Porous hydrated calcium silicate material, dry powder coating prepared from porous hydrated calcium silicate material and application of dry powder coating

Abstract

The invention discloses a porous hydrated calcium silicate material, a dry powder coating prepared from the porous hydrated calcium silicate material and application of the porous hydrated calcium silicate material. The preparation method comprises the following steps: taking tannic acid, carbon nanotubes and hydrated calcium silicate as main raw materials, preparing a porous hydrated calcium silicate material with an active oxygen free radical capturing function through a specific process, and stirring and mixing the porous hydrated calcium silicate material with various conventional dry powder coatings to prepare the building interior wall dry powder coating with the active oxygen free radical capturing function. The prepared building interior wall dry powder coating has good active oxygen free radical capturing capacity, can effectively purify indoor air and remarkably improve the indoor environment quality, and has certain application prospects in the field of building materials.

Description

Technical Field

[0001] The present invention relates to interior wall coatings for buildings, in particular to porous calcium silicate hydrate materials, dry powder coatings prepared therefrom, and their applications in building or decoration, belonging to the field of dry powder coatings. Background Art

[0002] Reactive oxygen free radicals refer to oxygen molecules with unpaired electrons, such as superoxide anion (O 2- ), hydroxyl radical (·OH), hydroperoxide radical (·HO2), singlet oxygen (^1O2), etc. They have highly reactive chemical activities and can undergo oxidation reactions with molecules in living organisms, leading to oxidative damage of biological macromolecules such as cell membranes, proteins, and nucleic acids. The excessive generation and accumulation of reactive oxygen free radicals can cause abnormal cell functions, damage to tissues and organs, and even trigger various diseases such as cancer, cardiovascular diseases, and neurological diseases. Therefore, it is of great significance to research and develop materials that can capture reactive oxygen free radicals. Currently, many materials have been found to have the ability to capture reactive oxygen free radicals. Common materials for capturing reactive oxygen free radicals include natural antioxidants (such as vitamin C, vitamin E, anthocyanins, etc.), synthetic antioxidants (such as BHT, BHA, etc.), metal ions (such as copper, iron, etc.), polyphenolic compounds (such as catechins, anthocyanins, etc.), selenium-rich compounds (such as selenate, ferrous selenite, etc.), etc.

[0003] In recent years, some new types of materials for capturing reactive oxygen free radicals have also emerged, such as nanomaterials and functional polymers. Nanomaterials have a large specific surface area and special physical and chemical properties, which can improve the capture efficiency and stability of the materials. For example, nanomaterials such as gold nanoparticles and titanium dioxide nanoparticles have been widely studied and applied in the capture of reactive oxygen free radicals. Functional polymers can achieve efficient capture of reactive oxygen free radicals by regulating the molecular structure and introduction of functional groups. In addition, some new types of materials for capturing reactive oxygen free radicals are being researched and developed, such as natural plant extracts and reactive oxygen free radical scavengers. Natural plant extracts contain rich antioxidant substances and have good reactive oxygen free radical capture ability. Reactive oxygen free radical scavengers are a class of compounds specifically designed to capture reactive oxygen free radicals and have high selectivity and activity. In short, the generation and harm of reactive oxygen free radicals have attracted wide attention. By researching and developing materials that can capture reactive oxygen free radicals, the damage of reactive oxygen free radicals to organisms can be effectively reduced, and it has important application prospects. With the continuous progress of science and technology, it is believed that more new types of materials for capturing reactive oxygen free radicals will be discovered and applied in the future to provide better protection for people's health.

[0004] The presence of reactive oxygen species (ROS) in the air of interior building walls is a common problem, especially in modern urban environments. The generation of ROS is mainly caused by factors such as air pollutants, ultraviolet radiation, and ionizing radiation. These ROS can lead to a decline in indoor air quality and have an adverse impact on human health. Therefore, developing interior wall coatings with the function of capturing ROS is of great significance.

[0005] Interior wall coatings with the function of capturing ROS can effectively capture and neutralize ROS in indoor air, thereby improving indoor air quality and reducing the risk of human exposure to ROS environments. Currently, some studies have focused on developing interior wall coatings with the function of capturing ROS. These coatings usually adopt the method of adding ROS scavengers to convert ROS into harmless substances through chemical reactions. For example, some studies have used coatings containing antioxidants such as vitamin C and vitamin E to capture ROS. In addition, some studies have also used coatings containing metal ions such as copper and iron to capture ROS. Moreover, some new ROS capture materials are being researched and developed, such as nanomaterials and functional polymers. Nanomaterials have a large specific surface area and special physical and chemical properties, which can improve the efficiency of ROS capture of the materials. Functional polymers can achieve efficient capture of ROS by regulating the molecular structure and introducing functional groups.

