POROUS NON-METALLIC MATERIAL

Abstract

The present invention provides a porous non-metallic material including a material body, the material body is composed of pore cavities and cavity walls formed by surrounding the pore cavities in three-dimensional space. The pore cavities are uniformly distributed, and each pore cavity is three-dimensionally interconnected. The pore cavities are uniformly distributed means that the pore cavities are uniformly distributed under any unit-level volume on the porous material. The present invention provides a specific and clear measurement method for pore cavities distribution uniformity of the porous material, that is, the pore distribution uniformity of the porous material and the hierarchical structure thereof is measured on the scale of the small unit-level volume. Such porous structure is highly uniform, thereby ensuring the uniformity of the properties of the porous material.

Claims

1. A porous non-metallic material, comprising a material body, wherein the material body is composed of pore cavities and cavity walls formed by surrounding the pore cavities in three-dimensional space, the pore cavities are uniformly distributed and each pore cavity is three-dimensionally interconnected, wherein the pore cavities are uniformly distributed refers to that the pore cavities are uniformly distributed under any unit-level volume on the porous non-metallic material.

2. The porous non-metallic material according to claim 1, wherein the unit-level volume refers to a cubic centimeter level volume, or a cubic millimeter level volume, or a smaller unit-level volume.

3. The porous non-metallic material according to claim 1, wherein the pore cavities are uniformly distributed refers to that masses of a first plurality of three-dimensional blocks randomly selected from the porous non-metallic material are substantially the same, wherein the first plurality of three-dimensional blocks have volumes of less than or equal to one cubic centimeter and same sizes.

4. The porous non-metallic material according to claim 3, wherein the masses are substantially the same means, the first plurality of three-dimensional blocks having the volumes of less than or equal to one cubic centimeter and the same sizes are randomly selected from the porous non-metallic material to measure masses, an average value of the masses is obtained, and an absolute deviation of the mass of any one of the plurality of three-dimensional blocks from the average value of the masses is less than or equal to 4% of the average value of the masses of the first plurality of the three-dimensional blocks.

5. The porous non-metallic material according to claim 1, wherein masses of a second plurality of three-dimensional blocks randomly selected from the porous material are substantially a same, wherein the second plurality of three-dimensional blocks have the volumes of less than or equal to one cubic millimeter and same sizes.

6. The porous non-metallic material according to claim 5, wherein the masses are substantially the same means, the second plurality of three-dimensional blocks having the volumes of less than or equal to one cubic millimeter and the same sizes are randomly selected from the porous non-metallic material to measure masses, an average value of the masses is obtained, and an absolute deviation of the mass of any one of the plurality of three-dimensional blocks from the average value of the masses is less than or equal to 4% of the average value of the masses of the second plurality of the three-dimensional blocks.

7. The porous non-metallic material according to claim 1, wherein the porous non-metallic material is composed of a multilevel porous material, wherein a body of the multilevel porous material is composed of pore cavities graded by a material pore size and cavity walls formed by surrounding the pore cavities in three-dimensional space, and the cavity walls are provided with lower-level pore cavities, and pore cavities of a same level are three-dimensionally interconnected and the pore cavities of different levels are also interconnected.

8. The porous non-metallic material according to claim 1, wherein next-level porous materials constitute cavity walls of previous-level pore cavities.

9. The porous non-metallic material according to claim 1, wherein cavity walls of upper-level pore cavities of the porous non-metallic material are composed of a lower-level multilevel porous material.

10. The porous non-metallic material according to claim 1, wherein cavity walls of upper-level pore cavities of the porous non-metallic material are composed of a composite of each level of lower-level porous materials.

11. The porous non-metallic material according to claim 2, wherein the pore cavities are uniformly distributed refers to that masses of a first plurality of three-dimensional blocks randomly selected from the porous non-metallic material are substantially a same, wherein the first plurality of three-dimensional blocks have volumes of less than or equal to one cubic centimeter and same sizes.

12. The porous non-metallic material according to claim 2, wherein masses of a second plurality of three-dimensional blocks randomly selected from the porous material are substantially a same, wherein the second plurality of three-dimensional blocks have the volumes of less than or equal to one cubic millimeter and same sizes.

13. The porous non-metallic material according to claim 3, wherein masses of a second plurality of three-dimensional blocks randomly selected from the porous material are substantially a same, wherein the second plurality of three-dimensional blocks have the volumes of less than or equal to one cubic millimeter and same sizes.

14. The porous non-metallic material according to claim 4, wherein masses of a second plurality of three-dimensional blocks randomly selected from the porous material are substantially a same, wherein the second plurality of three-dimensional blocks have the volumes of less than or equal to one cubic millimeter and same sizes.

15. The porous non-metallic material according to claim 2 wherein the porous non-metallic material is composed of a multilevel porous material, wherein a body of the multilevel porous material is composed of pore cavities graded by a material pore size and cavity walls formed by surrounding the pore cavities in three-dimensional space, and the cavity walls are provided with lower-level pore cavities, and pore cavities of a same level are three-dimensionally interconnected and the pore cavities of different levels are also interconnected.

16. The porous non-metallic material according to claim 3 wherein the porous non-metallic material is composed of a multilevel porous material, wherein a body of the multilevel porous material is composed of pore cavities graded by a material pore size and cavity walls formed by surrounding the pore cavities in three-dimensional space, and the cavity walls are provided with lower-level pore cavities, and pore cavities of a same level are three-dimensionally interconnected and the pore cavities of different levels are also interconnected.

17. The porous non-metallic material according to claim 4 wherein the porous non-metallic material is composed of a multilevel porous material, wherein a body of the multilevel porous material is composed of pore cavities graded by a material pore size and cavity walls formed by surrounding the pore cavities in three-dimensional space, and the cavity walls are provided with lower-level pore cavities, and pore cavities of a same level are three-dimensionally interconnected and the pore cavities of different levels are also interconnected.

18. The porous non-metallic material according to claim 5 wherein the porous non-metallic material is composed of a multilevel porous material, wherein a body of the multilevel porous material is composed of pore cavities graded by a material pore size and cavity walls formed by surrounding the pore cavities in three-dimensional space, and the cavity walls are provided with lower-level pore cavities, and pore cavities of a same level are three-dimensionally interconnected and the pore cavities of different levels are also interconnected.

19. The porous non-metallic material according to claim 6 wherein the porous non-metallic material is composed of a multilevel porous material, wherein a body of the multilevel porous material is composed of pore cavities graded by a material pore size and cavity walls formed by surrounding the pore cavities in three-dimensional space, and the cavity walls are provided with lower-level pore cavities, and pore cavities of a same level are three-dimensionally interconnected and the pore cavities of different levels are also interconnected.

20. The porous non-metallic material according to claim 2, wherein next-level porous materials constitute cavity walls of previous-level pore cavities.

Description

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The detailed embodiments are given on the premise of the technical solution of the present invention, but the protection scope of the present invention is not limited to the following embodiments. It is obvious that various alternatives or modifications can be made according to the ordinary skills in the art and/or conventional means without departing from or changing the spirit of the prevent invention, which are included within the scope of the present invention.

Embodiment 1

[0024] The porous material of the present invention is polytetrafluoroethylene having a secondary pore structure, wherein, the cavity walls of first-level pore cavities which are evenly distributed and interconnected are provided with the second-level pore cavities which are evenly distributed and interconnected. The two levels of pore cavities are also interconnected, and the interconnection is a three-dimensional interconnection. Each level porous material of the material body is a continuous structure respectively. The total effective porosity is 70%, the average pore size of the large pore cavities is 0.45 m, and the cavity walls of the large pore cavities are provided with interconnected small pore cavities having an average pore size of 30 nm.

[0025] Nine three-dimensional blocks with the same size of 10 mm10 mm10 mm were randomly taken from the porous material by mechanical processing method and the masses thereof were measured with a Mettler-Toledo XP26 Microbalance. The results are shown in Table 1, wherein an absolute value of a deviation from the average value is expressed as a percentage, and the value of the percentage can be obtain by the absolute value of the deviation from the average value dividing by the average value of the masses. As can be seen from Table 1, the deviations of the masses are not more than 4%.

TABLE-US-00001 TABLE 1 Absolute value of deviation from No Mass (mg) average value (%) 1 655.815 0.6% 2 633.422 2.9% 3 645.542 1.0% 4 665.844 2.1% 5 640.038 1.9% 6 675.967 3.6% 7 643.786 1.3% 8 658.871 1.0% 9 650.425 0.3% Average value 652.19 of the masses

[0026] The preparation method of the polytetrafluoroethylene porous material is as follows:

[0027] (1) Mixing a polytetrafluoroethylene emulsion having a solid content of 60%, a chitosan having a particle size of 30 nm, and a 5% (mass ratio) sodium alginate solution uniformly to prepare a spinning solution according to a mass ratio of 50:30:4;

[0028] (2) Preparing a polytetrafluoroethylene precursor film by using an electrospinning method in an oriented electrospinning device under vacuum conditions;

[0029] (3) Winding 5 layers of the precursor film onto a cylinder support mould, and sending to a tube furnace for sintering in a vacuum or a protective atmosphere, the sintering is carried out by multi-steps and successive sintering processing via a temperature control program, and heating from room temperature to 150 C. at a rate of 5 C./min, holding at 150 C. for 60 min, and then heating to 400 C. at a rate of 5 C./min, and holding at 400 C. for 120 min.

[0030] (4) After sintering, cooling via the temperature control program, and performing subsequent treatment according to conventional techniques to obtain a porous polytetrafluoroethylene hollow fiber membrane having a secondary pore structure.

[0031] The material can be used for gas-liquid separation and liquid-liquid separation to achieve accurate grading filtration. For example, it is suitable for filtration of two-component or multi-component gas (liquid) (such as volatile solute aqueous solution). Moreover, it has large flux, high rejection rate, high separation coefficient, and excellent hydrophobic property, and is not easily contaminated (such as liquid infiltration). Therefore, it has the advantages of high efficiency and long-term efficiency.

Embodiment 2

[0032] The porous material of the present invention is a porous ceramic having a tertiary pore structure, wherein, the cavity walls of first-level pore cavities which are evenly distributed and interconnected are provided with second-level pore cavities which are evenly distributed and interconnected, the cavity walls of the second-level pore cavities are provided with third-level pore cavities, which are evenly distributed and interconnected. The three levels of the pore cavities also interconnected, and the interconnection is a three-dimensional interconnection. The porous material of each level of the material body is a continuous structure respectively. A maximum outer boundary of each level porous material is equivalent to a space boundary of an entire material body. The total effective porosity is 75%, the average pore size of the large pore cavities is 500 it m, and the cavity walls of the large pore cavities are provided with interconnected second-level pores having an average pore size of 30 m, and the cavity walls of the second-level pores are provided with interconnected third-level pores having an average pore size of 800 nm.

[0033] Nine three-dimensional blocks with the same size of 10 mm10 mm10 mm were randomly taken from the porous material by mechanical processing method and the masses thereof were measured with a Mettler-Toledo XP26 microbalance. The results are shown in Table 2, wherein an absolute value of a deviation from the average value is expressed as a percentage, and the value of the percentage can be obtained by the absolute value of the deviation from the average value dividing by the average value of the masses. As can be seen from Table 2, the deviations of the masses are not more than 4%.

TABLE-US-00002 TABLE 2 Absolute value of deviation from No Mass (mg) average value (%) 1 1254.855 2.4% 2 1300.448 1.2% 3 1280.488 0.4% 4 1310.841 2.0% 5 1265.184 1.6% 6 1279.941 0.4% 7 1293.218 0.6% 8 1280.215 0.4% 9 1305.565 1.5% Average value 1285.639 of the masses

[0034] The preparation method of the porous ceramic is as follows:

[0035] (1) Selecting polystyrene spheres having a particle size of 80050 nm and assembling them into a three-dimensional ordered colloidal template. Preparing a ceramic nano solution and introducing the ceramic nano solution into the three-dimensional ordered colloidal template made of the polystyrene spheres to obtain a mixture. Drying the mixture and then crushing to obtain particles having a particle size of 5 m;

