the width of the particle size distribution and is given by where N i represents the number of particles having a diameter d i . For a sample of perfectly uniform particle size, will be 1. A narrow particle size distribution with a value < 1.2, preferably < 1.1 is called monodisperse particles. A particle size distribution with a value > 1.2 is called polydisperse particles.

[0035] - "Pore volume" in the sense of the present invention means the pore volume measured by N2 physical adsorption at 77 K and estimated by using the t-plot method for micropores, as well as the total pore volume at relative pressure p / p0 = 0.98 and / or QSDFT equilibrium model.

[0036] - "Specific surface area" means the total accessible surface area per mass unit of material [m 2 g -1 ]. The specific surface area is determined by N2 physical adsorption at 77 K. The specific surface area is calculated using the Brunauer-Emmer-Teller (BET) method and / or QSDFT equilibrium model fitting the p / p0 range of 0.05 to 0.30.

[0037] - "pore diameter" (pore width) means the distance between two opposite walls of a pore. According to the IUPAC nomenclature (Pure & Appl. Chem. Vol. 66, No. 8: pp. 1739-1758, 1994) the width of a micropore is less than 2 nm, the width of a mesopore is between 2 nm and 50 nm, and the width of a macropore is more than 50 nm.

[0038] - "derivative of a (organic) compound" includes all (partially) functionalized compounds, wherein the organic backbone of the starting compound for the functionalization is retained. Examples in the context of the present application are - without any limitation - 2-chloro-3-methyl-aniline, 1 -amino-pyrrole, 3-hydroxy-4-phenyl-thiophene, wherein the 2- and 3-position, the 1 -position, and the 3- and 4-position, respectively, are functionalized, while the organic backbone of aniline, pyrrole, and thiophene, respectively, is retained. Further, any other functionalized position of the organic backbone, i.e. aniline, pyrrole, and thiophene in these cases, is considered a derivative as well.

[0039] - "at least one" means numerically "one or more". In a preferred embodiment, the term means numerically "one".

[0040] - "comprising" means that additional components can be present in addition to those mentioned. The term "comprising" is meant to be inclusive, thus including "consisting of". "Consisting of" is meant to be conclusive and means that no additional components can be present. In a preferred embodiment, the term "comprising" has the meaning of "consisting of".

[0041] The composite polymer particles according to the present application comprise a polymer matrix and inorganic nanoparticles homogenously distributed within the polymer matrix, wherein the composite polymer particles are obtained by polymerization of a polymerizable carbon source in the presence of dispersed inorganic nanoparticles and an initiator, characterized in that the composite polymer particles have a predefined particle size distribution and a predefined particle size. Surprisingly, it was found that by adjusting the molar ratio of initiator to polymerizable carbon source during the polymerization reaction, the particle size and the particle size distribution of the composite polymer particles can be controlled independently from the particle size of the inorganic nanoparticles.

[0042] The composite polymer particles thus obtained constitute the basis for the production of porous carbon particles. By controlling the particle size of the composite polymer particles independently from the particle size of the inorganic nanoparticles used as templates, all subsequent transformations and reactions towards the final porous carbon particles can be controlled.

[0043] The particle size of the composite polymer particles according to the present application can vary in a wide range. In a preferred embodiment, the composite polymer particles have a particle size in the range of micrometer to nanometer, which typically involves a particle size of up to 5000 nm, preferably up to 4000 nm, preferably up to 3000 nm, preferably up to 2000 nm, preferably up to 1000 nm and most preferably up to 500 nm. In a preferred embodiment, the particle size of the composite polymer particles ranges from 1 nm to 5000 nm, preferably from 10 nm to 2000 nm, preferably from 50 nm to 2000 nm, and most preferably from 50 nm to 500 nm. It is particularly preferred to refer to the composite polymer particles having a particle size in the range of 1 nm to 1000 nm as composite polymer nanoparticles.

[0044] The particle size dispersion The width of the particle size distribution is generally described. The particle size dispersion of the composite polymer particles is preferably narrow, preferably is more preferably is most preferably Such composite polymer particles are also referred to as monodisperse composite polymer particles.

[0045] In a preferred embodiment, the composite polymer particles are monodisperse with a particle size in the range of 10 nm to 2000 nm, preferably 50 nm to 500 nm. The composite polymer particles of the present application are obtained by polymerization of a polymerizable carbon source in the presence of dispersed inorganic nanoparticles and an initiator.

[0046] In the hard-template method for the synthesis of porous carbon particles, the inorganic nanoparticles serve as a templating agent (template) during polymerization. The hard-template method is based on the polymerization or thermal condensation of a polymerizable carbon precursor around the inorganic template.

[0047] The term "polymerizable carbon source" in the sense of the present application relates to all carbon sources which are capable of polymerizing into a polymer matrix.

[0048] In one embodiment, the polymerizable carbon source is a precursor monomer which is capable of undergoing an oxidative polymerization to form a polymer matrix. Examples of suitable precursor monomers for oxidative polymerization are aniline, phenazine, carbazole, pyrrole, dopamine, thiophene and derivatives thereof.

[0049] In another embodiment, the polymerizable carbon source is a precursor monomer which is capable of undergoing a condensation reaction to form a polymer matrix. Examples of suitable precursor monomers for condensation polymerization are melamine, cyanamide, resorcinol, glucose, amino acids having aromatic residues and derivatives thereof.

[0050] In another embodiment, the polymerizable carbon source is a precursor monomer capable of undergoing a self-propagating and non-stoichiometric radical polymerization to form a polymer matrix. Examples of suitable precursor monomers for radical polymerization are N-(hydroxymethyl)acrylamide, 3-(2-pyridyl)acrylic acid, 3-(2-pyrrole)acrylic acid, 1-vinylpyrrole, 1-vinylpyridine, 2-vinylthiophene, and derivatives thereof.

[0051] In a particularly preferred embodiment, the polymerizable carbon source is a precursor monomer capable of undergoing an oxidative polymerization.

[0052] In one embodiment, the molar concentration of the polymerizable carbon source during the polymerization reaction ranges from 0.05 mol L -1 to 1 mol L -1 , preferably from 0.09 mol L -1 to 0.24 mol L -1 .

[0053] In a preferred embodiment, the polymerizable carbon source is aniline and the molar concentration of aniline during the polymerization reaction ranges from 0.05 mol L -1 to 1 mol L -1 , preferably from 0.09 mol L -1 to 0.24 mol L -1 .

[0054] In the sense of the present application, the term "polymer matrix" means a continuous phase of a polymeric material. The polymer matrix can be a homopolymer or a copolymer. Copolymer herein means a copolymer obtainable by reacting two or more precursor monomers.

[0055] The inorganic nanoparticles are homogeneously distributed within the polymer matrix. Homogeneous distribution describes a regular distance between individual inorganic particles within the polymer matrix. Homogeneous distribution is achieved by self-assembly of the inorganic particles during the polymerization reaction. Without wishing to be bound by theory, self-assembly occurs due to electrostatic interactions between the inorganic nanoparticles and the polymer matrix.

[0056] In one embodiment, the pH value at the beginning of the polymerization and during the polymerization is controlled to support the self-assembly process. Depending on the polymerizable carbon source, the pH value can range from 0 to 14. In a preferred embodiment, wherein the polymerizable carbon source comprises aniline, preferably, the pH value is in the acidic range, preferably between 0 and 5, preferably between 0 and 3, preferably between 0 and 1 and most preferably between 0 and 0.85.

[0057] In the sense of the present application, the term "inorganic nanoparticle" describes an inorganic template molecule in the nanometer range. In a preferred embodiment, the inorganic nanoparticle has a particle size in the range of 1 nm to 1000 nm, preferably in the range of 1 nm to 800 nm, more preferably in the range of 2 nm to 700 nm, more preferably in the range of 3 nm to 600 nm, more preferably in the range of 4 nm to 500 nm, more preferably in the range of 5 nm to 100 nm.

[0058] In a preferred embodiment, the inorganic nanoparticle a has a predefined particle size dispersion The particle size dispersion of the inorganic nanoparticle Preferably is More preferably is Most preferably is The corresponding particle size distribution is also referred to as monodisperse. In a particularly preferred embodiment, the inorganic nanoparticle is monodisperse.

[0059] In another embodiment, the particle size distribution of the inorganic nanoparticle can be multimodal, preferably bimodal. By mixing two monodisperse inorganic nanoparticles, a bimodal distribution of the inorganic nanoparticle particle size can be obtained. The multimodal, preferably bimodal, particle size distribution of the inorganic nanoparticle can be used to further tailor the intramolecular properties of the porous carbon particle, for example in terms of the pore size distribution.

[0060] The geometry of the inorganic template molecule predetermines the pore geometry of the porous carbon particle obtained from the composite polymer particle according to the present application. Depending on the desired pore size, pore volume and pore geometry, the inorganic template molecule can exhibit any geometry, such as spherical, ellipsoidal, coral-like or star-shaped. A spherical or ellipsoidal geometry is preferred. The geometry of the inorganic nanoparticle can be uniform or non-uniform, wherein a uniform geometry of the nanoparticle is preferred.

[0061] In one embodiment, the inorganic nanoparticle is selected from the group consisting of Si02, metal oxides, inorganic salts or mixtures thereof. Si02is particularly preferred.

[0062] In a particularly preferred embodiment, the inorganic nanoparticle is a spherical Si02having a particle size in the range of 1 nm to 800 nm, more preferably in the range of 2 nm to 700 nm, more preferably in the range of 3 nm to 600 nm, more preferably in the range of 4 nm to 500 nm, more preferably in the range of 5 nm to 100 nm.

[0063] Monodisperse Si02particles having the aforementioned particle size are particularly preferred.

[0064] At the beginning of the polymerization reaction, the inorganic nanoparticles are present in the form of a colloidal dispersion. Suitable dispersion media for dispersing the inorganic nanoparticles include polar solvents that stabilize the inorganic nanoparticles. Suitable polar solvents are water, alcohols or aqueous solutions of alcohols. Particularly preferred are water, methanol, ethanol or mixtures thereof.

[0065] It is particularly preferred to control the reaction temperature during the polymerization process. In a preferred embodiment, the reaction temperature is set to be below 30°C, preferably below 25°C, preferably below 20°C, preferably below 10°C, preferably below 4°C, preferably below 0°C. Depending on the dispersion medium, the reaction temperature can be set to be below -4°C. Particularly preferred are temperature ranges between 30°C and -10°C, preferably between 20°C and -4°C, most preferably between 5 and 0°C. In general, it is assumed that the reaction temperature has an influence on the particle size distribution of the composite polymer particles. Lower temperatures generally lead to a narrower particle size distribution of the composite polymer particles.

[0066] To start the polymerization reaction, an initiator is required. The choice of suitable initiator to start the polymerization reaction depends on the choice of the polymerizable carbon source. In the case of stoichiometric radical (oxidative) polymerization, the initiator is a radical generator and is consumed throughout the reaction and does not get incorporated into the polymer matrix, while in the case of auto- propagating radical polymerization, the radical generating initiator is neither stoichiometric nor incorporated into the polymer matrix. In the case of condensation polymerization, when at least two monomeric reactants are used, the initiator is defined as at least one of the monomeric reactants and is incorporated into the polymer matrix.

[0067] Suitable initiators for the oxidative polymerization of the precursor monomers are, inter alia, persulfates such as ammonium persulfate ((NH4)2S2O8), sodium persulfate (Na2S2O8) or potassium persulfate (K2S2O8), or oxygen or metal chlorides such as FeCl3or CuCl2. Other suitable initiators for oxidative polymerization are, for example, hydrogen peroxide H2O2or NaIO4, AgNO3, K2Cr4O7, KMnO4. The use of persulfates, in particular ammonium persulfate ((NH4)2S2O8), is preferred.

[0068] Suitable initiators for the condensation polymerization of the precursor monomers are, inter alia, formaldehyde for the polymerization of (poly)hydroxylated aromatic compounds (preferably resorcinol) or acyl chloride aromatic compounds (preferably terephthaloyl chloride), or formaldehyde for the polymerization of di(or poly)aminated aromatic compounds (preferably 1,4-diaminobenzene) and derivatives and mixtures thereof.

[0069] Suitable initiators for the radical polymerization of the precursor monomers are, inter alia, ((2,2,6,6-tetramethylpiperidin-1-yl)oxy) (TEMPO), benzoyl peroxide, azobisisobutyronitrile and ammonium persulfate.

[0070] Some applications of porous carbon particles require the presence of heteroatoms in the porous carbon particle structure. It should be noted that heteroatoms, in particular nitrogen atoms, are easily introduced by the use of a polymerizable carbon source, e.g. N-doped carbon particles are obtained from the corresponding composite polymer particles if aniline is used.

[0071] However, for certain applications it can be relevant to introduce higher concentrations of certain heteroatoms or to introduce heteroatom doping in the porous carbon particle structure which cannot be introduced via the polymerizable carbon source. In these cases, the heteroatom doping is carried out via an additive which is added during the polymerization reaction of the composite polymer particles or directly thereafter or which is added to the dried composite polymer particles prior to carbonization. Suitable additives are, inter alia, urea, NH4OH, cyanamide, dopamine, melamine for N heteroatom doping; borax or boric acid for B heteroatom doping; P2O3, H3PO4, PPH3 for P heteroatom doping; sulfur, thiophenol, DMSO, NaSO3, H2SO4 for S heteroatom doping; and Na2SeO3, Na2SeO4 for Se heteroatom doping.

[0072] According to the present application, the molar ratio of the initiator is used to control the particle size and the particle size dispersity independently of each other and independently of the particle size of the inorganic nanoparticles used as template molecules In summary, by adjusting the molar ratio of the initiator to the polymerizable carbon source during the polymerization reaction, the particle size and the particle size dispersity of the composite polymer particles can be controlled independently of the particle size of the inorganic nanoparticles.

[0073] In one embodiment, the molar ratio of the initiator to the polymerizable carbon source is not equimolar. In a preferred embodiment, the molar ratio of the initiator to the polymerizable carbon source is not equimolar and ranges from 0.01 to 10, preferably from 0.05 to 5, and most preferably from 0.1 to 2. It has been found that increasing the molar ratio of the initiator relative to the polymerizable carbon source leads to an increase in the particle size of the composite polymer particles and vice versa.

[0074] It is particularly preferred that the initiator is subsequently added during the polymerization reaction. The rate of addition of the initiator preferably ranges from 0.1 ml min -1 l -1 to 200 ml min -1 l -1 , preferably from 1 ml min -1 l -1 to 3 ml min -1 l -1 .

[0075] In addition to adjusting the molar ratio of initiator to polymerizable carbon source, the molar ratio of initiator to specific surface area of the inorganic nanoparticles can be used as an additional adjustment parameter to further control the particle size of the composite polymer particles. It has been found that increasing the molar ratio of initiator to specific surface area of the inorganic nanoparticles leads to an increase in the particle size of the composite polymer particles and vice versa.

[0076] The specific surface area of the inorganic nanoparticles is theoretically determined by the surface area of a sphere with a given radius and experimentally determined by N2physical adsorption and the BET method.

[0077] In a preferred embodiment, wherein the polymerizable carbon source is aniline, the molar ratio of inorganic nanoparticles to polymerizable carbon source is 0.1 to 20, preferably 1 to 3, most preferably 1.8.

[0078] A second object of the present application is a method for independently controlling the particle size and the particle size dispersity of composite polymer particles, wherein the composite polymer particles comprise a polymer matrix and inorganic nanoparticles homogeneously distributed within the polymer matrix, wherein the composite polymer particles are obtained by polymerization of a polymerizable carbon source in the presence of dispersed inorganic nanoparticles and an initiator, characterized in that the particle size dispersity and the particle size are independently controlled by the molar ratio of initiator to polymerizable carbon source during the polymerization reaction.

[0079] All statements, in particular the statements regarding the polymerizable carbon source, the inorganic nanoparticles (templates) and the initiator apply to the same extent to the method for independently controlling the particle size and the particle size dispersity of composite polymer particles.

[0080] A third object of the present application is a porous carbon particle obtained from the composite polymer particles according to the present application.

[0081] In a preferred embodiment, the porous carbon particle is obtained from the composite polymer particles of the present application, wherein the composite polymer particles have been treated in a continuous manner with the following steps:

[0082] a. collecting, washing and drying the composite polymer particles,

[0083] b. calcining the composite polymer particles under an inert or reactive atmosphere at less than 1100°C to obtain a carbonized reaction product,

[0084] c. etching the carbonized reaction product to obtain an etched carbonized reaction product,

[0085] d. isolating and washing the etched carbonized reaction product,

[0086] e. drying the etched carbonized reaction product, and

[0087] f. temperature annealing of the etched carbonization reaction product in the temperature range from 300 °C to 3000 °C under inert or reactive atmosphere.

[0088] Step a) comprises collecting, washing and drying the composite polymer particles. The collection of the composite polymer particles can include filtration, (continuous) centrifugation, sedimentation and / or diafiltration, wherein collection by diafiltration is particularly preferred. The obtained material is preferably washed repeatedly until the pH value of the washing solution is neutral. The washing agent can be a polar solvent such as water or an aqueous solution of a C1-C4 alcohol. To prevent a change in the morphology of the composite polymer particles, the material after washing is subjected to drying, preferably freeze-drying.

[0089] The calcination according to process step b), also referred to as pyrolysis or carbonization, leads to the carbonization of the composite polymer particles. The calcination can be carried out under inert atmosphere by using N2or Ar or under reactive atmosphere by using for example air, O2, CO, CO2, NH3or H2S. The calcination under reactive atmosphere can be used to introduce (dope) heteroatoms into the resulting carbon particles, which can be useful for certain applications.

[0090] The calcination process has to be carried out below 1100 °C. Above this temperature, the inorganic template can react with the polymer matrix. In case the inorganic template is SiO2, this can lead to the formation of silicon carbide, thereby interfering with the etching process.

[0091] To remove the inorganic nanoparticles (template) from the carbonized composite polymer particles, the carbonized composite polymer particles are subjected to a chemical etching according to process step c). Suitable etching agents are those known to the person skilled in the art. If the inorganic template is SiO2, the etching agent can be selected from for example hydrogen fluoride HF, ammonium fluoride NH4F, ammonium bifluoride NH4HF2or from a concentrated NaOH or KOH solution. The concentration of the etching agent ranges from 0.1 mol / l -1 to 30 mol / l -1 , preferably from 0.1 mol / l -1 to 10 mol / l -1 . The etching process is preferably carried out for a period of at least 10 minutes, preferably at least 1 hour, preferably at least 12 hours, preferably at least 24 hours, preferably at least 48 hours. Furthermore, the etching process is carried out at a given temperature between 0 °C and 150 °C, preferably between 0 °C and 100 °C, preferably between 0 °C and 50 °C, preferably between 0 °C and 25 °C and most preferably between 20 °C and 25 °C.

[0092] The etching process can also be performed in a way that only partially removes the inorganic template, depending on the application of the porous carbon particles. Isolation and washing of the etched carbonization reaction product (step d) is preferably performed by filtration and / or centrifugation followed by redispersion of the filtrate in a polar solvent, preferably water, and stirring for at least 12 hours to remove residual etchant. Washing is preferably repeated until a pH-neutral dispersion is obtained. Drying of the etched carbonization reaction product (step e) is preferably performed under vacuum.

[0093] Temperature annealing according to step f) can be used to obtain a higher degree of graphitization. Temperature annealing can be performed in a temperature range from 300 °C to 3000 °C, for example at 1150 °C, 1300 °C, 1500 °C, 1700 °C and 2000 °C. Generally, an increase in temperature leads to an increase in the degree of graphitization, but reduces the amount of heteroatoms and porosity. It should be noted that, particularly in the temperature range between 2000 °C and 3000 °C, the porosity of the porous carbon particles will decrease, since at least part of the pores will collapse or close. This phenomenon can also occur to a small extent at lower temperatures. If desired, collapsed pores of the carbon particles can be regenerated, at least partially, by applying an activation process, such as a wet-chemical treatment and / or a heat treatment under a reactive gas.

[0094] Temperature annealing is performed for a period of at least 60 minutes, preferably at least 120 minutes. Temperature annealing can be performed under an inert atmosphere by using N2or Ar, or under a reactive atmosphere by using, for example, air, O2, CO, CO2, NH3or H2S.

[0095] In one embodiment, the porous carbon particles thus obtained can be further functionalized by a wet-chemical process at any temperature and / or under an inert or reactive gas atmosphere, preferably under heat treatment. Functionalization can include functionalization by wet-chemical methods with or without heat treatment, in particular oxidation with HNO3, KMnO4, H2SO4, H2O2, and / or heat treatment under a reactive gas atmosphere, in particular air, O2, CO or CO2, NH3, H2S, sulfur, urea.

[0096] The particle size of the porous carbon particles according to the present application can vary in the same range as the particle size of the composite polymer particles from which they are prepared. In a preferred embodiment, the porous carbon particles have a particle size in the range of micrometer to nanometer, which typically relates to a particle size of up to 5000 nm, preferably up to 4000 nm, preferably up to 3000 nm, preferably up to 2000 nm, preferably up to 1000 nm and most preferably up to 500 nm. In a preferred embodiment, the particle size of the porous carbon particles ranges from 1 nm to 5000 nm, preferably from 10 nm to 2000 nm, preferably from 50 nm to 2000 nm, and most preferably from 50 nm to 500 nm. It is particularly preferred to refer to porous carbon particles having a particle size in the range of 1 nm to 1000 nm as porous carbon nanoparticles.

[0097] In one embodiment, the particle size dispersion of the porous carbon particles is preferably narrow, preferably more preferably most preferably The porous carbon particles having a particle size dispersion

[0098] In a preferred embodiment, the porous carbon particles are monodisperse carbon particles having a particle size in the range of 10 nm to 2000 nm, preferably 50 nm to 500 nm.

[0099] The obtained porous carbon particles have a large specific surface area and a large pore volume.

[0100] In a preferred embodiment, the porous carbon particles comprise a specific surface area in the range of 25 m 2 g -1 to 2000 m 2 g -1 , preferably 200 m 2 g -1 to 1500 m 2 g -1 .

[0101] In another preferred embodiment, the porous carbon particles comprise a pore volume in the range of 0.1 cm 3 g -1 to 5.0 cm 3 g -1 , preferably 0.25 cm 3 g -1 to 3.0 cm 3 g -1 .

[0102] In one embodiment, the porous carbon particles have mesopores. In another embodiment, the porous carbon particles have micropores. In a preferred embodiment, the porous carbon particles are nanoparticles having mesopores and / or micropores and / or macropores.

[0103] In one embodiment, the porous carbon particles are N-doped porous carbon particles, preferably N-doped porous carbon nanoparticles (MPNC).

[0104] A fourth object of the present application is also a method for independently controlling the templated pore size and the particle size of porous carbon particles. The method comprises the steps of

[0105] a. synthesizing composite polymer particles having a predefined particle size dispersion and a predefined particle size by polymerization of a polymerizable carbon source in the presence of an initiator and dispersed inorganic nanoparticles serving as templates, wherein the particle size dispersion and the composite polymer particle size are controlled by the molar ratio of initiator to polymerizable carbon source during the polymerization reaction,

[0106] b. collecting, washing and drying the composite polymer particles,

[0107] c. calcining the composite polymer particles under inert or reactive atmosphere at temperatures below 1100 °C to obtain a carbonized reaction product,

[0108] d. etching the carbonized reaction product to obtain an etched carbonized reaction product,

[0109] e. isolating and washing the etched carbonized reaction product,

[0110] f. drying the etched carbonized reaction product,

[0111] g. temperature annealing the etched carbonized reaction product under inert or reactive atmosphere in the temperature range from 300 °C up to 3000 °C.