[0006] In summary, it is of great necessity to develop interior wall coatings with the function of capturing ROS. Such coatings can improve indoor air quality and reduce the risk to human health. Summary of the Invention

[0007] One of the objectives of the present invention is to provide a porous calcium silicate hydrate material with the function of capturing ROS;

[0008] Another objective of the present invention is to provide a dry powder coating containing the porous calcium silicate hydrate material and its preparation method.

[0009] The above objectives of the present invention are achieved by the following technical solutions:

[0010] To solve the above problems, the technical solutions adopted by the present invention are as follows:

[0011] One aspect of the present invention is to provide a porous calcium silicate hydrate material, and its preparation method includes:

[0012] (1) Mix multi-walled carbon nanotubes and an aqueous NaOH solution, heat for reaction, and then add hydrogen peroxide for reaction to obtain modified multi-walled carbon nanotube powder;

[0013] (2) Add tannic acid as a reducing agent and stabilizer to the modified multi-walled carbon nanotube powder, use water as the reaction medium, and react under ultrasonic conditions to obtain an active oxygen radical scavenging nanomaterial;

[0014] (3) Mix calcium silicate hydrate and a pore-forming agent, then add a binder and dry-press to form pellets, and then calcine to obtain porous calcium silicate hydrate pellets. Grind the porous calcium silicate hydrate pellets into a powder to obtain a porous calcium silicate hydrate powder material;

[0015] (4) Use the porous calcium silicate hydrate powder material as an adsorbent and the active oxygen radical scavenging nanomaterial dispersion as an adsorbate for dynamic cyclic adsorption. Dry the adsorbed adsorbate to obtain a porous calcium silicate hydrate material with the function of scavenging active oxygen radicals.

[0016] In a preferred specific embodiment of the present invention, by mass ratio, in step (1), the multi-walled carbon nanotubes and the NaOH aqueous solution are mixed in a ratio of (2-6):(0.5-2). Preferably, the multi-walled carbon nanotubes and the NaOH aqueous solution with a concentration of 0.02 g / mL are mixed in a ratio of 3:1.

[0017] In a preferred specific embodiment of the present invention, in step (1), after mixing the multi-walled carbon nanotubes and the NaOH aqueous solution, heat to 60-80 °C for reaction. Preferably, after mixing the multi-walled carbon nanotubes and the NaOH aqueous solution with a concentration of 0.02 g / mL, heat to 70 °C and stir magnetically for 2 h for heat preservation reaction.

[0018] In a preferred specific embodiment of the present invention, in step (1), after mixing the multi-walled carbon nanotubes and the NaOH aqueous solution and heating for reaction, add hydrogen peroxide dropwise for reaction. Centrifuge the reaction product, wash the precipitate several times with deionized water and absolute ethanol respectively, and then dry to obtain the modified multi-walled carbon nanotube powder.

[0019] In a preferred specific embodiment of the present invention, in step (2), by mass ratio, the ratio of the modified multi-walled carbon nanotube powder to tannic acid is (1-3):(1-3), preferably 1:1.

[0020] In a preferred specific embodiment of the present invention, in step (2), centrifuge the reaction product, wash the precipitate with deionized water until the dispersion is neutral to obtain a dispersion of the active oxygen radical scavenging nanomaterial.

[0021] In a preferred specific embodiment of the present invention, in step (3), by mass ratio, the ratio of calcium silicate hydrate to the pore-forming agent is (2-5):(0.5-1), preferably 2:1; the calcination in step (3) is carried out at 900-1200 °C for 1-5 h.

[0022] In a preferred specific embodiment of the present invention, the calcination in step (3) is carried out at 1100 °C for 3 h. In step (3), the porous calcium silicate hydrate particles are ground into powder by ball milling. By the method of ball milling, the powder is subjected to collision, impact, shear, and extrusion under the repeated impact of the grinding ball medium. After grinding for a certain time, the powder becomes fully uniform and finally becomes a composite powder with uniformly dispersed reinforcing bodies.

[0023] In a preferred specific embodiment of the present invention, in step (4), by mass ratio, the porous calcium silicate hydrate powder material and the active oxygen free radical scavenging nanomaterial Dispersion are in the ratio of (1 - 5):(5 - 15), preferably 3:10; the dynamic cyclic adsorption time in step (4) is 9 - 12 h, preferably, the dynamic cyclic adsorption time is 10 h; the drying temperature of the porous calcium silicate hydrate material with the function of scavenging active oxygen free radicals in step (4) is 50 - 90 °C, and the drying time is 4 - 8 h.

[0024] In a preferred specific embodiment of the present invention, the drying temperature of the adsorbate after adsorption in step (4) is 70 °C, and the drying time is 6 h. Step (4) adopts a dynamic adsorption process. Through cyclic adsorption, the adsorbent can have higher efficiency and simple operation.

