Low-temperature environment-friendly soaping process for cotton knitted dyed fabric

Abstract

The invention relates to the technical field of textile printing and dyeing, and discloses a low-temperature environment-friendly soaping process of a cotton knitted dyed fabric, which comprises the following steps: step 1, performing interface modification treatment on the dyed fabric through ultrasonic wave and negative pressure dipping to form a micro-interface mass transfer channel; step 2, carrying out dynamic temperature-electric field coupling catalytic soaping on the fabric subjected to interface modification by adopting a temperature-sensitive catalytic system; step 3, performing gradient countercurrent rinsing of electric field vector regulation and control on the soaped fabric; and 4, regenerating the rinsing wastewater through membrane-electrolysis coupling treatment, and recycling the regenerated rinsing wastewater in the step 3. Multiple chemical bonding is formed by a surface modifier and a fiber matrix, a three-dimensional ordered pre-adsorption interface layer is constructed, the action efficiency and stability of a functional additive are remarkably improved, and the problem of quality fluctuation caused by non-uniform treatment is fundamentally solved.

Description

Technical Field

[0001] The invention relates to the technical field of textile printing and dyeing, in particular to a low-temperature environmentally friendly soaping process for cotton knitted dyed fabrics. Background Art

[0002] Traditional low-temperature, environmentally friendly soaping processes for dyed cotton knitted fabrics rely on a combination of surfactants and enzymes to reduce processing temperature and control energy consumption. However, the multi-scale pore structure of cotton fibers and the complex binding patterns of dye molecules make it difficult for conventional processes to effectively remove bound dyes from the fibers. Especially when meeting high colorfastness requirements, repeated washing is often required, which in turn increases water consumption and wastewater treatment pressure, creating a process paradox of low-temperature energy conservation but high water consumption.

[0003] While existing technologies enhance mass transfer through the introduction of physical methods such as electric field assistance and ultrasound, the random nature of fiber-treatment interface interactions significantly reduces energy transfer efficiency. The disordered adsorption of treatment molecules on the fiber surface results in a lack of effective sites for action, leading to significant blockage of microscopic mass transfer channels. This leads to macroscopic manifestations such as poor soaping uniformity and insufficient color stability. This inherent limitation results in a narrow process parameter window, necessitating frequent adjustments to treatment conditions to accommodate varying fabric structures in actual production, severely restricting the effectiveness of industrial applications.

[0004] This invention addresses the core issue of interfacial mismatch by constructing a pretreatment system with directional bonding capabilities through molecular design. This technology enables the treatment agent to form a three-dimensional, ordered pre-adsorption layer on the fiber surface, overcoming the energy barrier limitations of traditional physical adsorption and establishing a precise pathway for subsequent functional additives. This molecular-level interface manipulation fundamentally improves treatment uniformity, enabling a single treatment to achieve the same results as multiple washes in traditional processes. This reduces water consumption by over 60% while maintaining color fastness, successfully resolving the energy-saving and water-consumption trade-off inherent in low-temperature processes. Summary of the Invention

[0005] The purpose of the present invention is to provide a low-temperature environmentally friendly soaping process for cotton knitted dyed fabrics, which solves the multiple contradictions of uneven treatment, high water resource consumption and low energy efficiency caused by the mismatch of fiber-treatment agent interface in the traditional low-temperature soaping process.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: A low-temperature environmentally friendly soaping process for cotton knitted dyed fabrics, comprising the following steps: Step 1: performing interface modification treatment on the dyed fabric by ultrasonic coordinated negative pressure impregnation to form a micro-interface mass transfer channel; Step 2: performing dynamic temperature-electric field coupled catalytic soaping on the fabric after interface modification, using a temperature-sensitive catalytic system; Step 3: performing gradient countercurrent rinsing with electric field vector control on the soaped fabric; Step 4: Regenerate the rinse wastewater through membrane-electrolysis coupling treatment and reuse it in step 3 A surface-modified aerosol, composed of a silica core and a polystyrene sulfonic acid shell, was dispersed in deionized water via emulsion polymerization. The aerosol's D50 particle size was controlled to 300-400 nm, and the degree of sulfonic acid grafting was adjusted to ≥2.3 mmol / g by adjusting the sulfonation reaction time. The pretreatment solution concentration was controlled at 8-12 wt%, and 0.1-0.3 wt% of a nonionic dispersant was added to prevent particle agglomeration. The dyed fabric is immersed in the pretreatment solution and treated in a 38-42kHz ultrasonic field. The ultrasonic transducer array is arranged in a honeycomb pattern to ensure uniformity of the sound field (sound intensity variation <5%). A negative pressure of -0.06 to -0.10 MPa is simultaneously applied, and the pressure fluctuation is dynamically adjusted by a vacuum pump unit (fluctuation amplitude <0.005 MPa). The treatment time is 4-6 minutes, during which the fabric surface temperature is monitored by an infrared thermal imager (≤45°C). After impregnation, the fabric was treated with an air knife padder at a pressure of 0.15-0.25 MPa, with a controlled yield of 65±5%. Liquid uniformity was monitored in real time using an online capacitance sensor (CV value <3%) to ensure a continuous aerosol coating on the fiber surface. ZIF-8-immobilized laccase: Laccase was encapsulated within the ZIF-8 framework via a biomimetic mineralization method, with enzyme activity retention exceeding 85%. Particle size was 80-120 nm, with a zeta potential of +25 mV.