[0036] (2) Selecting starches with a particle size of 80050 nm and mixing with distilled water at a weight ratio of 1:50 to prepare a starch solution. Mixing the above-mentioned particles, ethyl cellulose having a particle size of 30 m and the starch solution into a slurry at a weight ratio of 15:2:7, and uniformly impregnating the slurry onto a polyurethane foam having a pore size of 55020 m;

[0037] (3) Sintering the impregnated polyurethane foam in a vacuum or a protective atmosphere, and then performing a conventional treatment according to a porous ceramic preparation process to obtain the porous ceramic having a tertiary pore structure.

[0038] The multilevel ceramic can be used as a medical implant material. The first-level pores are particularly suitable for meeting the needs of the ingrowth for living tissue such as blood vessels; the second-level pores are particularly suitable for colonies of cells; the third-level pores are particularly advantageous for satisfying the requirements of cell adhesion and differentiation due to its large number of nanopores, and the specific surface area thereof is large enough to load many growth factors. Moreover, the connectivity of the pores is good, and pores of the same level are interconnected and the pores of different levels are also interconnected, which can fully satisfy the requirements of infiltration and transmission of blood and tissues, and realize the excretion of protein degradation products and metabolic products. Therefore, it is a true bone regeneration material.

Embodiment 3

[0039] The porous material of the present invention is a porous glass having a tertiary pore structure, wherein, the cavity walls of first-level pore cavities, which are evenly distributed and interconnected, are provided with second-level pore cavities which are evenly distributed and interconnected, the cavity walls of the second-level pore cavities are provided with third-level pore cavities which are evenly distributed and interconnected. The three levels of the pore cavities are also interconnected, and the interconnection is a three-dimensional interconnection. The porous material of each level of the material body is a continuous structure respectively. A maximum outer boundary of each level porous material is equivalent to a space boundary of an entire material body. The total effective porosity is 80%, the average pore size of the large pore cavities is 20 m, and the cavity walls of the large pore cavities are provided with interconnected second-level pores having an average pore size of 800 nm, and the cavity walls of the second-level pores are provided with interconnected third-level pores having an average pore size of 10 nm.

[0040] Nine three-dimensional blocks with the same size of 10 mm10 mm10 mm were randomly taken from the porous material by mechanical processing method and the masses thereof are measured with a Mettler-Toledo XP26 Microbalance. The results are shown in Table 3, wherein an absolute value of a deviation from the average value is expressed as a percentage, and the value of the percentage can be obtained by the absolute value of the deviation from the average value dividing by the average value of the masses. As can be seen from Table 3, the deviations of the masses are not more than 4%.

TABLE-US-00003 TABLE 3 Absolute value of deviation from No Mass (mg) average value (%) 1 1898.125 2.0% 2 1900.321 2.1% 3 1875.653 0.8% 4 1798.214 3.4% 5 1854.941 0.3% 6 1868.651 0.4% 7 1825.632 1.9% 8 1888.715 1.5% 9 1835.675 1.3% Average 1860.659 value of the masses

[0041] The Preparation Method:

[0042] (1) Selecting pure SiO.sub.2, H.sub.3BO.sub.3 and Na.sub.2CO.sub.3 as main raw materials, according to Na.sub.2O 10%, B.sub.2O.sub.3 25% and SiO.sub.2 65% (molar percentage). Melting at 1400 C., constantly stirring and holding for 4 hours, and then casting into a mould;

[0043] (2) Phase separation: using a temperature control program to heat from room temperature to 520 C. at a rate of 25 C./min and holding at 520 C. for 24 hours; then heating to 670 C. at a rate of 20 C./min and holding at 670 C. for 36 hours; then cooling at a rate of 5-10 C./min;

[0044] (3) Leaching in a 1-2 mol/L acid solution at 95 C., performing subsequent treatment including washing, drying, crushing, etc. to obtain nano glass microbeads;

[0045] (4) Uniformly mixing methylcellulose having a particle size of 20 m and the nano glass microbeads at a volume ratio of 3:1, and uniformly pouring into a three-dimensionally interconnected polyester foam, and then pressing into a compact green body;

[0046] (5) Performing conventional heat treatments such as vacuum sintering, annealing, cooling, etc. to obtain the porous glass having a tertiary pore structure.