[0025] Another aspect of the present invention is to provide an interior wall dry powder coating for buildings with the function of scavenging active oxygen free radicals, including: dry powder coating and the porous calcium silicate hydrate material with the function of scavenging active oxygen free radicals provided by the present invention; wherein, the dry powder coating can be various dry powder coatings for interior walls of buildings in the prior art or on the market; by mass ratio, the ratio of the dry powder coating to the porous calcium silicate hydrate material with the function of scavenging active oxygen free radicals provided by the present invention is (80 - 100):(0.5 - 10); preferably, the ratio of the dry powder coating to the porous calcium silicate hydrate material with the function of scavenging active oxygen free radicals provided by the present invention is (90 - 100):(3 - 7).

[0026] Another aspect of the present invention is to provide a method for preparing the interior wall dry powder coating for buildings with the function of scavenging active oxygen free radicals, including:

[0027] (1) Mix and stir the dry powder coating and the porous calcium silicate hydrate material with the function of scavenging active oxygen free radicals to obtain a mixed dry powder;

[0028] (2) Grind the mixed dry powder into fine powder to obtain the product.

[0029] In a preferred specific embodiment of the present invention, the rotation speed of the stirring in step (1) is preferably 500 - 700 revolutions per minute; the grinding time in step (2) is 0.5 - 3 hours, preferably 1 hour.

[0030] The present invention is mainly prepared from active oxygen free radical scavengers through a specific process, achieving good active oxygen free radical scavenging ability, effectively purifying indoor air, and improving indoor environmental quality. The raw materials selected for the present invention, including tannic acid, carbon nanotubes, calcium silicate, etc., are all green ecological materials. Tannic acid, as a polyphenol-rich compound present in many natural plants, its antioxidant and antibacterial properties have been applied in biomedicine. Carbon nanotubes, as an adsorbent, pre-enrich and immobilize ROS in mainstream smoke. Porous calcium silicate has a high specific surface area and shows certain superiority in adsorbing active oxygen free radicals. By the dual adsorption properties of carbon nanotubes and porous calcium carbonate to capture ROS, and then combined with the natural reduction characteristics of tannic acid, the ROS that has been enriched and immobilized on the adsorbent material can be scavenged, playing the functions of purification and absorption and promoting health. In addition, calcium silicate has a low relative density, is light in weight and has good mechanical strength, which can make the coating after coating construction firm and reliable, and not easily damaged or cracked. And calcium silicate has a high melting point and a small thermal conductivity coefficient, which can improve the thermal stability of the coating and endow the coating with a certain fire resistance. Description of the Drawings

[0031] Figure 1 It is an experimental device for measuring the removal rate of active oxygen in cigarette smoke.

[0032] Figure 2 It is the fluorescence spectrum of the solution after the cigarette smoke loaded with the modified cellulose acetate filter tip flows through the DCFH solution. Detailed Embodiments

[0033] The present invention will be further described below in conjunction with specific embodiments, and the advantages and features of the present invention will become clearer as the description progresses. However, these embodiments are only exemplary and do not constitute any limitation to the scope of the present invention. Those skilled in the art should understand that without departing from the spirit and scope of the present invention, modifications or substitutions can be made to the details and forms of the present invention, but such modifications and substitutions all fall within the protection scope of the present invention.

[0034] Example 1 Preparation of Porous Hydrated Calcium Silicate Material with the Function of Capturing Active Oxygen Free Radicals

[0035] (I) Preparation of Modified Multi-Walled Carbon Nanotube Powder

[0036] The multi-walled carbon nanotubes were placed in an aqueous NaOH solution with a concentration of 0.02 g / mL at a mass ratio of 3:1, heated to 70 °C, continuously magnetically stirred and kept warm for 2 h, then 15 mL of 30 wt% hydrogen peroxide was added dropwise. After the reaction, the mixture was centrifuged, and the obtained precipitate was washed several times with deionized water and absolute ethanol respectively. Then the treated precipitate was transferred to a watch glass and dried at room temperature to obtain the modified multi-walled carbon nanotube powder.

[0037] (II) Preparation of active oxygen radical scavenging nanomaterials

[0038] Using the prepared modified multi-walled carbon nanotube powder as a precursor, tannic acid was added as a reducing agent and stabilizer at a mass ratio of 1:1, water was used as a reaction medium, and ultrasonic reaction was carried out at 240 W for 1 h. After centrifugation by a centrifuge, the centrifuged precipitate was washed with deionized water until the washing liquid was neutral. The obtained precipitate is the active oxygen radical scavenging nanomaterial.

