Preparation method of self-assembled composite nanofiltration membrane for water softening

A composite nanofiltration membrane and self-assembly technology, applied in the field of separation membranes, can solve the problems of long time and complicated operation, and achieve the effects of convenient operation, good hydrophilic performance and good applicability

Active Publication Date: 2017-12-19
NANJING UNIV OF SCI & TECH
View PDF4 Cites 13 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Chinese patent 201410751553.0 discloses a method for preparing a layer-by-layer self-assembled forward osmosis membrane and the layer-by-layer self-assembled forward osmosis membrane prepared by it. The final composite membrane has 4 polyelectrolyte double layers, and the operation is complicated and time-consuming.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Preparation method of self-assembled composite nanofiltration membrane for water softening
  • Preparation method of self-assembled composite nanofiltration membrane for water softening
  • Preparation method of self-assembled composite nanofiltration membrane for water softening

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0026] Prepare a dopamine solution with a concentration of 2g / L, adjust its pH to about 8 with Tris-HCl buffer solution, and prepare a concentration of 2g / L, 2.5g / L, 3g / L, 3.5g / L, 4g / L, 5g / L polyethyleneimine casting solution. Take 5 polyethersulfone ultrafiltration membranes, soak them in 2g / L polyethyleneimine casting solution for 15 minutes, then wash them in pure water for 3 minutes, soak them in dopamine solution after drying, self-polymerize and compound them in an oven at 50°C for 18 hours, and then Fully wash in pure water for 4 hours, after drying, soak in 2g / L, 2.5g / L, 3g / L, 3.5g / L, 4g / L, 5g / L polyethyleneimine casting solution for 15min, Wash for another 3 minutes and dry to prepare a self-assembled composite nanofiltration membrane. Store in pure water for testing.

[0027] The prepared composite nanofiltration membranes with polyethyleneimine concentrations of 2g / L, 2.5g / L, 3g / L, 3.5g / L, 4g / L, and 5g / L in the active layer, when the operating pressure is 0.8MPa ...

Embodiment 2

[0029] Prepare the dopamine solution with a concentration of 2g / L, adjust the pH to about 8 with Tris-HCl buffer solution, and polyethyleneimine casting solution with a concentration of 2g / L and 3g / L respectively. Take 5 polyethersulfone ultrafiltration membranes, soak them in 2g / L polyethyleneimine casting solution for 10min, 20min, 30min, 40min, 50min respectively, then wash them in pure water for 3min, dry them and soak them in dopamine solution at 50 Self-polymerization and compounding in an oven at ℃ for 18 hours, then fully washed in pure water for 4 hours, after drying, soak in 3g / L polyethyleneimine casting solution for 10min, 20min, 30min, 40min, 50min, wash for 3min and then dry , the self-assembled composite nanofiltration membrane can be prepared. Store in pure water for testing.

[0030] The prepared polyethyleneimine casting solution soaking time is 10min, 20min, 30min, 40min, 50min composite nanofiltration membrane, under the operating condition of 0.8MPa, the ...

Embodiment 3

[0032] Prepare dopamine solutions with concentrations of 1g / L, 2g / L, and 3g / L, adjust the pH to about 8 with Tris-HCl buffer solution, and polyethylene with concentrations of 1g / L, 2g / L, and 3g / L Imine casting solution. Take 5 polyethersulfone ultrafiltration membranes, soak them in different concentrations of polyethyleneimine casting solution for 30 minutes, wash them in pure water for 3 minutes, soak them in different concentrations of dopamine solutions after drying, self-polymerize and compound them in an oven at 50°C for 18 hours, and then Fully wash in pure water for 4 hours, after drying, soak in 3g / L polyethyleneimine casting solution for 30 minutes, wash for 3 minutes and then dry to prepare self-assembled composite nanofiltration membrane. Store in pure water for testing.

[0033] The prepared polyelectrolyte double layer polyethyleneimine concentration is 1g / L, dopamine concentration 2g / L; polyethyleneimine concentration is 2g / L, dopamine concentration is 1g / L; po...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
Water contact angleaaaaaaaaaa
Water contact angleaaaaaaaaaa
Login to view more

Abstract

The invention discloses a preparation method of a self-assembled composite nanofiltration membrane for water softening. According to the method, polyethyleneimine is taken as a polyelectrolyte cation layer, and polydopamine is taken as a polyelectrolyte anion layer; by relying on the electrostatic interaction between opposite charges and the strong adhesion property of the polydopamine, a layer-by-layer self-assembly technology is used for preparing the (polyethyleneimine / polydopamine / polyethyleneimine) / polyethersulfone composite nanofiltration membrane on a polyethersulfone ultrafiltration membrane by means of alternate deposition. The composite nanofiltration membrane provided by the invention is only provided with one polyelectrolyte double-layer and one active layer; the preparation method is simple to operate, the prepared membrane is controllable in thickness and good in stability, and preparation cost is lower. The pure water permeability coefficient of the composite nanofiltration membrane is 7.15L / m<2>.h.Mpa, and the molecular weight cut-off of the composite nanofiltration membrane is 480Da, so that the composite nanofiltration membrane belongs to the category of nanofiltration membranes. The maximum retention rates of the composite nanofiltration membrane for Mg<2+> and SO4<2-> in water reach up to 97.5%, but the retention rates of the composite nanofiltration membrane for Na<+>, K<+> and Cl<-> are only about 36.2%, so that the composite nanofiltration membrane can effectively achieve the retention of Mg<2 +> and SO4<2-> ions in the water, and accordingly has better application prospect in the aspect of water softening.

Description

technical field [0001] The invention belongs to the technical field of separation membranes, and in particular relates to a preparation method of a self-assembled composite nanofiltration membrane used for water softening. Background technique [0002] In the field of water treatment, nanofiltration membranes can obtain a large amount of high-quality water under the pressure drive, and compared with reverse osmosis membranes, they have excellent pollutant removal capabilities, low prices, low energy consumption, and long life. It is widely used in the removal of heavy metals in wastewater, the removal of micro-trace pollutants in drinking water, drug extraction, seawater desalination and other fields. [0003] Dopamine is a bioinspired surface coating substance with strong adhesion properties. Dopamine can be coated on the surface of the material to be modified by simple soaking. The coating thickness will increase with the soaking time. Dopamine It is widely used in the pr...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
IPC IPC(8): B01D61/02B01D67/00B01D69/12B01D71/60C02F5/00
CPCB01D61/027B01D67/0002B01D69/12B01D71/60C02F1/442C02F5/00
Inventor 黄中华李娜汤欣源欧阳志宇
Owner NANJING UNIV OF SCI & TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap