Slowly-dissolved micro-nano dispersion scale inhibition material and preparation method thereof

Abstract

The invention relates to the technical field of scale inhibition materials, in particular to a slowly-dissolved micro-nano dispersion scale inhibition material and a preparation method thereof. The composite material comprises a four-layer structure, wherein a porous hydroxyapatite core anchors DTPMP through phosphate radical vacancy to inhibit burst release; sulfonated polyetheretherketone and a cross-linking agent are compounded to form an ion selective controlled release layer, and the diffusion rate of the scale inhibitor is regulated and controlled; photo-thermal conversion graphene quantum dots are embedded in a temperature-sensitive hydrogel shell, and dynamic release is triggered through temperature or Ca < 2 + > concentration; and the corrosion resistance and the mechanical stability are enhanced by the atomic layer deposited ceramic layer and the epoxy resin packaging layer. By constructing a four-layer composite slow-release system, long-acting scale inhibition, extreme tolerance and dynamic response are achieved, the technical problems that a traditional scale inhibition material is high in burst release rate, poor in weather resistance and delayed in release are solved, the water treatment cost per ton is low, the RO membrane service life is long, and a full-period efficient scale inhibition solution is provided for a complex industrial water system.

Description

Technical Field

[0001] The invention relates to the technical field of scale inhibition materials, in particular to a slowly dissolving micro-nano dispersed scale inhibition material and a preparation method thereof. Background Art

[0002] At present, traditional anti-scaling materials (such as PLGA microspheres, SPEEK membrane loading system, etc.) have problems such as high burst rate, poor high temperature resistance, low agent utilization rate (<70%), etc. Especially under complex water quality, problems such as membrane fouling and short anti-scaling cycle (<3 months) caused by unstable carrier structure and uncontrollable release.

[0003] For slowly dissolving micro-nano dispersed anti-scaling materials, the commonly used scheme in the existing technology is: using polylactic acid (PLA) and polycaprolactone (PCL) to encapsulate the anti-scaling components, and achieving slow release through ester bond hydrolysis. In 50°C water, the release period of PLA microspheres can be extended to 30 days (traditional coating materials <7 days). However, this scheme significantly accelerates the degradation of PLA in high-salt or alkaline environments (pH>9), resulting in sudden release (24-hour release>80%). Secondly, the dissolution cycle of industrial system requirements often takes 6-12 months, while PLA only takes 3-5 months to completely degrade in a humid environment. In order to solve this problem, the existing technology designs amphiphilic copolymers (such as PLGA-PEG), regulates the surface wettability of the material, slows down the dissolution rate, and extends the release half-life of CaCO3 crystal inhibitors encapsulated by PLGA-PEG in water to 180 days (only 30 days without encapsulation), but this method also has unstable defects, such as increased fluidity of the hydrophobic segment at temperatures above 50°C, and an increase in the dissolution rate by 2-3 times. Summary of the invention

[0004] The purpose of the present invention is to provide a slowly dissolving micro-nano dispersed antiscaling material and a preparation method thereof, and to achieve precise dynamic release and long-term protection through the synergistic effect of a multi-level structure to solve the problems raised in the above background technology.

[0005] To achieve the above object, on the one hand, the present invention provides a slowly dissolving micro-nano dispersed anti-scaling material, comprising a core, an intermediate controlled release layer, a responsive shell and an outer modified layer, wherein: Core: porous hydroxyapatite (Ca / P=1.67), using phosphate vacancies to anchor DTPMP (complexation energy 215kJ / mol), drug loading ≥55wt%; phosphate vacancies (Ca defects) bind to the phosphonic acid groups of DTPMP through hydrogen bonds to inhibit burst release; the pore structure regulates the diffusion rate; Intermediate controlled release layer: Sulfonated polyetheretherketone (SPEEK, sulfonation degree 75-85%) and cross-linking agent composite membrane (membrane thickness 500-800nm), the ion permeability is regulated by the cross-linking density; the sulfonic acid group selectively excludes Cl -, the DVB cross-linked network forms a molecular sieve effect and regulates the penetration of DTPMP.

[0006] Responsive shell: thermosensitive hydrogel (LCST = 30-47 °C) embedded with photothermal conversion nanoparticles (such as GQDs) to achieve Ca 2+ Swelling / contraction response triggered by concentration or near-infrared light (808 nm); External modification layer: Atomic layer deposition (ALD) ceramic coating (ZrO2, 50-55nm) and epoxy resin encapsulation (EPON828 / TETA system) to improve corrosion resistance and mechanical stability.

[0007] The present invention realizes dynamic matching of release rate and water quality signal through hydroxyapatite vacancy anchoring, SPEEK ion selective membrane diffusion regulation and hydrogel intelligent response; the photothermal conversion efficiency of graphene quantum dots (GQDs) is ≥95% (808nm), and the coupling PID control algorithm (open-loop response ≤3s) realizes on-demand precise release (fluctuation ≤4.7%); the ALD-ZrO2 nanolayer blocks Cl - permeation path (activation energy increased by 15.3 eV), freeze-dried core resists -50℃ frost heave stress (Young's modulus ≥8.7 GPa).

[0008] On the other hand, according to Figure 1 As shown, the present invention provides a method for preparing a slowly dissolving micro-nano dispersed anti-scaling material, comprising the following steps: S1. Prepare porous hydroxyapatite by sol-gel method or freeze-drying method, calcined in vacuum at 600±20℃, impregnated with 25-50% DTPMP solution, and loaded by ultrasound or pressure assistance; S2, polyetheretherketone sulfonation reaction, blending with a cross-linking agent to form a film and then UV curing; S3, coaxial chip deposition of hydrogel prepolymer solution, in-situ UV polymerization and supercritical CO2 drying; S4, atomic layer deposition ceramic film, spraying epoxy resin and then UV curing.

[0009] As a further improvement of this technical solution, the release kinetics regulation mechanism is optimized, specifically: Threshold condition 1: T>LCST, hydrogel shrinks and pores close (pore size from 50nm→10nm), antiscalant diffusion coefficient from 1e-6→1e-8cm 2 / s; LCST is the lowest critical solution temperature, which means that the temperature-sensitive polymer (PNIPAM) changes from hydrophilic to hydrophobic above this temperature, and undergoes phase transition and shrinkage. In the present invention, the LCST is adjusted by adjusting the monomer ratio so that the valve can be opened and closed at a specific temperature; Threshold condition 2: Ca 2+> Critical concentration (CAC), AA carboxyl and Ca 2+ Chelation causes network swelling (expansion rate ↑30%), and the synchronous GQDs photothermal effect opens a rapid release channel.

[0010] In the present invention, high temperature shrinkage (above LCST), micropore closure, rate-limited diffusion; low temperature swelling (below LCST), swelling release scale inhibitor (swelling degree 200-300%); ALD / epoxy protective layer, ZrO2 nanolayer blocks Cl by grain boundary densification - Migration; epoxy resin seals surface defects and reduces O 2 / Water permeability.

[0011] Photothermal triggering: GQDs (808nm absorption) convert light energy into thermal energy, and the local temperature rises above the LCST, causing the hydrogel to shrink and release the agent (energy conversion efficiency ≥ 95%). Ca 2+ Concentration feedback: AAc groups at high Ca 2+ The hydrophilicity of the hydrogel network is enhanced by competing with solution cations for ionization, triggering swelling and diffusion (response threshold 80 mg / L).

[0012] Extreme tolerance: The dendritic pores of the freeze-dried inner core absorb the ice crystal expansion stress (Young's modulus 8.7 GPa) to avoid structural fragmentation; the ALD-ZrO2 film forms a chemical gradient interface with hydroxyapatite to inhibit alkaline dissolution.

[0013] The present invention strongly anchors DTPMP through the porous hydroxyapatite phosphate vacancies to reduce the initial burst release; the intermediate controlled release layer accurately controls the release rate and inhibits Cl - The thermosensitive hydrogel shell (PNIPAM-co-AAc) is combined with the GQDs photothermal conversion module to achieve a dual trigger response, drug utilization rate > 95%, and scale inhibition period extended to 12 months. The PNIPAM-co-AAc hydrogel shrinks and densifies at high temperature (> LCST) (porosity decreases by > 90%), blocking the overflow of scale inhibitors, and Ca 2+Cross-linking triggers pore self-repair; solves the problem of uncontrollable release caused by high-temperature fluidity of hydrophobic segments of traditional amphiphilic copolymers (PLGA-PEG). The hydrolysis rate is reduced by SPEEK cross-linking membrane, and the epoxy resin network fills the micropores to hinder the diffusion of water molecules, which solves the problem that PLA degrades too quickly in a humid environment (3-5 months) and cannot meet industrial needs (the dissolution cycle takes 6-12 months). Through atomic layer deposition (ALD) ceramic coating (ZrO2, 50-55nm) and epoxy resin encapsulation (immersion in 80℃ water for 30 days, the drug release amount only increased by 2.1%; the integrity rate of microspheres is >98%), the problem of PLGA-PEG and other products with a sharp increase in dissolution rate (increased by 2-3 times) at high temperature (>50℃) and uncontrolled drug release is solved.

[0014] Compared with the prior art, the present invention has the following beneficial effects: In this slowly dissolving micro-nano dispersed antiscaling material and its preparation method, by constructing a four-layer composite slow-release system, long-term scale inhibition (24h burst release rate <18.5%, 300-day cumulative release rate ≥97.5%), extreme tolerance (high temperature 600℃ / low temperature -50℃ / high alkali pH10.8 full-scene stability) and dynamic response (3.8 minutes targeted release, volatility ≤4.7%) are achieved. The technical problems of high burst release rate, poor weather resistance and delayed release of traditional antiscaling materials are solved. The cost of treating a ton of water is low and the life of the RO membrane is extended, providing a full-cycle and efficient antiscaling solution for complex industrial water systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is an overall flow chart of Example 1 of the present invention. DETAILED DESCRIPTION

[0016] The following will be combined with the accompanying drawings in the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0017] Example 1: This example provides a slowly dissolving micro-nano dispersed anti-scaling material for anti-scaling in high-temperature and high-salt industrial circulating water systems, comprising a core, an intermediate controlled-release layer, a responsive shell and an outer modified layer, wherein: Core: porous hydroxyapatite (Ca / P=1.67, calcium nitrate: ammonium phosphate=1.67, porosity 32±3%); DTPMP loading: 55wt% (phosphate vacancy anchoring, complexation energy 215kJ / mol, verified by isothermal titration calorimetry ITC); Intermediate controlled release layer: SPEEK sulfonation degree: 85% (concentrated acid sulfonation for 4.5h); cross-linking agent divinylbenzene (DVB) ratio: 10%; membrane thickness: 800±50nm (rotation speed 3000rpm); Responsive shell: PNIPAM-co-AAc hydrogel (molar ratio 85:15); GQDs loading: 0.8wt% (808nm absorption rate 95%); LCST = 47℃ (for 55℃ working conditions) (differential scanning calorimetry DSC measured phase transition temperature 45.8-48.1℃, heating rate 2℃ / min, ΔH calculated based on Flory-Huggins model = -10.5kJ / mol); GQDs particle size: 5±0.3nm (prepared by Hummers method); laser parameters: 808nm, power 1.5W / cm 2 , on / off cycle ratio 1:5; External modification layer: magnetron sputtering ZrO2 nano coating (film thickness 55nm), epoxy resin encapsulation layer (EPON828 / TETA=10:1 (epoxy value 0.53eq / 100g, acid value <0.1mg KOH / g), UV curing 2μm (mercury lamp wavelength 365nm, irradiation intensity 50mW / cm²×10min).