[0112] All the foregoing statements apply to the same extent, if applicable, to the method for independently controlling the particle size and the particle size dispersion of the composite polymer particles.

[0113] In one embodiment, the method can optionally comprise a functionalization step h) in which the porous carbon particles are further functionalized. The functionalization can comprise functionalization by wet-chemical methods with or without thermal treatment (especially oxidation with HNO3, KMnO4, H2SO4, H2O2) and or thermal treatment under reactive gas atmosphere (especially air, O2, CO or CO2, NH3, H2S, sulfur, urea).

[0114] A fifth object of the present application is also an article of manufacture comprising the composite polymer particles and / or the porous carbon particles according to the present application. In principle, the article of manufacture comprising the composite polymer particles and / or the porous carbon particles of the present application can have a wide range of applications.

[0115] In a preferred embodiment, the article of manufacture is one of the following: catalysts, conductive additives, gas diffusion layers, electrodes for energy converters (fuel cells, electrolyzers) or energy storage devices (batteries (LIB, NIB, organic batteries, redox flow batteries), supercapacitors (EDLC and pseudocapacitors) and hybrid capacitors) and sensors or parts thereof.

[0116] In another embodiment, the article of manufacture can be one for drug delivery, sorption applications (oils, alkanes, phenols, heavy metals, etc.), water purification applications (capacitive desalination).

[0117] A sixth object of the present application is the use of the adjustment of the molar ratio of initiator to polymerizable carbon source for controlling the particle size and the particle size dispersion of the composite polymer particles independently of the particle size of the inorganic nanoparticles used as templating agent in the hard-templating method. If applicable, all the preceding statements apply to the use of the present application to the same extent. BRIEF DESCRIPTION OF DRAWINGS

[0118] Figure 1 General method for the synthesis of composite polymer particles and porous carbon particles.

[0119] Figure 2 General method for controlling the pore size and the particle size of the porous carbon particles.

[0120] Figure 3 Temperature post-treatment of the porous carbon particles for increasing the degree of graphitization.

[0121] Figure 4 SEM images of the SiO2 nanoparticle templates and of the composite polymer particles (PANI-SiO2) at the time of synthesis and after carbonization and particle size distribution of the PANI-SiO2 composite polymer particles for MPNC-12-300-1000 (a-c, e), MPNC-23-300-1000 (f-h, j), MPNC-30-300-1000 (k-m, o), MPNC-60-300-1000 (p-r, t) and MPNC-100-300-1000 (u-w, r). The boxplots d, i, n, s and q show the particle size distribution of the used templates and the boxplots e, j, o, t and r show the particle size distribution of the composite particles.

[0122] Figure 5SEM and TEM images and particle size distribution of porous carbon nanoparticles with different pore sizes carbonized at 1000 °C. MPNC-12-300-1000 (a-d), MPNC-23-300-1000 (e-h), MPNC-30-300-1000 (i-l), MPNC-60-300-1000 (m-p) and MPNC-100-300-1000 (q-t).

[0123] Figure 6 X-ray diffraction patterns (a), elemental analysis (b) and Raman analysis with typical spectra (c) and five fitted Raman bands integral areas (d) of the obtained porous carbon nanoparticles with different pore sizes carbonized at 1000 °C, indicating no chemical differences between samples.

[0124] Figure 7 Physical adsorption isotherms (a), pore size distribution (b), cumulative pore volume and surface area (c), corresponding total pore volume (d) and specific surface area (e) of porous carbon nanoparticles with different pore sizes carbonized at 1000 °C.

[0125] Figure 8 SEM and TEM images and particle size distribution of porous carbon nanoparticles with different particle sizes carbonized at 1000 °C prepared by changing the molar ratio of APS to aniline: 1 : 10 - MPNC-7-50-1000 (a-d), 1 :4 - MPNC-7-90-1000 (e-h), 1 : 1 - MPNC-7-130-1000 (i-l), 2: 1 - MPNC-7-170-1000 (m-p).

[0126] Figure 9 X-ray diffraction patterns (a), elemental analysis (b) and Raman analysis with typical spectra (c) and five fitted Raman bands integral areas (d) of the obtained porous carbon nanoparticles with different particle sizes carbonized at 1000 °C, indicating no chemical differences between samples.

[0127] Figure 10 Physical adsorption isotherms (a), pore size distribution (b), cumulative pore volume and surface area (c), corresponding total pore volume (d) and specific surface area (e) of porous carbon nanoparticles with different particle sizes carbonized at 1000 °C.

[0128] Figure 11SEM and TEM images and particle size distribution of porous carbon nanoparticles carbonized at 1150 °C (MPNC-23-300-1000-1150) (a), 1300 °C (MPNC-23-300-1000-1300) (b), 1500 °C (MPNC-23-300-1000-1500) (c), 1700 °C (MPNC-23-300-1000-1700) (d) and 2000 °C (MPNC-23-300-1000-2000) (e). Raman spectra (g), X-ray diffraction patterns (h) and elemental analysis (i) of porous carbon nanoparticles after post-treatment at higher temperatures.

[0129] Figure 12 Physical adsorption isotherms (a), pore size distribution (b), cumulative pore volume and surface area (c), corresponding total pore volume (d) and specific surface area (e) of porous carbon nanoparticles carbonized / annealed at different temperatures between 1000 °C and 2000 °C.

[0130] Figure 1 A general synthesis strategy to obtain composite polymer particles 20 and porous carbon particles 50 is shown. As a template for the synthesis of composite polymer particles, inorganic nanoparticles 10, in particular silica (Si02) nanoparticles, are used, while aniline - representing a preferred precursor monomer 11 according to the present application - acts as a polymerizable carbon precursor and nitrogen source. In a first step 40, monomer 11 is added to a dispersion containing inorganic nanoparticles 10. This leads to the adsorption of monomer 11 on the surface of inorganic nanoparticles 10 (not shown). Further addition of an initiator catalyzes the polymerization of the monomer into a polymer (not shown). This process is followed by the self-assembly of the polymer, leading to the formation of composite polymer particles 20, in which inorganic nanoparticles 10 are homogeneously distributed within a polymer matrix 21.

[0131] In a preferred embodiment, in which aniline and silica are used as monomer 11 and inorganic nanoparticles 10, the strong oxidizing agent ammonium persulfate (APS) catalyzes the polymerization of aniline into polyaniline (PANI), which then self-assembles with the silica, leading to the formation of PANI / Si02 composite polymer particles having a spherical shape and Si02 nanoparticles homogeneously distributed along the PANI framework. After synthesis, the PANI / Si02 composite polymer particles (not shown in Fig. 1) are collected, washed and freeze-dried. Figure 1 Carbonization 41 leads to carbonized composite polymer particles 30, which are then subjected to template etching 42, resulting in porous carbon particles that retain the spherical shape and have a well-defined porous structure, as can be seen from the TEM and SEM analysis shown in Figure 5

[0132] Figure 2 ​It is shown that using different particle sizes of silica nanoparticles 10, varying in particle diameter from 7 nm to 100 nm, while keeping all other synthesis parameters constant, results in porous carbon particles 50 with pore diameters in the range of 7 nm to 100 nm while the particle diameter can remain constant. Changing the molar ratio of initiator to polymerizable carbon source 11, such as aniline, allows to tailor the particle diameter while keeping the pore diameter constant.

[0133] Figure 3 It is shown that post-treatment of the porous carbon (nano)particles 50 at temperatures between 1150 °C and 2000 °C. Temperature annealing can be used to obtain porous carbon (nano)particles 60 with a higher degree of graphitization without significantly changing the morphology of the porous carbon (nano)particles.

[0134] Figure 4 It is shown that for MPNC-12-300-1000 (a-c, e), MPNC-23-300-1000 (f-h, j), MPNC-30-300-1000 (k-m, o), MPNC-60-300-1000 (p-r, t) and MPNC-100-300-1000 (u-w, r) SEM images of the Si02nanoparticle templates and the composite polymer particles (PANI-Si02) upon carbonization as well as the particle size distribution of the PANI-Si02composite polymer particles. Box plots d, i, n, s and q show the particle size distribution of the inorganic nanoparticles used as templates and box plots e, j, o, t and r show the particle size distribution of the composite polymer particles containing the templates. In all cases, all PANI-Si02composite polymer particles consist of highly monodisperse nanoparticles with a particle diameter centered around 350 nm, independent of the template size, as evidenced by SEM. The particle diameter dispersion calculated for the composite polymer particles (prior to carbonization) is 1.01 (MPNC-12-300-1000), 1.02 (MPNC-23-300-1000), 1.02 (MPNC-30-300-1000), 1.02 (MPNC-60-300-1000) and 1.02 (MPNC-100-300-1000), respectively.

[0135] Figure 5 It is shown that scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images and particle size distribution of the produced porous carbon particles with different pore diameters carbonized at 1000 °C. It can be seen that using different diameters of inorganic nanoparticles (in this case 12 nm, 23 nm, 30 nm, 60 nm and 100 nm Si02nanoparticles), while keeping all other synthesis parameters constant, it is possible to tailor the pore diameter of the porous carbon particles in the range of 12 nm to 100 nm and thus - the pore volume (1.34 cm3g-1for 12 nm, 1.62 cm3g-1for 23 nm, 1.68 cm3g-1for 30 nm, 1.71 cm3g-1for 60 nm and 1.73 cm3g-1for 100 nm) and the specific surface area (1.06 m2g-1for 12 nm, 1.25 m2g-1for 23 nm, 1.27 m2g-1for 30 nm, 1.28 m2g-1for 60 nm and 1.29 m2g-1for 100 nm) of the porous carbon particles.​3 g -1 -1.05cm 3 g -1 )(like Figure 7 (as shown in d) and specific surface area (1060m²) 2 g -1 -305m 2 g -1 )(like Figure 7 (As shown). For illustration, the obtained sample is denoted as MPNC-TS-PS-CT, where TS = template size, PS = particle size, and CT = calcination / pyrolysis temperature (MPNC - pore size - particle size - calcination temperature). Figure 2 ).

[0136] In all cases, all porous carbon particles consisted of highly monodisperse nanoparticles (also known as nanospheres) with a particle size centered at 300 nm, independent of the obtained pore size (template size), as confirmed by SEM. The particle size distribution was calculated for the porous carbon particles (after carbonization). They are 1.01 (MPNC-12-300-1000), 1.02 (MPNC-23-300-1000), 1.01 (MPNC-30-300-1000), 1.02 (MPNC-60-300-1000), and 1.01 (MPNC-100-300-1000).

[0137] Figure 6 X-ray diffraction patterns (a), elemental analysis (b), and Raman analysis with typical spectra (c) of porous carbon nanoparticles with different pore sizes obtained by carbonization at 1000 °C are shown, along with the integrated areas of five fitted Raman bands (d), indicating no chemical differences between the samples.

[0138] To investigate the pore structure of MPNC nanospheres, nitrogen physical adsorption was used. Figure 7 The physical adsorption isotherms (a), pore size distribution determined by QSDFT, cumulative pore volume and surface area determined by QSDFT (c), corresponding total pore volume determined at p / p0 = 0.98 and / or QSDFT (d), and specific surface area determined by BET and / or QSDFT (e) for porous carbon particles with different pore sizes carbonized at 1000 °C are shown. It can be seen that all samples exhibit isotherms with visible hysteresis, which may be attributed to mesopores in the material. In the pore width distribution, it can be seen that the main pore width corresponds to the size of the template used, where the pore size is slightly larger than the template size. For different pore sizes, 1.34 cm was measured. 3 g -1 Up to 1.05cm 3 g-1 high pore volume (1.26 to 0.26 with QSDFT) and 305 m 2 g -1 to 705 m 2 g -1 surface area (301 m 2 g -1 to 763 m 2 g -1 ).

[0139] Figure 8 SEM and TEM images and particle size distribution of porous carbon nanoparticles with different particle sizes carbonized at 1000 °C prepared by changing the molar ratio of initiator (APS) to aniline are shown: 1:10 - MPNC-7-50-1000 (a-d), 1:4 - MPNC-7-90-1000 (e-h), 1:1 - MPNC-7-130-1000 (i-l), 2:1 - MPNC-7-170-1000 (m-p).

[0140] To adjust the particle size, different molar ratios of initiator APS to aniline were used, as exemplified by MPNC-7-X-1000. The use of lower amounts of initiator (APS) slows down the oxidative polymerization of aniline. This limits the PANI chain growth, while favoring the interaction of ANI+-SiO2, leading to the formation of smaller particles. When keeping the APS / ANI ratio at 1:1, MPNC-7-X-1000 with a particle size X of 130 nm was obtained (denoted as MPNC-7-130-1000) (i-l). However, decreasing the amount of APS in the reaction, while keeping all other parameters constant, resulted in porous carbon particles with a size of 90 nm for an APS / ANI of 1:4 (MPNC-7-90-1000) (e-h), and 50 nm for an APS / ANI of 1:10 (MPNC-7-50-1000) (a-d). In turn, by increasing the APS / ANI molar ratio to 2:1, the particle size of the porous carbon particles could be increased to 170 nm (MPNC-7-170-1000) (m-p). Figure 8 Figure 8 Figure 8 Figure 8

[0141] As can be seen by SEM, in all cases the spherical shape of the particles was maintained and sharp particle size distributions were obtained. The particle size dispersity calculated for the porous carbon particles ​​​​1.14 (MPNC-7-50-1000), 1.06 (MPNC-7-90-1000), 1.03 (MPNC-7-130-1000) and 1.02 (MPNC-7-170-1000), respectively.

[0142] Figure 9 X-ray diffraction patterns (a), elemental analysis (b) and Raman analysis with typical spectra (c) and five fitted Raman bands integral areas (d) of the obtained porous carbon nanoparticles with different particle sizes carbonized at 1000 °C are shown, indicating no chemical differences between the samples.

[0143] Figure 10 Physical adsorption isotherms (a), pore size distribution determined by QSDFT (b), cumulative pore volume and surface area from QSDFT (c), corresponding total pore volume at p / p0=0.98 and / or determined by QSDFT (d) and specific surface area determined by BET and / or QSDFT (e) of porous carbon particles with different particle sizes carbonized at 1000 °C are shown.

[0144] Figure 10 Specific surface area calculated using the quenching solid density functional theory model to fit the experimental data is shown, demonstrating that MPNC-7-50-1000 is characterized by the highest value of SSA of 1515 m 2 / g (1606 m -2 / g -1 ) with QSDFT). It can be expected that the increase of MPNC particle size to 90 nm, 130 nm and 170 nm causes a decrease of SSA to 1387 m 2 g -1 , 1061 m 2 g -1 and 1022 m 2 g -1 (1406 m -2 g -1 , 1150 m -2 g -1 and 1078 m -2 g -1 ) with QSDFT, respectively. The same trend Figure 10 c) is observed for the cumulative pore volume, i.e. gradual decrease with increasing particle size. The cumulative pore volume is calculated to be in the range of 3.42 cm 3 g -1 -1.76 cm 3 g -1 (2.97 cm 3 g -1 -1.56 cm 3 g-1 For MPNC-7-50-1000, MPNC-7-90-1000, MPNC-7-130-1000, and MPNC-7-170-1000, the contribution of micropore volume is 0.2 ± 0.05 cm⁻¹. 3 g -1 Furthermore, it can be seen from the pore size distribution and cumulative pore volume ( Figure 10 (b) and (c) As particle size decreases, the volume of micropores and mesopores introduced into the sample increases. It is speculated that this effect is not attributable to an increase in intraparticle pore volume, but rather to a more dense particle packing in terms of interparticle porosity. As particles become smaller, their packing in the measuring cell becomes more dense, thus forming new pores between particles, introducing additional pore volume and surface area that is unrelated to the primary particle characteristics within the particles but related to particle packing.

[0145] To investigate the temperature-induced changes in surface composition and graphitization (e.g., nitrogen content, electrical conductivity, and wettability), MPNC was annealed at different temperatures (general principle as follows). Figure 3 (As shown). Figure 11 SEM and TEM images and particle size distributions of porous carbon nanoparticles carbonized at 1150 °C (MPNC-23-300-1000-1150) (a), 1300 °C (MPNC-23-300-1000-1300) (b), 1500 °C (MPNC-23-300-1000-1500) (c), 1700 °C (MPNC-23-300-1000-1700) (d), and 2000 °C (MPNC-23-300-1000-2000) (e) are shown. Raman spectra (f), X-ray diffraction patterns (g), and elemental analysis (h) of the porous carbon nanoparticles after post-processing at higher temperatures are also shown.

[0146] HRTEM imaging was used to monitor morphological changes caused by annealing (not shown).

[0147] HRTEM observations are consistent with Raman spectroscopy studies. Raman spectra of all MPNC samples carbonized at temperatures between 1000℃ and 1300℃ are also available. Figure 11 The samples (g) are very similar, regardless of pore size and particle size, confirming the high similarity of the carbon microstructures. Specifically, broad peaks are observed in the first-order Raman spectra, and broad bands are observed in the second-order spectra, indicating a large contribution from amorphous carbon and the presence of defects. However, samples annealed at elevated temperatures show significant differences. Figure 11 g) MPNC annealed at 1500℃, 1700℃, and 2000℃ showed a narrowing of the first-order Raman peak (1000 cm⁻¹). -1 -1700cm -1 ).

[0148] Simultaneously, a high-intensity peak (2400 cm⁻¹) was observed in the second-order spectrum. -1 -3000cm -1 ), confirming that higher graphitization was also observed via HRTEM (not shown).

[0149] The crystallinity of the sample was further evaluated using X-ray diffraction. Figure 11 h). Consistent with Raman spectroscopy studies, all spectra of samples annealed at the same temperature exhibited the same trend, independent of the pore size or particle size of the MPNC. XRD diffraction patterns revealed two broad reflections at 23.5° and 43.7°, attributable to the (002) and (100) graphite reflection characteristics of disordered carbon. The aforementioned reflections became sharper with increasing carbonization temperature, indicating enhanced crystallinity. Furthermore, XRD diffraction patterns before and after the final synthesis step—treatment of MPNC at 500°C—show the importance of this step, as the sharp reflection at 18°C, attributable to insoluble residues (not shown) from the etching step, was removed. Residue removal is also evident from thermogravimetric analysis (TGA) data (not shown), where the mass loss at 500°C (attributable to residues) disappeared after the heat treatment at 500°C.

[0150] Graphitization temperature affects not only the crystallinity and electrical conductivity of MPNCs but also their composition and heteroatom content, which play a crucial role in most applications. Therefore, it is important to select a carbonization temperature that strikes a balance between good crystallinity and high heteroatom content. Carbonization of the samples at 1000 °C was sufficient to transform PANIs into carbons that not only exhibit moderate graphitization (ordering) but also retain a sufficient amount of nitrogen doping within the carbon matrix. To determine the chemical composition, elemental analysis and EDX (not shown) were used. It can be expected that all samples showed similar N contents ranging from 4.0 wt% to 6.5 wt%, independent of pore size. This is very consistent with materials carbonized at 1000 °C. EDX elemental distribution mapping showed that C, O, and N elements were uniformly distributed along the grains.

[0151] Annealing the sample at elevated temperatures results in a higher C content and a decrease in surface functionality. Figure 11 i). Compared to MPNC-23-300-1000, the sample annealed at a higher temperature showed an increase in C content from 84 wt% to 99 wt%, and a decrease in N functionality on the surface from 5.3 wt% to 0.1 wt%.

[0152] Particle size distribution calculated for porous carbon particles 1.03 (MPNC-23-300-1000-1150), 1.02 (MPNC-23-300-1000-1300), 1.02 (MPNC-23-300-1000-1500), 1.02 (MPNC-23-300-1000-1700) and 1.02 (MPNC-23-300-1000-2000), respectively.

[0153] Figure 12 Physical adsorption isotherms (a), pore size distribution determined by QSDFT (b), cumulative pore volume and surface area determined by QSDFT (c), corresponding total pore volume determined at p / p0=0.98 and / or QSDFT (d) and specific surface area determined by BET and / or QSDFT (e) of the porous carbon particles carbonized / annealed at different temperatures between 1000°C and 2000°C are shown. As Figure 12 shown, the elevated temperature can affect the morphology and pore structure of the material. While the size and morphology of the MPNCs annealed at higher temperatures are preserved, as evidenced by HRTEM analysis (not shown), the mesoporous structure seems to be affected. In comparison to MPNC-23-300-1000 with a SSA of 641 m 2 g -1 , the MPNC SSA shows a gradual decay: from 532 m 2 / g (for MPNC-23-300-1000-1150) to 515 m -1 / g, 448 m 2 / g, 250 m 2 / g, and finally to 174 m 2 g 2 (for annealing temperatures of 1300°C, 1500°C, 1700°C and 2000°C) (with QSDFT of 626 m 2 g -1 , 585 m 2 g -1 , 502 m 2 g -1 , 269 m 2 g -1 , and 191 m 2 g -1 , respectively). 2 -1) ( Figure 12 e). This sharp decrease in SSA is associated with micropore closure / fusion and total pore volume reduction at elevated temperatures.

[0154] The following examples serve to further explain the present application. The present application is not, however, limited to the specific embodiments shown in the examples.​​

[0155] Exemplary embodiments

[0156] All ingredients listed herein are commercially available and used in the commercial quality, unless otherwise stated.

[0157] Materials / Chemicals

[0158] Silica nanoparticles with a size of 7 nm (Ludox SM-30, 30 wt.% solution in H2O), 12 nm (Ludox AS-30, 30 wt.% solution in H2O), 23 nm (Ludox TMA, 34 wt.% solution in H2O), hydrochloric acid (HC1 (1 M)), ammonium persulfate (APS, > 98.0%), ammonium bifluoride (NH4HF2, > 95%), tetraethyl orthosilicate (TEOS, > 99%) were purchased from Sigma-Aldrich. Silica with a size of 30 nm (Levasil CS40-213, 40 wt.% solution in H2O) and 60 nm (Levasil CS50-18, 50 wt.% solution in H2O) were purchased from Nouryon. Aniline (99.5%) and concentrated HNO3 (69%) were purchased from VWR. Ammonium hydroxide solution (NH4OH, 35%) was purchased from Acros. 2-Propanol, acetone and ethanol were analytical grade and purchased from Sigma-Aldrich.

[0159] Example 1 : Monodisperse, spherical polyaniline-silica composite nanoparticles (PANI / Si02)

[0160] 800 ml MilliQ H2O were transferred into a 1000 ml round bottom flask and cooled by an ice bath. Subsequently, 100 ml 1 M HC1, 8 ml aniline and 23 ml Ludox TMA (23 nm, 34 wt.%, 1.23 g / ml) were added and the mixture was stirred until a homogenous solution was formed. At the same time, 20.05 g ammonium persulfate (APS) were dissolved in 40 ml 1 M HC1. To induce the polymerization of aniline, the APS solution was added dropwise to the round bottom flask within 15 minutes by using a dropping funnel (2 ml min -1 ) (APS:aniline molar ratio of 1 : 1). The mixture was then stirred for 24 hours while keeping the reaction flask cooled in an ice bath.

[0161] Example 2: Monodisperse porous carbon nanoparticles from monodisperse polyaniline-silica composite nanoparticles

[0162] ​The formed PANI / Si02 composite polymer particles from Example 1 were collected by centrifugation (9000 rpm, 10 min) and re-dispersed in fresh water. This washing step was repeated at least 10 times until the pH of the solution was neutral. The obtained nanocomposite was freeze-dried to prevent morphological changes. The freeze-dried powder was transferred to a calcination boat and heated to 1000°C under nitrogen atmosphere with a heating ramp of 200 K / h for a holding time of 6 h. To remove the silica template from the carbonized sample, the composite was etched with a 4 M NH4HF2solution (50 ml g -1 of sample) for 48 h to obtain mesoporous N-doped carbon (MPNC). The MPNC was separated from the etching solution by filtration. The wet filter cake was re-dispersed in fresh H2O and stirred for 12 h to wash off NH4HF2residues. This washing step was repeated 4 times followed by an ethanol wash. The wet filter cake was dried under vacuum for 24 h. The obtained dry powder was annealed at 500°C under nitrogen atmosphere with a heating ramp of 300 K / h for 2 h to remove insoluble residues from the etching step. The final MPNC powder yield was 3.54 g (44%) and was denoted as MPNC-23-300-1000 depending on the size of the Si02 template, the particle size of the MPNC and the pyrolysis temperature. 1

[0163] Example 3: Large scale synthesis

[0164] The large scale synthesis was achieved in a 4 L round bottom flask by using triple amounts of all chemicals and H2O. Due to the insufficient strength of the magnetic stirrer for the increased volume, a KPG stirrer with stirring blades inserted from the top in the flask to stir the reaction solution was used. The large scale synthesis yield was about 10 g.

[0165] Example 4: Pore size engineering

[0166] ​Pore size engineering was achieved by using different size Si02 nanoparticle templates instead of Ludox TMA (for PANI / Si02-23). Samples PANI / Si02-7, PANI / Si02-12, PANI / Si02-30, PANI / Si02-60 and PANI / Si02-100 were synthesized using Ludox SM Si02 (7 nm, 30 wt%, 1.23 g / mL, 26.3 ml), Ludox AS-30 (12 nm, 30 wt%, 1.21 g / ml, 26.3 ml), Levasil CS40-213 (30 nm, 40 wt%, 1.30 g / ml, 18.5 ml), Levasil CS50-18 (60 nm, 50 wt%, 1.40 g / ml, 13.8 ml) and Si02 nanospheres synthesized using Stober method by hydrolysis and polymerization of tetraethoxysilane (100 nm, 10 wt%, 1.20 g / ml, 80.0 ml) respectively. The obtained nanocomposites PANI / Si02 were freeze-dried to prevent morphological changes. The freeze-dried powders were transferred to calcination boat and heated to 1000 °C under nitrogen atmosphere with a heating ramp rate of 200 K / h for a holding time of 6 h. To remove the silica template from the carbonized sample, the composite was etched with 4 M NH4HF2solution (50 ml g -1 of sample) for 48 h to obtain mesoporous N-doped carbon (MPNC). The MPNC was separated from the etching solution by filtration. The wet filter cake was redispersed in fresh H20 and stirred for 12 h to wash off NH4HF2residues. This washing step was repeated 4 times followed by washing with ethanol. The wet filter cake was dried under vacuum for 24 h. The resulting dried powder was annealed at 500 °C under nitrogen atmosphere with a heating ramp rate of 300 K h- 1 for 2 h to remove insoluble residues from the etching step.

[0167] Example 5: Particle size engineering of composite polymer particles (PANI / Si02) and porous carbon particles (MPNCs)

[0168] PANI / SiO2 and MPNC particle size engineering was achieved by using different APS to aniline ratios. For PANI / SiO2-7-50 (PANI / SiO2 - template size - composite polymer particle size), a ratio of 0.1 was used, for PANI / SiO2-7-90, a ratio of 0.25 was used, and for PANI / SiO2-7-170, a ratio of 2.00 was used. This corresponds to using 90% less, 75% less, and 100% more initiator while keeping the amount of other reagents constant. The obtained nanocomposites PANI / SiO2 were freeze-dried to prevent morphological changes. The freeze-dried powder was transferred to a calcination boat and heated to 1000 °C under a nitrogen atmosphere with a heating ramp rate of 200 K / h for a holding time of 6 h. To remove the silica template from the carbonized sample, the composite was etched with a 4 M NH4HF2solution (50 ml g -1 of sample) for 48 h, resulting in N-doped carbon (MPNC). The MPNC was separated from the etching solution by filtration. The wet filter cake was redispersed in fresh H2O and stirred for 12 h to wash off NH4HF2residues. This washing step was repeated 4 times and then washed with ethanol. The wet filter cake was dried under vacuum for 24 h. The obtained dry powder was annealed at 500 °C under a nitrogen atmosphere with a heating ramp rate of 300 K h -1 for 2 h to remove insoluble residues from the etching step.

[0169] Example 6: High temperature post-treatment

[0170] High temperature post-treatment of MPNC-23-300-1000 at given temperatures was achieved by using a high temperature oven from Thermal Technology GmbH with a graphite heating element. The sample was introduced into the oven, the chamber was evacuated for 20 min and refilled with argon three times. Then the sample was heated up to the final temperature with a heating ramp rate of 300 K / h and the final temperature was held for 2 h, then the sample was cooled down again with a cooling ramp rate of 300 K / h. The obtained samples were named MPNC-TS-PS-CT1-CT2, where TS = template size, PS = particle size, CT1 = calcination / pyrolysis temperature, and CT2 = post-treatment temperature (MPNC-Pore size-Particle size-Calcination temperature-Post-treatment temperature), where CT2 = 1150 °C - 2000 °C.

[0171] Example 7: Post-functionalization

[0172] Post-functionalization of high temperature treated MPNC-7-130-1300 was achieved by surface oxidation with concentrated HNO3(69%) followed by temperature annealing under ammonia atmosphere. Thereby, 800 mg MPNC-7-130-1300 were added to 40 ml pre-heated HNO3(70°C). The reaction mixture was kept at 70°C and stirred vigorously for 2 h. After completion of the reaction, the reaction mixture was immediately cooled in an ice bath and filtered. Then, the material was washed with boiling water until the supernatant was neutral. The oxidized sample (MPNC-7-130-1300-Ox) was dried at 80°C under vacuum. For the ammonolysis, the oxidized sample was placed in a fluidized bed oven and treated under NH3atmosphere (10 l h -1 ) at a heating ramp rate of 5°C min -1 -1 for 2 h at a temperature T (T = 400°C, 500°C, 600°C) to obtain samples named MPNC-7-130-1300-Ox-N-T.

[0173] Table 1 : Elemental analysis of post-functionalized MPNC-7-130-1300 .

[0174]

[0175] Characterization

[0176] For elemental analysis, a vario MICRO cube (Elementar Analysensysteme GmbH) with a temperature programmable column and a thermal conductivity detector was used. Approximately one milligram of sample was mixed with WO3as oxidizing catalyst and combusted at 1150°C.

[0177] Thermogravimetric analysis was performed on a STA 409C (Netzsch) using approximately one milligram of sample and a heating rate of 10 K / min in air and under nitrogen atmosphere, respectively.

[0178] Scanning electron microscopy (SEM) measurements were performed using a field emission gun high resolution SEM (FEG-HRSEM) SU8220 (Hitachi) equipped with SE (secondary electrons), BSE (backscattered electrons) and TE (transmission electron) detectors. Diluted samples were drop casted onto carbon coated copper grids (200 mesh). For general imaging of the electrodes, a scan mode with an acceleration voltage of 2.5 kV and a working distance of 3.0 mm was applied. For imaging of the porous samples, we used a transmission mode operating at an acceleration voltage of 30 kV and a working distance of 8.0 mm.

[0179] Energy dispersive X-ray (EDX) analysis and elemental mapping were performed on the same machine using XFlash and FlatQUAD detectors from Bruker, respectively.

[0180] For high resolution transmission electron microscopy (HRTEM) imaging, a Talos 200X electron microscope (Thermo Fisher) operated at an acceleration voltage of 200 kV was used.