[0007] Thermosensitive copolymer: N-isopropylacrylamide and acrylic acid copolymer (molar ratio 7:3), LCST is 55±2℃, molecular weight is 50-80kDa.

[0008] pH-responsive microspheres: Made with dimethylaminoethyl methacrylate as the shell material and hydrogen peroxide as the core material, prepared via microfluidics. Particle size 200-300 nm, H2O2 loading 15-20 wt%; Stage 1 (53-57°C / 4-6 minutes) A 90-110 Hz square wave electric field with a 1:1 positive-to-negative pulse width ratio was applied. The electric field was directed at a 45° angle to the fabric's direction of travel, inducing laccase migration along the fiber axis. At this temperature, the thermosensitive copolymer undergoes a phase transition, with hydrophobic microdomains capturing free dye.

[0009] Second stage (58-62℃ / 4-6min) The field strength was reduced to 3.0-3.5 V / cm, maintaining the square wave frequency. The temperature increase prompted the pH-responsive microspheres to release H2O2, which formed a cascade catalytic system with laccase to degrade the chromophore of the dye molecule.

[0010] The third stage (56-59℃ / 1-3min) Switching to a DC electric field with a field strength of 0.8-1.2 V / cm, the thermosensitive copolymer partially redissolves, carrying the degradation products and migrating into the solution phase. Electroosmosis then removes the residue from the fiber pores. Multi-stage rinsing parameters First level rinse (43-47°C); Square wave electric field 2.8-3.2V / cm, in the same direction as the soaping electric field (angle 0-30°); The water flow velocity is 0.8-1.2m / s, forming turbulent flow to flush out surface pollutants; The MnO2-TiO2 catalytic layer on the honeycomb electrode surface degrades the trapped dye via a Fenton-like reaction; Second level rinse (38-42℃) DC electric field 0.9-1.1 V / cm, direction opposite to the soaping electric field (angle 150-180°); The water flow velocity is 1.0-1.4m / s, generating countercurrent shear force to strip off the bound pollutants; Dynamic adjustment of electrode spacing (8-12cm) to adapt to different fabric thicknesses; Third level rinse (33-37℃) Pulsed electric field 0.4-0.6 V / cm (duty cycle 30-50%), direction at an orthogonal angle (90-120°); The water flow rate is 1.2-1.6m / s, forming a cyclonic flow field to remove residual particles; The amount of recycled water replenished is controlled at 75-85% of the total flow; The ceramic membrane has a pore size of 50 ± 5 nm and its surface is modified with aminosilane (Zeta potential -25 mV); Cross-flow velocity 2.3-2.7m / s, transmembrane pressure difference 0.38-0.42MPa; Contaminants on the membrane surface are removed by backwash pulses (frequency 0.5-1Hz, pressure 0.6-0.8MPa); Boron-doped diamond anode (boron content 1.2-1.8at%), and cathode with titanium-based ruthenium dioxide coating; Current density 14-16 mA / cm 2 , plate spacing 8-12mm, electrolysis time 7-9min; The cell voltage is monitored in real time, and the plate self-cleaning program is triggered when it exceeds 5.5V; Online conductivity meter (measuring range 0-2000μS / cm) and turbidity meter (0-50NTU) are linked and controlled; The recycled water is disinfected by ultraviolet light (dosage 40-60mJ / cm 2 ) and then injected into the third-stage rinsing tank.

[0011] Preferably, the interface modification treatment in step 1 specifically includes: Preparing a pretreatment liquid containing a surface-modified aerosol, wherein the aerosol has a D50 particle size of 300-400 nm and a surface sulfonic acid group grafting degree of ≥2.3 mmol / g; Treat under 38-42kHz ultrasonic wave and -0.06~-0.10MPa negative pressure for 4-6min; The fabric liquid carrying rate was controlled to be 65±5%.

[0012] Preferably, the dynamic temperature-electric field coupled catalytic soaping in step 2 specifically includes: The working solution consists of: ZIF-8 immobilized laccase 0.5-0.8 wt%, thermosensitive copolymer 5.8-7.2 wt%, pH-responsive microspheres 0.3-0.5 wt%, wherein the mass ratio of thermosensitive copolymer to nanozyme is (8-10):1; Execute three-stage temperature control: The first stage was 53-57°C / 4-6 min, with simultaneous application of a 90-110 Hz square wave electric field with a field strength of 4.5-5.5 V / cm; The second stage is 58-62℃ / 4-6min, the electric field frequency remains unchanged, and the field strength is reduced to 3.0-3.5V / cm; The third stage is 56-59℃ / 1-3min, switching to a DC electric field with a field strength of 0.8-1.2V / cm.

[0013] Preferably, the gradient countercurrent rinsing controlled by the electric field vector in step 3 specifically includes: First stage rinsing: water temperature 43-47°C, square wave electric field 2.8-3.2V / cm, water flow direction and the electric field direction of step 2 are at an angle of 0-30°, water flow speed 0.8-1.2m / s, rinsing time 3-5min Second stage rinsing: water temperature 38-42°C, DC electric field 0.9-1.1V / cm, water flow direction and the electric field direction of step 2 are at an angle of 150-180°, water flow speed 1.0-1.4m / s, rinsing time 2-4min Third stage rinsing: water temperature 33-37℃, pulse electric field 0.4-0.6V / cm, water flow direction and the electric field direction of step 2 are at an angle of 90-120°, water flow speed 1.2-1.6m / s, and rinsing time 1-3min.

[0014] Preferably, the membrane-electrolysis coupling treatment in step 4 specifically includes: Membrane separation: ceramic membrane components with a pore size of 50±5nm, cross-flow velocity of 2.3-2.7m / s, operating pressure of 0.38-0.42MPa, and solid content of retained liquid controlled at 12-18% before discharge from the system. Electrolytic regeneration: boron-doped diamond anode with a boron atomic content of 1.2-1.8at%, current density of 14-16mA / cm 2 , plate spacing 8-12mm, electrolysis time 7-9min, cell voltage 4.5-5.5V Recycled water control: Recycled water conductivity is 150-200μS / cm, turbidity is ≤5NTU, and the reuse ratio is 75-85%. It is given priority to be added to the third-level rinsing process.

[0015] Preferably, a transition process is provided between step 2 and step 3, and the process includes: The soaped fabric is rapidly cooled by gas-liquid two-phase flow, and the cooling medium is atomized water containing 0.1-0.3% nanobubbles; Apply a rotating magnetic field with a magnetic field strength of 50-80 mT and a rotation frequency of 2-4 Hz; Control the fabric surface temperature at 45±2℃ and proceed to step 3.

[0016] Preferably, the rinsing tank in step 3 is configured with a porous electrode structure, and the electrode has: Honeycomb through-holes, pore diameter 3-5mm, open porosity 60-70%; The surface is loaded with a MnO2-TiO2 composite catalytic layer with a loading of 2.5-3.5 mg / cm 2 ; The electrode spacing is dynamically adjustable, with an adjustment range of 8-12cm.

[0017] Preferably, a multi-stage pretreatment device is provided before the membrane separation unit in step 4, comprising: Cyclone separator: removes particles larger than 100 μm, cone angle 15-20°, feed speed 2.5-3.5 m / s; Electrocoagulation reactor: uses aluminum-iron composite electrodes, with alternating plates and an inter-electrode distance of 10-15 mm; Micro-nano aeration unit: bubble diameter 50-200nm, gas-liquid ratio 1:(8-12).

[0018] Preferably, the steps include a dye recovery subsystem comprising: A supercritical CO2 extraction device is used to extract the dye from the retentate in step 4, with a pressure of 25-30 MPa and a temperature of 45°C. A molecularly imprinted adsorption column is used for dye purification, with an imprinted cavity size of 1.2-1.8 nm; The recovered dyes are reused in the dyeing process, with a recycling rate of ≥85%.

[0019] Preferably, the catalytic soap washing tank in step 2 is configured with a double circulation system, comprising: Main circulation: axial flow circulation, flow rate 0.8-1.2m / s, promotes directional migration of catalyst; Secondary circulation: tangential flow circulation, flow rate 0.3-0.5m / s, to prevent the deposition of temperature-sensitive copolymers; The dual circulation flow ratio is controlled at (2.5-3.5):1.

[0020] In summary, the present invention includes at least one of the following beneficial technical effects: 1. This invention creates a three-dimensional, ordered pre-adsorption interface layer by forming multiple chemical bonds between the surface modifier and the fiber matrix. This structure overcomes the randomness limitations of traditional physical adsorption, establishing a directional mass transfer channel for subsequent processing, significantly improving the efficiency and stability of the functional additive, and fundamentally resolving the problem of quality fluctuations caused by uneven processing.

[0021] 2. The dynamic electric field and ultrasonic cavitation effect of this invention generate a spatiotemporal coupling effect, forming a controllable energy gradient field at the mesoscopic scale. This non-equilibrium environment forces pollutants to migrate along a predetermined path while simultaneously inducing conformational changes in functional molecules, achieving dual optimization of material transfer and energy utilization during the treatment process.

[0022] 3. The intelligent coupling of the present invention's temperature-sensitive material and electric field response enables the physical properties of the treatment fluid to be matched to the process requirements in real time. This dynamic adjustment capability overcomes the limitations of traditional process parameter fixation, demonstrating excellent process tolerance and stability, particularly when dealing with complex fabric structures. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the method of the present invention. DETAILED DESCRIPTION

[0024] The following is combined with Figure 1 , the present invention is described in further detail.

[0025] Example 1: Step 1: Preparation of pretreatment solution: Sulfonated aerosol D50 = 350 nm, sulfonic acid group grafting degree 2.5 mmol / g; Addition amount: 1.5 g / L, [BMIM]BF4 ionic liquid: 0.8 mL / L; Interface modification treatment: Ultrasonic frequency 40kHz, negative pressure -0.08MPa; Processing time: 5 min, power density: 0.25×0.08+0.5=0.52 W / cm 2 ; Liquid carrying rate is controlled at 65%; Step 2 Working fluid composition: ZIF-8 laccase 0.6 wt %, P(NIPAM-co-DMAEMA) 6.5 wt %; pH microspheres 0.4wt%, mass ratio 9:1; Temperature-electric field program: 55°C / 5 min (square wave 100 Hz / 5.0 V / cm); 60℃ / 5min (square wave 100Hz / 3.2V / cm); 57°C / 2 min (DC 1.0 V / cm); Step 3 First-stage rinse: 45°C, 3.0V / cm square wave, 15° angle, 1.0m / s, 4min; Second-stage rinse: 40°C, 1.0V / cm DC, 170° angle, 1.2m / s, 3min; Third-stage rinse: 35°C, 0.5V / cm pulse, 100° angle, 1.4m / s, 2min; Step 4: Membrane separation: 52nm ceramic membrane, 2.5m / s, 0.40MPa, solid content 15%; electrolysis: 1.5at% boron doping, 15mA / cm 2 ,10mm electrode distance,8min,5.0V;recycled water conductivity 180μS / cm, turbidity 4NTU, reuse 80%.

[0026] Example 2: Step 1: Preparation of pretreatment solution: Sulfonated aerosol D50 = 380 nm, sulfonic acid grafting degree 2.8 mmol / g; addition amount 1.8 g / L, [BMIM] BF4 ionic liquid 1.0 mL / L; Interface modification treatment: Ultrasonic frequency 42kHz, negative pressure -0.10MPa; Treatment time: 4 min, power density: 0.25×0.10+0.5=0.75 W / cm 2 ; Liquid carrying rate is controlled at 68%; Step 2 Working fluid composition: ZIF-8 laccase 0.8wt%, P(NIPAM-co-DMAEMA) 7.0wt%; pH microspheres 0.5wt%, mass ratio 10:1; Temperature-electric field program: 57°C / 4 min (square wave 110 Hz / 5.5 V / cm); 62°C / 4 min (square wave 110 Hz / 3.5 V / cm); 59°C / 1min (DC 1.2V / cm); Step 3 First-stage rinse: 47°C, 3.2V / cm square wave, 30° angle, 1.2m / s, 3min; Second-stage rinse: 42°C, 1.1V / cm DC, 180° angle, 1.4m / s, 2min; Third-stage rinse: 37°C, 0.6V / cm pulse, 120° angle, 1.6m / s, 1min; Step 4: Membrane separation: 55nm ceramic membrane, 2.7m / s, 0.42MPa, solid content 18%; electrolysis: 1.8at% boron doping, 16mA / cm 2 ,12mm electrode distance,7min,5.5V;recycled water conductivity 200μS / cm, turbidity 3NTU, reuse 85%.

[0027] Example 3: Step 1: Preparation of pretreatment solution: Sulfonated aerosol D50 = 320 nm, sulfonic acid grafting degree 2.3 mmol / g; added amount 1.2 g / L, [BMIM] BF4 ionic liquid 0.6 mL / L; Interface modification treatment: Ultrasonic frequency 38kHz, negative pressure -0.06MPa; Processing time: 6 min, power density: 0.25×0.06+0.5=0.515 W / cm 2 ; Liquid carrying rate is controlled at 63%; Step 2 Working fluid composition: ZIF-8 laccase 0.5wt%, P(NIPAM-co-DMAEMA) 5.8wt%; pH microspheres 0.3wt%, mass ratio 8:1; Temperature-electric field program: 53°C / 6 min (square wave 90 Hz / 4.5 V / cm); 58°C / 6 min (square wave 90 Hz / 3.0 V / cm); 56°C / 3 min (DC 0.8 V / cm); Step 3 First-stage rinse: 43°C, 2.8V / cm square wave, 0° angle, 0.8m / s, 5min; Second-stage rinse: 38°C, 0.9V / cm DC, 150° angle, 1.0m / s, 4min; Third-stage rinse: 33°C, 0.4V / cm pulse, 90° angle, 1.2m / s, 3min; Step 4: Membrane separation: 45nm ceramic membrane, 2.3m / s, 0.38MPa, solid content 12%; electrolysis: 1.2at% boron doping, 14mA / cm 2 ,8mm pole distance,9min,4.5V; The conductivity of the recycled water is 150μS / cm, the turbidity is 5NTU, and the reuse rate is 75%.

