CN118878203A - A kind of high-efficiency alkali-resistant porous glass and preparation method thereof - Google Patents

Abstract

The present invention relates to a high-efficiency alkali-resistant porous glass and a preparation method thereof, comprising a sodium borosilicate glass batch material, characterized in that: containing 2% to 20% ZrO ₂ by weight of the sodium borosilicate glass batch material; (1) batching and mixing according to the above weight percentage, placing the mixed materials in a high-temperature furnace for melting and clarification, and then forming and annealing; (2) heat-treating the annealed glass at a temperature slightly higher than the glass transition temperature, so that the glass is phase-separated into a silicon dioxide-rich phase and a boron oxide-rich phase; (3) soaking the phase-separated glass in an acid solution, then repeatedly washing with distilled water and ethanol, and drying to obtain a porous glass; (4) soaking the porous glass in a NaOH solution at room temperature, washing, and drying. Advantages of the present invention: The high-efficiency alkali-resistant porous glass obtained by the present invention can improve the problem that the porous glass is limited in use under alkaline conditions, and can be widely used in the fields of seawater desalination, catalyst carrier, adsorption, etc.

Description

A kind of high-efficiency alkali-resistant porous glass and preparation method thereof

Technical Field

The invention belongs to the technical field of glass preparation, and relates to a high-efficiency alkali-resistant porous glass and a preparation method thereof.

Background Art

Porous glass has sharp pore distribution, large specific surface area, heat resistance, resistance to organic solvents and other properties. It exhibits optical transparency, good mechanical stability and high chemical resistance to most organic solvents and acids (except HF). It is widely used in separation membranes, diffuser tubes, electrode materials and other fields.

Compared with other techniques for preparing porous glass (such as partial sintering, high-temperature bonding, foaming agent method, and sol-gel method), generating pores by phase separation and acid leaching is easier to control the pore topology and is more suitable for low-cost, large-scale production.

However, the poor alkali resistance of conventional porous glass limits its application in alkaline environments. Therefore, developing an efficient alkali-resistant porous glass can increase its application prospects in optical chemical sensors and drug delivery systems and improve its application value.

Summary of the invention

The purpose of the present invention is to solve the problem that the existing porous glass has poor alkali resistance and cannot be used in alkaline environments, and to provide a high-efficiency alkali-resistant porous glass and a preparation method thereof; the present invention treats borosilicate glass containing _ZrO2 by a phase separation method to separate the glass into a silica-rich phase and a boron oxide-rich phase, and then removes the boron oxide-rich phase by an acid treatment technology to obtain a porous glass with enhanced alkali resistance.

To achieve the above purpose, the technical solution adopted by the present invention is as follows:

A high-efficiency alkali-resistant porous glass comprises a sodium borosilicate glass batch material, and is characterized in that it contains ZrO ₂ in an amount of 2% to 20% by weight of the sodium borosilicate glass batch material.

Furthermore, the sodium borosilicate glass batch material is composed of the following raw materials in percentage by weight: 40% to 60% SiO ₂ , 20% to 40% B ₂ O ₃ , 1% to 3% Al ₂ O ₃ , and 5% to 10% Na ₂ O.

A method for preparing high-efficiency alkali-resistant porous glass, characterized by comprising the following steps:

(1) Preparation of glass melting: batching and mixing the materials according to the above weight percentages, placing the mixed materials in a high temperature furnace for melting and clarification, and then forming and annealing;

(2) Phase separation treatment: The annealed glass is heat treated at a temperature slightly above the glass transition temperature (Tg) to separate the glass into a silicon dioxide-rich phase and a boron oxide-rich phase;

(3) Acid treatment: The separated glass is immersed in an acid solution, then repeatedly washed with distilled water and ethanol, and dried in an oven at 85-95°C for 4-10 hours to obtain porous glass;

(4) Alkali treatment: The porous glass is soaked in NaOH solution at room temperature, washed and dried in an oven at 85-100°C for 2-4 hours to obtain a highly efficient alkali-resistant porous glass.

Furthermore, the glass batch material is melted at a temperature of 1200-1500° C. for a time of 2-24 h.

Furthermore, the heat treatment temperature is 500-700°C and the time is 8-48 hours.

Furthermore, the acid solution is a 0.5-1 mol/L HCl solution.

Furthermore, in step (3), the soaking time is 24-48 hours and the temperature is 70-100°C.

Furthermore, the concentration of the NaOH solution is 0.5-1 mol/L.

Furthermore, in step (4), the soaking time is 0.5-4 hours and the temperature is 10-30°C.

Beneficial effects of the present invention:

Borosilicate glass containing _ZrO2 is treated by a phase separation method to separate the glass into a silica-rich phase and a boron oxide-rich phase. The boron oxide-rich phase is then removed by an acid treatment technique. The silica clusters remaining in the acid-impregnated glass matrix channels (boric acid-rich phase) can be further removed by alkali treatment. A highly efficient alkali-resistant porous glass is obtained. The highly efficient alkali-resistant porous glass can improve the problem of porous glass being limited in use under alkaline conditions and can be widely used in seawater desalination, catalyst carriers, adsorption and other fields.

DETAILED DESCRIPTION

The present invention is further described in detail below through specific implementation modes. The specific implementation modes described herein are only used to illustrate and explain the present invention, but are not used to limit the present invention.

A method for preparing high-efficiency alkali-resistant porous glass, the specific implementation steps are as follows:

Example

(1) Glass melting preparation: Select the following weight percentages of 55.7% SiO ₂ , 33.6% B ₂ O ₃ , 1.5% Al ₂ O ₃ , and 9.2% Na ₂ O as glass batch materials, add 2% ZrO ₂ , mix, place the mixed materials in a high-temperature furnace at 1300° C. for melting and clarification for 2 hours, and then perform forming annealing;

(2) Phase separation treatment: The annealed glass was heat treated at 500 °C to induce phase separation, so that the glass was separated into a silicon dioxide-rich phase and a boron oxide-rich phase. The glass was then cut into 2 cm square pieces and mechanically polished to obtain samples.

(3) Acid treatment: The separated glass sample was immersed in a 1 M HCl solution and treated with acid at 80 °C for 24 h. It was then repeatedly washed with distilled water and ethanol and dried in an oven at 90 °C for 3 h to obtain porous glass.

(4) Alkali treatment: The glass was further treated with 0.5 M NaOH solution at room temperature for 2 h. After washing and drying in an oven at 90°C for 3 h, a highly efficient alkali-resistant porous glass was obtained (the obtained sample was designated as Sample 1).

Example 2 (Changing the heat treatment temperature to control the pore size of the pore structure)

The same preparation method as in Example 1 was used, except that the heat treatment temperature in this example was 500°C. (The obtained product is recorded as Sample 2)

Example 3 (Changing the type, concentration and time of acid treatment to detect the effect of selective leaching of borate phase)

The same preparation method as in Example 1 was used, except that step (3) in this example was as follows: the sample glass piece after phase separation was immersed in a 1M HNO ₃ solution and treated with acid at 90°C for 24h. After that, it was repeatedly washed with distilled water and ethanol and dried in an oven at 200°C for 3h to obtain porous glass. (The obtained sample was recorded as sample 3)

Example 4 (minus the alkaline washing step to explore the effect of clustered _SiO2 on pore size, etc.)

The same preparation method as in Example 1 was used, except that step (4) was not performed in this example. (The result was recorded as sample 4)

Comparative Example 1 (No ZrO ₂ is added to the glass melting batch to test the alkali resistance)

The same preparation method as in Example 1 was used, except that 2% ZrO ₂ was not added in this example. (The obtained product was recorded as Sample 5)

Comparative Example 2 (Preparation of porous glass using magnesium thermal method)

(1) Select the following weight percentages: 55.7% SiO ₂ , 33.6% B ₂ O ₃ , 1.5% Al ₂ O ₃ , and 9.2% Na ₂ O as glass batch materials, add 2% ZrO ₂ , mix, place the mixed materials in a high-temperature furnace at 1300° C. for melting and clarification for 2 hours, and then perform forming annealing;

(2) The annealed glass was heat treated at 500°C to induce phase separation, so that the glass was separated into a silicon dioxide-rich phase and a boron oxide-rich phase. The glass was then cut into 2 cm square pieces and mechanically polished to obtain samples.

(3) The sample was crushed, and the magnesium powder was rinsed in a 0.1 M hydrochloric acid solution to remove the surface oxide, and then dried before use; 1 g of glass powder and 1 g of magnesium powder were mixed separately in a glove box filled with argon; the powder mixture was placed in a stainless steel tube with an outer diameter of 3/8 inches and a length of 6 cm (the two sides of the tube were sealed with stainless steel caps), and the stainless steel tube was heated at 600°C for 6 hours to react the porous silica glass and magnesium powder;

(4) Subsequently, the reduced product was immersed in a 1.2 M HCl solution for 2 hours. Finally, the hydrochloric acid-treated product was immersed in a 5.75% HF ethanol/water solution for 1 hour, and dried in an oven at 85-100°C for 2-4 hours to obtain a porous glass sample. (The obtained sample is recorded as sample 6)

The present invention uniformly refers to the standard YBB00352004-2015 to test the alkali resistance of the obtained samples, and the obtained glass samples are made into 10-15 ^cm2 test samples, and are etched with an equal volume of 0.5 mol/L sodium carbonate and 1 mol/L sodium hydroxide boiling mixed solution for 3 hours, and the mass loss per unit surface area of the glass test sample is measured. The alkali resistance test results of the obtained samples are shown in Table 1, and the alkali resistance test classification is shown in Table 2.

The obtained samples were tested for alkali resistance according to standard YBB00352004-2015:

S is the total specific surface area of the test sample, ^cm2

_m1 is the initial mass of the test sample, mg

_m2 is the initial mass of the test sample, mg

ρ _A is the mass lost per unit surface area of the test sample, mg/dm ²

The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form; any technician familiar with the field can make many possible changes and modifications to the technical solution of the present invention by using the above disclosed methods and technical contents without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Therefore, any simple modification, equivalent replacement, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims (10)

1. A high-efficiency alkali-resistant porous glass, comprising a sodium borosilicate glass batch material, characterized in that it contains 2% to 20% ZrO ₂ by weight of the sodium borosilicate glass batch material. 2. The high-efficiency alkali-resistant porous glass according to claim 1, characterized in that the sodium borosilicate glass batch material is composed of the following raw materials in percentage by weight: 40% to 60% _SiO2 , 20% to 40% _{B2O3 ,} 1% to 3% _{Al2O3 ,} and 5% to 10% _Na2O . 3. The method for preparing a high-efficiency alkali-resistant porous glass according to claim 1, characterized in that it comprises the following steps: (1) Preparation of glass melting: batching and mixing the materials according to the above weight percentages, placing the mixed materials in a high temperature furnace for melting and clarification, and then forming and annealing; (2) Phase separation treatment: The annealed glass is heat treated at a temperature slightly above the glass transition temperature to separate the glass into a silicon dioxide-rich phase and a boron oxide-rich phase. (3) Acid treatment: The separated glass is immersed in an acid solution, then repeatedly washed with distilled water and ethanol, and dried to obtain porous glass; (4) Alkali treatment: The porous glass is soaked in NaOH solution at room temperature, cleaned, and dried to obtain a highly efficient alkali-resistant porous glass. 4. A method for preparing a high-efficiency alkali-resistant porous glass according to claim 3, characterized in that the glass batch material is melted at a temperature of 1200-1500°C for a time of 2-24 hours. 5. The method for preparing a high-efficiency alkali-resistant porous glass according to claim 3, characterized in that the heat treatment temperature is 500-700°C and the time is 8-48 hours. 6. The method for preparing a high-efficiency alkali-resistant porous glass according to claim 3, characterized in that the acid solution is a 0.5-1 mol/L HCl solution. 7. A method for preparing a high-efficiency alkali-resistant porous glass according to claim 3, characterized in that: the soaking time in step (3) is 24-48 hours and the temperature is 70-100°C. 8. The method for preparing a high-efficiency alkali-resistant porous glass according to claim 3, characterized in that the concentration of the NaOH solution is 0.5-1 mol/L. 9. The method for preparing a high-efficiency alkali-resistant porous glass according to claim 3, characterized in that: in the step (4), the soaking time is 0.5-4 hours and the temperature is 10-30°C. 10. A method for preparing a high-efficiency alkali-resistant porous glass according to any one of claims 3 to 9, characterized in that: the drying temperature in step (3) is 85-95°C and the time is 4-10 hours; the drying temperature in step (4) is 85-100°C and the time is 2-4 hours.