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CN-121972115-A - Electronic grade vitamin C trace iron ion directional capturing and multistage membrane composite purifying system

CN121972115ACN 121972115 ACN121972115 ACN 121972115ACN-121972115-A

Abstract

The invention provides an electronic grade vitamin C trace iron ion directional capturing and multistage membrane composite purifying system and method, which relate to the technical field of semiconductor high purity reagent preparation, the method comprises the steps of firstly constructing a heterogeneous composite membrane system based on conductive polymer, forming a forward polarization gradient at a membrane interface by using a potential trap model, inhibiting the reduction effect of vitamin C on the iron ion by using an electron shielding effect, and solving the problem of capturing failure caused by unstable valence state of impurities under a strong reduction matrix; then introducing an acoustic flow field reinforced mass transfer mechanism, and breaking the mass transfer boundary layer resistance at ppb level concentration by utilizing a micro vortex generated by high-frequency acoustic micro flow to realize active directional impact and capture of trace impurities; finally, irreversible locking is carried out based on the track hybridization in the nanometer limit area, and the self-adaptive adjustment of the system is realized by matching with a PID acousto-electric coupling compensation algorithm.

Inventors

  • YAN CHAO
  • LI JUAN

Assignees

  • 湖北倍思电子材料有限公司

Dates

Publication Date
20260505
Application Date
20260126

Claims (8)

  1. 1. The electronic grade vitamin C trace iron ion directional capturing and multistage membrane composite purifying system is characterized by comprising a charge polarization regulating unit, an electronic shielding type nano-finite field capturing reactor and a flow field forced diffusion unit which are sequentially arranged; the electron shielding type nano confinement capture reactor is internally packaged with a redox active composite film with an electric field enhancement effect, wherein the composite film consists of a porous support base film, a middle-layer electron transfer dielectric layer and a supermolecule potential trap layer on the inner surface; The supermolecule potential trap layer is formed by interweaving a rigid macrocyclic ligand with a pi-pi conjugated system and an electron conduction network formed by a carbon nano tube or graphene, and a positive potential gradient relative to a vitamin C bulk solution is generated on the surface of the film through the induction of the electron transfer medium layer to form a charge trapping potential well aiming at trace iron ions; The system realizes the cross-energy barrier migration of trace iron ions from flowing to film solid phase through the electron cloud reconstruction of iron ions with different valence states in the vitamin C solution by the potential trap, and the content of the iron ions after capturing is lower than 10ppb.
  2. 2. The electronic grade vitamin C trace iron ion directional capturing and multistage membrane composite purifying system as claimed in claim 1, wherein the rigid macrocyclic ligand adopted by the supermolecule potential trap layer is porphyrin derivative or phthalocyanine macrocyclic compound with electron-deficient group, the spatial configuration of the rigid macrocyclic ligand is matched with the d orbit energy level of the iron ion, and a stable coordination structure with reverse electron supply effect is formed through orbital hybridization so as to counteract the reduction passivation effect of vitamin C on the iron ion.
  3. 3. The system for directional capture and multistage membrane composite purification of iron ions in electron-grade vitamin C trace as claimed in claim 1, wherein the electron-transfer medium layer of the middle layer is filled in the pore canal of the support base membrane by conducting polymer in situ electrochemical polymerization, and the conducting polymer is selected from polyaniline, polypyrrole or polythiophene and derivatives thereof.
  4. 4. The system for directional capture and multistage membrane composite purification of electronic vitamin C trace iron ions according to claim 1, wherein the flow field forced diffusion unit comprises an acoustic flow field generator arranged at the upstream of the composite membrane, and the acoustic flow field generator generates high-frequency ultrasonic waves to force the iron ions to the effective action radius of the supermolecular potential trap layer by utilizing acoustic flow effect to disturb the retention layer of the membrane interface.
  5. 5. The system for directional capture and multistage membrane composite purification of electronic grade vitamin C trace iron ions as set forth in claim 1, wherein the system is further provided with an on-line potential monitoring feedback loop which adjusts the applied voltage of the electron transfer mediator layer in real time according to the concentration of the effluent iron ions so as to maintain the optimal capture potential of the membrane surface.
  6. 6. The method for preparing the electronic grade vitamin C by using the electronic grade vitamin C trace iron ion directional capturing and multistage membrane composite purifying system according to any one of claims 1 to 5, which is characterized by comprising the following steps: Sp1, polarization pre-adjustment, namely introducing an industrial vitamin C solution into a charge polarization regulation unit, and changing a solvation layer structure around iron ions by applying a high-frequency pulse electric field to reduce desolvation energy barriers of the iron ions; Sp2, interface sound flow reinforcement, namely starting a sound flow field generator to enable a solution to generate micro turbulence before flowing through an electron shielding type nano-confinement capture reactor so as to ensure that trace iron ions break through a diffusion boundary layer on the surface of a membrane; Sp3. Oxidation-reduction mediated capture, wherein the solution enters a composite membrane pore canal, and the iron ions in the fluid are forced to be absorbed into a central cavity of the rigid macrocyclic ligand under the induction of positive potential of the supermolecule potential trap layer; Sp4. Nanometer confinement fixation, wherein in the confined space with the pore diameter of 2-10 nanometers, iron ions and macrocyclic ligands are subjected to strong orbital overlapping and are converted into irreversible chelation state; Sp5. Grading, refining and collecting, namely gradually increasing the energy level depth of the capturing site by multistage serial capturing, and cooling and crystallizing the finally produced purified liquid after sterile filtration at a terminal; sp6 membrane in situ activation, namely stripping the captured iron ions from the potential trap by reverse pulse current when the capturing capacity is attenuated, and recovering the activity of the membrane layer by low-concentration acid washing.
  7. 7. The method for preparing electronic grade vitamin C by utilizing the electronic grade vitamin C trace iron ion directional capturing and multistage membrane composite purifying system as claimed in claim 6, wherein in Sp3, the forward potential gradient of the surface of the membrane is controlled between 0.1 and 0.8 volts, and the potential range can specifically increase the collision frequency of iron ions and capturing sites without causing oxidative decomposition of vitamin C molecules.
  8. 8. The method for preparing electronic grade vitamin C by utilizing the electronic grade vitamin C trace iron ion directional capturing and multistage membrane composite purifying system as claimed in claim 6, wherein in Sp4, the capturing dynamics of iron ions are controlled by the charge compensation rate in the nanometer limit domain, and the adsorption process does not generate desorption along with the increase of the shearing force of fluid, and is represented by unidirectional vector capturing in an unbalanced state.

Description

Electronic grade vitamin C trace iron ion directional capturing and multistage membrane composite purifying system Technical Field The invention relates to the technical field of preparation of semiconductor high-purity reagents, in particular to an electronic grade vitamin C trace iron ion directional capturing and multistage membrane composite purifying system. Background Vitamin C (ascorbic acid) is widely used as a high-performance wet chemical etchant, a cleaning agent and a reduction stabilizer in the semiconductor industry, as the integrated circuit process evolves to 3nm and below, the requirement on trace metal impurities (especially iron ions) in chemicals is extremely harsh (usually less than 10 ppb), at present, the main means for industrially purifying vitamin C and similar organic acids comprise a multi-stage recrystallization and rectification method, namely, separation is carried out by utilizing solubility difference or boiling point difference, however, the vitamin C has poor thermal stability, high-temperature rectification is easy to cause decomposition, the iron ions are often present in the form of volatile organic metal complex or tiny aerosol, physical entrainment in the rectification process is not accurately locked, the conventional ion exchange and chelating resin method is used for adsorbing metals through functional groups on the surface of resin, but in the electronic-grade purification, firstly, the vitamin C is used as a strong reducing agent, fe 3+ in the solution is reduced to Fe 2+, and most of high-efficiency chelating agents are easy to reduce the bonding energy of low-valence iron, so that the iron ions are easy to fall off, and the iron ions are difficult to be absorbed by the conventional ion exchange and chelating agent, and the ion exchange and chelating agent is difficult to realize the effect of high-grade separation, the high-purity is easy to reach the defect of electrostatic absorption, the specific filtration performance, the high-grade impurities, the high-purity is difficult to reach the quality of impurities, and the quality of the film is difficult to reach the quality of quality due to the defect of the impurities, and the defect of high-quality of the quality of impurities. In the process of ultra-purification of electronic grade vitamin C, the existing purification system faces the following technical problems to be solved urgently: The stability problem under redox interference is that under the strong reduction background of vitamin C, the valence state of iron ions is in dynamic change, and the capture site in the prior art often causes unstable coordination bonds due to electronic interference, so that the permanent locking of trace iron in a strong reducing substrate is difficult to realize. When the concentration of iron ions in the solution is reduced to below 100ppb, the diffusion of impurity ions to the surface of the membrane or adsorption sites is extremely severely controlled by the resistance of the liquid membrane, and the traditional static adsorption or laminar flow filtration mode has low treatment efficiency and cannot reach the limit index of <10ppb due to extremely low collision probability. The lack of accurate recognition under the non-equilibrium state is that the existing purification system lacks a directional induction mechanism aiming at the characteristic of the electron energy level of the iron ions, so that the capture precision is insufficient when the system faces trace iron complex with complex structure. Therefore, developing a deep purification system capable of shielding the reductive interference of vitamin C, strengthening ion mass transfer under ultra-low concentration and having potential induction capturing capability becomes a key for preparing semiconductor-grade vitamin C etchant. Disclosure of Invention Technical problem to be solved Aiming at the defects of the prior art, the invention provides an electronic grade vitamin C trace iron ion directional capturing and multistage membrane composite purifying system, which solves the following problems: 1. solves the problems of unstable valence state and capture failure of iron ions caused by a strong reducing matrix: The vitamin C has extremely strong reducibility, fe 3+ in the solution can be rapidly reduced into Fe 2+, and the complexing capacity of chelate resin or functional film commonly used in industry on Fe 2+ is far weaker than that of Fe 3+, so that iron ions in Vc system are extremely easy to desorb or penetrate, an electron shielding effect is formed on a microscopic interface by constructing a supermolecule potential trap layer and utilizing a forward potential gradient mediated by a conductive polymer, the path of the vitamin C for transferring electrons to the iron ions is blocked, the iron ions can still be locked in a high affinity energy state under the background of strong reducibility, and the problem of incomplete capture caused by valence s