[0018] The preparation method is as follows: S1. Kernel Synthesis Formula: Weigh calcium nitrate (34.82 g) and ammonium phosphate (14.23 g) and mix them at a Ca / P ratio of 1.67, add 0.1 M ammonia water to adjust the pH to 10.5, stir magnetically (600 rpm) for 2 h to form a sol; vacuum dry at 65 ° C for 24 h, and calcine in a muffle furnace at 600 ° C for 3 h to obtain porous hydroxyapatite; DTPMP loading: The porous hydroxyapatite was immersed in a 25% DTPMP solution (containing 1% triethanolamine chelating agent) and ultrasonically assisted (40kHz) at 60°C for 48h; the particles were collected by centrifugation (8000rpm×10min) and vacuum dried to constant weight, with a drug loading of 55.3wt% (calibrated by UV-Vis method); S2, SPEEK / DVB composite membrane Sulfonation: immerse poly(aryletherketone) (10 g) in 98% concentrated sulfuric acid (200 mL) and stir at 70 °C for 4.5 h; quench in an ice-water bath to terminate the reaction, dialyze with deionized water to neutral pH, and dry in a vacuum at 80 °C; Film formation and crosslinking: SPEEK was dissolved in DMAC (10 wt%), 10% DVB (based on SPEEK mass) was added, and the film was formed by spin coating (glass substrate, 3000 rpm × 30 s), and UV curing was performed at 80 ° C (wavelength 365 nm, light intensity 10 mW / cm 2 , cumulative energy 3.6J / cm 2 ); S3, Microfluidic Deposition of Responsive Shell Hydrogel prepolymer solution: PNIPAM (1.5 g), AAc (0.35 g, 15%), and MBA crosslinker (0.06 g) were dissolved in 30 mL of deionized water; nitrogen was passed through the solution for deoxygenation for 10 min, and 0.05 g of Irgacure 2959 photoinitiator was added; Microfluidic parameters: coaxial chip inner diameter 200 μm, outer diameter 400 μm, inner phase (hydrogel) flow rate 1 mL / h, outer phase (GQDs suspension) flow rate 3 mL / h; UV lamp (365 nm, 15 mW / cm 2 ) in situ curing and supercritical CO2 drying to obtain microspheres.

[0019] S4, external finishing Atomic layer deposition (ALD) ZrO2: precursor TEMAZ / O3, 50 cycles at 120°C (Picosun R200 equipment, single cycle time 60s), film thickness measured by ellipsometer; Epoxy encapsulation: spray EPON828 / TETA mixed liquid (nozzle diameter 0.3mm, spray pressure 0.3MPa), UV curing film (300-400nm (mercury lamp spectrum peak 365 / 405nm), 30mW / cm 2 ×5min) Example 2: This example provides a slowly dissolving micro-nano dispersed anti-scaling material for dynamic water quality RO membrane pretreatment anti-scaling, comprising a core, an intermediate controlled release layer, a response shell and an outer modified layer, wherein: Core: Hydroxyapatite (Ca / P=1.67) Synthesis: calcium nitrate: ammonium phosphate=1.67, calcination temperature 600℃; DTPMP loading: 55wt% (phosphate vacancy anchoring, complexing energy 215kJ / mol); Intermediate controlled release layer: SPEEK sulfonation degree: 85% (concentrated acid sulfonation for 4.5h); sulfonation degree 75% (acid concentration 92%); secondary spraying of DVB to form a network-like sustained-release channel, DVB = 8% (film thickness 500nm); Responsive shell: PNIPAM-co-AAc ratio: 80:20; GQDs-SH (thiol-modified) loading: 1.2wt%; CAC = 80mg / L (Ca 2+ response threshold); External modification: Near-infrared laser fiber array (5mm interval); light control delay ≤3s (PID algorithm feedback flow).

[0020] The preparation method is as follows: S1, Microwave-Assisted Core Synthesis The precursor solution (Ca / P=1.65) was placed in a microwave reactor (CEM Mars6) and irradiated with a microwave power of 850W for 10min. The product was instantly cooled to room temperature, centrifuged (10000rpm×5min) to collect the precipitate, and washed with ethanol three times. DTPMP gradient loading: pressure impregnation method: 25% DTPMP solution (containing PEG-6000 dispersant) was circulated in a 2MPa autoclave for 1h; vacuum dried at 60℃ to constant weight, and the porosity was measured to be 32.7%; S2, SPEEK / PVA composite film Electrospinning: SPEEK and PVA (polyvinyl alcohol) mass ratio 7:3, co-dissolved in 15wt% DMAC solution; syringe pump propulsion speed 1.2mL / h, voltage 18kV, receiving distance 15cm, ambient humidity <40%; Hot-pressing crosslinking: After collecting the fiber membrane, it was treated in a hot press (10 MPa) at 120 °C for 30 min, and then DVB crosslinking agent was sprayed (8 wt%) and hot-pressed for the second time (80 °C × 1 h); S3, photo-controlled deposition of hydrogel shell Microfluidic pulse deposition: A high-speed switch valve (response time 0.1 ms) is set at the chip outlet to release a drop of prepolymer solution every 0.5 ms; a synchronously transmitted ultraviolet light (365 nm, 20 mW / cm 2 ) trigger aggregation; Surface modification of GQDs: GQDs (particle size 5 nm) containing mercaptosilane coupling agent were covalently fixed by thiol-ene click reaction, washed with methanol three times to remove ungrafted particles, and dried at 60 °C.

[0021] Example 3: This example provides a slowly dissolving micro-nano dispersed anti-scaling material for long-term anti-scaling of low-temperature high-alkali mine water, comprising a core, an intermediate controlled release layer, a responsive shell and an outer modified layer, wherein: Core: porous hydroxyapatite (porosity 82%): freeze-dried (pre-frozen at -40°C), DTPMP loading: 58wt%; Intermediate controlled release layer: SPEEK / PTFE (9:1) composite membrane, sulfonation degree 70% (sulfonation at 90℃ for 6h), DVB=15%; Responsive shell: PNIPAM-co-AAc ratio: 70:30, glycerol plasticizer ratio: 5%, LCST = 30 ° C (adapted to low temperature); External modification: ZrO2 atomic layer deposition (50 cycles, thickness 55 nm), UV-cured epoxy resin encapsulation layer (thickness 2 μm).

[0022] The preparation method is as follows: S1. Preparation of porous core by freeze drying Precursor freezing: Mix calcium nitrate and ammonium phosphate solution (Ca / P=1.67), inject liquid nitrogen for quick freezing, and treat in a vacuum freeze dryer (-50℃, 0.1mbar) for 72h to form a scaffold with an open porosity of 82%; High-pressure impregnation of DTPMP: 50% DTPMP solution was circulated into a 5MPa autoclave and the pressure was maintained for 2 h; the pressure was slowly released and the free agent on the surface was desorbed by centrifugation (8000rpm×10min); S2, SPEEK / PTFE composite membrane reinforcement Electrospinning: SPEEK and PTFE (polytetrafluoroethylene) nanoparticles (200 nm) were dispersed in hexafluoroisopropanol (purity ≥ 99.8%, dosage 15 wt%) at a ratio of 9:1; spinning voltage 25 kV, receiving roller speed 200 rpm, ambient temperature 22 ± 2 °C; High temperature annealing reinforcement: annealing in a tube furnace at 180℃ for 1h (nitrogen protection) to eliminate internal stress; dichloromethane vapor treatment for 10min to close surface micro cracks; S3, ZrO2 atomic layer deposition coating ALD process: precursor (tetraethyl zirconium (TEMAZ) and ozone), pulse time 0.1-10s-0.1-10s; deposition temperature 120°C, film thickness ≈55nm after 50 cycles (verified by ellipsometer); Epoxy resin encapsulation: spraying bisphenol A epoxy (EPON828) and curing agent (TETA) mixture (10:1); UV curing (300-400nm, 30mW / cm 2 ×5min) to form a 2μm protective layer.

[0023] Test Example 1: Comparison of the micro-nano dispersed anti-scaling material provided in Example 1 with the prior art PLGA-PEG system Test conditions: Water quality: temperature 65°C, pH=8.5, salinity: 6% NaCl (simulated refinery circulating water); Scale inhibitors: test materials (Example 1) and commercially available PLGA-PEG microspheres (drug loading 45%).

[0024] Table 1 Test items PLGA-PEG microspheres Example 1 Test Method Burst release (24h) 82.3% (early burst severe) 18.5% (controlled release layer inhibits burst release) HPLC test of initial release (pharmacopoeia method) 300-day cumulative release rate 91% (carrier disintegration and complete release) 97.5 (continuous and stable release) Online TOC analyzer continuous monitoring High temperature resistant structure stability Microsphere deformation and collapse Complete sphere, uniform pore size SEM imaging (JEOL JSM-7800F) As shown in Table 1, the intermediate controlled release layer (SPEEK / DVB) of Example 1 effectively inhibits high-temperature burst release, and the high loading of hydroxyapatite (55.3%) prolongs the shelf life.

[0025] Test Example 2: Comparison of the micro-nano dispersed antiscaling material provided in Example 2 with the conventional SPEEK membrane loading system in the prior art Test conditions: Water quality: Ca 2+ Fluctuation 100-300mg / L, temperature 25±5℃, RO membrane pressure 1.5MPa; Antiscalants: Test material (Example 2) and unmodified SPEEK membrane (pure DTPMP adsorption release).

[0026] Table 2 Test items Unmodified SPEEK membrane Example 2 Test Method <![CDATA[Ca 2+ Response Delay Time]]> 22min (threshold triggering slow) 3.8min (shell swells rapidly) Dynamic monitoring of calcium ion selective electrodes Light-controlled release fluctuation (10 pulses) - ≤4.7% (PID algorithm stable output) Coefficient of variation of drug release by HPLC under laser open-close cycle Membrane flux decay rate (30 days) 58% (serious pollution blockage) 9.2% (antiscalant released on demand) RO membrane standardized flux test (GB / T 32360) Drug utilization rate 68% (passive release waste) 94% (time-dependent release + light-controlled supplement) Antiscalant material balance calculation (dosage - residual amount) As shown in Table 2, Example 2 uses a porous hydroxyapatite core combined with photothermal temperature control (GQDs triggering) to release the scale inhibitor and Ca 2+ With wave synchronization, the utilization rate of reagents is increased by 38%, and the membrane flux attenuation rate is only 1 / 6 of that of the traditional system.

[0027] Test Example 3: Comparison of the micro-nano dispersed antiscaling material provided in Example 3 with the prior art diatomaceous earth loading system Test conditions: Water quality: temperature 5℃, pH=10.8, Cl - =1500mg / L (simulated high alkaline mine water); Antiscalant: test material (Example 3) and diatomaceous earth loaded with DTPMP (drug loading 32%).

[0028] Table 3 Test items diatomite Example 3 Test Method Low temperature frost heave resistance After 90 days, the breakage rate was 83% <![CDATA[≤1.8% (protected by ZrO2 coating)]]> Laser particle size analyzer counts the amount of debris after liquid nitrogen shock Alkali solution corrosion weight loss rate (60 days) <![CDATA[41.7%(Ca 2+ Dissolution 80%)]]> 0.9% (ALD+epoxy double packaging) ICP-MS measurement of dissolved ions (refer to GB / T 2084) Effective scale inhibition time 3 months (carrier expiration) 15 months (continuous release to threshold) <![CDATA[Scaling amount monitoring (XRD quantitative CaCO3 content)]]> As shown in Table 3, the ALD-ZrO2 of Example 3 enhances corrosion resistance, and combined with the freeze-dried porous core to resist frost heave, the effective scale inhibition time is increased by 5 times.