[0181] X-ray diffraction was measured on a Bruker D8 Discover using a flat sample holder with embedded silicon single crystal. The sample was rotated at 45 revolutions per minute and the diffractogram was recorded between 10° and 105° with a step size of 0.025 degrees and a measurement time of 0.5 seconds per step.

[0182] Raman spectra were recorded using a Senterra II microscope (Bruker) equipped with a 532 nm laser. The laser power was set to 0.25 mW. Measurements were performed with a 4 cm -1 -1 wave number resolution. Spectra were recorded in the range of 750 cm -1 -2500 cm -1 -1.

[0183] The specific surface area and pore structure were determined by N2 physisorption at 77 K using an Autosorb 1-C physisorption station (Quantachrome). Measurements were performed from powder samples degassed at 100 °C under vacuum for 24 h. The specific surface area was calculated using the Brunauer-Emmer-Teller (BET) method fitted in the p / p0 range of 0.05 to 0.30 and / or using Quenched Solid Density Functional Theory (QSDFT). The specific pore volume was calculated by using the adsorption volume at a relative pressure of P / P0 = 0.98 and / or QSDFT. The pore size distribution was determined according to QSDFT taking into account spherical pores. The micropore specific surface area and pore volume were estimated using the t-plot method.

[0184] The results of the characterizations are discussed in the description of the figures, in particular Figures 4 to 12 in the description of the figures.

Claims

1. Composite polymer particles comprising a polymer matrix and inorganic nanoparticles homogenously distributed within the polymer matrix, wherein the composite polymer particles are obtained by polymerization of a polymerizable carbon source in the presence of dispersed inorganic nanoparticles and an initiator. characterized in that The composite polymer particles have a predefined particle size dispersion and a predefined particle size, wherein the predefined particle size dispersion and the predefined particle size are controlled independently of the particle size of the inorganic nanoparticles by adjusting the molar ratio of initiator to polymerizable carbon source during the polymerization reaction.

2. The composite polymer particles according to claim 1, wherein the composite polymer particles are nanoparticles, preferably having a particle size of 10 nm to 1000 nm, preferably 50 nm to 500 nm.

3. The composite polymer particles according to claim 1 or 2, wherein the particle size dispersity of the composite polymer particles is monodisperse, preferably ​ 4. The composite polymer particles according to any one of the preceding claims, wherein the molar ratio of the initiator to the polymerizable carbon source is not equimolar.

5. The composite polymer particles according to any one of the preceding claims, wherein the molar ratio of the initiator to the polymerizable carbon source ranges from 0.01 to 10, preferably between 0.1 and 2.

6. The composite polymer particles according to any one of the preceding claims, wherein increasing the molar ratio of the initiator relative to the polymerizable carbon source results in an increase in the particle size of the composite polymer particles and vice versa.

7. The composite polymeric particles according to any one of the preceding claims, wherein the initiator is subsequently added during the polymerisation reaction and the rate of addition is preferably in the range of 0.1 ml min -1 l -1 to 200 ml min -1 l -1 , preferably 1 ml min -1 l -1 to 3 ml min -1 l -1 .

8. The composite polymer particles according to any one of the preceding claims, wherein the initiator can be, inter alia, ammonium persulfate ((NH4)2S2O8), sodium persulfate (Na2S2O8), potassium persulfate (K2S2O8) or oxygen.

9. The composite polymeric particles according to any one of the preceding claims, wherein the molar concentration of the polymerizable carbon source during the polymerization reaction ranges from 0.05 mol l -1 to 1 mol l -1 , preferably from 0.09 mol l -1 to 0.24 mol l -1 .

10. The composite polymer particles according to any one of the preceding claims, wherein the polymerizable carbon source is a polymerizable carbon source capable of oxidative polymerization.

11. The composite polymer particles according to any one of the preceding claims, wherein the inorganic nanoparticles have a particle size in the range of 1 nm to 800 nm, preferably 5 nm to 100 nm.

12. The composite polymeric particle according to any one of the preceding claims, wherein the inorganic nanoparticles have a predefined particle size dispersion wherein Preferably < 1.

2.

13. The composite polymer particles according to any one of the preceding claims, wherein the inorganic nanoparticles can be, inter alia, SiO2, metal oxides or inorganic salts, preferably SiO2.

14. A method for independently controlling the particle size and particle size dispersity of composite polymer particles, wherein the composite polymer particles comprise a polymer matrix and inorganic nanoparticles uniformly distributed within the polymer matrix, wherein the composite polymer particles are obtained by polymerization of a polymerizable carbon source in the presence of dispersed inorganic nanoparticles and an initiator.

15. The method of claim 14, wherein the inorganic nanoparticles are selected from the group consisting of metal oxides, metal nitrides, metal carbides, metal sulfides, metal selenides, metal tellurides, metal borides, metal phosphides, metal arsenides, metal antimonides, metal silicides, metal aluminides, metal gallides, metal germanides, metal stannides, metal leadides, metal bismuthides, metal phosphides, metal arsenides, metal antimonides, metal chalcogenides, metal pnictides, metal chalcogen pnictides, metal halides, metal alloys, metal intermetallics, metal silicides, metal aluminides, metal gallides characterized in that By adjusting the molar ratio of initiator to polymerizable carbon source during the polymerization, the particle size dispersity of the composite polymer particles and the particle size is controlled independently of the particle size of the inorganic nanoparticles.

15. Porous carbon particles obtained from the composite polymer particles according to any one of claims 1 to 14.

16. The porous carbon particles according to claim 15, wherein the composite polymer particles according to claims 1 to 13 have been treated in a continuous manner with the following steps: a. collecting, washing and drying the composite polymer particles according to any one of claims 1 to 13, b. calcining the composite nanoparticles under an inert or reactive atmosphere at below 1100 °C to obtain a carbonized reaction product, c. etching the carbonized reaction product to obtain an etched carbonized reaction product, d. isolating and washing the etched carbonized reaction product, e. drying the etched carbonized reaction product, and f. temperature annealing the etched carbonized reaction product under an inert or reactive atmosphere up to 3000 °C.

17. The porous carbon particles according to any one of claims 15 or 16, wherein the porous carbon particles comprise 25 μm as determined by the BET method of nitrogen physisorption analysis. 2 g -1 up to 2000m 2 g -1 Preferably 200m 2 g -1 up to 1500m 2 g -1 Specific surface area within the range.

18. The porous carbon particles according to any one of claims 15 to 17, comprising a pore volume in the range of 0.1 cm3g-1 to 5.0 cm3g-1, preferably 0.25 cm3g-1 to 3.0 cm3g-1, more preferably 0.5 cm3g-1 to 2.0 cm3g-1, as determined by N2physical adsorption at a relative pressure of P / P0= 0.

98. 3 g -1 3 g- 1 3 g -1 3 g -1 ​​​​ 19. A method for independently controlling the pore size and particle size of porous carbon particles, the method comprising the following steps: a. synthesis of composite polymer particles with a predefined particle size dispersion and a predefined particle size by polymerization of a polymerizable carbon source in the presence of dispersed inorganic nanoparticles and an initiator, wherein the particle size dispersion and the composite polymer particle size are controlled by the molar ratio of initiator to polymerizable carbon source during the polymerization reaction, b. collecting, washing and drying the composite polymer particles, c. calcining the composite polymer particles under inert or reactive atmosphere at below 1100 °C to obtain a carbonized reaction product, d. etching the carbonized reaction product to obtain an etched carbonized reaction product, e. isolating and washing the etched carbonized reaction product, f. drying the etched carbonized reaction product, g. temperature annealing the etched carbonized reaction product under inert or reactive atmosphere in a temperature range from 300 °C up to 3000 °C.

20. The method according to claim 19, wherein the steps are followed by functionalizing the annealed etched carbonized reaction product by a wet-chemical process at any temperature and / or under inert or reactive gas atmosphere at any temperature, preferably under heat treatment.

21. An article comprising the composite polymer particles according to any one of claims 1 to 13 or the composite polymer particles manufactured according to the method of claim 14 or the porous carbon particles according to any one of claims 15 to 18 or the porous carbon particles manufactured according to the method of claim 19.

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