1. A preparation method of a polyamide total heat exchange membrane based on interfacial polymerization is characterized by comprising the following steps: the method comprises the following steps:

(1) soaking the polysulfone ultrafiltration membrane in an aqueous phase monomer solution for a period of time and then airing;

(2) contacting the membrane obtained in the step (1) with an organic phase solution for a period of time, and drying in an oven, wherein an organic phase monomer is trimesoyl chloride;

(3) and (3) soaking the film obtained in the step (2) in deionized water for a period of time, and then cleaning, air-drying and storing.

2. The method for preparing polyamide full heat exchange membrane based on interfacial polymerization according to claim 1, wherein: the water phase monomer is one or a mixture of m-phenylenediamine, p-phenylenediamine and piperazine.

3. The method for preparing polyamide full heat exchange membrane based on interfacial polymerization according to claim 1, wherein: the mass fraction of the water phase monomer in the step (1) is 0.1-5 wt%, and the soaking time is 0.5-10 min.

4. The method for preparing polyamide full heat exchange membrane based on interfacial polymerization according to claim 1, wherein: the mass fraction of the organic phase monomer in the step (2) is 0.01-0.5 wt%, and the contact time is 0.5-10 min.

5. The method for preparing polyamide full heat exchange membrane based on interfacial polymerization according to claim 1, wherein: the temperature of the oven in the step (2) is 40-90 ℃, and the drying time is 5-20 min.

6. A polyamide total heat exchange membrane prepared by the method of any one of claims 1 to 5, wherein: comprises a polysulfone porous supporting layer and a polyamide compact skin layer.

Background

Research data show that nearly one third of electricity energy consumption in China is used for residential buildings and shopping malls, and nearly half of electricity is used for air conditioners. In the frequent use process of the air conditioner, the ventilation is very important, and the ventilation system using the total heat exchange energy-saving principle plays an important role in keeping the human health and saving energy from the viewpoints of saving energy and protecting the environment and the body health. While improving the quality of indoor air by exchanging indoor polluted air with outdoor fresh air, in order to reduce the energy required for adjusting the temperature of the fresh air, scientists design a total heat exchanger as a core device of an energy-saving fresh air system to recover energy between the outdoor fresh air and the indoor polluted air.

The total heat exchanger is used for obtaining high-efficiency recovery through sensible heat exchange and latent heat exchange by taking a total heat exchange membrane as a medium. Sensible heat exchange has no mass transfer process, and only fresh air and exhaust air are transferred through energy, so that the temperature is changed; the latent heat exchange is the water vapor mass exchange between the fresh air and the exhaust air, so that the concentration of water vapor in the air is adjusted, the latent heat of the water vapor is increased or reduced, and the purpose of energy conservation is achieved. Since the latent heat of vaporization of water vapor in air is high, the specific gravity of energy in humid air is large. Therefore, the latent heat contribution rate of the total heat exchange of the indoor and outdoor air is much greater than the sensible heat contribution rate. Therefore, in order to improve the energy recovery rate of the total heat exchanger, to ensure fresh air in a closed space, and to improve the moisture and gas barrier properties of the total heat exchange membrane, it is an important research direction.

At present, the core component of the total heat exchange device, the total heat exchange membrane, is mostly made of commercial paper membrane, and the membrane has the following disadvantages: 1. the paper film is a full-permeable film which can not effectively block CO₂Gas, while having poor mechanical properties; 2. the paper film is not flame-retardant, and is easy to mildew in use, thereby causing secondary pollution to air; 3. "trade-off" exists between moisture permeability and gas barrier properties.

Disclosure of Invention

The invention aims to overcome the defects in the prior art and provides a polyamide total heat exchange membrane based on interfacial polymerization and a preparation method thereof.

The technical scheme of the invention is to provide a preparation method of a polyamide total heat exchange membrane based on interfacial polymerization, which comprises the following steps:

(1) soaking the polysulfone ultrafiltration membrane in an aqueous phase monomer solution for a period of time and then airing;

(2) contacting the membrane obtained in the step (1) with an organic phase solution for a period of time, and drying in an oven, wherein an organic phase monomer is trimesoyl chloride;

(3) and (3) soaking the film obtained in the step (2) in deionized water for a period of time, and then cleaning, air-drying and storing.

The water phase monomer is one or a mixture of m-phenylenediamine, p-phenylenediamine and piperazine.

The mass fraction of the water phase monomer in the step (1) is 0.1-5 wt%, and the soaking time is 0.5-10 min.

The mass fraction of the organic phase monomer in the step (2) is 0.01-0.5 wt%, and the contact time is 0.5-10 min.

The temperature of the oven in the step (2) is 40-90 ℃, and the drying time is 5-20 min.

The other technical scheme of the invention is as follows: the polyamide total heat exchange membrane based on interfacial polymerization comprises a polysulfone porous supporting layer and a polyamide compact skin layer, and is prepared by the method.

The invention provides a novel polyamide total heat exchange membrane based on interfacial polymerization and a preparation method thereof, the membrane has high moisture permeability and high heat recovery efficiency, and is mainly applied to the fields of air total heat recovery, air conditioning heating and ventilating energy recovery, indoor air purification, air dehumidification and heat and humidity recovery, and chemical industry environmental protection.

Drawings

The following detailed description is made with reference to the accompanying drawings and embodiments of the present invention

FIG. 1 is a scanning electron microscope of a polyamide total heat exchange membrane prepared in example 4;

fig. 2 is a contact angle of the polyamide total heat exchange membrane prepared in example 1, the contact angle CA being 75.5 °;

FIG. 3 is an enthalpy exchange test apparatus for a polyamide total heat exchange membrane of the present invention; 1 is a blower, 2 is an adjustable gas flowmeter, 3 is a bubbling machine, 4 is a temperature controller, 5 is a temperature and humidity recorder, and 6 is a total heat exchange membrane; a is air, a1 is stream 1, a2 is stream 2, a3 is stream 3, and a4 is stream 4.

Detailed Description

The invention further provides a novel polyamide total heat exchange membrane based on interfacial polymerization and a preparation method thereof by the following examples. It is to be understood that the following examples are given by way of illustration only and are not to be construed as limiting the scope of the present invention, and that various changes and modifications apparent to those skilled in the art in light of the teachings herein are deemed to be within the scope of the present invention.

Example 1

(1) 0.25g of m-phenylenediamine is weighed and dissolved in 100mL of deionized water, and the polysulfone ultrafiltration membrane is soaked in the aqueous phase monomer for 4min and then dried to form an aqueous phase layer.

(2) 0.1g of trimesoyl chloride is weighed and dissolved in 100mL of normal hexane, and the membrane obtained in the step (1) is contacted with an organic phase monomer for 1min and then is dried in an oven for 15min at the temperature of 60 ℃.

(3) And (3) soaking the membrane obtained in the step (2) in deionized water for a period of time, cleaning, air-drying and storing to be tested.

Example 1 Water vapor Transmission Capacity, CO of an interfacial polymerization based Polyamide Total Heat exchange Membrane₂The transmission capacity and the enthalpy exchange efficiency are shown in table 1, the thickness of the novel total heat exchange membrane is 120 +/-5 mu m, and the moisture transmission capacity is 2006.05g/m².24h，CO₂The permeation amount was 6559.2cm³/m²s.MPa, enthalpy exchange efficiency 59.0%.

Example 2

(1) 0.25g of m-phenylenediamine is weighed and dissolved in 100mL of deionized water, and the polysulfone ultrafiltration membrane is soaked in the aqueous phase monomer for 4min and then dried to form an aqueous phase layer.

(2) 0.1g of trimesoyl chloride is weighed and dissolved in 100mL of normal hexane, and the membrane obtained in the step (1) is contacted with an organic phase monomer for 8min and then dried in an oven for 15min at the temperature of 60 ℃.

(3) And (3) soaking the membrane obtained in the step (2) in deionized water for a period of time, cleaning, air-drying and storing to be tested.

Example 2 Water vapor deposition of an interfacial polymerization-based Polyamide Total Heat exchange MembraneGas transmission amount, CO₂The transmission capacity and the enthalpy exchange efficiency are shown in table 1, the thickness of the novel total heat exchange membrane is 120 +/-5 mu m, and the moisture transmission capacity is 1841.40g/m².24h，CO₂The permeation amount was 5376.98cm³/m²s.MPa, enthalpy exchange efficiency 60.5%.

