Preceramic Resins and Porous Polymer-Derived Ceramics

Abstract

The present disclosure relates to organosilicon preceramic resin compositions for forming porous polymer-derived ceramic materials. The present disclosure also relates to porous organosilicon polymer-derived ceramic materials, methods of forming porous organosilicon polymer-derived ceramic materials.

Description

[Technical field]

[0001] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of Australian Provisional Patent Application No. 2022900557, filed March 8, 2022, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present invention relates to organosilicon preceramic resin compositions for forming porous polymer-derived ceramic materials. The present invention also relates to porous organosilicon polymer-derived ceramic materials and methods for forming porous organosilicon polymer-derived ceramic materials. [Background technology]

[0003] Ceramic material articles are widely used in various socio-economically important applications such as sustainable energy generation and storage, pharmaceutical development, environmental and health monitoring, and engineering fields. Specific applications include high speed impellers, heat shields, and wear resistant parts. These uses are due to the fact that ceramic materials are generally characterized by excellent thermal stability and mechanical strength. However, for this reason, ceramic materials are difficult to machine into the specific shapes required for these various applications.

[0004] This is aided by the development of polymer-derived ceramic (PDC) materials, which can be pre-shaped from softer, more malleable preceramic polymer precursors and then the shaped article converted to ceramic.

[0005] A typical process for making PDC materials involves subjecting a preceramic polymer article to pyrolysis conditions at temperatures in excess of 1000° C. This causes a thermally induced conversion of organic materials to inorganic materials (i.e., ceramic) and thermal decomposition of certain components of the preceramic polymer. The decomposition tends to release gases that may include carbon dioxide, carbon monoxide, methane, water, etc. This tends to produce a solid, non-porous PDC material.

[0006] Some porous ceramic articles have been produced on a small scale. These ceramic materials are mostly made using soft or hard templates (including biotemplates), sol-gel processes, phase separation, or chemical etching, all of which are difficult to implement. They are also limited to forming relatively simple articles, resulting in limited control of porosity and the degree of porosity.

[0007] The production of ceramics has been aided by the recent advent of 3D printing, which involves printing and shaping preceramic polymers, silanes, or composites of ceramics and organic binders followed by pyrolysis or sol-gel processing. However, 3D printing of ceramics is still in its infancy. Most ceramic 3D printing methods are limited to the use of direct ink-writing techniques, which limits their use to the creation of articles of relatively simple, non-porous materials. More recently, photopolymerization-based 3D printing techniques such as stereolithography, which circumvent the limitations of direct ink-writing, have been investigated for the production of ceramic articles. However, these methods use resins that phase separate, resulting in high linear shrinkage and lack of porosity.

[0008] Although ceramic materials have excellent properties that are desirable to implement in many other fields of endeavor, limitations in their physical structure, including lack of porosity, and difficult manufacturing methods have prevented their adoption in a wider range of applications. It would be beneficial to provide preceramic resins for the production of alternative PDC materials that can be utilized in new and existing applications. It would also be beneficial to provide an effective method for their manufacture. Summary of the Invention

[0009] The present invention is based on the learned knowledge that certain components used in preceramic resins result in porous PDC materials being formed from the resin through a process that includes polymerization and pyrolysis.

[0010] In one aspect, the present invention provides a preceramic resin for forming a porous polymer-derived ceramic material, comprising: a) a first functionalized organosilicon monomer having a first ceramic yield; b) Below: i. a second functionalized organosilicon monomer having a second ceramic yield; ii. functionalized organic monomers; iii. porous ceramic particles, and iv. porogens, One or more of the following: The present invention provides a preceramic resin comprising:

[0011] In certain embodiments, the preceramic resin comprises a combination selected from the following: (a) through (g): a) a combination of a first functionalized organosilicon monomer having a first ceramic yield with one or both of a second functionalized organosilicon monomer and a functionalized organic monomer having a second ceramic yield; b) combining a first functionalized organosilicon monomer having a first ceramic yield with porous ceramic particles; c) combining a first functionalized organosilicon monomer having a first ceramic yield with a porogen; d) combining a first functionalized organosilicon monomer having a first ceramic yield, porous ceramic particles, and a porogen; e) combining a first functionalized organosilicon monomer having a first ceramic yield, and one or both of a second functionalized organosilicon monomer and a functionalized organic monomer having a second ceramic yield, with porous ceramic particles; f) combining a first functionalized organosilicon monomer having a first ceramic yield, one or both of a second functionalized organosilicon monomer and a functionalized organic monomer having a second ceramic yield, and a porogen; and g) combining a first functionalized organosilicon monomer having a first ceramic yield, one or both of a second functionalized organosilicon monomer and a functionalized organic monomer having a second ceramic yield, porous ceramic particles, and a porogen; Contains one of the following:

[0012] In another aspect, the present invention provides porous polymer-derived ceramic materials formed from the preceramic resins described herein.

[0013] In another aspect, the present invention provides a 70m 2 The present invention provides a porous polymer-derived ceramic material characterized by a specific surface area of ​​0.1 μm / g or more.

[0014] In another aspect, the present invention provides a microporous polymer-derived ceramic material.

[0015] In another aspect, the present invention provides porous polymer-derived ceramic materials as described herein formed from the preceramic resins as described herein.

[0016] In another aspect, the present invention provides a method of forming a porous polymer-derived ceramic material, comprising the steps of: a) subjecting a preceramic resin forming a porous polymer-derived ceramic material to polymerization conditions to form a preceramic polymer; b) subjecting the preceramic polymer to pyrolysis conditions; Including, Here, a method is provided in which the formation of a polymer-derived ceramic material from a preceramic polymer proceeds through a porous stage and the pyrolysis conditions are characterized by a maximum temperature within the porous stage.

[0017] In another aspect, the present invention provides a method of forming a porous polymer-derived ceramic material, comprising the steps of: a) subjecting a preceramic resin forming a porous polymer-derived ceramic material to polymerization conditions to form a preceramic polymer; b) subjecting the preceramic polymer to pyrolysis conditions to form a porous polymer-derived ceramic material; Including, A method is provided herein, wherein the pyrolysis conditions are characterized by a maximum temperature of less than or equal to about 1000°C.

[0018] In another aspect, the present invention provides a method of forming a porous polymer-derived silica ceramic material, comprising the steps of: a) subjecting a preceramic resin forming a porous polymer-derived silica ceramic material to polymerization conditions to form a preceramic polymer; b) subjecting the preceramic polymer to pyrolysis conditions; Including, wherein the formation of a polymer-derived silica ceramic material from a preceramic polymer proceeds through a porous stage, the pyrolysis conditions being characterized by the presence of oxygen and a maximum temperature within the porous stage, and Preceramic resins are a) a first functionalized polycarbosiloxane or polycarbosilane monomer having a first ceramic yield; b) Below: i. a second functionalized organosilicon monomer having a second ceramic yield; ii. porous ceramic particles, and iii. porogens; One or more of the following: The present invention provides a method comprising:

[0019] In another aspect, the present invention provides a polymer-derived ceramic material formed from the method described herein. [Brief description of the drawings]

[0020] [Figure 1]FIG. 3 shows the 3D printed and injection molded porous silicon oxycarbide PDC articles of Example 1: (a) 3D printed green body, (b) pyrolyzed 3D printed body, (c) injection molded green body, and (d) pyrolyzed injection molded body. [Diagram 2] FIG. 3D printed and injection molded porous silicon oxycarbide PDC articles of Example 2: (a) 3D printed green body, (b) pyrolyzed 3D printed body, (c) injection molded green body, and (d) pyrolyzed injection molded body. [Diagram 3] FIG. 1 shows a pore size distribution plot of the 3D printed silicon oxycarbide PDC article of Example 2, as determined using a BET surface analyzer. [Figure 4] 3D printed porous silicon oxycarbide PDC articles of Example 3: (a) 3D printed green body, and (b) pyrolyzed 3D printed body. [Diagram 5] 3D printed and injection molded porous silicon dioxide PDC articles of Example 4: (a) 3D printed green body, (b) pyrolyzed 3D printed body, (c) molded green body, and (d) pyrolyzed injection molded body. [Figure 6] 3D printed and injection molded porous silicon dioxide PDC articles of Example 5: (a) 3D printed green body, (b) pyrolyzed 3D printed body, (c) injection molded green body, (d) pyrolyzed injection molded body. [Figure 7] FIG. 1 shows the pore size distribution plot of the 3D printed silicon dioxide PDC article of Example 5, as determined using a BET surface analyzer. [Figure 8] FIG. 1 shows the pore size distribution plot of the 3D printed silicon dioxide PDC article of Example 5, as determined using mercury porosimetry. [Figure 9] 3D printed and injection molded porous silicon dioxide PDC articles of Example 6: (a) 3D printed green body, (b) pyrolyzed 3D printed body, (c) molded green body, and (d) pyrolyzed molded body. [Figure 10] 1 shows injection molded silicon oxycarbide PDC articles of Example 7: (a) green body, and (b) pyrolyzed body. [Figure 11] 1 shows injection molded porous silica PDC articles of Example 8: (a) green body, and (b) pyrolyzed body. [Figure 12] 1 shows injection molded porous silicon dioxide PDC articles of Example 9: (a) molded green body, and (b) pyrolyzed body. [Figure 13] 1 shows injection molded porous silicon dioxide PDC articles of Example 10: (a) molded green body, and (b) pyrolyzed body. [Figure 14] 1 shows injection molded porous silica PDC articles of Example 11: (a) green body, and (b) pyrolyzed body. [Figure 15] FIG. 14 shows a scanning electron microscope (SEM) image of pyrolyzed 3D printed microneedles showing micropores. [Figure 16] FIG. 16. Characterization of the preceramic resin used to form the pyrolyzed 3D printed microneedles of FIG. 15 and the resulting silicon oxycarbide PDC material: (a) TGA of the resin, (b) EDEX (elemental analysis) of the pyrolyzate, and (c) X-ray powder diffraction (XRD) of the pyrolyzate. [Figure 17] FIG. 14 shows SEM images of pyrolyzed 3D printed microneedles exhibiting micro- and mesopores. [Figure 18]FIG. 18 shows characterization of the preceramic resin used to form the pyrolyzed 3D printed microneedles of FIG. 17 and the resulting silicon oxycarbide PDC material: (a) TGA of the resin, (b) EDEX (elemental analysis) of the pyrolyzate, and (c) X-ray powder diffraction (XRD) of the pyrolyzate. [Figure 19] FIG. 14 shows SEM images of pyrolyzed 3D printed microneedles exhibiting micro-, meso-, and macro-pores. [Figure 20] FIG. 19 shows characterization of the preceramic resin used to form the pyrolyzed 3D printed microneedles and the resulting silicon oxycarbide PDC material: (a) TGA of the resin, (b) EDEX (elemental analysis) of the pyrolyzate, and (c) X-ray powder diffraction (XRD) of the pyrolyzate. [Figure 21] Figure 1 shows images of pyrolyzed 3D printed leaf articles (top) and insect wing articles (bottom) replicating naturally occurring porous structures, along with two magnified SEM images of portions of the articles. [Figure 22] FIG. 13 shows three progressively more magnified SEM images of pyrolyzed 3D printed diatom articles replicating the naturally occurring porous structure. [Diagram 23] The right side shows the 3D printed and shrink-fabricated porous ceramic microfluidic chip, and the left side shows the corresponding green body from which the chip was generated after pyrolysis. [Figure 24] FIG. 14 shows the pore size distribution plot of the 3D printed silicon oxycarbide PDC article of Example 12, as determined using a BET surface analyzer. [Diagram 25] FIG. 14 shows the pore size distribution plot of the 3D printed silicon oxycarbide PDC article of Example 13, as determined using a BET surface analyzer. [Figure 26]FIG. 14 shows the pore size distribution plot of the 3D printed silicon oxycarbide PDC article of Example 14, as determined using a BET surface analyzer. [Figure 27] FIG. 14 shows the pore size distribution plot of the 3D printed silicon oxycarbide PDC article of Example 14, as determined using a mercury porosimeter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art of the present invention. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, preferred methods and materials are described. For purposes of the present invention, a number of terms are defined throughout.

[0022] The produced ceramic materials are generally formed by a process that includes polymerizing a suitable monomeric material (which may constitute or form part of a preceramic resin) to form a suitable polymeric material, and pyrolyzing the polymeric material. Generally speaking, during pyrolysis, the preceramic resin is converted from an organic material to an inorganic material. The inorganic material may exist in one or more material phases, depending on the temperature to which the material is exposed. For example, during the increase in pyrolysis temperature, the inorganic material will generally initially exist in an amorphous phase and then transition to a crystalline phase as the temperature is increased. The present invention relates to resins that include monomeric materials suitable for being formed into a polymeric material and then formed into the produced porous PDC material. The pyrolysis conditions used to form the porous materials described herein tend to result in amorphous polymer-derived ceramic materials.

[0023] "Polymer-derived ceramic" (PDC) materials are manufactured ceramic materials formed by the pyrolysis of preceramic polymers and are distinct from naturally occurring ceramic materials.

[0024] The term "preceramic" gives the potential for being formed into a ceramic material using the step of pyrolysis alone or in combination with other process steps. Thus, a "preceramic polymer" is a polymeric material that can be formed by subjecting a monomer to polymerization conditions and pyrolyzed into a ceramic material. Furthermore, a "preceramic resin" is a material or composition that includes at least one monomer that can be polymerized to form a preceramic polymer. Such monomers are sometimes referred to as "preceramic monomers."

[0025] A porous PDC material is a material that contains pores. A "pore" is a space that is free of solid matter that constitutes a substance. In the PDC material of the present invention, the pores can be considered hierarchically in terms of pore size, such as micropores, mesopores, and macropores. "Micropore" refers to a pore having a diameter of less than 2 nm. "Mesopore" refers to a pore having a diameter of 2 nm to 50 nm. "Macropore" refers to a pore having a diameter of 50 nm to 100 micrometers. Macropores can be further considered as sub-macropores, inter-macropores, and super-macropores, which refer to macropores having diameters of 50 nm to 1 micrometer, 1 micrometer to 10 micrometers, and 10 micrometers to 100 micrometers, respectively. "Diameter" does not limit the shape of the pore, but refers to the maximum axial dimension. Similarly, "microporous" refers to the inclusion of micropores, while "mesoporous" refers to the inclusion of mesopores and "macroporous" refers to the inclusion of macropores. Pore ​​size can be determined experimentally using methods known in the art, including gas adsorption (including the use of a BET surface analyzer), scanning electron microscopy, and liquid immersion (including mercury porosimetry). Preferably, BET surface analysis and / or mercury porosimetry are used to compare pore sizes of different materials.

[0026] Depending on the composition of the preceramic resin, the porous PDC material may be formed to contain micropores, mesopores, and / or macropores (i.e., it may be microporous, mesoporous, and / or macroporous). Pores of various sizes may also be formed in various amounts. Taken together, this results in the formation of PDC materials with various porosities. That is, by varying the relative amounts and / or components in the preceramic resin composition, PDC materials with micropores, mesopores, and / or macropores can be designed to achieve a target porosity as desired, i.e., they are "tunable." This is explained in more detail below. In certain preferred embodiments, the formed porous PDC material contains mesopores and one or both of micropores and macropores, i.e., it is mesoporous and one or both of microporous and macroporous.

[0027] Porosity is directly related to the specific surface area; the more porous the PDC material, the higher the specific surface area. Thus, the term "porosity" refers to the specific surface area of ​​the PDC material. Specific surface area can be determined experimentally using methods known in the art, including gas adsorption methods (including the use of a BET surface analyzer) and liquid immersion methods (including mercury porosimetry). Preferably, BET surface analysis and / or mercury porosimetry should be used to compare the porosity of different materials.

[0028] BET surface analyzers are generally considered to be able to reliably analyze micropores and mesopores. Mercury porosimetry is generally considered to be able to reliably analyze macropores. BET surface analysis is generally performed using a gas (often N 2porosimetry relies on pressure measurements to represent the adsorption and desorption of PDC molecules, whereas mercury porosimetry generally relies on volume measurements to represent the intrusion of liquids. Both test samples of PDC materials, usually less than 100 mg. From both, the pore size and specific surface area can be calculated and represented in a plot of specific surface area versus pore size, sometimes called a "pore size distribution plot." BET surface analysis of microporous and / or mesoporous PDC materials will yield a pore size distribution plot showing the contribution of micropores and / or mesopores to the specific surface area of ​​the material. Similarly, mercury porosimetry analysis of macroporous PDC materials will yield a pore size distribution plot showing the contribution of macropores to the specific surface area of ​​the material. The area under the curve represents the total specific surface area of ​​the material contributed by those pore sizes. Taken together, BET surface analysis and mercury porosimetry allow the total specific surface area to be obtained. The micropores may account for at least about 5%, 10%, 20%, 30%, 40%, 50%, 60%, or even 70% of the specific surface area of ​​the PDC materials of the invention, relative to either or both of the BET specific surface area and the total specific surface area. For example, the pore size distribution plot in Figure 3 shows that the micropores account for at least about 20% of the specific surface area of ​​the BET specific surface area of ​​the PDC material of Example 1. As generally used herein, and unless the context indicates otherwise, specific surface area refers to the total specific surface area of ​​the porous PDC materials having micropores, mesopores, and / or macropores described herein.

[0029] Porosity can be classified as high, medium, and low. "High porosity" means a porosity greater than 70 m 2 / g or more. "Medium porosity" refers to a specific surface area of ​​40m 2 / g to 70m 2 / g. "Low porosity" refers to a specific surface area between 40m 2 / g. Generally, PDC materials that contain only macropores have a specific surface area of ​​50 m 2The specific surface area of ​​the PDC produced using a phase-separated resin is expected to be about 50 m 2 It is anticipated that the resulting PDC materials will have specific surface areas not exceeding 100 m / g. In some embodiments, the present invention will provide PDC materials with specific surface areas not exceeding 100 m / g, which may be described as "very porous." 2 The present invention also provides highly porous PDC materials with specific surface areas of over 130 m 2 / g, 150m 2 / g over 200m 2 / g, 300m 2 / g over 400m 2 / g or even 500m 2 The PDC material has a specific surface area of ​​70 m / g or more. Thus, in certain preferred embodiments, the porous PDC material has a specific surface area of ​​70 m 2 / g or more, 80m 2 / g or more, 90m 2 / g or even 100m 2 / g or more, or in some embodiments, 130m 2 / g, 150m 2 / g over 200m 2 / g, 300m 2 / g over 400m 2 / g and even 500m 2 The PDC materials are characterized by high or very high porosity, with specific surface areas of greater than 100 nm / g. Furthermore, in certain embodiments, the porous PDC materials are characterized by high or very high porosity when analyzed by BET surface analysis alone. That is, in certain embodiments, the porous PDC materials are characterized by high or very high BET specific surface areas, in other words, a combination of high or very high microporosity and mesoporosity.

[0030] The resins of the present invention are particularly useful in forming PDC material articles made from shaped preceramic polymer articles (also known as "green bodies"). Green bodies can be formed by shaping processes known in the art. Particularly applicable to the present invention are injection molding methods such as liquid silicone rubber injection molding, and 3D printing methods such as stereolithography, digital light projection, two-photon lithography, and continuous liquid interface methods, and direct ink writing. The resulting articles can be used in many engineering and scientific fields where ceramic materials are used, and because the PDC materials are porous, this opens up the utility of the PDC materials in new applications such as those using membranes and chromatography.

[0031] Porous Ceramic Particles By including porous ceramic particles in the preceramic resin, pores can be formed in the PDC material. This provides an advantage of the present invention since it allows the introduction of pores of sizes that may not otherwise exist or be formed in the PDC material. It also allows for enhanced control or "tuning" of the porosity of the PDC ceramic material based on the selection of particles with specific pore sizes. For example, micropores can be introduced into the PDC material by using microporous ceramic particles. Similarly, micropores and / or mesopores can be introduced into the PDC material by using mesoporous ceramic particles (micropores may be formed from mesoporous ceramic particles by pore shrinkage during pyrolysis. For example, mesopores with a diameter of 2 nm to 3 nm may become micropores with a diameter of 1 nm to 2 nm during pyrolysis). This opens up the utility of the PDC material in new applications that require specific pore sizes or porosity. The use of these particles can also impart strength to the PDC material.

[0032] Thus, in certain preferred embodiments, the preceramic resin comprises a first functionalized organosilicon monomer having a first ceramic yield and porous ceramic particles, optionally together with one or all of a second functionalized organosilicon monomer having a second ceramic yield, a functionalized organic monomer, and a porogen.

[0033] Since the PDC materials are based on organosilicon monomers that form silicon-based ceramic materials after pyrolysis (as described further below), the porous ceramic particles are preferably also formed from a silicon ceramic material. Examples of silicon ceramic materials from which the porous ceramic particles can be made include SiO 2 , Si 3 N 4 , SiC, SiCN, SiCO, SiCNO, SiBCN, SiBCO, SiAlCN, and SiAlCO. These forms of porous ceramic particles can be described as silicon ceramic particles. In a preferred embodiment, the porous ceramic particles are silica (SiO 2 ) particles.

[0034] Porous ceramic particles can be tailored to any size depending on the purpose: for example, particle sizes up to 1 mm are acceptable for many 3D printing methods, while particle sizes up to a few millimeters are acceptable for many injection molding methods.

[0035] In some embodiments, the ceramic particles are microparticles. By "microparticles" is meant a plurality of particles having a particle size comprised between 1 μm and 1 mm. Preferably, the microparticles have a size comprised between 1 μm and 500 μm, between 1 μm and 200 μm, between 1 μm and 100 μm, and between 1 μm and 50 μm. Particulate materials are typically provided in a specified particle size range, which usually means that at least a majority of the particles have a size within that range. This can be described as a particle size distribution. The particles may be predominantly (e.g., greater than 95%, greater than 99%) or entirely within the particle size range. In some embodiments, at least 90%, 95%, 98%, 99%, 99.5%, or even 99.9% of the ceramic microparticles in the resin have a size comprised between about 1 μm and 200 μm, between about 1 μm and 100 μm, or between about 1 μm and 50 μm. In other embodiments, the porous ceramic particles are nanoparticles. By "nanoparticles" is meant a plurality of particles having a particle size comprised below 1 μm. Preferably, the nanoparticles have a size comprised below 500 nm, below 200 nm, preferably below 100 nm, or even below 50 nm. In preferred embodiments, at least 90%, 95%, 98%, 99%, 99.5%, or even 99.9% of the porous ceramic nanoparticles contained in the resin have a size comprised between about 1 nm and about 100 nm, preferably between about 1 nm and 50 nm, and more preferably between about 5 nm and 20 nm. In some embodiments, the ceramic particles include both microparticles and nanoparticles, in which case the preceramic resin can be considered to include ceramic particles having a particle size comprised below 1 mm for a plurality of particles. Preferably, the ceramic particles have a size comprised below 500 μm, below 200 μm, below 100 μm, or below 50 μm.In a preferred embodiment, at least 90%, 95%, 98%, 99%, 99.5%, or even 99.9% of the ceramic particles contained in the resin have a size between about 1 nm and 1 mm, between about 1 nm and 500 μm, between about 1 nm and 200 μm, between about 1 nm and 100 μm, or between about 1 nm and 50 μm. Methods for determining particle size and particle size distribution are known in the art and include small angle X-ray scattering, dynamic light scattering, and transmission electron microscopy. Preferably, the particle size distribution is determined using transmission electron microscopy (TEM).

[0036] The porous ceramic particles may contain pores of various sizes, but in preferred embodiments, the porous ceramic particles are microporous and / or mesoporous. This is at least in part because there are other methods of introducing mesopores and macropores into PDC materials, as outlined below. The use of microporous (and in some cases mesoporous) ceramic particles allows for the introduction of micropores that may not otherwise be possible to form, which in turn allows for the production of microporous PDC materials, and even hierarchically porous PDC materials, i.e., PDC materials that contain micropores, mesopores, and macropores.

[0037] When present, the porous ceramic particles may be present in the preceramic resin in an amount of at least about 0.5%, 1%, 2%, 5%, 8%, 10%, or at least about 15% based on the weight of the preceramic resin. When present, the amount of the porous ceramic particles is preferably about 95% or less, 90%, 70%, 50%, 30%, or about 25% or less based on the weight of the preceramic resin. The amount of the porous ceramic particles based on the weight of the preceramic resin may be affected by the size and density of the particles, and therefore may be included in the preceramic resin by volume, in which case the porous ceramic particles may be present in the preceramic resin in an amount of at least about 0.1%, 0.5%, 1%, 2%, 5%, 8%, or at least about 10% based on the volume of the preceramic resin. The amount of the porous ceramic particles may be about 98% or less, 95%, 90%, 80%, or about 70% or less based on the volume of the preceramic resin. Any minimum and maximum values ​​may be combined without limitation. For example, the amount may be between 0.5% and 95% by weight of the preceramic resin, between 0.5% and 25% by weight of the preceramic resin, between about 0.1% and 98% by volume of the preceramic resin, or between 0.1% and 70% by volume of the preceramic resin, etc. For example, for microporous and mesoporous nanoparticles, it has been found that an amount of between about 1% and about 30% by weight of the preceramic resin, preferably between about 2% and about 25% by weight, and more preferably between about 2% and about 20% by weight, provides a PDC material with micropores that contribute to the porosity useful for the above applications. The porous ceramic particles can be determined as microporous, mesoporous, and / or macroporous using the same BET surface analysis and / or mercury porosimetry analysis described above.

[0038] monomer As described herein, the preceramic resin may include, in addition to a first functionalized organosilicon monomer, one or both of (i) a second functionalized organosilicon monomer and (ii) a functionalized organic monomer. Monomer (i) and / or monomer (ii) may be collectively referred to as the "second functionalized monomer(s)." Thus, the preceramic resin may include, along with the first functionalized organosilicon monomer, a second functionalized monomer that is one or both of a second functionalized organosilicon monomer and a functionalized organic monomer having a second ceramic yield.

[0039] In certain preferred embodiments, the preceramic resin comprises one of the following combinations: a) combining a first functionalized organosilicon monomer having a first ceramic yield and a second functionalized organosilicon monomer having a second ceramic yield; b) combining a first functionalized organosilicon monomer having a first ceramic yield with a functionalized organic monomer; c) combining a first functionalized organosilicon monomer having a first ceramic yield, a second functionalized organosilicon monomer having a second ceramic yield, and porous ceramic particles; and d) combining a first functionalized organosilicon monomer having a first ceramic yield, a functionalized organic monomer, and porous ceramic particles.

[0040] In certain preferred embodiments, the preceramic resin comprises a first functionalized organosilicon monomer having a first ceramic yield and a second functionalized organosilicon monomer having a second ceramic yield, optionally together with one or both of porous ceramic particles and a porogen.

[0041] A first functionalized organosilicon monomer having a "first ceramic yield" and a second functionalized organosilicon monomer having a "second ceramic yield" are meant to be different from one another, i.e., the first functionalized organosilicon monomer having a first ceramic yield is a monomer having a ceramic yield that is different from the ceramic yield of the second functionalized organosilicon monomer having the second ceramic yield.

[0042] The advantages of the present invention are provided by the presence of a first organosilicon monomer having a first ceramic yield and a second organosilicon monomer having a second ceramic yield. It has been found that this allows for the formation of mesopores and macropores. It also allows for the formation of micropores in the PDC material, but to a lesser extent. Without wishing to be limited by theory, it is believed that organosilicon monomers with different ceramic yields undergo different degrees of linear contraction under pyrolysis conditions, which results in the formation of these pores in the structure of the resulting PDC material. This allows for the "tuning" of the porosity of the PDC material by using first and second organosilicon monomers (optionally in combination with porous ceramic particles) with slightly to significantly different ceramic yields. For example, the use of a preceramic resin comprising a first organosilicon monomer and a second organosilicon monomer with ceramic yields differing by about 30% or more tends to result in a PDC material with higher porosity compared to a preceramic resin comprising a first organosilicon monomer and a second organosilicon monomer with ceramic yields differing by less than 30%, particularly by about 5% or less. It is therefore possible to obtain a PDC material with tailored porosity. Of course, this is compounded when used in combination with porous ceramic particles and the advantages thereof described above. The same advantage is provided by using a first organosilicon monomer with a first ceramic yield and a second functionalized monomer that is a functionalized organic monomer. It has also been found that this allows the formation of mesopores and macropores and (to a lesser extent) micropores in the PDC material, even if it results in less overall porosity compared to the use of the second organosilicon monomer. Without wishing to be limited by theory, it is believed that the functionalized organic monomers are able to crosslink with the organosilicon monomers in a random molecular pattern such that different molecules and / or molecular regions of the organosilicon monomer undergo different degrees of linear shrinkage under pyrolysis conditions, resulting in the formation of pores in the structure of the resulting PDC material.This allows the porosity of the PDC material to be "tuned" by using different amounts of different functionalized organic monomers that form different crosslinking structures. It is therefore possible to obtain PDC materials with tailored porosity. Of course, this is compounded when used in combination with porous ceramic particles and their advantages described below.

[0043] The monomers, including the first functionalized organosilicon monomer, as well as one or both of the second functionalized organosilicon monomer and the functionalized organic monomer, may be present in a combined amount of at least about 30%, 40%, 50%, 60%, or at least about 70% by weight of the preceramic resin, and up to about 98%, 95%, 90%, or about 80% by weight of the preceramic resin. The monomers may also be present in the preceramic resin in an amount of at least about 10%, 15%, 20%, 25%, or at least about 30% by volume of the preceramic resin. The amount of monomer may be about 95% or less, 90%, 80%, 75%, or about 70% or less by volume of the preceramic resin. All minimum and maximum values ​​may be combined without limitation. For example, the amount may be between 30% and 98% by weight of the preceramic resin, between 30% and 80% by weight of the composition, etc. In a preferred embodiment, the monomers may be present in an amount, combined, of at least about 60% to about 90% by weight of the preceramic resin, preferably between about 65% and about 85% by weight, and more preferably between about 70% and about 80% by weight.

[0044] Organosilicon Monomers Organosilicon preceramic monomers can be characterized by their ceramic yield. "Ceramic yield" refers to the mass of PDC material obtainable by pyrolysis expressed as a percentage of the mass of the preceramic monomer (i.e., the mass of converted PDC material expressed as a percentage of the preceramic material). For example, if 10 g of PDC material is formed by pyrolysis of 11 g of preceramic monomer, then the organosilicon preceramic monomer has a ceramic yield of (10 / 11) x 100 = 91%.

[0045] The ceramic yield of an organosilicon preceramic monomer is a chemical property that is generally influenced by the chemical structure of the monomer. Methods for determining the ceramic yield of an organosilicon preceramic monomer are known in the art and generally involve subjecting the monomer to pyrolysis conditions in a thermogravimetric analyzer (TGA). Generally, in the TGA, the weight of the monomer is measured as it undergoes conversion to a PDC material during pyrolysis. The maximum pyrolysis temperature is usually at least about 600°C, and often about 850°C to ensure complete conversion to a PDC material. Complete conversion is generally indicated by an experimentally determined weight change between time points to be zero. The TGA can determine the starting weight and the final weight after pyrolysis, from which the ceramic yield can be calculated. A detailed methodology is provided in the Examples. In a preferred embodiment, the ceramic yield is determined using this method, which is referred to herein as "TGA. 850 Ceramic Yield" or "TGA 850 This is sometimes referred to as the "850" method, where "850" represents the maximum temperature reached during the analysis.

[0046] An "organosilicon" is a chemical compound having a chemical structure that includes a silicon atom covalently bonded to a carbon atom. Preceramic organosilicon monomers are generally based on a long chain backbone structure of repeating motifs that include silicon atoms, and in that sense, they are generally polymeric materials themselves. Examples applicable to the present invention include polysiloxanes, polycarbosiloxanes, polysilsesquioxanes, polycarbosilanes, polysilylcarbodiimides, polysilsesquicarbodiimides, polysilazanes, polysilsesquiazanes, polyborosilanes, polyborosiloxanes, and polyborosilazanes. Since silicon and carbon atoms are generally tetravalent, organosilicon containing backbone structures of polymeric monomers are generally substituted with carbon-containing organic chemical groups. "Substituted" with respect to organosilicon means that any one or more hydrogen atoms bonded to the atom under consideration may be replaced, as long as the valence of the atom is not exceeded and a stable compound is obtained. Non-limiting examples of suitable substituents include the R group substituents defined below.

[0047] Since the organosilicon preceramic monomers used in the preceramic resins are polymerizable, they can be considered to be "functionalized", meaning that they contain a polymerizable functional group. The polymerizable functional group can be substituted at one or more points on the organosilicon, including substitution at any point(s) along the backbone structure in the case of polymeric organosilicon monomers. Alternatively or additionally, particularly in the case of polymeric organosilicon monomers, the polymerizable functional group can be substituted at a terminal, i.e., at one or more end groups of the backbone structure. "Substituted" in the context of functionalized organosilicon means that any one or more non-polymerizable chemical groups attached to the atom under consideration are replaced by a polymerizable functional group, so long as the valence of the atom is not exceeded and a stable compound is obtained. Non-limiting examples of suitable substitutes include the substitutes of the polymerizable functional group defined below.

[0048] Considering first the identity of the organosilicon monomer before it is functionalized, in a preferred embodiment, the first organosilicon monomer is selected from one or more of polysiloxane, polycarbosiloxane, polycarbosilane, polysilylcarbodiimide, and polysilazane, which have the chemical structures of the following formulas 1, 2, 3, 4, and 5, respectively: [ka] (In the formula, n represents a main chain structure of a repeating motif containing a silicon atom, and is independently an integer of 2 to 15; R 1 , R 2 , R 3 , and R 4 H, C, independently for each integer n 1 ~C 18 substituted or unsubstituted alkyl, C 1 ~C 18 independently selected from the group consisting of substituted or unsubstituted alkyl ethers, phenyl, and halides, with the proviso that R 1 and R 2 Pair with and R 3 and R 4 and (wherein both are not H, alkyl ether, or halide for all integers n). 1 and R 2 Pair with and R 3 and R 4 and R are not both H, alkyl ether, or halide for any integer n. 1 and R 2 Pair with and R 3 and R 4 Each of the pairs with is identical for all integers n.

[0049] In formula 2, formula 3, and formula 5, CH 2 The hydrogen atoms of the groups and NH groups are R 1As discussed above, organosilicon is a chemical compound having a chemical structure that includes a silicon atom covalently bonded to a carbon atom, which includes organosilicon monomers of formulas 1-5, where n is an integer equal to 1. That is, in formulas 1-5, n can independently be an integer equal to 1 or greater, or an integer between 1 and 15.

[0050] The first organosilicon monomer may be a polyoctahedral silsesquioxane. The first organosilicon monomer may be R 1 The silsesquioxanes may be selected from one or more of polysilsesquioxanes, polysilsesquicarbodiimides, and polysilsesquiazanes substituted with one or more groups defined for

[0051] In an alternative embodiment, the first organosilicon monomer is selected from one or more of polyborosilanes, polyborosiloxanes, and polyborosilazanes, which have the chemical structures of Formula 6, Formula 7, and Formula 8: [ka] (In the formula, n represents a main chain structure of a repeating motif containing a silicon atom, and is independently an integer of 2 to 15; R 1 , R 2 , R 3 , and R 4 is as defined above, and R 5 and R 6 is independently H, OH, C for each integer n. 1 ~C 18 substituted or unsubstituted alkyl, C 1 ~C 18 substituted or unsubstituted alkyl ethers of R 1 , R 2 , R 3 , and R 4 Like, R 5 and R 6 is the same for all integers of n.

[0052] In a more preferred embodiment, the first organosilicon monomer is selected from one or more of polysiloxanes, polycarbosiloxanes, and polycarbosilanes, where n is independently an integer from 3 to 5, and R 1 , R 2 , R 3 , and R 4 are the same for all n integers and are independently selected from the group consisting of H, methyl, and isobutyl, with the proviso that R 1 and R 2 Pair with and R 3 and R 4 The pair with and cannot both be H and R 1 embedded image is a polysilsesquioxane substituted with the group defined for embedded image

[0053] As discussed above, organosilicon is a chemical compound having a chemical structure that includes a silicon atom covalently bonded to a carbon atom, including organosilicon monomers of Formulae 6-8, where n is an integer equal to 1. That is, in Formulae 6-8, n can independently be an integer of 1 or greater, or an integer from 1 to 15.

[0054] Next, looking at the characteristics of the functionalized organosilicon monomer, the first functionalized organosilicon monomer is R 1 , R 2 , R 3 , and R 4 or the end group(s) of the monomer with one or more of one or more types of polymerizable functional groups. Different "types" of polymerizable groups are groups with different chemical structures. The type of functional group(s) used is not particularly important as long as it results in the polymerization of the monomer(s).

[0055] In resins that contain a first functionalized organosilicon monomer but not a second functionalized organosilicon monomer, one type of polymerizable functional group selected to react with itself may be used, or alternatively, two or more types selected to react with each other (i.e., be complementary) may be used. In either case, the preceramic resin may optionally further contain a crosslinker to crosslink the monomers of the resin via the crosslinker groups.

[0056] In a preferred embodiment, the polymerizable functional group is compatible and therefore thermally or photopolymerizable, since the resin of the present invention is particularly useful in forming shaped preceramic polymer articles by 3D printing and injection molding, which often rely on thermal polymerization and / or photopolymerization.In this case, the polymerizable functional group(s) is preferably selected from a group or group containing a motif selected from one or more of ester, amine, hydroxyl, epoxide, vinyl, allyl, ethynyl, thiol, glycidyl, isocyanurate, alkacrylate, cyano, cyanate, and thiocyanate.In a preferred embodiment, the first functionalized organosilicon monomer contains one type of polymerizable functional group, preferably allyl, vinyl, thiol, or acrylate.

[0057] In a preferred embodiment, the first functionalized organosilicon monomer is a polysiloxane, polysilsesquioxane, polycarbosilane, or polycarbosilazane selected from methacryloxypropyl terminated polydimethylsiloxane, vinylmethoxysiloxane homopolymer, methacryloxypropyl substituted poly(isobutyl-t8-silsesquioxane), allylhydridopolycarbosilane, and methylvinylhydrogenpolycarbosilazane.

[0058] The first functionalized organosilicon monomer may be present in an amount of at least about 15%, 20%, 25%, 30%, or at least about 35% by weight of the preceramic resin, and up to about 98%, 95%, 90%, or about 80% by weight of the preceramic resin. The first functionalized organosilicon monomer may also be present in the preceramic resin in an amount of at least about 10%, 15%, 20%, 25%, or at least about 30% by volume of the preceramic resin. The amount of the first functionalized organosilicon monomer may be up to about 95%, 90%, 80%, 75%, or up to about 70% by volume of the preceramic resin. Any minimum and maximum values ​​may be combined without limitation. For example, the amount may be between 15% and 98% by weight of the preceramic resin, between 15% and 80% by weight of the composition, etc. In embodiments that include a first functionalized organosilicon monomer but no second functionalized organosilicon monomer, it is preferred that the first functionalized organosilicon monomer may be present in an amount of at least about 60% to about 90% by weight, preferably between about 65% to about 85% by weight, and more preferably between about 70% to about 80% by weight.

[0059] The second functionalized organosilicon monomer is selected from the functionalized organosilicon monomer class described above for the first functionalized organosilicon monomer, but will have different ceramic yields.Nevertheless, the broad class and functional group that the second functionalized organosilicon monomer is selected from are as described above for the first functionalized organosilicon monomer, including polymerizable functional groups.This includes those related to preferred features.In general, to ensure different ceramic yields, the second functionalized organosilicon monomer will have a different chemical structure from the chemical structure of the first functionalized organosilicon monomer, whether through the main chain or through the polymerizable functional group.

[0060] In a preferred embodiment, the second functionalized organosilicon monomer is selected from the group consisting of polysiloxanes, polycarbosiloxanes, polysilsesquioxanes, polycarbosilanes, polysilylcarbodiimides, polysilsesquicarbodiimides, polysilazanes, polysilsesquiazanes, polyborosilanes, polyborosiloxanes, and polyborosilazanes, each substituted with one or more polymerizable functional groups selected from groups containing a group or motif selected from one or more of esters, amines, hydroxyls, epoxides, vinyls, allyls, ethynyls, thiols, glycidyls, isocyanurates, alkaacrylates, cyanos, cyanates, and thiocyanates, with the proviso that the second functionalized organosilicon monomer has a different ceramic yield than the first functionalized organosilicon monomer. Thus, the second functionalized organosilicon monomer may have the structure of formula 1, 2, 3, 4, 5, 6, 7, or 8, or may be a polysilsesquioxane, polysilsesquicarbodiimide, and polysilsesquiazane as defined above, each substituted with one or more polymerizable functional groups selected from groups containing a group or motif selected from one or more of ester, amine, hydroxyl, epoxide, vinyl, allyl, ethynyl, thiol, glycidyl, isocyanurate, alkaacrylate, cyano, cyanate, and thiocyanate, with the proviso that the second functionalized organosilicon monomer has a different ceramic yield than the first functionalized organosilicon monomer. In each case, the polymerizable functional group is preferably one or more of vinyl, allyl, thiol, and acrylate.

[0061] In certain preferred embodiments, the second organosilicon monomer is polyoctahedral silsesquioxane.Polyoctahedral silsesquioxane is preferably selected from one or more of polysilsesquioxane, polysilsesquicarbodiimide, and polysilsesquiazane.The use of polyoctahedral silsesquioxane provides additional advantages, because it has been found that polyoctahedral silsesquioxane tends to produce larger pores, and even tends toward the macropore size range, thereby increasing the available "tuning" of the porosity of PDC materials.

[0062] The second functionalized organosilicon monomer may contain a polymerizable functional group that is different from but complementary to the polymerizable functional group of the first functionalized organosilicon monomer, such that under polymerization conditions, the first polymerizable functional group and the second polymerizable functional group react with each other, optionally via a crosslinker group, to crosslink the monomers together. Alternatively, the second functionalized organosilicon monomer may contain a polymerizable functional group that is the same as the polymerizable functional group of the first functionalized organosilicon monomer, such that under polymerization conditions, the first polymerizable functional group and the second polymerizable functional group react with each other, optionally via a crosslinker, to crosslink the monomers together.

[0063] The preceramic resin may include a crosslinker that includes a crosslinker group. The crosslinker is generally a chemical compound that may be considered functionalized in that it includes at least two or more functional groups that are complementary to the functional groups described above for the polymerizable functional groups of any one or all of the functionalized organosilicon monomers included in the preceramic resin. The functional groups of the crosslinker react with the polymerizable functional groups of the functionalized organosilicon monomer(s), resulting in a crosslinker group within the structure of the preceramic polymer. Examples of crosslinkers include functionalized silane monomers or oligomers, diacrylates, and dithiols, among others. If present, the crosslinker with the crosslinker group will be selected based on the polymerizable functional groups of the functionalized organosilicon monomer(s). Thus, the crosslinker group may be selected from the polymerizable functional groups described above for the first functionalized organosilicon monomer and the second functionalized organosilicon monomer, which in preferred embodiments include those selected from one or more of vinyl, allyl, thiol, and acrylate.

[0064] Exemplary pairs of first and second functionalized organosilicon monomers and crosslinkers are shown in Tables 1 and 2 below.

[0065] In resins comprising a first functionalized organosilicon monomer and a second functionalized organosilicon monomer, the monomers are preferably present in a stoichiometric amount that matches the complete reactivity, or as close to complete reactivity as possible, of the polymerizable functional groups, i.e., the first functionalized organosilicon monomer and the second functionalized organosilicon monomer are preferably present in a 1:1 ratio with respect to the polymerizable functional groups.

[0066] Within these preferred parameters, the amount of the second functionalized organosilicon monomer, if present in the preceramic resin, may be present in an amount of at least about 15%, 20%, 25%, 30%, or at least about 35% based on the weight of the preceramic resin, and up to about 80%, 75%, 70%, or about 65% based on the weight of the preceramic resin. The second functionalized organosilicon monomer may also be present in the preceramic resin in an amount of at least about 5%, 10%, 15%, 20%, or at least about 25% based on the volume of the preceramic resin. The amount of the second functionalized organosilicon monomer may be up to about 75%, 70%, 65%, 60%, or up to about 55% based on the volume of the preceramic resin. Any minimum and maximum values ​​may be combined without limitation. For example, the amount may be between 15% and 80% based on the weight of the preceramic resin, between 15% and 65% based on the weight of the composition, etc.

[0067] Organic Monomers An "organic monomer" is a carbon-containing chemical compound, other than the organosilicon monomers described herein. An organic monomer is typically a silicon-free organic monomer. Organic compounds tend to contain carbon-carbon and carbon-hydrogen covalent bonds, and often contain covalently bonded heteroatoms such as oxygen and nitrogen. Organic compounds are identifiable to those skilled in the art. A "functionalized" organic monomer is one that contains two or more reactive functional groups, each of which is reactive with at least a first functionalized organosilicon monomer to form crosslinks. This may be by crosslinking with the organosilicon monomer functional groups. Thus, the functional group of the functionalized organic monomer may be referred to as a polymerizable functional group. The portion of the chemical structure between the reactive groups may be referred to as a "spacer". Thus, a functionalized organic monomer may be of the formula: Spacer (L) n where Spacer is a spacer group, L is a reactive group reactive with at least the first functionalized organosilicon monomer, and n is an integer equal to or greater than 2. In a preferred embodiment, n is an integer from 2 to 4, preferably 2.

[0068] The spacer group may be based on short or long chain, arbitrarily branched backbone structures, including, for example, ethylene, ethylene glycol, polyethylene, polyethylene glycol propylene, polypropylene glycol, polypropylene, polypropylene glycol, ethylamine, polyethyleneimine, propylamine, polypropyleneimine, etc. "Substituted" in reference to the organic monomer means that any one or more atoms or chemical groups attached to the atoms of the backbone are replaced, as long as the valence of the atom is not exceeded and a stable compound is obtained. The reactive group may be substituted at any position(s) of the backbone, and is preferably substituted at the terminals, i.e., at the two end groups of the backbone structure. The at least two reactive groups may be the same or different, depending on the desired crosslinking with the first functionalized organosilicon monomer. The two or more reactive groups are preferably the same. The reactive group is preferably selected from a group or group containing motifs selected from one or more of ester, amine, hydroxyl, epoxide, vinyl, allyl, ethynyl, thiol, glycidyl, isocyanurate, alkaacrylate, cyano, cyanate, and thiocyanate. In a preferred embodiment, the reactive group is an allyl, vinyl, thiol, or acrylate.

[0069] Exemplary preferred functionalized organic monomers include ethylene glycol diacrylate, polyethylene glycol diacrylate, ethylene glycol dithiol, polyethylene glycol dithiol, ethylene glycol divinyl ether, polyethylene glycol divinyl ether, ethylene glycol diallyl ether, and polyethylene glycol diallyl ether.

[0070] In some cases, the crosslinking agent described above constitutes a functionalized organic monomer.

[0071] An advantage of using functionalized organic monomers is that they tend to be more reactive under the polymerization conditions than functionalized organosilicon monomers and can serve to increase the rate of polymerization and the extent of crosslinking, allowing further control over the porosity formed within the polymer-derived ceramic material.

[0072] In the resins containing the first functionalized organosilicon monomer and the functionalized organic monomer, and optionally the second functionalized organic monomer, the monomers are preferably present in a stoichiometric amount that matches the complete reactivity or as close to complete reactivity as possible of the polymerizable functional group. That is, the first functionalized organosilicon monomer and the organosilicon monomer can be present in a ratio of 1:1 with respect to the polymerizable functional group. When the second functionalized organosilicon monomer is present, the ratio can be 1:0.5:0.5, 1:0.2:0.8, 1:0.7:0.3, etc., in any particular order. Within this preferred parameter range, the amount of the functionalized organic monomer, when present in the preceramic resin, can be at least about 1%, 2%, 5%, 8%, or 10%, 15%, 20%, 25%, 30%, or at least about 35% based on the weight of the preceramic resin, and up to about 80%, 75%, 70%, or about 65% based on the weight of the preceramic resin. Any of the minimum and maximum values ​​can be combined without limitation. For example, the amount can be between 15% and 80% by weight of the preceramic resin, between 1% and 65% by weight of the composition, etc.

[0073] Porogen A "porogen" is an organic compound added to a preceramic resin that can escape when the preceramic resin is pyrolyzed to form a PDC material. Without wishing to be limited by theory, it is believed that the porogen escapes as a gas during pyrolysis and upon escape leaves pores in the PDC material. The pores created by the porogen are typically mesopores and / or macropores. This provides an advantage of the present invention because it allows for the introduction of pores in situ into the PDC material, providing a high degree of control over the porosity of the resulting PDC material. That is, this allows for the porosity of the PDC material to be "tuned."

[0074] Thus, in certain embodiments, the preceramic resin comprises a first functionalized organosilicon monomer having a first ceramic yield and a porogen, optionally together with one or more of a second functionalized organosilicon monomer having a second ceramic yield, a functionalized organic monomer, and a porous ceramic particle. That is, in certain embodiments, the preceramic resin comprises one of the following combinations: a) combining a first functionalized organosilicon monomer having a first ceramic yield with a porogen; b) combining a first functionalized organosilicon monomer having a first ceramic yield, porous ceramic particles, and a porogen; c) combining a first functionalized organosilicon monomer having a first ceramic yield, a second functionalized organosilicon monomer having a second ceramic yield, and / or a functionalized organic monomer with a porogen; and d) combining a first functionalized organosilicon monomer having a first ceramic yield, a second functionalized organosilicon monomer having a second ceramic yield, and / or a functionalized organic monomer, porous ceramic particles, and a porogen.

[0075] The size of the pores introduced into the PDC material by the porogen depends on the size of the porogen itself: mesoporogens tend to result in mesopores (and in some cases micropores), whereas macroporogens tend to result in macropores (and in some cases mesopores). Similarly, the combination of mesoporogens and macroporogens tends to result in a combination of mesopores and macropores.

[0076] Examples of preferred mesoporogens include toluene, methanol, cyclohexanol, hexane, dodecanol, 1,2-propanediol, water, 1-propanol, 1,4-butanediol, dimethylformamide, acetonitrile, decane, and decanol, while examples of preferred macroporogens include polyethylene glycols (PEGs) such as PEG 200, PEG 400, and PEG 20000, and polyethylene glycol diacrylates (PEGDAs) such as PEGDA 250 and PEGDA 575. In a preferred embodiment, the mesoporogen is toluene and the macroporogen is PEG 400.

[0077] The porogen may be present in an amount of at least about 0.5%, 1%, 2%, 5%, 7%, 10%, 15%, or 20% by weight of the preceramic resin, and up to about 35%, 40%, 45%, 50%, or 55% by weight of the preceramic resin. All amounts may be combined without limitation. For example, the amount may be between 0.5% and 20% by weight of the preceramic resin, between 1% and 10% by weight of the composition, between 20% and 50% by weight of the composition, between 0.5% and 50% by weight of the composition, etc. In some embodiments, the porogen is present in an amount of about 40%-55%, or 45%-55%, or 50%-55%. In other embodiments, the porogen is present in an amount of about 1% to about 10%, or about 2%-7%, or about 5% by weight of the preceramic resin.

[0078] Other Ingredients Resins of the present invention may include a variety of other ingredients, including, but not limited to, one or more of a free radical initiator, a free radical inhibitor, a light blocking agent, a 3D printing resolution agent, a colorant, a surfactant, a dispersing agent, or an emulsifier.

[0079] As explained above, since the resins of the present invention are particularly useful in forming shaped preceramic polymeric articles and PDC articles using 3D printing and injection molding techniques, the polymerizable functional group of the organosilicon monomer(s) is preferably thus compatible and therefore in many embodiments is thermally or photopolymerizable. In that case, the resin may often further comprise a free radical generator such as a thermal initiator or photoinitiator that forms free radicals that catalyze the reaction of the thermally or photopolymerizable functional groups, respectively. When present, the thermal initiator or photoinitiator may be present in an amount of between about 0.01% and about 20% by weight of the preceramic resin, preferably between about 0.1% and about 5% by weight, more preferably between about 0.2% and about 1% by weight.

[0080] Examples of thermal initiators include benzoyl peroxide, dicumyl peroxide, and 2,2'-azobisisobutyronitrile.

[0081] Examples of photoinitiators include 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methylpropiophenone, camphorquinone, phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO), benzophenone, and benzoyl peroxide.

[0082] In a preferred embodiment, the free radical generator is a photoinitiator that forms free radicals under ultraviolet light (wavelength of about 100 nm to about 405 nm). A preferred example is phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide.

[0083] When a free radical generator is included, the resin may further include a free radical inhibitor (also known as a free radical scavenger). Examples include hydroquinone, methylhydroquinone, ethylhydroquinone, methoxyhydroquinone, ethoxyhydroquinone, monomethyletherhydroquinone, propylhydroquinone, propoxyhydroquinone, tert-butylhydroquinone (TBHQ), and n-butylhydroquinone. In a preferred embodiment, the free radical inhibitor is tert-butylhydroquinone. When present, the free radical inhibitor may be present in an amount between about 0.01% and about 20% by weight of the preceramic resin, preferably between about 0.05% and about 5% by weight, and more preferably between about 0.1% and about 2% by weight.

[0084] Examples of light blocking agents (also known as photoblockers) include 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene (BBOT), 4,4'-bis(benzoxazolyl)-cis-stilbene, and 4,4-diamino-2,2-stilbene disulfonic acid. In a preferred embodiment, the light blocking agent is BBOT. When present, the light blocking agent may be present in an amount between about 0.01% and about 20% by weight of the preceramic resin, preferably between about 0.1% and about 5% by weight, and more preferably between about 0.2% and about 1% by weight.

[0085] Another component that may be included in the resin of the present invention is a third or subsequent functionalized organosilicon monomer. The third or subsequent functionalized organosilicon monomer may be selected in the same manner as the first and second functionalized organosilicon monomers described above, and with the same identity and polymerizable functional group. The polymerizable functional group of the third functionalized organosilicon monomer is selected to react with one or more of the polymerizable functional groups of the first and / or second functionalized organosilicon monomers, optionally via a crosslinker group. The third or subsequent functionalized organosilicon monomer does not need to have a ceramic yield different from the first and / or second functionalized organosilicon monomers. However, if it has a (third) ceramic yield different from the first and second ceramic yields, this may further contribute to the formation of pores in the PDC material.

[0086] When present, the third or subsequent functionalized organosilicon monomer is preferably a polysiloxane, polysilsesquioxane, polycarbosilane, or polycarbosilazane. The third (or subsequent) functionalized organosilicon monomer may be selected from one or more of methacryloxypropyl terminated polydimethylsiloxane, vinylmethoxysiloxane homopolymer, methacryloxypropyl substituted poly(isobutyl-t8-silsesquioxane), allylhydridopolycarbosilane, and methylvinylhydrogenpolycarbosilazane. When present, the third or subsequent functionalized organosilicon monomer may be present in an amount of about 1% to about 50% by weight of the preceramic resin, preferably between about 5% and about 30% by weight, and more preferably between about 10% and about 20% by weight.

[0087] Another component that may be included in the resins of the present invention is a second or subsequent functionalized organic monomer, as described above.

[0088] Methods of the Invention The method of the present invention involves subjecting a preceramic resin to polymerization conditions to form a preceramic polymer, and pyrolyzing the preceramic polymer to form a PDC material.

[0089] "Polymerization conditions" are conditions under which a polymerization reaction occurs. Numerous polymerization reaction chemistries are applicable, including, but not limited to, step-growth polymerizations, including condensation reactions, and chain-growth polymerizations, including cationic or anionic addition reactions, or thermal or photocatalytic free radical reactions. The polymerization conditions selected will depend on the polymerizable functional groups of the functionalized organosilicon monomer(s) that are intended to crosslink the monomers together.

[0090] As noted above, the polymerizable functional groups are thus compatible and preferably photopolymerizable, since the resins of the present invention are particularly useful in forming shaped preceramic polymeric and PDC material articles using 3D printing and injection molding processes. Thus, in a preferred embodiment, the polymerization conditions include the presence of other components in the preceramic resin that aid in photopolymerization, as described above.

[0091] "Pyrolysis" is the thermally induced conversion of a preceramic polymer from an organic material to an inorganic (i.e., PDC) material. Similarly, "pyrolysis conditions" are conditions that include an elevated temperature at which pyrolysis occurs. During pyrolysis, the inorganic material formed may exist in one or more material phases depending on the temperature to which it is exposed, for example, the inorganic material may go through an amorphous phase and then transition to a crystalline phase as the temperature is increased. Pyrolysis conditions as used herein tend to result in amorphous polymer-derived ceramic materials because the maximum temperature of pyrolysis tends to be lower than the temperature that causes the transition from the amorphous phase to the crystalline phase. Similarly, when a preceramic resin includes a component that can form pores during pyrolysis (e.g., a preceramic resin described herein), the amorphous phase can encompass a "porous phase" and a "nonporous phase." A porous phase is characterized by including pores, whereas a nonporous phase is other than a porous phase. A nonporous phase occurs at a higher temperature than a porous phase, which occurs due to the collapse of pores present in the porous phase. The temperature at which the porous phase is no longer present and a non-porous phase is present is sometimes referred to as the "porosity transition temperature."

[0092] The temperature ranges in which the porous and non-porous phases exist may vary depending on the composition of the preceramic resin. Generally speaking, the greater the number of components in the preceramic resin, the higher the porosity transition temperature tends to be. For example, a preceramic resin that includes a first functionalized organosilicon monomer, a second functionalized organosilicon resin, a porous ceramic particle, a porogen, a photoinitiator, a free radical generator, and a light blocking agent may exhibit a higher porosity transition temperature than a preceramic resin that does not have one of these components, such as a preceramic resin that includes a first functionalized organosilicon monomer, a second functionalized organosilicon resin, a porous ceramic particle, a photoinitiator, a free radical generator, and a light blocking agent (i.e., no porogen). In embodiments that include a greater number of components, the porosity transition temperature may be as high as, for example, about 1100°C. In other words, the maximum temperature of pyrolysis may be 1100°C. By "maximum temperature" it is meant that the maximum temperature reached during pyrolysis does not exceed the "maximum temperature" value given. Generally speaking, however, the porous phase may occur below 1000°C, often within the range of about 300°C to 900°C. For example, in embodiments where the porous phase is absent at 900°C, 900°C is taken to be the porosity transition temperature. Whether a PDC material is formed by pyrolysis at a maximum temperature below the porosity transition temperature, i.e., within the range of the porous stage, can be determined by measuring the porosity of the formed material, e.g., using BET surface analysis as described herein. The porosity transition temperature can likewise be determined, e.g., by analyzing the porosity of PDC materials formed at various temperatures. Thus, by controlling the temperature of pyrolysis, a porous PDC material can be produced, and a porous PDC material can be produced by not exceeding the porosity transition temperature. That is, in other words, a porous PDC material can be produced by pyrolysis conditions characterized by a maximum temperature within the range of the porous stage, i.e., in other words, by pyrolysis conditions characterized by a maximum temperature below the porosity transition temperature.

[0093] Pyrolysis conditions characterized by a maximum temperature within the range of the porous stage, which may be about 1000° C. or less, provide certain advantages of the present invention. Typically, PDC materials are formed using pyrolysis conditions at temperatures above a temperature that may correspond to a porosity transition temperature, i.e., much higher than 1000° C., for example. It has been found that these high temperatures induce the necessary organic-to-inorganic conversion of the preceramic polymer to form the PDC material, but that the high temperatures result in a solid PDC material that is essentially devoid of porous character. It has been found that much lower temperatures within the range of temperatures that may correspond to the porous stage, i.e., below the temperature that may correspond to the porosity transition temperature, which may be, for example, less than 1000° C., are suitable for inducing the organic-to-inorganic conversion while having the added advantage of forming and / or maintaining a porous structure. Temperatures in the region of about 950°C or less, 900°C or less, 850°C or less, 800°C or less, 750°C or less, 700°C or less, 650°C or less, or even 600°C or less, may be suitable to induce organic to inorganic conversion while forming and / or maintaining a porous structure, and often tend toward maximum porosity at the lower end of this range, for example, 700°C or less. The relevant temperatures will depend on the monomers selected (i.e., the first organosilicon monomer, and if present, the second organosilicon monomer and / or functionalized organic monomer). Guidance regarding the relevant temperatures can be obtained by TGA analysis of the monomer(s) and by review and comparison of the examples presented herein. The maximum pyrolysis temperature can be combined with the minimum temperature of pyrolysis within the porous stage that still forms pores. By "minimum temperature" is meant that the temperature during pyrolysis increases to a value above the given "minimum temperature". In a preferred embodiment, the minimum temperature can be as low as about 300°C. This minimum temperature is favorable for efficient conversion of organic to inorganic materials and for the initial appearance of porosity (sometimes referred to as the "pore formation temperature" even though pre-existing pores are due to the use of porous ceramic particles). Higher minimum temperatures, including 325°C, 350°C, 375°C, 400°C, 425°C, or 500°C, are applicable to achieve the same results and are favorable for increasing porosity.Thus, expressed as ranges, in preferred embodiments pyrolysis is carried out at a minimum and maximum temperature between 300°C and 900°C, between 325°C and 850°C, preferably between 350°C and 800°C, between 375°C and 750°C, more preferably between 400°C and 700°C, and in some embodiments between 425°C and 650°C, or between 450°C and 600°C.

[0094] The particular PDC material produced will depend on the composition of the preceramic resin, as this will result from the identity of the functionalized organosilicon monomer(s) and the porous ceramic particles (if any) selected. The particular PDC material produced may also depend on the pyrolysis conditions used. In particular, pyrolysis may be carried out in an inert or reactive atmosphere. A reactive atmosphere is generally characterized by the presence of a reactive gas, i.e., a gas that is reactive with at least one component of the preceramic polymeric material under the pyrolysis conditions. An inert atmosphere is generally characterized by the absence of a reactive gas. Examples of reactive gases include oxygen, carbon dioxide, water (e.g., air), methane, ammonia, and the like. Examples of inert environments are a nitrogen gas environment or an environment under vacuum. The presence of a reactive environment will generally affect the nature of the gases that escape the material during pyrolysis, and thus the nature of the PDC material produced.

[0095] For example, pyrolysis of polysiloxane organosilicon monomers in an inert atmosphere will generally produce silicon oxycarbide ceramic materials, whereas pyrolysis of polysiloxane organosilicon monomers in a reactive air environment will generally produce silica ceramic materials. This is because the gases in the air react with the carbon atoms in the organosilicon backbone structure of the polysiloxane and escape as carbon-containing gases. Amorphous silica ceramic materials are often referred to as "glasses."

[0096] Other PDC materials that can be produced depending on the composition of the preceramic polymer and the pyrolysis conditions include Si 3 N 4, SiC, SiCN, SiCO, SiCNO, SiBCN, SiBCO, SiAlCN, SiAlCO, SiON, and / or SiBN.

[0097] In a preferred embodiment, the pyrolysis conditions include an inert environment and a maximum temperature of about 600°C, while in another preferred embodiment, the pyrolysis conditions include a reactive environment and a maximum temperature of about 700°C.

[0098] Methods of pyrolysis are otherwise known to those skilled in the art. Generally speaking, the preceramic polymeric material is placed in a cold furnace, the temperature is increased at a specified rate(s) to a maximum value, held for a period of time, and the temperature is decreased again at a specified rate(s). The ramp-up and ramp-down rates may be selected based on the thermogravimetric profile of the organosilicon monomer used, as known to those skilled in the art.

[0099] The rate of temperature increase during pyrolysis (sometimes referred to as the temperature "ramp") and the period of time that the article is maintained at the maximum pyrolysis temperature can be controlled to create and / or maintain the desired porous structure. In some instances, the rate of temperature increase is controlled to be as low (i.e., slow) as appropriate to control pyrolysis. A ramp rate of 10°C / min or less (or slower as described below) is referred to as a "slow ramp rate". Suitable rates of temperature increase over the period during the porous stage can be between 0.1°C / min and 10°C / min, e.g., between 0.1°C / min and 7°C / min, between 0.1°C / min and 5°C / min, between 0.2°C / min and 3°C / min, between 0.2°C / min and 2°C / min, and preferably between 0.3°C / min and 1°C / min. In certain embodiments, the ramp rate can be specifically about 0.3°C / min or about 1°C / min over the period within the porous stage. A slow ramp rate can be used over the entire period of the porous stage or over a portion of the porous stage. In a preferred embodiment, a slow temperature ramp rate is used over a period that includes the pore-forming temperature.

[0100] The duration of the period during which the slow ramp is used may vary depending on the ramp rate, pore-forming temperature, and maximum pyrolysis temperature used. The duration of the slow ramp may be expressed in reference to a period. Typically, the duration of the period during which the slow ramp is used within the porous stage will be at least 30 minutes, preferably at least 1 hour. This period may be longer, for example at least 1.5 hours, 2 hours, 3 hours, 5 hours, 10 hours, 15 hours, 20 hours, or longer. This period may be up to 40 hours, 45 hours, 50 hours, or 55 hours. Expressed as a range, the slow ramp may be used for a duration of 1 hour to 55 hours, or 1.5 hours to 50 hours, or 2 hours to 45 hours, or 3 hours to 40 hours, or 15 hours to 40 hours, for example 20 hours to 25 hours. In a preferred embodiment, the slow temperature ramp rate is used throughout the entire porous stage up to the maximum pyrolysis temperature (i.e., from the pore-forming temperature to the maximum pyrolysis temperature). For example, if the pore formation temperature is 300°C and the maximum pyrolysis temperature is 700°C, the duration of the slow ramp rate can be about 40 minutes (using a ramp rate of 10°C / min), about 57 minutes (using a ramp rate of 7°C / min), 1 hour 20 minutes (using a ramp rate of 5°C / min), 2 hours 13 minutes (using a ramp rate of 3°C / min), 3 hours 20 minutes (using a ramp rate of 2°C / min), 6 hours 40 minutes (using a ramp rate of 1°C / min), 13 hours 20 minutes (using a ramp rate of 0.5°C / min), and 22 hours 13 minutes (using a ramp rate of 0.3°C / min). For example, suitable rates of temperature increase between room temperature (about 20° C.) and 600° C. may be between 0.1° C. / min and 2° C. / min, preferably between about 0.2° C. / min and 1° C. / min, while suitable rates of temperature increase between 600° C. and 1000° C. may be between 1° C. / min and 10° C. / min, preferably between 3° C. / min and 7° C. / min. The rate of temperature decrease can be similarly controlled, and is generally between about 0.5° C. / min and 10° C. / min, preferably between 2° C. / min and 7° C. / min, as appropriate. The period during which the temperature is held at the highest target temperature may be, for example, between 30 and 300 minutes, or between 60 and 240 minutes, preferably between 60 and 120 minutes. Thus, the total period of pyrolysis from room temperature back to room temperature may take up several hours.In contrast, previous processes for pyrolytic conversion of green bodies to PDC materials tend to have higher rates of temperature increase and higher maximum pyrolysis temperatures. In some cases, the duration of pyrolysis is shorter. The conditions favorable for forming porous ceramic articles are much milder, which allows for controlled formation of the porous structure. EXAMPLES

[0101] TGA to determine ceramic yields of organosilicon monomers 850 The law is as follows:

[0102] A known amount of functionalized organosilicon monomer (preferably between 10 mg and 20 mg) was transferred to an alumina crucible approved for use in a thermogravimetric analyzer. The crucible was placed in the analyzer and its weight change versus time and temperature was determined according to the manufacturer's instructions. The sample crucible was subjected to a thermal cycle from room temperature to 850°C under nitrogen and then returned to room temperature. The sample was equilibrated at 30°C for 30 minutes and the resulting weight was tared before the temperature was increased from 30°C to 850°C at a ramp rate of 1°C / min. The sample was further equilibrated at 850°C for 60 minutes and then cooled from 850°C to room temperature at a rate of 5°C / min. The percentage of weight change of the sample during this thermal cycle is used to calculate the ceramic yield, where the percentage of ceramic yield is calculated as (1-weight loss of sample / initial weight of sample) x 100.

[0103] The materials and pyrolysis conditions used to produce the porous PDC materials are outlined in Table 1.

[0104] [Table 1] TIFF2025508087000004.tif254170

[0105] Example 1 - Porous Silicon Oxycarbide First functionalized organosilicon monomer + porous ceramic nanoparticles The resin was prepared by mixing 100 parts (wt / wt) methacryloxypropyl-terminated polydimethylsiloxane with 0.9 parts (wt / wt) phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 0.23 parts (wt / wt) 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene, and 0.8 parts (wt / wt) tert-butylhydroquinone (TBHQ). Porous silicon dioxide nanoparticles (spherical, particle size (TEM) of 5 nm to 20 nm, mesoporous 3 nm to 5 nm, Sigma-Aldrich) (20% (wt / wt)) were also added to the resin formulation.

[0106] After thoroughly mixing the resin components in a vortex mixer and ultrasonic bath, the prepared resin was purged with nitrogen and vacuumed for 1 hour.

[0107] This resin was 3D printed using a digital light projection (DLP) printer (Miicraft Ultra) following the manufacturer's standard operating procedures to generate 3D printed green bodies.

[0108] Injection molded green bodies were also produced by photopolymerizing the resin under a wavelength of 365 nm by pouring the resin into a disk-shaped mold (10 mm diameter and 2 mm thickness).

[0109] The green bodies were pyrolyzed in a tube furnace under a constant (3 L / min) nitrogen flow. Pyrolysis was carried out from 25° C. to 100° C. at a ramp rate of 1° C. / min, followed by a ramp rate of 0.5° C. / min from 100° C. to 600° C. The furnace was held at 600° C. for 180 minutes. The furnace was then cooled from 600° C. to 450° C. at a ramp rate of 2° C. / min, followed by cooling to 300° C. The furnace was held at 450° C. and 300° C. for 60 minutes, respectively. Final cooling to 25° C. at a ramp rate of 2° C. / min produced 3D printed and injection molded ceramic articles.

[0110] 1 shows the 3D printed and injection molded green bodies, as well as the pyrolyzed 3D printed and pyrolyzed injection molded articles. Both the 3D printed and molded green bodies were pyrolyzed into porous silicon oxycarbide, retaining all the features of the printed and molded structures, with approximately 30% linear shrinkage.

[0111] Example 2 - Porous Silicon Oxycarbide First functionalized organosilicon monomer and second functionalized organosilicon monomer + porous ceramic nanoparticles A resin was prepared by mixing 100 parts (wt / wt) of (mercaptopropyl)methylsiloxane homopolymer (about 55% ceramic yield) and 100 parts (wt / wt) of methacryloxypropyl terminated polydimethylsiloxane (about 18% ceramic yield) with 0.9 parts (wt / wt) of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 0.23 parts (wt / wt) of 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene, and 0.8 parts (wt / wt) of tert-butylhydroquinone (TBHQ). Porous silicon dioxide nanoparticles (spherical, particle size (TEM) of 5 nm to 20 nm, mesoporous 3 nm to 5 nm, Sigma-Aldrich) (20% (wt / wt)) were added to this resin.

[0112] After thoroughly mixing the resin components in a vortex mixer and ultrasonic bath, the prepared resin was purged with nitrogen and vacuumed for 1 hour.

[0113] This resin was 3D printed using a digital light projection (DLP) printer (Miicraft Ultra) following the manufacturer's standard operating procedures to generate 3D printed green bodies.

[0114] Injection molded green bodies were also produced by photopolymerizing the resin under a wavelength of 365 nm by pouring the resin into a disk-shaped mold (10 mm diameter and 2 mm thickness).

[0115] The green bodies were pyrolyzed in a tube furnace under a constant (3 L / min) nitrogen flow. Pyrolysis was carried out from 25° C. to 100° C. at a ramp rate of 1° C. / min, followed by a ramp rate of 0.5° C. / min from 100° C. to 600° C. The furnace was held at 600° C. for 180 minutes. The furnace was then cooled from 600° C. to 450° C. at a ramp rate of 2° C. / min, followed by cooling to 300° C. The furnace was held at 450° C. and 300° C. for 60 minutes, respectively. Final cooling to 25° C. at a ramp rate of 2° C. / min produced 3D printed and injection molded ceramic articles.

[0116] 2 shows the 3D printed and injection molded green bodies, as well as the pyrolyzed 3D printed and pyrolyzed injection molded articles. Both the 3D printed and injection molded green bodies were pyrolyzed into porous silicon oxycarbide, retaining all the features of the printed and molded structures, with approximately 30% linear shrinkage.

[0117] FIG. 3 is a pore size distribution plot of the pyrolyzed 3D printed article as determined by using a BET surface analyzer. BET surface area analysis reveals the presence of both micropores (less than 20 Å) and mesopores (20 Å to 500 Å), with a pore size distribution of 474 m 2 It is shown that the total specific surface area is 1 / g.

[0118] Example 3 - Porous Silicon Oxycarbide First functionalized organosilicon monomer and second functionalized organosilicon monomer + porous ceramic nanoparticles Resins were prepared by mixing 100 parts (wt / wt) of (mercaptopropyl)methylsiloxane homopolymer (about 55% ceramic yield) and 100 parts (wt / wt) of vinylmethoxysilane homopolymer (about 50% ceramic yield) with 0.9 parts (wt / wt) of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 0.23 parts (wt / wt) of 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene, and 0.8 parts (wt / wt) of tert-butylhydroquinone (TBHQ). Porous silicon dioxide nanoparticles (spherical, particle size (TEM) of 5 nm to 20 nm, mesoporous 3 nm to 5 nm, Sigma-Aldrich) (20% (wt / wt)) were also added to the resin formulation.

[0119] After thoroughly mixing the resin components in a vortex mixer and ultrasonic bath, the prepared resin was purged with nitrogen and vacuumed for 1 hour.

[0120] This resin was 3D printed using a digital light projection (DLP) printer (Miicraft Ultra) following the manufacturer's standard operating procedures to generate 3D printed green bodies.

[0121] Injection molded green bodies were also produced by photopolymerizing the resin under a wavelength of 365 nm by pouring the resin into a disk-shaped mold (10 mm diameter and 2 mm thickness).

[0122] The green bodies were pyrolyzed in a tube furnace under a constant (3 L / min) nitrogen flow. Pyrolysis was carried out from 25° C. to 100° C. at a ramp rate of 1° C. / min, followed by a ramp rate of 0.5° C. / min from 100° C. to 600° C. The furnace was held at 600° C. for 180 minutes. The furnace was then cooled from 600° C. to 450° C. at a ramp rate of 2° C. / min, followed by cooling to 300° C. The furnace was held at 450° C. and 300° C. for 60 minutes, respectively. Final cooling to 25° C. at a ramp rate of 2° C. / min produced 3D printed and injection molded ceramic articles.

[0123] The 3D printed green body and pyrolyzed 3D printed article are shown in Figure 4. The 3D printed green body was pyrolyzed into porous silicon oxycarbide, retaining all the features of the printed structure and resulting in approximately 20% linear shrinkage.

[0124] Example 4 - Porous Silica First functionalized organosilicon monomer + porous ceramic nanoparticles The resin was prepared by mixing 100 parts (wt / wt) methacryloxypropyl-terminated polydimethylsiloxane with 0.9 parts (wt / wt) phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 0.23 parts (wt / wt) 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene, and 0.8 parts (wt / wt) tert-butylhydroquinone (TBHQ). Porous silicon dioxide nanoparticles (spherical, particle size (TEM) of 5 nm to 20 nm, mesoporous 3 nm to 5 nm, Sigma-Aldrich) (20% (wt / wt)) were also added to the resin formulation.

[0125] After thoroughly mixing the resin components in a vortex mixer and ultrasonic bath, the prepared resin was purged with nitrogen and vacuumed for 1 hour.

[0126] This resin was 3D printed using a digital light projection (DLP) printer (Miicraft Ultra) following the manufacturer's standard operating procedures to generate 3D printed green bodies.

[0127] Injection molded green bodies were also produced by photopolymerizing the resin under a wavelength of 365 nm by pouring the resin into a disk-shaped mold (10 mm diameter and 2 mm thickness).

[0128] The green bodies were pyrolyzed in a tube furnace under constant (1 L / min) air flow. Pyrolysis was carried out from 25°C to 100°C at a ramp rate of 1°C / min, followed by 100°C to 600°C at a ramp rate of 0.5°C / min. The furnace was held at 600°C for 180 minutes, followed by a ramp rate of 7°C / min from 600°C to 700°C, followed by a hold at 700°C for 60 minutes. The furnace was then cooled from 700°C to 450°C at a ramp rate of 7°C / min, followed by a ramp rate of 2°C / min to 300°C. The furnace was held at 450°C and 300°C for 60 minutes, respectively. A final cool down to 25°C at a ramp rate of 2°C / min produced the 3D printed and injection molded ceramic articles.

[0129] 5 shows the 3D printed and injection molded green bodies, as well as the pyrolyzed 3D printed and pyrolyzed injection molded articles. Both the 3D printed and injection molded green bodies were pyrolyzed into porous silica, retaining all the features of the printed and molded structures, with approximately 20% linear shrinkage.

[0130] Example 5 - Porous Silica First functionalized organosilicon monomer and second functionalized organosilicon monomer + porous ceramic nanoparticles A resin was prepared by mixing 100 parts (wt / wt) of (mercaptopropyl)methylsiloxane homopolymer (about 55% ceramic yield) and 100 parts (wt / wt) of methacryloxypropyl terminated polydimethylsiloxane (about 18% ceramic yield) with 0.9 parts (wt / wt) of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 0.23 parts (wt / wt) of 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene, and 0.8 parts (wt / wt) of tert-butylhydroquinone (TBHQ). Porous silicon dioxide nanoparticles (spherical, particle size (TEM) of 5 nm to 20 nm, mesoporous 3 nm to 5 nm, Sigma-Aldrich) (20% (wt / wt)) were added to this resin.

[0131] After thoroughly mixing the resin components in a vortex mixer and ultrasonic bath, the prepared resin was purged with nitrogen and vacuumed for 1 hour.

[0132] This resin was 3D printed using a digital light projection (DLP) printer (Miicraft Ultra) following the manufacturer's standard operating procedures to generate 3D printed green bodies.

[0133] Injection molded green bodies were also produced by photopolymerizing the resin under a wavelength of 365 nm by pouring the resin into a disk-shaped mold (10 mm diameter and 2 mm thickness).

[0134] The green bodies were pyrolyzed in a tube furnace under constant (1 L / min) air flow. Pyrolysis was carried out from 25°C to 100°C at a ramp rate of 1°C / min, followed by 100°C to 600°C at a ramp rate of 0.5°C / min. The furnace was held at 600°C for 180 minutes, followed by a ramp rate of 7°C / min from 600°C to 700°C, followed by a hold at 700°C for 60 minutes. The furnace was then cooled from 700°C to 450°C at a ramp rate of 7°C / min, followed by a ramp rate of 2°C / min to 300°C. The furnace was held at 450°C and 300°C for 60 minutes, respectively. A final cool down to 25°C at a ramp rate of 2°C / min produced the 3D printed and injection molded ceramic articles.

[0135] 3D printed and injection molded green bodies, as well as pyrolyzed 3D printed and pyrolyzed injection molded articles, are shown in Figure 6. The 3D printed and molded green bodies were pyrolyzed into porous silica, retaining all the features of the printed structures and only experiencing 15% linear shrinkage.

[0136] FIG. 7 is a pore size distribution plot of the pyrolyzed 3D printed article as determined by using a BET surface analyzer. BET surface area analysis reveals the presence of both micropores (less than 20 Å) and mesopores (20 Å to 500 Å), with a pore size distribution of 165 m 2It is shown that the total specific surface area is 1 / g.

[0137] 8 is a pore size distribution plot of the pyrolyzed 3D printed article as determined using mercury porosimetry. Mercury porosimetry measurements confirmed the presence of macropores (>0.05 μm).

[0138] Example 6 - Porous Silica First functionalized organosilicon monomer and second functionalized organosilicon monomer + porous ceramic nanoparticles Resins were prepared by mixing 100 parts (wt / wt) of (mercaptopropyl)methylsiloxane homopolymer (about 55% ceramic yield) and 100 parts (wt / wt) of vinylmethoxysiloxane homopolymer (about 50% ceramic yield) with 0.9 parts (wt / wt) of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 0.23 parts (wt / wt) of 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene, and 0.8 parts (wt / wt) of tert-butylhydroquinone (TBHQ). Porous silicon dioxide nanoparticles (spherical, particle size (TEM) of 5 nm to 20 nm, mesoporous 3 nm to 5 nm, Sigma-Aldrich) (20% (wt / wt)) were also added to the resin formulation.

[0139] After thoroughly mixing the resin components in a vortex mixer and ultrasonic bath, the prepared resin was purged with nitrogen and vacuumed for 1 hour.

[0140] This resin was 3D printed using a digital light projection (DLP) printer (Miicraft Ultra) following the manufacturer's standard operating procedures to generate 3D printed green bodies.

[0141] Injection molded green bodies were also produced by photopolymerizing the resin under a wavelength of 365 nm by pouring the resin into a disk-shaped mold (10 mm diameter and 2 mm thickness).

[0142] The green bodies were pyrolyzed in a tube furnace under constant (1 L / min) air flow. Pyrolysis was carried out from 25°C to 100°C at a ramp rate of 1°C / min, followed by 100°C to 600°C at a ramp rate of 0.5°C / min. The furnace was held at 600°C for 180 minutes, followed by a ramp rate of 7°C / min from 600°C to 700°C, followed by a hold at 700°C for 60 minutes. The furnace was then cooled from 700°C to 450°C at a ramp rate of 7°C / min, followed by a ramp rate of 2°C / min to 300°C. The furnace was held at 450°C and 300°C for 60 minutes, respectively. A final cool down to 25°C at a ramp rate of 2°C / min produced the 3D printed and injection molded ceramic articles.

[0143] 9 shows the 3D printed and injection molded green bodies, as well as the pyrolyzed 3D printed and pyrolyzed injection molded articles. Both the 3D printed and molded green bodies were pyrolyzed into porous silica, retaining all the features of the printed and molded structures and resulting in approximately 20% linear shrinkage.

[0144] BET surface area analysis reveals 57.6 m 2 The total specific surface area was measured in g / g.

[0145] Example 7 - Porous silicon oxycarbide A first functionalized organosilicon monomer and a second functionalized organosilicon monomer A resin was prepared by mixing 100 parts (wt / wt) of (mercaptopropyl)methylsiloxane homopolymer (about 55% ceramic yield) and 100 parts (wt / wt) of methacryloxypropyl terminated polydimethylsiloxane (about 18% ceramic yield) with 0.9 parts (wt / wt) of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 0.23 parts (wt / wt) of 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene, and 0.8 parts (wt / wt) of tert-butylhydroquinone (TBHQ).

[0146] After thoroughly mixing the resin components in a vortex mixer and ultrasonic bath, the prepared resin was purged with nitrogen and vacuumed for 1 hour.

[0147] The resin was photopolymerized under a wavelength of 365 nm by pouring it into a disk-shaped mold (diameter of 10 mm and thickness of 2 mm) to produce an injection molded green body.

[0148] The green bodies were pyrolyzed in a tube furnace under a constant (3 L / min) nitrogen flow. Pyrolysis was carried out from 25° C. to 100° C. at a ramp rate of 1° C. / min, followed by a ramp rate of 0.5° C. / min from 100° C. to 600° C. The furnace was held at 600° C. for 180 minutes. The furnace was then cooled from 600° C. to 450° C. at a ramp rate of 2° C. / min, followed by cooling to 300° C. The furnace was held at 450° C. and 300° C. for 60 minutes each. Final cooling to 25° C. at a ramp rate of 2° C. / min produced the injection molded ceramic articles.

[0149] The injection molded green body and pyrolyzed injection molded article are shown in Figure 10. Pyrolysis of the body retained all of its features and resulted in approximately 40% linear shrinkage.

[0150] Example 8 - Porous Silica A first functionalized organosilicon monomer comprising a polyoctahedral silsesquioxane, a second functionalized organosilicon monomer, and a third functionalized organosilicon monomer. The resin was prepared by mixing 100 parts (wt / wt) of (mercaptopropyl)methylsiloxane homopolymer, 100 parts (wt / wt) of methacryloxypropyl-terminated polydimethylsiloxane, and 30 parts (wt / wt) of methacryloxypropyl-substituted poly(isobutyl-t8-silsesquioxane) with 0.9 parts (wt / wt) of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 0.23 parts (wt / wt) of 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene, and 0.8 parts (wt / wt) of tert-butylhydroquinone (TBHQ).

[0151] After thoroughly mixing the resin components in a vortex mixer and ultrasonic bath, the prepared resin was purged with nitrogen and vacuumed for 1 hour.

[0152] The resin was photopolymerized under a wavelength of 365 nm by pouring it into a disk-shaped mold (diameter of 10 mm and thickness of 2 mm) to produce an injection molded green body.

[0153] The green bodies were pyrolyzed in a tube furnace under constant (1 L / min) air flow. Pyrolysis was carried out from 25°C to 100°C at a ramp rate of 1°C / min, followed by a ramp rate of 0.5°C / min from 100°C to 600°C. The furnace was held at 600°C for 180 minutes, followed by a ramp rate of 7°C / min from 600°C to 700°C, and then held at 700°C for 60 minutes. The furnace was then cooled from 700°C to 450°C at a ramp rate of 7°C / min, followed by a ramp rate of 2°C / min to 300°C. The furnace was held at 450°C and 300°C for 60 minutes each. Final cooling to 25°C at a ramp rate of 2°C / min produced the injection molded ceramic articles.

[0154] The injection molded green body and pyrolyzed injection molded article are shown in Figure 11. The injection molded green body was pyrolyzed to porous silicon oxycarbide, retaining all the characteristics of the molded structure and resulting in approximately 15% linear shrinkage.

[0155] BET surface area analysis reveals 46.7m 2 The total specific surface area was measured in g / g.

[0156] Example 9 - Porous Silica First Functionalized Organosilicon Monomer and Second Functionalized Organosilicon Monomer + Porous Ceramic Nanoparticles + Porogen The resin was prepared by mixing 100 parts (wt / wt) of (mercaptopropyl)methylsiloxane homopolymer and 100 parts (wt / wt) of methacryloxypropyl terminated polydimethylsiloxane with 10 parts (wt / wt) of polyethylene glycol 400 as porogen, 0.9 parts (wt / wt) of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 0.23 parts (wt / wt) of 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene, and 0.8 parts (wt / wt) of tert-butylhydroquinone (TBHQ). Porous silicon dioxide nanoparticles (spherical, particle size (TEM) of 5 nm to 20 nm, mesoporous 3 nm to 5 nm, Sigma-Aldrich) (20% (wt / wt)) were also added to the resin formulation.

[0157] After thoroughly mixing the resin components in a vortex mixer and ultrasonic bath, the prepared resin was purged with nitrogen and vacuumed for 1 hour.

[0158] Injection molded green bodies were also produced by photopolymerizing the resin under a wavelength of 365 nm by pouring the resin into a disk-shaped mold (10 mm diameter and 2 mm thickness).

[0159] The green bodies were pyrolyzed in a tube furnace under constant (1 L / min) air flow. Pyrolysis was carried out from 25°C to 100°C at a ramp rate of 1°C / min, followed by a ramp rate of 0.5°C / min from 100°C to 600°C. The furnace was held at 600°C for 180 minutes, followed by a ramp rate of 7°C / min from 600°C to 700°C, and then held at 700°C for 60 minutes. The furnace was then cooled from 700°C to 450°C at a ramp rate of 7°C / min, followed by a ramp rate of 2°C / min to 300°C. The furnace was held at 450°C and 300°C for 60 minutes each. Final cooling to 25°C at a ramp rate of 2°C / min produced the injection molded ceramic articles.

[0160] The injection molded green body and pyrolyzed injection molded article are shown in Figure 12. Upon pyrolysis, all the characteristics of the green body were retained, with approximately 20% linear shrinkage.

[0161] BET surface area analysis reveals 137m 2 The total specific surface area was measured in g / g.

[0162] Example 10 - Porous Silica First Functionalized Organosilicon Monomer and Second Functionalized Organosilicon Monomer + Porous Ceramic Nanoparticles + Porogen The resin was prepared by mixing 100 parts (wt / wt) of (mercaptopropyl)methylsiloxane homopolymer and 100 parts (wt / wt) of methacryloxypropyl terminated polydimethylsiloxane with 10 parts (wt / wt) of toluene as a porogen, 0.9 parts (wt / wt) of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 0.23 parts (wt / wt) of 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene, and 0.8 parts (wt / wt) of tert-butylhydroquinone (TBHQ). Porous silicon dioxide nanoparticles (spherical, particle size (TEM) of 5 nm to 20 nm, mesoporous 3 nm to 5 nm, Sigma-Aldrich) (20% (wt / wt)) were also added to the resin formulation.

[0163] After thoroughly mixing the resin components in a vortex mixer and ultrasonic bath, the prepared resin was purged with nitrogen and vacuumed for 1 hour.

[0164] The resin was photopolymerized under a wavelength of 365 nm by pouring it into a disk-shaped mold (diameter of 10 mm and thickness of 2 mm) to produce an injection molded green body.

[0165] The green bodies were pyrolyzed in a tube furnace under constant (1 L / min) air flow. Pyrolysis was carried out from 25°C to 100°C at a ramp rate of 1°C / min, followed by a ramp rate of 0.5°C / min from 100°C to 600°C. The furnace was held at 600°C for 180 minutes, followed by a ramp rate of 7°C / min from 600°C to 700°C, and then held at 700°C for 60 minutes. The furnace was then cooled from 700°C to 450°C at a ramp rate of 7°C / min, followed by a ramp rate of 2°C / min to 300°C. The furnace was held at 450°C and 300°C for 60 minutes each. Final cooling to 25°C at a ramp rate of 2°C / min produced the injection molded ceramic articles.

[0166] The injection molded green body and pyrolyzed injection molded article are shown in Figure 13. Upon pyrolysis, all characteristics of the green body were retained, with approximately 20% linear shrinkage.

[0167] BET surface area analysis reveals 164m 2 The total specific surface area was measured in g / g.

[0168] Example 11 - Porous Silica A first functionalized organosilicon PDC monomer and a second functionalized organosilicon PDC monomer comprising a polyoctahedral silsesquioxane The resin was prepared by mixing 100 parts (wt / wt) of (mercaptopropyl)methylsiloxane homopolymer, 100 parts (wt / wt) of methacryloxypropyl-terminated polydimethylsiloxane, and 30 parts (wt / wt) of methacryloxypropyl-substituted poly(isobutyl-t8-silsesquioxane) with 0.9 parts (wt / wt) of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 0.23 parts (wt / wt) of 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene, and 0.8 parts (wt / wt) of tert-butylhydroquinone (TBHQ).

[0169] After thoroughly mixing the resin components in a vortex mixer and ultrasonic bath, the prepared resin was purged with nitrogen and vacuumed for 1 hour.

[0170] The resin was photopolymerized under a wavelength of 365 nm by pouring it into a disk-shaped mold (diameter of 10 mm and thickness of 2 mm) to produce an injection molded green body.

[0171] The green bodies were pyrolyzed in a tube furnace under constant (1 L / min) air flow. Pyrolysis was carried out from 25°C to 100°C at a ramp rate of 1°C / min, followed by a ramp rate of 0.5°C / min from 100°C to 600°C. The furnace was held at 600°C for 180 minutes, followed by a ramp rate of 7°C / min from 600°C to 700°C, and then held at 700°C for 60 minutes. The furnace was then cooled from 700°C to 450°C at a ramp rate of 7°C / min, followed by a ramp rate of 2°C / min to 300°C. The furnace was held at 450°C and 300°C for 60 minutes each. Final cooling to 25°C at a ramp rate of 2°C / min produced the injection molded ceramic articles.

[0172] The injection molded green body and pyrolyzed injection molded article are shown in Figure 14. The injection molded green body was pyrolyzed to porous silica, retaining all the characteristics of the molded structure and resulting in approximately 15% linear shrinkage.

[0173] BET surface area analysis reveals 47m 2 The total specific surface area was measured in g / g.

[0174] Example 12 - Porous Silicon Oxycarbide First functionalized organosilicon monomer and second functionalized organosilicon monomer + porous ceramic nanoparticles A resin was prepared by mixing 100 parts (wt / wt) of (mercaptopropyl)methylsiloxane homopolymer (about 55% ceramic yield) and 70 parts (wt / wt) of vinylmethoxysiloxane homopolymer (about 50% ceramic yield) with 0.9 parts (wt / wt) of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 0.23 parts (wt / wt) of 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene, and 0.8 parts (wt / wt) of tert-butylhydroquinone (TBHQ). Porous silicon dioxide nanoparticles (spherical, particle size (TEM) of 5 nm to 20 nm, mesoporous 3 nm to 5 nm, Sigma-Aldrich) (16% (wt / wt), 34 parts) were added to this resin.

[0175] After thoroughly mixing the resin components in a vortex mixer and ultrasonic bath, the prepared resin was purged with nitrogen and vacuumed for 1 hour.

[0176] This resin was 3D printed into the designed microneedle patch constructs according to the manufacturer's standard operating procedures using a digital light projection (DLP) printer (Miicraft Ultra) to generate 3D printed green bodies.

[0177] The green bodies were pyrolyzed in a tube furnace under a constant (3 L / min) nitrogen flow. Pyrolysis was carried out from 25°C to 100°C at a ramp rate of 1°C / min, followed by a ramp rate of 0.2°C / min from 100°C to 600°C. The furnace was held at 600°C for 180 minutes. The furnace was then cooled from 600°C to 450°C at a ramp rate of 2°C / min, followed by cooling to 300°C. The furnace was held at 450°C and 300°C for 60 minutes each. Final cooling to 25°C at a ramp rate of 7°C / min produced the 3D printed ceramic microneedle patch article.

[0178] Figure 15 shows a close-up image of pyrolyzed 3D printed microneedles. Pyrolysis of the 3D printed molded green bodies into porous silicon oxycarbide retained all the features of the printed and molded structures, with approximately 15% linear shrinkage. BET surface area analysis revealed an average pore size of 1.6 nm (as shown in Figure 24), 357 m 2 / g, and a total specific surface area of ​​0.12 cm 3 The pyrolyzed structure had a pore volume of SiO 2.05 C 1.06 S 0.04 It was found to have an empirical formula of: and to be amorphous. Figure 16 shows the results of (a) TGA of the resin, (b) EDEX (elemental analysis) of the pyrolysate, and (c) XRD of the pyrolysate.

[0179] Example 13 - Porous Silicon Oxycarbide First functionalized organosilicon monomer and second functionalized organosilicon monomer + porous ceramic nanoparticles A resin was prepared by mixing 100 parts (wt / wt) of (mercaptopropyl)methylsiloxane homopolymer (about 55% ceramic yield) and 100 parts (wt / wt) of methacryloxypropyl terminated polydimethylsiloxane (about 18% ceramic yield) with 0.9 parts (wt / wt) of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 0.23 parts (wt / wt) of 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene, and 0.8 parts (wt / wt) of tert-butylhydroquinone (TBHQ). Porous silicon dioxide nanoparticles (spherical, particle size (TEM) of 5 nm to 20 nm, mesoporous 3 nm to 5 nm, Sigma-Aldrich) (20% (wt / wt), 40 parts) were added to this resin.

[0180] After thoroughly mixing the resin components in a vortex mixer and ultrasonic bath, the prepared resin was purged with nitrogen and vacuumed for 1 hour.

[0181] This resin was 3D printed into the designed microneedle patch constructs according to the manufacturer's standard operating procedures using a digital light projection (DLP) printer (Miicraft Ultra) to generate 3D printed green bodies.

[0182] The green bodies were pyrolyzed in a tube furnace under a constant (3 L / min) nitrogen flow. Pyrolysis was carried out from 25°C to 100°C at a ramp rate of 1°C / min, followed by a ramp rate of 0.2°C / min from 100°C to 600°C. The furnace was held at 600°C for 180 minutes. The furnace was then cooled from 600°C to 450°C at a ramp rate of 2°C / min, followed by cooling to 300°C. The furnace was held at 450°C and 300°C for 60 minutes each. Final cooling to 25°C at a ramp rate of 7°C / min produced the 3D printed ceramic microneedle patch article.

[0183] Figure 17 shows a close-up image of the pyrolyzed 3D printed microneedle patch. Pyrolysis of the 3D printed molded green body into porous silicon oxycarbide retained all the features of the printed and molded structures, with approximately 30% linear shrinkage. BET surface area analysis revealed pore sizes ranging from 1.6 nm to 7 nm (as shown in Figure 25), 524.7 m 2 / g, and a total specific surface area of ​​0.38 cm 3 The resin was obtained with a ceramic yield of 35%. The pyrolyzed structure had a total carbon content of 14 wt.%, with a SiO 2.01 C 1.19 S 0.004 It was found to have an empirical formula of: and to be amorphous. Figure 18 shows the results of (a) TGA of the resin, (b) EDEX (elemental analysis) of the pyrolysate, and (c) XRD of the pyrolysate.

[0184] Example 14 - Porous silicon oxycarbide First Functionalized Organosilicon Monomer and Second Functionalized Organosilicon Monomer + Porous Ceramic Nanoparticles + Porogen A resin was prepared by mixing 100 parts (wt / wt) of (mercaptopropyl)methylsiloxane homopolymer (about 55% ceramic yield) and 100 parts (wt / wt) of methacryloxypropyl terminated polydimethylsiloxane (about 18% ceramic yield) with 0.9 parts (wt / wt) of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide, 0.23 parts (wt / wt) of 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene, and 0.8 parts (wt / wt) of tert-butylhydroquinone (TBHQ). Porous silicon dioxide nanoparticles (spherical, particle size (TEM) of 5 nm to 20 nm, mesoporous 3 nm to 5 nm, Sigma-Aldrich) (20% (wt / wt), 40 parts) and PEG400 porogen (20 parts) were added to the resin.

[0185] After thoroughly mixing the resin components in a vortex mixer and ultrasonic bath, the prepared resin was purged with nitrogen and vacuumed for 1 hour.

[0186] This resin was 3D printed into the designed microneedle patch constructs according to the manufacturer's standard operating procedures using a digital light projection (DLP) printer (Miicraft Ultra) to generate 3D printed green bodies.

[0187] The green bodies were pyrolyzed in a tube furnace under a constant (3 L / min) nitrogen flow. Pyrolysis was carried out from 25°C to 100°C at a ramp rate of 1°C / min, followed by a ramp rate of 0.2°C / min from 100°C to 600°C. The furnace was held at 600°C for 180 minutes. The furnace was then cooled from 600°C to 450°C at a ramp rate of 2°C / min, followed by cooling to 300°C. The furnace was held at 450°C and 300°C for 60 minutes each. Finally, cooling to 25°C at a ramp rate of 7°C / min produced the 3D printed ceramic microneedle patch article. During the ramp, complete loss of PEG400 was observed by 500°C.

[0188] Figure 19 shows a close-up image of pyrolyzed 3D printed microneedles. Pyrolysis of the 3D printed molded green bodies into porous silicon oxycarbide retained all the features of the printed and molded structures, resulting in a linear shrinkage of about 30%. BET surface area analysis and mercury porosimetry revealed the presence of micro- and mesoporosity along with macropores in the size range of 20 nm to 200 nm (as shown in Figures 26 and 27), with a linear shrinkage of 527.1 m. 2 Total specific surface area / g, 0.3 cm 3 / g and a porosity of 47.6%. The resin was obtained with a ceramic yield of 30%. The pyrolyzed structure was Si 1 O 1.92 C 1.02 S 0.015 It was found to have an empirical formula of: and to be amorphous. Figure 20 shows the results of (a) TGA of the resin, (b) EDEX (elemental analysis) of the pyrolysate, and (c) XRD of the pyrolysate.

[0189] We also demonstrated the ability to 3D print complex shapes and structures at high resolution using the same resin, replicating naturally occurring porous structures. The resin was 3D printed into leaf and insect wing structures using a digital light projection (DLP) printer as described above to produce 3D printed green bodies that were pyrolyzed as described above. As shown in FIG. 21, the leaf maintained its external features such as reticulate venation and ovoid shape, as well as its internal multi-level porosity. Similarly, the insect wing maintained the shape and structure of its cross veins and scales.

[0190] Example 15 - Porous silicon oxycarbide The resins of Examples 13 and 14 were also 3D printed onto diatoms using the digital light projection (DLP) printer described above, changing vats of different resins for different print layers as needed. The resin of Example 13 was used to 3D print the shells, while the resin of Example 14 was used to 3D print the frustules.

[0191] The diatoms maintained their structural integrity and high definition, as shown in Figure 22. SEM imaging demonstrated the micro-, meso-, and macroporous nature of the printed frustules, and the micro- and mesoporous nature of the shells.

[0192] Example 16 - Porous silicon oxycarbide First functionalized organosilicon monomer and second functionalized organosilicon monomer and porous ceramic particles The resin was prepared by mixing 100 parts (wt / wt) of methacryloxypropyl-terminated polydimethylsiloxane (about 12% ceramic yield) with 100 parts (wt / wt) of (mercaptopropyl)methylsiloxane homopolymer (about 55% ceramic yield) (i.e., a 1:1 weight ratio of a first functionalized organosilicon monomer to a second functionalized organosilicon monomer), 5 parts (wt / wt) of porous silica nanoparticles (particle size of 10 nm to 20 nm), 0.4 parts (wt / wt) of phenylbis(2,4,6-trimethylbenzoyl)phosphine oxide (BAPO), 0.23 parts (wt / wt) of 2,5-bis(5-tert-butyl-benzoxazol-2-yl)thiophene (BBOT), and 0.8 parts (wt / wt) of tert-butylhydroquinone (TBHQ).

[0193] After thoroughly mixing the resin components in a vortex mixer and ultrasonic bath, the prepared resin was purged with nitrogen and vacuumed for 1 hour.

[0194] The microfluidic chip was 3D printed using this resin using a digital light projection (DLP) printer (Miicraft Ultra) following the manufacturer's standard operating procedures to generate a 3D printed green body.

[0195] The printed chips were pyrolyzed under vacuum in a tube furnace. Pyrolysis was carried out from 25° C. to 100° C. at a ramp rate of 1° C. / min, followed by 100° C. to 600° C. at a ramp rate of 0.5° C. / min. The temperature was held at 600° C. for 180 minutes, followed by cooling at a ramp rate of 2° C. / min to 450° C. and held for 60 minutes, then cooling at a ramp rate of 2° C. / min to 300° C. and held for 60 minutes. Cooling then continued to 25° C. at a ramp rate of 2° C. / min.

[0196] FIG. 23 shows the microfluidic chip before (left) and after (right) pyrolysis.

[0197] Table 2 summarizes the materials and conditions used to produce additional prophetic example porous polymer-derived ceramic materials.

[0198] [Table 2]

[0199] The above embodiments are merely preferred examples of the present disclosure. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present disclosure, and they shall fall within the protection scope of the present disclosure.

[0200] Where any prior art publication is referenced in this specification, it should be understood that such reference is not an admission that this publication forms part of the common general knowledge in the art in Australia or any other country.

[0201] In the appended claims and the above detailed description of the invention, unless the context otherwise requires, either by express language or necessary implication, the term "comprise" or variations such as "comprises" or "comprising" are used in their inclusive sense, i.e., they are used to specify the presence of stated features but are not used to exclude the presence or addition of further features in various embodiments of the invention.

[0202] As used herein, unless the context otherwise requires by express language or necessary implication, the articles "a" and "an" are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, "an element" means one element or more than one element.

Claims

1. A preceramic resin that forms a porous polymer-derived ceramic material, a) A first functionalized organosilicon monomer having a first ceramic yield, b) Below: i. A second functionalized organosilicon monomer having a second ceramic yield, ii. Functionalized organic monomers, iii. Porous ceramic particles, and, iv. pologen, One or more of the following, A pre-ceramic resin containing [a specific component].

2. The following combinations: a) A combination of a first functionalized organosilicon monomer having a first ceramic yield and one or both of a second functionalized organosilicon monomer and a functionalized organic monomer having a second ceramic yield. b) A combination of a first functionalized organosilicon monomer having a first ceramic yield and porous ceramic particles, c) A combination of a first functionalized organosilicon monomer having a first ceramic yield and a pologen, d) A combination of a first functionalized organosilicon monomer having a first ceramic yield, porous ceramic particles, and a porogen. e) A combination of a first functionalized organosilicon monomer having a first ceramic yield, a second functionalized organosilicon monomer having a second ceramic yield, and one or both of the functionalized organic monomer, and porous ceramic particles. f) Combinations of a first functionalized organosilicon monomer having a first ceramic yield, a second functionalized organosilicon monomer having a second ceramic yield, and one or both of the functionalized organic monomers, and a pologen, g) A combination of a first functionalized organosilicon monomer having a first ceramic yield, a second functionalized organosilicon monomer having a second ceramic yield, one or both of a functionalized organic monomer, porous ceramic particles, and porogen. A preceramic resin according to claim 1, comprising one of the following.

3. The preceramic resin according to claim 1 or 2, wherein the porous ceramic particles are present, and at least 90% of the ceramic particles have a size between about 1 nm and about 1 mm, as determined using TEM.

4. The first functionalized organosilicon monomer is The chemical structures of the following equations 1, 2, 3, 4, and 5 are as follows: 【Chemistry 1】 (In the formula, n represents the main chain structure of repeating motifs containing silicon atoms, and is an independent integer between 2 and 15, and R １ 、 R ２ 、 R ３ 、 and R ４ are each independently selected, for each integer n, from the group consisting of H, C １ to C １８ substituted or unsubstituted alkyl, C １ to C １８ substituted or unsubstituted alkyl ether, phenyl, and halide, provided that the pair of R １ and R ２ and the pair of R ３ and R ４ are not both H, alkyl ether, or halide for all integers n), a polysiloxane, polycarbosiloxane, polycarbosilane, polysilylcarbodiimide, and polysilazane having C １ ~C １８ Substituted or unsubstituted alkyl, C １ ~C １８ One or more R selected from the group consisting of substituted or unsubstituted alkyl ethers, phenyls, and halides. １ Polysilsesquioxanes, polysilsesquicarbodiimides, and polysilsesquiazanes substituted with the group, The chemical structures of formulas 6, 7, and 8 are as follows: 【Chemistry 2】 (In the formula, n represents the main chain structure of repeating motifs containing silicon atoms, and is an independent integer between 2 and 15. R １ , R ２ , R ３ , and R ４ This is as defined above, and, R ５ and R ６ For each integer n, H, OH, and C are independent. １ ~C １８ Substituted or unsubstituted alkyl, C １ ~C １８ A preceramic resin according to claim 1 or 2, independently selected from the group consisting of substituted or unsubstituted alkyl ethers and phenyl.

5. The preceramic resin according to claim 1 or 2, wherein the first functionalized organosilicon monomer is selected from the group consisting of methacrylateoxypropyl-terminated polydimethylsiloxane, (mercaptopropyl)methylsiloxane homopolymer, and vinyl methoxysiloxane homopolymer.

6. The preceramic resin according to claim 1 or 2, wherein the second functionalized organosilicon monomer is present, and the first ceramic yield and the second ceramic yield differ by about 5% or more.

7. The preceramic resin according to claim 1 or 2, wherein the second functionalized organosilicon monomer is present and selected from the group consisting of methacrylateoxypropyl-terminated polydimethylsiloxane, (mercaptopropyl)methylsiloxane homopolymer, vinyl methoxysiloxane homopolymer, and methacrylateoxypropyl-substituted poly(isobutyl-t8-silsesquioxane).

8. The aforementioned functionalized organic monomer exists and has the following formula: Spacer (L) ｎ (The preceramic resin according to claim 1 or 2, wherein the spacer is a spacer group, L is a reactive group that reacts with at least the first functionalized organosilicon monomer, and n is an integer of 2 or more.)

9. The preceramic resin according to claim 1 or 2, wherein the pologen is present and selected from the group consisting of toluene, methanol, cyclohexanol, hexane, dodecanol, 1,2-propanediol, water, 1-propanol, 1,4-butanediol, dimethylformamide, acetonitrile, decane and decanol, polyethylene glycol (PEG), and polyethylene glycol diacrylate (PEGDA).

10. A porous polymer-derived ceramic material formed from the preceramic resin according to claim 1 or 2.

11. 70m ２ A porous polymer-derived ceramic material characterized by a specific surface area of ​​1 / g or more.

12. The porous polymer-derived ceramic material according to claim 10, wherein the porous polymer-derived ceramic material is microporous, mesoporous, and macroporous.

13. Microporous polymer-derived ceramic material.

14. A porous polymer-derived ceramic material according to claim 11 or 13, formed from the preceramic resin according to claim 1 or 2.

15. A method for forming a porous polymer-derived ceramic material, a) Forming a preceramic polymer by subjecting a preceramic resin, which forms a porous polymer-derived ceramic material, to polymerization conditions, b) Exposing the preceramic polymer to thermal decomposition conditions, Includes, Herein, the formation of the polymer-derived ceramic material from the preceramic polymer proceeds through a porous stage, and the thermal decomposition conditions are characterized by the highest temperature within the range of the porous stage.

16. A method for forming a porous polymer-derived ceramic material, a) Forming a preceramic polymer by subjecting a preceramic resin, which forms a porous polymer-derived ceramic material, to polymerization conditions, b) Subjecting the preceramic polymer to thermal decomposition conditions to form a porous polymer-derived ceramic material, Includes, Here, the thermal decomposition conditions are characterized by a maximum temperature of approximately 1000°C or less.

17. A method for forming a porous polymer-derived silica ceramic material, a) Forming a preceramic polymer by subjecting a preceramic resin, which forms a porous polymer-derived silica ceramic material, to polymerization conditions, b) Exposing the preceramic polymer to thermal decomposition conditions, Includes, Here, the formation of the polymer-derived silica ceramic material from the preceramic polymer proceeds through a porous stage, and the thermal decomposition conditions are characterized by the presence of oxygen and the highest temperature within the range of the porous stage, The aforementioned preceramic resin is c) A first functionalized polycarbosiloxane or polycarbosilane monomer having a first ceramic yield, d) Below: i. A second functionalized organosilicon monomer having a second ceramic yield, ii. Porous ceramic particles, and iii. Pologen, One or more of the following, Methods that include...

18. The method according to any one of claims 15 to 17, wherein the thermal decomposition conditions include a maximum temperature of 900°C or less.

19. The method according to any one of claims 15 to 17, further comprising a preliminary step of shaping the preceramic resin using a 3D printer.

20. A polymer-derived ceramic material formed by the method according to any one of claims 15 to 17.

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