[0047] The multilevel glass can be used as a carrier for various purposes, such as a reaction template of a substance to prepare a multilevel nano/micron-sized product; such as a catalyst carrier or a drug sustained-release carrier, which has the advantages of low dosage, high efficiency, constant, uniform and long-term efficiency.

Embodiment 4

[0048] The porous material of the present invention is polytetrafluoroethylene having a tertiary pore structure, wherein, the cavity walls of first-level pore cavities which are evenly distributed and interconnected are provided with second-level pore cavities which are evenly distributed and interconnected, the two levels of the pore cavities are also interconnected, and the interconnection is a three-dimensional interconnection. Each level porous material of the material body is a continuous structure respectively. The total effective porosity is 80%, the average pore size of the large pores is 1000 nm, and the cavity walls of the large pores are provided with interconnected second-level pores having an average pore size of 100 nm, and the cavity walls of the second-level pores are provided with interconnected third-level pores having an average pore size of 10 nm.

[0049] Nine three-dimensional blocks with the same size of 10 mm10 mm10 mm were randomly taken from the porous material by mechanical processing method and the masses thereof were measured with a Mettler-Toledo XP26 Microbalance. The results are shown in Table 4, wherein an absolute value of a deviation from the average value is expressed as a percentage, and the value of the percentage can be obtained by the absolute value of the deviation from the average value dividing by the average value of the masses. As can be seen from Table 4, the deviations of the masses are not more than 4%.

TABLE-US-00004 TABLE 4 Absolute value of deviation from No Mass (mg) average value (%) 1 521.317 2.0% 2 508.624 0.5% 3 505.145 1.2% 4 501.528 1.9% 5 518.521 1.5% 6 516.752 1.1% 7 504.883 1.2% 8 510.615 0.1% 9 512.125 0.2% Average 511.0567 value of the masses

[0050] The preparation method of the polytetrafluoroethylene porous material is as follows:

[0051] (1) Mixing PTFE fine powder with polyethylene glycol having a molecular weight of 1000; stirring and heating to 380 tC, and keeping stirring for 60 min; then rapidly cooling to room temperature for crushing, and pulverizing at below 0 C. to obtain polytetrafluoroethylene particles;

[0052] (2) Dispersing the polytetrafluoroethylene particles having a particle size of 200 nm to prepare an emulsion with a solid content of 60%, and uniformly mixing them with chitosan having a particle size of 100 nm and a sodium alginate solution of 5% (mass ratio) according to a mass ratio of 50:30:4 to formulate into a spinning solution;

[0053] (3) Preparing a polytetrafluoroethylene precursor film by using an electrospinning method in an oriented electrospinning device under vacuum conditions;

[0054] (4) Winding 5 layers of the precursor film onto a cylinder support mould, and sending to a tube furnace for sintering in a vacuum or a protective atmosphere, the sintering is carried out by multi-steps and successive sintering processing via a temperature control program, and heating from room temperature to 160 C. at a rate of 6 C./min, holding at 160 C. for 100 min; and then heating to 280 C. at a rate of 6 C./min, and holding at 280 C. for 60 min; and then heating to 400 C. at a rate of 6 C./min, and holding at 400 C. for 100 min.

[0055] (5) After sintering, cooling via the temperature control program, and performing subsequent treatment according to conventional techniques to obtain a porous polytetrafluoroethylene hollow fiber membrane having a tertiary pore structure.

[0056] The material can be used for gas-liquid separation and liquid-liquid separation to achieve accurate grading filtration. For example, it is suitable for filtration of two-component or multi-component gas (iquid) (such as volatile solute aqueous solution). Moreover, it has large flux, high rejection rate, high separation coefficient, and excellent hydrophobic property, and is not easily contaminated (such as liquid infiltration). Therefore, it has the advantages of high efficiency and long-term efficiency.