Example 3

(1) 0.25g of piperazine is weighed and dissolved in 100mL of deionized water, and the polysulfone ultrafiltration membrane is soaked in the aqueous phase monomer for 4min and then dried to form an aqueous phase layer.

(2) 0.1g of trimesoyl chloride is weighed and dissolved in 100mL of normal hexane, and the membrane obtained in the step (1) is contacted with an organic phase monomer for 1min and then is dried in an oven for 15min at the temperature of 60 ℃.

(3) And (3) soaking the membrane obtained in the step (2) in deionized water for a period of time, cleaning, air-drying and storing to be tested.

Example 3 Water vapor Transmission Capacity of an interfacial polymerization based Polyamide Total Heat exchange Membrane₂The transmission capacity and the enthalpy exchange efficiency are shown in table 1, the thickness of the novel total heat exchange membrane is 120 +/-5 mu m, and the moisture transmission capacity is 1941.10g/m².24h，CO₂The permeation amount was 31600.04cm³/m²s.MPa, enthalpy exchange efficiency 57.6%.

Example 4

(1) Weighing 2g of m-phenylenediamine, dissolving in 100mL of deionized water, soaking the polysulfone ultrafiltration membrane in an aqueous phase monomer for 4min, and then airing to form an aqueous phase layer.

(2) 0.1g of trimesoyl chloride is weighed and dissolved in 100mL of normal hexane, and the membrane obtained in the step (1) is contacted with an organic phase monomer for 4min and then is dried in an oven for 15min at the temperature of 60 ℃.

(3) And (3) soaking the membrane obtained in the step (2) in deionized water for a period of time, cleaning, air-drying and storing to be tested.

Example 4 Water vapor Transmission Capacity, CO of an interfacial polymerization based Polyamide Total Heat exchange Membrane₂The transmission capacity and the enthalpy exchange efficiency are shown in table 1, the thickness of the novel total heat exchange membrane is 120 +/-5 mu m, and the moisture transmission capacity is 1730.70g/m².24h，CO₂The permeation amount was 203.78cm³/m²s.MPa, enthalpy exchange efficiency 65.7%.

Example 5

(1) Weighing 1g of m-phenylenediamine, dissolving in 100mL of deionized water, soaking the polysulfone ultrafiltration membrane in an aqueous phase monomer for 4min, and then airing to form an aqueous phase layer.

(2) 0.1g of trimesoyl chloride is weighed and dissolved in 100mL of normal hexane, and the membrane obtained in the step (1) is contacted with an organic phase monomer for 8min and then dried in an oven for 15min at the temperature of 60 ℃.

(3) And (3) soaking the membrane obtained in the step (2) in deionized water for a period of time, cleaning, air-drying and storing to be tested.

Example 5 a polyamide total heat exchange membrane based on interfacial polymerization was prepared.

Table 1 shows the moisture permeability and CO of the novel total heat exchange membrane of some examples of the present invention₂The amount of permeate and the enthalpy exchange efficiency.

TABLE 1

Table 1 summarizes that the novel total heat exchange membrane of some embodiments of the present invention has advantages compared with the novel ternary mixed matrix total heat exchange membrane disclosed in chinese patent No. CN 202110047653.5. The functional layer of the film comprises inorganic salt, clay mineral and high polymer, the thickness of the film is 70 +/-5 mu m, and the moisture permeability is 1702.08g/m².24h，CO₂The permeation amount was 37.68cm³/m²24h.0.1MPa, enthalpy exchange efficiency 65.1%. But has poor moisture permeability and the mechanical properties of the film are reduced due to the lack of a support layer. The membrane of the invention meets the latest requirements of the total heat exchange membrane on moisture and gas barrier performance, enthalpy exchange efficiency, mechanical performance and durability required in the practical process.

Moisture permeability test conditions: the temperature was 38 ℃ and RH 90%.

CO₂The permeability test conditions were: the temperature is 25 ℃, and the positive pressure method is adopted for testing.

Enthalpy exchange efficiency test conditions: the fresh air temperature is 35 ℃ and RH 60%; the air exhaust temperature is 25 ℃ and RH35 percent.

The above embodiments are not intended to limit the present invention, and the present invention is not limited to the above embodiments, and all embodiments are within the scope of the present invention as long as the requirements of the present invention are met.