[0028] Comparative Example 1 Compared with Example 1, the difference is that in step 1, no sulfonated aerosol is added to the pretreatment liquid, and an equal amount of sodium dodecylbenzenesulfonate is added instead, and the rest are the same.

[0029] Comparative Example 2 Compared with Example 1, the difference is that: in step 2, the square wave electric field input is cancelled and only the constant temperature of 55° C. is maintained for treatment. The rest are the same.

[0030] Comparative Example 3 Compared with Example 2, the difference is that the three-stage rinsing in step 3 adopts the same direction electric field (all forming an angle of 0° with the direction of the electric field in step 2), and the rest are the same.

[0031] Comparative Example 4 Compared with Example 2, the difference is that in step 4, wastewater is directly discharged after membrane separation without electrolytic regeneration and reuse, and the rest are the same.

[0032] Comparative Example 5 Compared with Example 3, the difference is that in step 1, the interface modification treatment eliminates ultrasound and only uses negative pressure immersion, and the rest are the same.

[0033] Comparative Example 6 Compared with Example 3, the difference is that the pH-responsive microspheres are removed from the working solution in step 2, and the rest are the same.

[0034] Experiment 1: Verification of the function of the interfacial modifier; Description of experimental steps; Sample preparation; Take 6 groups of cotton knitted dyed fabrics of the same specifications (200g / m 2 , reactive dye dyeing); Example group: treated according to the process of Example 1 (containing sulfonated aerosol); Comparative Example Group: Processed according to Comparative Example 1 (sodium dodecylbenzenesulfonate substituted); Processing; The temperature of the pretreatment solution is kept constant at 30±1℃; The ultrasonic tank volume is 50L and the fabric running speed is 2m / min; The pressure fluctuation of the negative pressure system is controlled at ±0.005MPa.

[0035] Table 1 Comparative test data of interface modifier functions Sample Group Sulfonic acid group density Average pore size Specific surface area Pre-adsorption layer thickness Example 1-1 2.47 18.3 34.7 82.5 Example 1-2 2.39 17.9 33.2 79.8 Examples 1-3 2.53 19.1 35.4 84.2 Comparative Example 1-1 0.86 14.2 28.5 41.3 Comparative Example 1-2 0.92 13.8 27.9 38.7 Comparative Examples 1-3 0.81 15.1 29.2 43.6 According to Table 1 above, we can see that: The experimental data revealed the core role of surface modifiers in interfacial modification. Sulfonated aerosols form a three-dimensional hydrogen bond network with cellulose hydroxyl groups through surface sulfonic acid groups, constructing a stable pre-adsorption layer (the experimentally measured sulfonic acid group density is 2.4-2.5mmol / g). This chemical anchoring effect enables the aerosol to effectively fill the submicron pores of the fiber (average pore size 18-19nm). In contrast, traditional surfactants only form a discontinuous monolayer structure through physical adsorption (the pre-adsorption layer thickness is less than 45nm), which is prone to desorption in subsequent processes.

[0036] The transient high pressure (>100MPa) and directional penetration effect generated by the synergistic effect of ultrasound and negative pressure enable the aerosol to break through the energy barrier of the fiber surface. Nitrogen adsorption data show that the specific surface area of ​​the fiber treated by this invention is increased to 34m 2 / g or more, forming a through-type mass transfer channel. However, due to the lack of nanostructure support of aerosol, it is difficult to establish an effective channel by relying solely on mechanical penetration (specific surface area <29m 2 / g), resulting in a decrease in the mass transfer efficiency of subsequent catalytic reactions.

[0037] The optimized design of the pre-adsorption layer thickness and pore structure (82-84nm) provides a directional path for ion migration under the action of the electric field. Atomic force microscopy analysis shows that a uniform dielectric gradient layer is formed on the fiber surface of the embodiment group. This structure enables the subsequent electric field to accurately control the distribution of the catalyst. However, due to insufficient interface modification in the control group, local charge accumulation occurs when the electric field is applied (the pre-adsorption layer thickness fluctuates by >5nm), which destroys the continuity of energy transfer in the process stage. Experiment 2: Verification of electric field synergy effect Description of experimental steps; Sample preparation; Take 6 groups of interface-modified fabrics of the same specifications (treated in step 1 of Example 1); Example group: electric field coupled catalytic soaping was performed according to the process of Example 1; Comparative Example Group: Processed according to Comparative Example 2 (square wave electric field canceled, constant temperature 55°C); Processing; The working fluid circulation flow rate is controlled at 1.2m 3 / h; The current density fluctuation (±5%) was monitored during the electric field application; Laccase activity pretreatment: pre-activation at 30°C for 20 min.

[0038] Table 2 Comparative test data of electric field synergy effect Sample Group Laccase distribution CV value Dielectrophoretic rate Dielectric constant Current density fluctuation Example 1-1 12.3 8.7 68.4 4.2 Example 1-2 13.8 7.9 66.9 3.8 Examples 1-3 11.6 9.2 70.1 4.6 Comparative Example 2-1 37.5 1.2 52.3 12.4 Comparative Example 2-2 41.2 0.8 49.7 14.1 Comparative Examples 2-3 35.8 1.5 54.6 11.3 According to Table 2 above, we can see that: The introduction of a dynamic electric field significantly changed the mass transfer and energy distribution patterns of the catalytic system. The asymmetric polarization effect generated by the square wave electric field induced the laccase carrier to undergo dielectrophoretic migration (the experimentally measured rate was 8-9μm / s). This directional motion overcame the random limitations of traditional thermal diffusion and caused the catalyst to form a gradient distribution within the fiber pores (the laccase distribution CV value was <14%). In the control group, due to the lack of electric field drive, the nanoparticles only relied on Brownian motion to migrate (rate <1.5μm / s), causing the catalyst to aggregate on the fiber surface (CV value >35%) and unable to effectively act on the deep-bound dye.

[0039] The electric field frequency and the phase-change properties of the thermosensitive copolymer produce a synergistic response. Dielectric constant measurements show that the dielectric constant of the example system remains stable at 67-70, indicating that the square-wave electric field induces periodic expansion and contraction of the copolymer molecular chains, with their conformational changes synchronized with the electric field period (current density fluctuations <5%). This dynamic regulation maintains the appropriate binding force of the enzyme-substrate complex, avoiding the catalytic efficiency loss caused by molecular chain rigidity during traditional constant temperature treatment (dielectric constant <55, current fluctuations >10%).

[0040] High-frequency alternating electric fields regulate the reaction microenvironment through the dielectric relaxation effect. Experimental data revealed that the polarization of water molecules under the action of the electric field produces transient high-dielectric regions (local ε > 80). This micro-region effect reduces the van der Waals interaction energy between the dye and the fiber. In contrast, the comparative system lacks electric field-induced polarization, resulting in a weak dielectric barrier formed by the random arrangement of water molecules. This leads to an approximately 40% increase in the binding energy of the residual dye on the fabric surface after soaping, directly affecting the subsequent rinsing effect.

[0041] Experiment 3: Vector Rinse Direction Verification Description of experimental steps Sample preparation Take 6 groups of soaped fabrics of the same specifications (treated in step 2 of Example 2); Example group: three-stage vector rinsing was performed according to the process of Example 2; Comparative Example Group: Processed according to Comparative Example 3 (the directions of the three-stage rinsing electric fields are all 0°); Process Dynamic adjustment of the distance between the electrodes in the rinse tank (8-12cm random fluctuation); Water flow speed control accuracy ±0.1m / s; The rinsing water temperature is controlled by PID (±0.5℃).

[0042] Table 3 Vector rinsing effect comparison test data Sample Group Fiber core residue Surface residue Conductivity drop Wet rubbing color fastness Example 2-1 0.9 1.1 42.3 4.6 Example 2-2 1.2 0.8 38.7 4.5 Example 2-3 0.8 1 45.1 4.7 Comparative Example 3-1 2.7 3.1 18.4 3.9 Comparative Example 3-2 2.3 2.8 15.9 4 Comparative Example 3-3 3 2.5 21.3 3.8 According to Table 3 above, we can see that: The spatial regulation of the vector electric field triggers an asymmetric dielectrophoresis effect. When the direction of the rinsing electric field forms a specific angle with the water flow, the charged pollutant particles move in a spiral trajectory under the coupling of the Lorentz force and the fluid shear force (the experimentally measured conductivity drop is >38μS / cm·min). This three-dimensional migration mode breaks through the laminar flow limitations of traditional unidirectional rinsing, improving the uniformity of pollutant residue distribution on the fiber cross-section by more than 60% (core residue <1.2%). In the control group, the unidirectional force causes the dye particles to form micro-vortices and be retained in the fiber pores (core residue >2.3%).

[0043] The alternating electric field vector and the dynamic response of the thermosensitive polymer produce a synergistic cleaning effect. Experimental data show that the surface / core residue ratio of the Example group is close to 1:1, indicating that the periodic changes in the electric field direction induce conformational oscillations in the polymer molecules. The resulting mechanical stress waves (frequency 10-100 Hz) effectively disrupt the dye-fiber hydrogen bond network. The control group, due to the lack of vector changes, retains a static polymer chain configuration (wet rubbing color fastness decreases by 0.7 levels), failing to achieve deep cleaning.

[0044] Multi-stage vector rinsing optimizes the mass transfer path by establishing a dynamic dielectric gradient field. SEM-EDS analysis shows that an electric potential gradient (approximately 0.5 V / mm) is formed from the surface to the inside of the fibers in the example group, driving the directional migration of charged pollutants along the direction of the electric field vector. This electroosmotic pumping effect increases the efficiency of rinsing liquid renewal by 2.4 times (the conductivity decreases by 45 μS / cm·min). In contrast, the uniform electric field in the control group results in a flattened potential distribution, and pollutants diffuse only through the concentration gradient, limiting cleaning efficiency.

[0045] Experiment 4: Water circulation system efficiency verification Description of experimental steps Sample preparation Take 6 groups of rinsing wastewater of the same specifications (from step 3 of Example 2); Example group: electrolytic regeneration was carried out according to the process of Example 2 (boron-doped anode); Comparative Example Group: Directly discharged according to the process of Comparative Example 4 (without treatment); The electrolysis current density during the treatment process was controlled at 15±0.5mA / cm 2 ; The number of cycle treatments was set to 10 times (5% fresh water was added each time).

[0046] Table 4 Comparative data of water circulation system efficiency Sample Group Regeneration times surface tension D50 particle size ClO-concentration Conductivity Example 2-1 8 52.3 128 0.8 1240 Example 2-2 10 54.1 142 1.2 1360 Example 2-3 9 53.7 135 0.9 1290 Comparative Example 4-1 3 68.9 354 Not detected 2980 Comparative Example 4-2 2 72.4 418 Not detected 3250 Comparative Example 4-3 4 70.2 387 Not detected 3100 According to Table 4 above, we can see that: The selective oxidation pathway initiated by the boron-doped electrode is key to water recycling. Experimental data showed that the surface tension of the water dropped to below 53 mN / m after electrolysis (>68 mN / m in the untreated group), indicating that the hydroxyl radicals generated on the anode surface preferentially attacked the benzene ring structure in the dye molecule, converting it into a water-soluble sulfonic acid group. This targeted oxidation avoided macromolecular condensation reactions (D50 particle size <150 nm), while the p-type doping characteristics of the boron atoms suppressed oxidative competition with chloride ions (ClO- concentration <1.2 mg / L), thus controlling the formation of byproducts at the source.

[0047] The gradient dielectric membrane structure achieves precise separation through the space charge effect. The conductivity data show that the ionic strength of the circulating water system of the embodiment group is stable at about 1300μS / cm, which is due to the electric double layer repulsion generated by the Zeta potential of -35mV on the membrane surface. When the charged pollutants approach the membrane pores, their migration trajectory is deflected by the dielectrophoretic force (dielectric constant difference>15), which effectively prevents particles with a particle size of 128-142nm from depositing on the membrane surface. Due to the lack of potential regulation in the control group, the pollutants forcibly penetrate the membrane pores through mechanical screening (conductivity>3000μS / cm), resulting in irreversible blockage of the membrane structure.

[0048] The dynamic coupling of electrolysis and membrane separation establishes a self-regulating purification system. The regeneration data shows that when the conductivity of the circulating water rises to the threshold of 1400μS / cm, the control system automatically increases the electrolysis current density to 16mA / cm 2 By increasing the oxidation intensity, the particle size of newly generated pollutants is controlled within the membrane retention threshold (<200nm). This negative feedback mechanism enables the system to operate continuously for 8-10 cycles, while traditional processes, due to the disconnection between oxidation and separation, can only maintain effective cycles for 2-4 cycles before becoming ineffective.

[0049] Experiment 5: Verification of ultrasonic synergistic effect Description of experimental steps Sample preparation Take 6 groups of cotton knitted dyed fabrics of the same specifications (200g / m 2 , reactive dye dyeing); Example group: treated according to the process of Example 3 (ultrasound + negative pressure synergy); Comparative Example Group: Processed according to Comparative Example 5 (mechanical stirring instead of ultrasonic wave); Process Ultrasonic frequency 40kHz±5%, power density 0.8W / cm 2 ; Negative pressure system pressure -0.08MPa, fluctuation ±0.003MPa; The blade speed of the mechanical stirring group was 120 rpm (Reynolds number matching).

[0050] Table 5 Comparative test data of ultrasonic synergistic effect Sample Group OH concentration Penetration depth Energy consumption Surface dye residue Example 3-1 12.7 183 0.32 0.8 Example 3-2 11.9 176 0.35 0.9 Example 3-3 13.2 191 0.29 0.7 Comparative Example 5-1 2.4 62 0.58 2.7 Comparative Example 5-2 3.1 58 0.63 3.1 Comparative Example 5-3 2.8 65 0.61 2.9 According to Table 5 above, we can see that: The ultrasonic cavitation effect coupled with a negative pressure environment produces controllable microjets. Experimental data show that OH concentrations reached over 12 μmol / L (<3 μmol / L in the mechanically agitated group), indicating that the negative pressure environment (-0.08 MPa) prolonged the collapse of cavitation bubbles, increasing the microjets generated upon bubble collapse to >300 m / s. This high-energy microjets penetrated the hydration layer on the fiber surface (penetration depth >175 μm), while the mechanical agitation in the control group relied solely on macroscopic turbulence (penetration depth <65 μm), unable to break through the interfacial energy barrier.

[0051] Pulsed cavitation dissociates dye aggregates through a synergistic mechanical-chemical effect. Surface residual data show that the residual dye in the Example group is less than 1%, demonstrating that the cavitation shock wave (peak pressure >100 MPa) effectively disrupts the π-π stacking of dye and fiber. However, in the Control group, due to the lack of high-frequency mechanical shock (only low-frequency shear), dye molecules remain in a multimeric form (residual content >2.7%), making subsequent rinsing difficult.

[0052] The negative pressure system optimizes energy transfer efficiency by regulating the cavitation threshold. Energy consumption data shows that the unit energy consumption of the embodiment group is reduced by more than 45%, which is due to the negative pressure environment reducing the cavitation threshold from 0.5W / cm2 at normal pressure to 0.5W / cm2 at normal pressure. 2 Reduced to 0.3W / cm 2 , so that more electrical energy is converted into effective cavitation energy. However, the mechanical stirring of the control group has serious eddy current dissipation (energy consumption>0.58kWh / kg), and the energy utilization rate is less than 50%.

[0053] Experiment 6: Verification of Cyclic Stability of Thermosensitive Materials Description of experimental steps: Sample preparation: Take 6 groups of thermosensitive copolymers (N-isopropylacrylamide / acrylic acid copolymer) of the same specifications; Example group: silica nanocores were grafted according to the process of Example 3; Comparative example group: unmodified pure copolymer; Process Cycle test: Phase change cycle 100 times (5 min each); Mechanical stress: ultrasonic treatment (40kHz, 0.5W / cm 2 ) are applied synchronously; Chemical environment: pH 3-11 alternating (switching every cycle).

[0054] Table 6 Cyclic stability test data of temperature-sensitive materials Sample Group Number of cycles Phase transition time Swelling rate elastic modulus Particle size change rate Example 3-1 98 8.7 620 2.34 3.1 Example 3-2 100 9.2 605 2.28 4.3 Example 3-3 97 8.3 634 2.41 2.8 Comparative Example 5-1 35 15.6 824 1.07 18.7 Comparative Example 5-2 28 17.3 857 0.92 22.4 Comparative Example 5-3 41 14.1 798 1.15 15.9 According to Table 6 above, we can see that: The silica nanocores stabilize the polymer network through topological confinement. Experimental data show that even after 100 cycles, the swelling ratio of the example group remained at 605-634%, demonstrating that the nanocores (50 nm in diameter) act as physical crosslinks, limiting excessive chain slip. In contrast, the pure copolymer in the comparative example, lacking anchoring points, irreversibly disentangled the molecular chains during pH fluctuations (swelling ratio >790%), leading to the collapse of the three-dimensional network structure.

[0055] The dynamic reconfiguration of hydrogen bonds at the core-shell interface enhances environmental tolerance. Elastic modulus data show that the Example group maintains a modulus of 2.3 GPa after chemical-mechanical synergy. This is due to the reversible hydrogen bonding between the silanol groups on the SiO2 surface and the carboxyl groups on the polymer (reconfiguration occurs 3-5 times per cycle). The control group, lacking a dynamic bonding mechanism, experiences a modulus drop below 1 GPa, demonstrating the critical role of interface engineering in durability.

[0056] The confined space effect slows down the decay of phase transition kinetics. Phase transition time data revealed that the response time of the Example group fluctuated by less than 1 second (8.3-9.2 seconds), demonstrating that the steric hindrance generated by the nanocores maintains the cooperative motion of the polymer chains. In contrast, the control group, due to the excessive free volume of the molecular chains (particle size expansion >15%), required more cooperative motion units for the phase transition, resulting in a response time extension of over 70%.

[0057] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A low-temperature environmentally friendly soaping process for cotton knitted dyed fabrics, characterized in that: The following steps are involved: Step 1: performing interface modification treatment on the dyed fabric by ultrasonic coordinated negative pressure impregnation to form a micro-interface mass transfer channel; Step 2: performing dynamic temperature-electric field coupled catalytic soaping on the fabric after interface modification, using a temperature-sensitive catalytic system; Step 3: performing gradient countercurrent rinsing with electric field vector control on the soaped fabric; Step 4: The rinse wastewater is regenerated by membrane-electrolysis coupling treatment and then reused in step 3.

2. A low-temperature environmentally friendly soaping process for cotton knitted dyed fabrics according to claim 1, characterized in that: The interface modification treatment in step 1 specifically includes: Preparing a pretreatment liquid containing a surface-modified aerosol, wherein the aerosol has a D50 particle size of 300-400 nm and a surface sulfonic acid group grafting degree of ≥2.3 mmol / g; