Narrow pore size distributed hydrophilic filtering membrane sensitive to temperature and pH and preparation method thereof

Abstract

For the problems that a large quantity of organic solvents and pore-foaming agents which are difficult to recycle are used in the traditional membrane preparing process, environmental contamination is caused, the pore size distribution of membranes is wide, and the membranes lack of responsiveness, the invention provides a narrow pore size distributed hydrophilic filtering membrane sensitive to temperature and pH on the basis of the idea of bionics by taking a metal chloride saline solution as the solvent. A preparation method of the membrane comprises the steps that fibroin is grafted with polyacrylonitrile and poly(N-isopropylacrylamide) in a homogeneous mode, and a membrane casting solution is obtained; the membrane casting solution is put into a water coagulating bath, metal ions and chloride ions are gradually scattered in water, an the fibroin grafted with poly(N-isopropylacrylamide) and polyacrylonitrile is subjected to phase transformation to form the membrane. The metal ions and the chloride ions play the role of hole forming, the fibroin, poly(N-isopropylacrylamide) and polyacrylonitrile are subjected to microphase separation, and water channels subjected to ion hole forming are formed in the interface. By means of the fibroin and poly(N-isopropylacrylamide), the pH value sensitivity and temperature sensitivity of the membrane are achieved. By means of the hole forming effect of the metal ions and the chloride ions, the hole size of the membrane is smaller, and the hole size distribution is narrow.

Description

technical field

[0001] The invention relates to a temperature- and pH-sensitive narrow pore size distribution hydrophilic filter membrane and a preparation method thereof, belonging to the field of polymer materials and membranes. Background technique

[0002] Membrane technology has been widely used in water treatment due to its advantages of high efficiency, low energy consumption and low investment cost. Membrane materials in the traditional sense that have been used in production cannot respond to changes in the environment, and the pore size of the membrane will not change with changes in the environment. When separating multi-component substances with different molecular weights, it is often necessary to use different pore sizes. Several types of filter membranes in China can only obtain the required components through multiple filtrations, which complicates the separation process, increases production costs, and affects the modernization process of separation. Theref...

Examples

Embodiment 1

[0017] a) prepare a zinc chloride aqueous solution with a mass percentage concentration of 10%, weigh the silk protein that accounts for 2% of the water mass percentage, dissolve the silk protein in the zinc chloride aqueous solution, pour the silk protein zinc chloride aqueous solution into a three-necked flask, and Nitrogen and oxygen were exhausted for 30 minutes, and acrylonitrile accounting for 2% by mass of deionized water and isopropylacrylamide accounting for 20% by mass of deionized water were added to the three-necked flask under stirring;

[0018] b) under stirring, add dropwise the ammonium persulfate-ferrous sulfate that accounts for 10% of the total mass percentage of acrylonitrile and isopropylacrylamide to initiate the graft polymerization of acrylonitrile and isopropylacrylamide on the silk protein, and the reaction time For 20min, the solution after polymerization was cooled to room temperature, and vacuum defoamed to obtain the casting solution;

[0019] c) ...

Embodiment 2

[0023] a) prepare a zinc chloride aqueous solution with a mass percentage concentration of 100%, weigh the silk protein that accounts for 30% of the water mass percentage, dissolve the silk protein in the zinc chloride aqueous solution, pour the silk protein zinc chloride aqueous solution into a three-necked flask, and Nitrogen and oxygen were exhausted for 1 min, and acrylonitrile accounting for 50% by mass of deionized water and isopropylacrylamide accounting for 1% by mass of deionized water were added to the three-necked flask under stirring;

[0024] b) under stirring, add potassium persulfate which accounts for 0.1% of the total mass percentage of acrylonitrile and isopropylacrylamide dropwise to initiate graft polymerization of acrylonitrile and isopropylacrylamide on the silk protein, and the reaction time is 240min. The polymerized solution was cooled to room temperature, and vacuum degassed to obtain a casting solution;

[0025] c) preparing an aqueous solution with ...

Embodiment 3

[0029] a) prepare the calcium chloride aqueous solution of mass percentage concentration 60%, weigh the silk protein that accounts for 10% of water mass percentage, silk protein is dissolved in calcium chloride aqueous solution, silk protein calcium chloride aqueous solution is poured in the there-necked flask, pass Nitrogen and oxygen were exhausted for 10 minutes, and acrylonitrile accounting for 10% by mass of deionized water and isopropylacrylamide accounting for 10% by mass of deionized water were added to the three-necked flask under stirring;

[0030]b) under stirring, add dropwise sodium persulfate-sodium bisulfite accounting for 1% of the total mass percentage of acrylonitrile and isopropylacrylamide to initiate graft polymerization of acrylonitrile and isopropylacrylamide on the silk protein, and react The time is 60min, the solution after the polymerization is cooled to room temperature, vacuum defoaming, and the casting solution is obtained;

[0031] c) preparing a...

technical field

[0001] The invention relates to a temperature- and pH-sensitive narrow pore size distribution hydrophilic filter membrane and a preparation method thereof, belonging to the field of polymer materials and membranes. Background technique

[0002] Membrane technology has been widely used in water treatment due to its advantages of high efficiency, low energy consumption and low investment cost. Membrane materials in the traditional sense that have been used in production cannot respond to changes in the environment, and the pore size of the membrane will not change with changes in the environment. When separating multi-component substances with different molecular weights, it is often necessary to use different pore sizes. Several types of filter membranes in China can only obtain the required components through multiple filtrations, which complicates the separation process, increases production costs, and affects the modernization process of separation. Theref...

Examples

Embodiment 1

[0017] a) prepare a zinc chloride aqueous solution with a mass percentage concentration of 10%, weigh the silk protein that accounts for 2% of the water mass percentage, dissolve the silk protein in the zinc chloride aqueous solution, pour the silk protein zinc chloride aqueous solution into a three-necked flask, and Nitrogen and oxygen were exhausted for 30 minutes, and acrylonitrile accounting for 2% by mass of deionized water and isopropylacrylamide accounting for 20% by mass of deionized water were added to the three-necked flask under stirring;

[0018] b) under stirring, add dropwise the ammonium persulfate-ferrous sulfate that accounts for 10% of the total mass percentage of acrylonitrile and isopropylacrylamide to initiate the graft polymerization of acrylonitrile and isopropylacrylamide on the silk protein, and the reaction time For 20min, the solution after polymerization was cooled to room temperature, and vacuum defoamed to obtain the casting solution;

[0019] c) ...

Embodiment 2

[0023] a) prepare a zinc chloride aqueous solution with a mass percentage concentration of 100%, weigh the silk protein that accounts for 30% of the water mass percentage, dissolve the silk protein in the zinc chloride aqueous solution, pour the silk protein zinc chloride aqueous solution into a three-necked flask, and Nitrogen and oxygen were exhausted for 1 min, and acrylonitrile accounting for 50% by mass of deionized water and isopropylacrylamide accounting for 1% by mass of deionized water were added to the three-necked flask under stirring;

[0024] b) under stirring, add potassium persulfate which accounts for 0.1% of the total mass percentage of acrylonitrile and isopropylacrylamide dropwise to initiate graft polymerization of acrylonitrile and isopropylacrylamide on the silk protein, and the reaction time is 240min. The polymerized solution was cooled to room temperature, and vacuum degassed to obtain a casting solution;

[0025] c) preparing an aqueous solution with ...

Embodiment 3

[0029] a) prepare the calcium chloride aqueous solution of mass percentage concentration 60%, weigh the silk protein that accounts for 10% of water mass percentage, silk protein is dissolved in calcium chloride aqueous solution, silk protein calcium chloride aqueous solution is poured in the there-necked flask, pass Nitrogen and oxygen were exhausted for 10 minutes, and acrylonitrile accounting for 10% by mass of deionized water and isopropylacrylamide accounting for 10% by mass of deionized water were added to the three-necked flask under stirring;

[0030]b) under stirring, add dropwise sodium persulfate-sodium bisulfite accounting for 1% of the total mass percentage of acrylonitrile and isopropylacrylamide to initiate graft polymerization of acrylonitrile and isopropylacrylamide on the silk protein, and react The time is 60min, the solution after the polymerization is cooled to room temperature, vacuum defoaming, and the casting solution is obtained;

[0031] c) preparing a...