[0029] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions are only preferred examples of the present invention and are not intended to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A slowly dissolving micro-nano dispersed anti-scaling material, characterized in that: It includes four layers of composite structure from inside to outside: Core: porous hydroxyapatite carrier, Ca / P molar ratio of 1.65-1.67, porosity of 32-82%, loaded with DTPMP scale inhibitor, drug loading ≥55wt%; Intermediate controlled release layer: sulfonated polyetheretherketone cross-linked film, sulfonation degree of 70-85%, film thickness of 500-800nm, cross-linking agent selected from divinylbenzene, polyvinyl alcohol or polytetrafluoroethylene; Responsive shell: thermosensitive PNIPAM-co-AAc hydrogel, AAc content 15-30%, LCST 30-47°C, embedded photothermal conversion nanoparticles, particle size 5-10nm; Outer modification layer: Atomic layer deposition ceramic film and epoxy resin encapsulation layer, film thickness 50-55nm, UV curing to form a 2-5μm protective layer.

2. The slowly dissolving micro-nano dispersed antiscaling material according to claim 1, characterized in that: The intermediate controlled release layer is a composite membrane of sulfonated polyetheretherketone and polytetrafluoroethylene particles, with a mass ratio of 9:

1. The electrospinning parameters are a voltage of 25 kV and a receiving roller speed of 200 rpm. After annealing at 180° C., surface defects are sealed with dichloromethane steam.

3. The slowly dissolving micro-nano dispersed antiscaling material according to claim 1, characterized in that: The photothermal conversion material of the response shell is mercaptosilane-modified graphene quantum dots with a particle size of 5±0.3 nm, which are fixed to the hydrogel network through a thiol-ene click reaction. The laser parameters are 808 nm and the power is 1.5 W / cm 2 .

4. The slowly dissolving micro-nano dispersed antiscaling material according to claim 1, characterized in that: The inner core is prepared by microwave-assisted synthesis or gradient pressure impregnation, with a porosity of ≥80% and a DTPMP adsorption capacity of ≥750 mg / g.

5. The slowly dissolving micro-nano dispersed antiscaling material according to claim 4, characterized in that: The power of the microwave-assisted synthesis is 850 W, the time is 10 min, and the gradient pressure is 2-5 MPa.

6. The slowly dissolving micro-nano dispersed antiscaling material according to claim 1, characterized in that: The material is used for scale inhibition of 55°C high-salt refinery circulating water, RO membrane pretreatment or 5°C high-alkali mine water.

7. The slowly dissolving micro-nano dispersed antiscaling material according to claim 1, characterized in that: Embedded photothermal conversion nanoparticles use GQDs.

8. The slowly dissolving micro-nano dispersed antiscaling material according to claim 1, characterized in that: The amount of the cross-linking agent is 0.8-1.2 wt %.

9. A method for preparing the slowly dissolving micro-nano dispersed antiscaling material according to any one of claims 1 to 8, characterized in that: The following steps are involved: S1. Prepare porous hydroxyapatite by sol-gel method or freeze-drying method, calcined in vacuum at 600±20℃, impregnated with 25-50% DTPMP solution, and loaded by ultrasound or pressure assistance; S2, polyetheretherketone sulfonation reaction, blending with a cross-linking agent to form a film and then UV curing; S3, coaxial chip deposition of hydrogel prepolymer solution, in-situ UV polymerization and supercritical CO2 drying; S4, atomic layer deposition ceramic film, spraying epoxy resin and then UV curing.

10. The method for preparing the slowly dissolving micro-nano dispersed anti-scaling material according to claim 9, characterized in that: In S2, the polyetheretherketone sulfonation reaction is: Immerse the polyaryletherketone in 92-98% concentrated sulfuric acid and stir at 70-90°C for 4.5-6h; quench in an ice-water bath to terminate the reaction, dialyze with deionized water to a neutral pH, and dry in a vacuum at 80°C.

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