A preparation method of cofs@hpan nanofiltration composite membrane

A composite membrane and nanofiltration technology, applied in chemical instruments and methods, membrane technology, semi-permeable membrane separation, etc., can solve the problem of chemical resistance and cycle stability that have not been reported, and hybrid membranes with poor mechanical properties and service stability , anti-pollution and unstable flux recovery rate, etc., to achieve the effects of excellent cycle stability, eliminating solvent recovery and three waste treatment, excellent permeability and selectivity

Active Publication Date: 2022-05-03
TIANJIN POLYTECHNIC UNIV
View PDF9 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

When the COFs composite membrane is prepared by the surface growth method or the spin coating method, the crystallization of the nanofiltration separation layer is not perfect or the force between the substrate and the matrix is ​​weak. With the increase of the number of layers, the selectivity of the COFs composite membrane increases and the permeability decreases significantly. Pollution resistance and flux recovery rate instability
[0005] The document with application number 201911048401.3 discloses a method for preparing a covalent organic framework hybrid membrane, which prepares a film-forming solution of COFs and polyether copolyamide (PERAX) by ultrasonic stirring, and then coats the film-forming solution by dipping and pulling Coated on the surface of inorganic porous membrane, and then heat-treated to make PERAX self-crosslinked to form a film, so as to obtain a covalent organic framework hybrid membrane, but the maximum doping amount of COFs in the hybrid membrane is only 10%, and the COFs are distributed in the hybrid membrane Inhomogeneity, resulting in poor mechanical properties and service stability of the obtained hybrid film
In the literature "Shi X.S., Wang R., Xiao.A.K, et al.ACS Applied NanoMaterials, 2018, 1(11): 6320-26", the hydrolyzed polyacrylonitrile (HPAN) microfiltration membrane is used as the substrate, and the layer The COFs composite membrane (TpBD-HPAN) was prepared by the layer growth method. The experimental results showed that when the number of COFs layers increased from 3 layers to 11 layers, the pure water flux of the composite membrane increased from 415L m -2 h -1 · bar -1 Reduced to 2L·m -2 h -1 · bar -1 , the chemical resistance and cycle stability of composite membranes have not been reported

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
  • A preparation method of cofs@hpan nanofiltration composite membrane
  • A preparation method of cofs@hpan nanofiltration composite membrane
  • A preparation method of cofs@hpan nanofiltration composite membrane

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0023] The invention provides a method for preparing a COFs@HPAN nanofiltration composite membrane (method for short), which is characterized in that the method comprises the following steps:

[0024] 1) Add COFs and meltable PAN-based copolymers into a twin-rotor high-speed mixer, and mix at a speed of 500-1500 rpm and a temperature of 200-230°C for 5-60 minutes to obtain COFs-PAN masterbatch;

[0025] In step 1), the meltable PAN-based copolymer can be prepared using the materials or preparation methods disclosed in patent ZL201510694690.X or ZL200810053936.5.

[0026] In step 1), the COFs can be but not limited to COF-1 (pore size 1.5nm), COF-5 (pore size 2.7nm), COF-8 (pore size 1.64nm), COF-10 (pore size 3.2nm), COF -DhaTab (pore diameter 3.7nm), COF-TpPa-1 (pore diameter 1.8nm), COF-TpPa-2 (pore diameter 1.5nm), COF-TpBD (pore diameter 2.4nm), COF-TpBD-Me 2 (pore size 2.3nm), COF-TpBD-(OMe) 2 At least one of (pore diameter 2.3nm), COF-TpTGcl (pore diameter 1.3nm), COF-...

Embodiment 1

[0055] 1) Add 50g COF-TpBD-Me 2 Mix with 200g of meltable PAN at 1000rpm and 210°C for 20min to prepare COF-TpBD-Me 2 COFs-PAN masterbatch with a content of 20wt%;

[0056] 2) Stir the composite diluent composed of 180g COFs-PAN masterbatch, 700g caprolactam and 320g glycerol triacetate at 150°C under the protection of nitrogen for 3 hours and defoam for 24 hours to obtain a uniform and foam-free casting solution; The film solution was poured into a mold at 110°C for calendering, and after curing in an air bath at 25°C for 12 hours, the compound diluent was extracted and removed in an aqueous solution to obtain a COFs-PAN blend flat film;

[0057] 3) Primary cross-linking: put the COFs-PAN blend flat film obtained in step 2) into 10wt% NaOH solution for hydrolysis for 2 hours, rinse with ethanol and distilled water to remove NaOH on the film surface, and dry in a vacuum oven at 60°C for 24 hours Obtain the dry COFs@HPAN hybrid membrane;

[0058] Secondary cross-linking: put...

Embodiment 2

[0062] 1) Mix 100g of COF-TpPa-2 and 150g of meltable PAN at a speed of 500rpm and 200°C for 40min to prepare a COFs-PAN masterbatch with a COF-TpPa-2 content of 40wt%;

[0063] 2) Mix 220g COFs-PAN masterbatch, 810g caprolactam and 90g dibutyl sebacate in a composite diluent, stir for 3 hours at 160°C under argon protection, and defoam for 24 hours to obtain a uniform and foam-free casting film liquid; then pour the casting solution into a mold at 90°C for calendering, solidify in an air bath at 20°C for 10 hours, extract and remove the composite diluent in a mixed solution of water and ethanol, and obtain a COFs-PAN blended plate membrane;

[0064] 3) Primary cross-linking: put the COFs-PAN blend flat film obtained in step 2) into 25wt% KOH solution and hydrolyze for 0.5h, rinse with ethanol and distilled water to remove KOH on the film surface, and dry in a vacuum oven at 80°C 15h to obtain a dry COFs@HPAN hybrid membrane;

[0065] Secondary cross-linking: place it in an ...

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
sizeaaaaaaaaaa
strengthaaaaaaaaaa
strengthaaaaaaaaaa
Login to view more

Abstract

The invention discloses a method for preparing a COFs@HPAN nanofiltration composite membrane. COFs and a meltable PAN-based copolymer are fully blended by a high-speed mixing technology to prepare a uniformly distributed COFs-PAN masterbatch, and then the COFs with a uniform distribution are prepared. COFs-PAN blend membrane, and then through three levels of cross-linking in sequence to obtain COFs@HPAN nanofiltration composite membrane. In this method, by adjusting the process parameters of hydrolysis, irradiation and pre-oxidation reaction, the COFs-PAN blend film is processed by hydrolysis-irradiation-pre-oxidation reaction in sequence, and a multi-level adjustable network cross-linked structure can be constructed. According to the needs of different purposes, the network cross-linking structure of the nanofiltration composite membrane can be adjusted to achieve different pore sizes, so as to achieve the functions of efficient decolorization, desalination and virus removal. The prepared asymmetric structure COFs@HPAN nanofiltration composite membrane has excellent permeability and selectivity, high porosity, uniform pore size distribution, excellent thermodynamic stability, chemical resistance, and cycle stability, and can be applied in harsh water environments Separation and purification.

Description

technical field [0001] The invention belongs to the field of COFs nanofiltration membranes, in particular to a method for preparing a COFs@HPAN nanofiltration composite membrane. Background technique [0002] Printing and dyeing wastewater contains complex and difficult-to-degrade dyes and salts, which are characterized by high chroma, high salinity and high toxicity, causing great harm to the ecological environment and human health. With the continuous improvement of my country's printing and dyeing wastewater discharge standards, how to separate and remove the dyes and salts in the printing and dyeing wastewater so that the printing and dyeing wastewater can reach the dischargeable standard has received widespread attention. [0003] Membrane separation technology is a process that uses the selective permeability of separation membranes to pollutants of different particle sizes to achieve the classification, separation, purification and enrichment of multi-component mixtur...

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
Patent Type & Authority Patents(China)
IPC IPC(8): B01D71/72B01D69/12B01D61/00B01D67/00C02F1/44
CPCB01D71/72B01D69/125B01D61/027C02F1/442Y02A20/131
Inventor 韩娜张雅琪张兴祥张总宣张浩然
Owner TIANJIN POLYTECHNIC UNIV
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