Electrochemical synthesis method for face-outwards-oriented phosphorous and aluminum molecular sieve membrane

Abstract

The invention discloses an electrochemical synthesis method for a face-outwards-oriented phosphorous and aluminum molecular sieve membrane in the technical field of synthesis of molecular sieve membranes. The electrochemical synthesis method for the face-outwards-oriented phosphorous and aluminum molecular sieve membrane includes the following specific steps that S1, a porous stainless steel sheetis ground and polished; S2, drying is conducted after ultrasonic cleaning; S3, an alumina wafer is obtained in a pressed mode and dried; S4, the alumina wafer is roasted and ground to be flat; S5, analumina wafer carrier is cleaned to be neutral; S6, seed crystal liquid is prepared; S7, the alumina wafer carrier is coated with the seed crystal liquid; S8, the alumina wafer carrier is dried in adrying box and mixed with sol mixed liquid; S9, aging is conducted through a three-electrode system; and S10, the molecular sieve membrane is obtained in a roasting mode. The molecular sieve membraneprepared through the method is short in synthesis time, the formed membrane is uniform and fine, and the formed membrane thickness is easy to control by adjusting the synthesis time and voltage; the membrane is not affected by the hydrothermal condition; the oriented-growing high-crystalline molecular sieve membrane is easy to prepare; and the molecular sieve membrane is high in adhesion strength,sufficient in covering and good in dispersibility.

Description

technical field [0001] The invention relates to the technical field of synthesis of molecular sieve membranes, in particular to an electrochemical synthesis method of an out-of-plane orientation phosphorus-aluminum molecular sieve membrane. Background technique [0002] In the field of molecular sieve synthesis, the most traditional, simplest and most extensive synthesis method is the hydrothermal synthesis method. After the molecular sieve membrane synthesis liquid is prepared, the substrate is directly immersed in the synthesis liquid. , control the appropriate reaction conditions, such as temperature, pressure and synthesis time, etc., to directly grow molecular sieve membranes on the substrate surface. This method has a simple process, does not require pre-modification of the carrier, is low in cost, and has no restrictions on the shape of the substrate, which is conducive to the industrial batch production of molecular sieve membranes, but its biggest disadvantage is th...

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Problems solved by technology

This method has a simple process, does not require pre-modification of the carrier, is low in cost, and has no restrictions on the shape of the substrate, which is conducive to the industrial batch production of molecular sieve membranes, but its biggest disadvantage is that the synthesized molecular sieve membranes are usually defective. And the orientation is poor, which brings great difficulties to the application of molecular sieve membranes.

The seed crystal method, also known as the secondary growth method, was developed to make up for these defects. This method separates the nucleation process from the film formation process. First, the molecular sieve seed crystal is modified on the substrate by dip coating, spin coating, etc. , to make a seed layer, and then immerse the substrate containing the seed layer in the secondary synthesis solution, and generally use hydrothermal treatment to grow the seed crystal into a film. This method can greatly reduce the number of defects in the molecular sieve film, and through precise control The highly oriented molecular sieve film is prepared by the nucleation and film formation process, but this method has many steps and requires high seed crystals, especially when synthesized on large-area or complex-shaped substrates, due to defects in the seed layer or Shedding will lead to defects in the synthesized molecular sieve membrane, which is not conducive to the large-scale production of molecular sieve membranes

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