[0039] (III) Preparation of porous calcium silicate hydrate material

[0040] Calcium silicate hydrate (purchased from Shanxi Yuzhu New Materials Technology Co., Ltd.) and a pore-forming agent (polyethylene glycol) were mixed evenly at a mass ratio of 2:1, and 0.048 g / mL of a binder (polyvinyl alcohol) was added and dry-pressed into pellets in a mold, and then calcined at 1100 °C for 3 h to obtain porous calcium silicate hydrate pellets. The porous calcium silicate hydrate pellets were ball-milled for 2 h by physical solid-phase mixing technology (this technology mainly uses mechanical force, such as pressure, to act on the components of the material to promote the uniform mixing of each phase) to obtain a powder raw material of about 800 mesh, which is the porous calcium silicate hydrate powder material.

[0041] (IV) Preparation of porous calcium silicate hydrate material with the function of scavenging active oxygen radicals

[0042] Using the porous calcium silicate hydrate powder material as an adsorbent and the active oxygen radical scavenging nanomaterial dispersion as an adsorbate, the porous calcium silicate hydrate powder material and the active oxygen radical scavenging nanomaterial dispersion were mixed evenly at a mass ratio of 3:10, and dynamically circulated and adsorbed for 10 h. The adsorbed adsorbate was dried in an oven at 70 °C under normal pressure for 6 h. Through simple adsorption until the active oxygen radical scavenging nanomaterial dispersion was almost clear, the adsorbed adsorbate was dried by vacuum to obtain the porous calcium silicate hydrate functional powder material with the function of scavenging active oxygen radicals.

[0043] Example 2 Preparation of porous calcium silicate hydrate material with the function of scavenging active oxygen radicals

[0044] (I) Preparation of modified multi-walled carbon nanotube powder

[0045] The multi-walled carbon nanotubes were placed in an aqueous NaOH solution with a concentration of 0.02 g / mL at a mass ratio of 3:1, heated to 75 °C, continuously magnetically stirred and kept warm for 2 h, then 15 mL of hydrogen peroxide was added dropwise. After the reaction, the mixture was centrifuged, and the obtained precipitate was washed several times with deionized water and absolute ethanol respectively. Then the treated precipitate was transferred to a watch glass and dried at room temperature to obtain the modified multi-walled carbon nanotube powder.

[0046] (II) Preparation of the dispersion of the active oxygen free radical scavenging nanomaterial

[0047] Using the prepared modified multi-walled carbon nanotube powder as the precursor and water as the reaction medium, ultrasonic reaction was carried out for 1.5 h. The substance obtained by centrifugation with a centrifuge was washed with deionized water until the dispersion was neutral, and thus the dispersion of the active oxygen free radical scavenging nanomaterial was obtained.

[0048] (III) Preparation of the porous calcium silicate hydrate material

[0049] Calcium silicate hydrate and the pore-forming agent (PEG) were mixed evenly at a mass ratio of 2:1, and an appropriate concentration of binder (PVA) was added and dry-pressed into pellets in a mold, and then calcined at 1200 °C for 2 h to obtain porous calcium silicate hydrate pellets. The porous calcium silicate hydrate pellets were ball-milled for 2 h by physical solid-phase mixing technology to obtain a powder raw material with a certain fineness, which was the porous calcium silicate hydrate powder material;

[0050] (IV) Preparation of the porous calcium silicate hydrate material with the function of scavenging active oxygen free radicals

[0051] Using the porous calcium silicate hydrate powder material as the adsorbent and the dispersion of the active oxygen free radical scavenging nanomaterial as the adsorbate, the porous calcium silicate hydrate powder material and the dispersion of the active oxygen free radical scavenging nanomaterial were mixed evenly at a mass ratio of 3:11, and dynamic cyclic adsorption was carried out for 9 h. The adsorbed adsorbate was dried in an oven at 60 °C under normal pressure for 7 h, and simple adsorption was carried out until the dispersion of the active oxygen free radical scavenging nanomaterial was almost clear. The adsorbed adsorbate was dried by vacuum drying to obtain the porous calcium silicate hydrate functional powder material with the function of scavenging active oxygen free radicals.

[0052] Example 3 Preparation of the porous calcium silicate hydrate material with the function of scavenging active oxygen free radicals

[0053] (I) Preparation of the modified multi-walled carbon nanotube powder

[0054] The multi-walled carbon nanotubes were placed in an aqueous NaOH solution with a concentration of 0.02 g / mL at a mass ratio of 3:1, heated to 80 °C, continuously magnetically stirred and kept warm for 2 h, then 12 mL of hydrogen peroxide was added dropwise. After the reaction, the mixture was centrifuged, and the obtained precipitate was washed several times with deionized water and absolute ethanol respectively. Then the treated precipitate was transferred to a watch glass and dried at room temperature to obtain modified multi-walled carbon nanotube powder.

[0055] (II) Preparation of the dispersion of the active oxygen radical scavenging nanomaterial

[0056] Using the prepared modified multi-walled carbon nanotube powder as a precursor, tannic acid was added as a reducing agent and a stabilizer at a mass ratio of 1:1, water was used as a reaction medium, and ultrasonic reaction was carried out for 1.5 h. The substance obtained by centrifugation with a centrifuge was washed with deionized water until the dispersion was neutral, and thus the dispersion of the active oxygen radical scavenging nanomaterial was obtained.

[0057] (III) Preparation of the porous calcium silicate hydrate material

[0058] Calcium silicate hydrate and a pore-forming agent (PEG) were mixed evenly at a mass ratio of 3:1, an appropriate concentration of a binder (PVA) was added, and granules were obtained by dry pressing in a mold. The granules were calcined at 1050 °C for 3 h to obtain porous calcium silicate hydrate granules. The porous calcium silicate hydrate granules were ball-milled for 2 h by physical solid-phase mixing technology to obtain a powder raw material with a certain fineness, which was the porous calcium silicate hydrate powder material;

[0059] (IV) Preparation of the porous calcium silicate hydrate material with the function of scavenging active oxygen radicals

[0060] Using the porous calcium silicate hydrate powder material as an adsorbent and the dispersion of the active oxygen radical scavenging nanomaterial as an adsorbate, the porous calcium silicate hydrate powder material and the dispersion of the active oxygen radical scavenging nanomaterial were mixed evenly at a mass ratio of 3:9, and dynamic cyclic adsorption was carried out for 11 h. The adsorbed adsorbate was dried at 80 °C under normal pressure in an oven for 6 h. Through simple adsorption until the dispersion of the active oxygen radical scavenging nanomaterial was almost clear, the adsorbed adsorbate was dried by vacuum to obtain the porous calcium silicate hydrate functional powder material with the function of scavenging active oxygen radicals.

[0061] Example 4 Preparation of the interior wall dry powder coating for buildings with the function of scavenging active oxygen radicals

[0062] Weigh 93 parts of the dry powder coating by weight and place it in a stirring kettle, then add 7 parts of the porous calcium silicate hydrate material prepared in Example 1, and use a stirring device to stir, maintaining a stirring speed of 700 r / min to obtain a mixed dry powder; the mixed dry powder was added to a grinding device and ground for 1 h to obtain it.

[0063] Preparation of Interior Wall Dry Powder Coating for Buildings with the Function of Capturing Reactive Oxygen Species

[0064] Weigh 95 parts by weight of dry powder coating and place it in a stirring kettle. Then add 5 parts of the porous calcium silicate hydrate material prepared in Example 2. Use a stirring device to stir at a speed of 500 revolutions per minute to obtain a mixed dry powder. Add the mixed dry powder into a grinding device and grind for 1 hour to obtain the product.

[0065] Example 6 Preparation of Interior Wall Dry Powder Coating for Buildings with the Function of Capturing Reactive Oxygen Species

[0066] Weigh 90 parts by weight of dry powder coating and place it in a stirring kettle. Then add 8 parts of the porous calcium silicate hydrate material prepared in Example 3. Use a stirring device to stir at a speed of 600 revolutions per minute to obtain a mixed dry powder. Add the mixed dry powder into a grinding device and grind for 1 hour to obtain the product. Comparative Example 1 Preparation of Porous Calcium Silicate Hydrate Material

[0067] (I) Preparation of Reactive Oxygen Species Capturing Nanomaterials

[0068] Take the prepared modified multi-walled carbon nanotube powder as a precursor, add tannic acid as a reducing agent and stabilizer in a mass ratio of 1:1, and water as a reaction medium. React for 1 hour by 240W ultrasonic wave. Centrifuge with a centrifuge, and wash the centrifuged precipitate with deionized water until the washing liquid is neutral. The obtained precipitate is the reactive oxygen species capturing nanomaterial.

[0069] (II) Preparation of Porous Calcium Silicate Hydrate Material

[0070] Mix calcium silicate hydrate (purchased from Shanxi Yuzhu New Material Technology Co., Ltd.) and a pore-forming agent (polyethylene glycol) evenly in a mass ratio of 2:1. Add 0.048g / mL binder (polyvinyl alcohol) and dry-press and form granules in a mold. Calcinate at 1100°C for 3 hours to obtain porous calcium silicate hydrate granules. Use physical solid-phase mixing technology (this technology mainly uses mechanical force, such as pressure, on the components of the material to promote the uniform mixing of each phase) to ball-mill the porous calcium silicate hydrate granules for 2 hours to obtain a powder raw material of about 800 mesh, which is the porous calcium silicate hydrate powder material.

[0071] (III) Preparation of Porous Calcium Silicate Hydrate Material

[0072] Using porous calcium silicate hydrate powder material as an adsorbent and an active oxygen free radical capturing nanomaterial dispersion as an adsorbate, the porous calcium silicate hydrate powder material and the active oxygen free radical capturing nanomaterial dispersion are mixed evenly at a mass ratio of 3:13. After simple adsorption for 10 h until the active oxygen free radical capturing nanomaterial dispersion is almost clear, the adsorbed adsorbate is vacuum dried at 75 °C for 6 h to obtain a porous calcium silicate hydrate functional powder material.

[0073] Preparation of porous calcium silicate hydrate material in Comparative Example 2

[0074] (I) Preparation of modified multi-walled carbon nanotube powder

[0075] Multi-walled carbon nanotubes are placed in an aqueous NaOH solution with a concentration of 0.02 g / mL at a mass ratio of 3:1, heated to 70 °C, continuously magnetically stirred and kept warm for 2 h, and then 15 mL of 30 wt% hydrogen peroxide is added dropwise. After the reaction, the mixture is centrifuged, and the obtained precipitate is washed several times with deionized water and absolute ethanol respectively. Then the treated precipitate is transferred to a watch glass and dried at room temperature to obtain modified multi-walled carbon nanotube powder.

[0076] (II) Preparation of porous calcium silicate hydrate material

[0077] Calcium silicate hydrate (purchased from Shanxi Yuzhu New Materials Technology Co., Ltd.) and a pore-forming agent (polyethylene glycol) are mixed evenly at a mass ratio of 2:1, and 0.048 g / mL of a binder (polyvinyl alcohol) is added. The mixture is dry-pressed into pellets in a mold and calcined at 1100 °C for 3 h to obtain porous calcium silicate hydrate pellets. The porous calcium silicate hydrate pellets are ball-milled for 2 h by physical solid-phase mixing technology (this technology mainly uses mechanical force, such as pressure, on the components of the material to promote the uniform mixing of each phase) to obtain a powder raw material of about 800 mesh, which is the porous calcium silicate hydrate powder material.

[0078] (III) Preparation of porous calcium silicate hydrate material

[0079] Using the porous calcium silicate hydrate powder material as an adsorbent and the modified multi-walled carbon nanotube powder dispersion as an adsorbate, the porous calcium silicate hydrate powder material and the modified multi-walled carbon nanotube powder dispersion are mixed evenly at a mass ratio of 3:9. After simple adsorption for 9 h until the active oxygen free radical capturing nanomaterial dispersion is almost clear, the adsorbed adsorbate is vacuum dried at 80 °C for 7 h to obtain a porous calcium silicate hydrate functional powder material with the function of capturing active oxygen free radicals.

[0080] Test Example 1 Test on the capture of active oxygen free radicals by porous calcium silicate hydrate material

[0081] (I) Preparation of modified cellulose acetate filter tips

[0082] Disperse the porous calcium silicate hydrate material with the function of scavenging active oxygen free radicals prepared in Example 1 into deionized water to prepare a 20 wt% dispersion. Immerse two identical cellulose acetate filter tips in the above dispersion and deionized water respectively for 24 h, take them out and dry them in an oven at 80 °C.

[0083] (II) In vitro ROS scavenging evaluation

[0084] Control the smoking airflow at 2.8 Nl / min by a vacuum pump so that the cigarette smoke loaded with the modified cellulose acetate evenly flows through the DCFH solution (0.02 mM, in phosphate buffer at pH = 7.2, excitation wavelength is 485 nm), and perform fluorescence detection on the solution.

[0085] The ROS removal rate in the smoke is calculated by the following formula:

[0086] ROS removal rate (%) = [(F0 - F1) / (F2 - F1)] × 100%,

[0087] where F0 is the DCFH fluorescence, and the fluorescence intensities of F1 and F2 are the fluorescence intensities of DCFH at 525 nm after the cigarette smoke of the filter tip modified with the porous calcium silicate hydrate material and the filter tip treated with deionized water flows through DCFH, respectively.

[0088] It is calculated that the ROS removal rate reaches 69%, indicating that the modified porous calcium silicate hydrate material has excellent performance in scavenging active oxygen free radicals.

[0089] Test Example 1 Test on the capture of active oxygen free radicals by the porous calcium silicate hydrate material

[0090] (I) Preparation of the modified cellulose acetate filter tip

[0091] Disperse the porous calcium silicate hydrate material with the function of scavenging active oxygen free radicals prepared in Example 2 into deionized water to prepare a 20 wt% dispersion. Immerse two identical cellulose acetate filter tips in the above dispersion and deionized water respectively for 24 h, take them out and dry them in an oven at 80 °C.

[0092] (II) In vitro ROS scavenging evaluation

[0093] Control the smoking airflow at 2.8 Nl / min by a vacuum pump so that the cigarette smoke loaded with the modified cellulose acetate evenly flows through the DCFH solution (0.02 mM, in phosphate buffer at pH = 7.2, excitation wavelength is 485 nm), and perform fluorescence detection on the solution.

[0094] The ROS removal rate in the smoke is calculated by the following formula:

[0095] ROS removal rate (%) = [(F0 - F1) / (F2 - F1)] × 100%,

[0096] where F0 is the DCFH fluorescence, and the fluorescence intensities of F1 and F2 are the fluorescence intensities of DCFH at 525 nm after cigarette smoke passing through DCFH, where the cigarette smoke is from the filter tip modified with porous calcium silicate hydrate material and the filter tip treated with deionized water, respectively.

[0097] The ROS removal rate was calculated to reach 67%, indicating that the modified porous calcium silicate hydrate material has excellent performance in capturing reactive oxygen species.

[0098] Experimental Example 3 Experiment on the capture of reactive oxygen species by porous calcium silicate hydrate material

[0099] (I) Preparation of modified cellulose acetate filter tip

[0100] Disperse the porous calcium silicate hydrate material with the function of capturing reactive oxygen species prepared in Example 3 in deionized water to prepare a 20 wt% dispersion. Immerse two identical cellulose acetate filter tips in the above dispersion and deionized water respectively for 24 h, take them out and dry them in an oven at 80 °C.

[0101] (II) In vitro ROS scavenging evaluation

[0102] Control the smoking airflow at 2.8 Nl / min by a vacuum pump to make the cigarette smoke loaded with modified cellulose acetate flow uniformly through the DCFH solution (0.02 mM, in phosphate buffer at pH = 7.2, excitation wavelength is 485 nm), and perform fluorescence detection on the solution.

[0103] The ROS removal rate in the smoke is calculated by the following formula:

[0104] ROS removal rate (%) = [(F0 - F1) / (F2 - F1)] × 100%,

[0105] where F0 is the DCFH fluorescence, and the fluorescence intensities of F1 and F2 are the fluorescence intensities of DCFH at 525 nm after cigarette smoke passing through DCFH, where the cigarette smoke is from the filter tip modified with porous calcium silicate hydrate material and the filter tip treated with deionized water, respectively.

[0106] The ROS removal rate was calculated to reach 68%, indicating that the modified porous calcium silicate hydrate material has excellent performance in capturing reactive oxygen species.

[0107] Experimental Example 4 Experiment on the capture of reactive oxygen species by porous calcium silicate hydrate material

[0108] (I) Preparation of modified cellulose acetate filter tip

[0109] Disperse the porous calcium silicate hydrate material prepared in Comparative Example 1 into deionized water to prepare a 20 wt% dispersion. Immerse two identical cellulose acetate filters in the above dispersion and deionized water respectively for 24 h, take them out and dry them in an oven at 80 °C.

[0110] (II) In vitro ROS scavenging evaluation

[0111] Control the smoking airflow at 2.8 Nl / min through a vacuum pump, so that the cigarette smoke loaded with modified cellulose acetate evenly flows through the DCFH solution (0.02 mM, in phosphate buffer at pH = 7.2, excitation wavelength is 485 nm), and perform fluorescence detection on the solution.

[0112] The ROS removal rate in the smoke is calculated by the following formula:

[0113] ROS removal rate (%) = [(F0 - F1) / (F2 - F1)] × 100%,

[0114] where F0 is the DCFH fluorescence, and the fluorescence intensities of F1 and F2 are the fluorescence intensities of DCFH at 525 nm after the cigarette smoke of the filter loaded with the porous calcium silicate hydrate material and the filter treated with deionized water flows through DCFH.

[0115] The calculated ROS removal rate is 40%, indicating that the porous calcium silicate hydrate material has certain performance in capturing reactive oxygen free radicals.

[0116] Test Example 5 Test on the capture of reactive oxygen free radicals by the porous calcium silicate hydrate material

[0117] (I) Preparation of the modified cellulose acetate filter

[0118] Disperse the porous calcium silicate hydrate material prepared in Comparative Example 2 into deionized water to prepare a 20 wt% dispersion. Immerse two identical cellulose acetate filters in the above dispersion and deionized water respectively for 24 h, take them out and dry them in an oven at 80 °C.

[0119] (II) In vitro ROS scavenging evaluation

[0120] Control the smoking airflow at 2.8 Nl / min through a vacuum pump, so that the cigarette smoke loaded with modified cellulose acetate evenly flows through the DCFH solution (0.02 mM, in phosphate buffer at pH = 7.2, excitation wavelength is 485 nm), and perform fluorescence detection on the solution.

[0121] The ROS removal rate in the smoke is calculated by the following formula:

[0122] ROS removal rate (%) = [(F0 - F1) / (F2 - F1)] × 100%,

[0123] Among them, F0 is the DCFH fluorescence, and the fluorescence intensities of F1 and F2 are the fluorescence intensities of DCFH at 525 nm after cigarette smoke flowing through DCFH of the modified filter tip with the porous hydrated calcium silicate material loaded and the filter tip after deionized water treatment, respectively.

[0124] The ROS removal rate was calculated to be 41%, indicating that the porous hydrated calcium silicate material has certain performance in capturing active oxygen free radicals.

[0125] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be regarded as limiting the claimed rights.

Claims

1. A method for preparing a porous hydrated calcium silicate material, characterized in that: The preparation method comprises: (1) mixing multi-walled carbon nanotubes and a NaOH aqueous solution, heating them to react, and then adding hydrogen peroxide to react to obtain modified multi-walled carbon nanotube powder; (2) adding tannic acid as a reducing agent and a stabilizer to the modified multi-walled carbon nanotube powder, using water as a reaction medium, and reacting under ultrasonic conditions to obtain an active oxygen free radical capturing nanomaterial; (3) mixing hydrated calcium silicate and a pore-forming agent, adding a binder, dry-pressing and molding to obtain particles, calcining to obtain porous hydrated calcium silicate particles, and grinding the porous hydrated calcium silicate particles into powder to obtain a porous hydrated calcium silicate powder material; (4) The porous hydrated calcium silicate powder material is used as an adsorbent and the active oxygen free radical capturing nanomaterial dispersion is used as an adsorbent for dynamic cyclic adsorption, and the adsorbent is dried to obtain a porous hydrated calcium silicate material having the function of capturing active oxygen free radicals.

2. The preparation method according to claim 1, characterized in that: According to the mass ratio, in step (1), the multi-walled carbon nanotubes and the NaOH aqueous solution are mixed in a ratio of (2-6): (0.5-2), preferably, the multi-walled carbon nanotubes and the NaOH aqueous solution with a concentration of 0.02 g / mL are mixed in a ratio of 3:1; in step (1), the multi-walled carbon nanotubes and the NaOH aqueous solution are mixed and heated to 60-80° C. for reaction, preferably, the multi-walled carbon nanotubes and the NaOH aqueous solution with a concentration of 0.02 g / mL are mixed and heated to 70° C. for magnetic stirring and insulation reaction for 2 hours; in step (1), the multi-walled carbon nanotubes and the NaOH aqueous solution with a concentration of 0.02 g / mL are mixed and heated for reaction, and then hydrogen peroxide is added dropwise for reaction, the reaction product is centrifuged, and the precipitate is washed several times with deionized water and anhydrous ethanol respectively, and then dried to obtain modified multi-walled carbon nanotube powder.

3. The preparation method according to claim 1, wherein in step (2), the ratio of the modified multi-walled carbon nanotube powder to tannic acid is (1-3): (1-3), preferably 1:1, by mass ratio; in step (2), the reaction product is centrifuged, and the precipitate is washed with deionized water until the dispersion is neutral, and the obtained precipitate is an active oxygen free radical capturing nanomaterial.

4. The preparation method according to claim 1, wherein in step (3), the ratio of hydrated calcium silicate to pore-forming agent is (2-5): (0.5-1), preferably 2:1, by mass ratio; the calcination in step (3) is performed at 900-1200° C. for 1-5 h, preferably at 1100° C. for 3 h; in step (3), the porous hydrated calcium silicate particles are ground into powder by ball milling; In step (4), the ratio of the porous hydrated calcium silicate powder material to the active oxygen free radical capturing nanomaterial dispersion is (1-5): (5-15), preferably 3:10, according to the mass ratio; the dynamic cycle adsorption time described in step (4) is 9-12h, preferably, the dynamic cycle adsorption time is 10h; the drying temperature of the adsorbate after adsorption described in step (4) is 50-90°C, and the drying time is 4-8h, preferably, the drying temperature is 70°C, and the drying time is 6h.

5. The porous hydrated calcium silicate material prepared according to the preparation method according to any one of claims 1 to 4.

6. A dry powder coating for interior walls of buildings having the function of capturing active oxygen free radicals, characterized in that: include: A dry powder coating and a porous hydrated calcium silicate material prepared by the preparation method according to any one of claims 1 to 4.

7. The building interior wall dry powder coating according to claim 6, characterized in that: In terms of mass ratio, the ratio of the dry powder coating to the porous hydrated calcium silicate material is (80-100):(0.5-10); preferably, the ratio of the dry powder coating to the porous hydrated calcium silicate material is (90-100):(3-7).

8. A method for preparing the building interior wall dry powder coating having the function of capturing active oxygen free radicals as claimed in claim 6 or 7, characterized in that: include: (1) mixing a dry powder coating and a porous hydrated calcium silicate material having a function of capturing active oxygen free radicals to obtain a mixed dry powder; (2) Grinding the mixed dry powder into fine powder to obtain; Preferably, the stirring speed in step (1) is 500-700 rpm; and the grinding time in step (2) is 0.5-3 hours, more preferably 1 hour.

9. Use of the porous hydrated calcium silicate material according to claim 5 in preparing dry powder coating for interior walls of buildings.

10. Use of the building interior wall dry powder coating having the function of capturing active oxygen free radicals as claimed in claim 6 or 7 in the preparation of building or decoration materials.

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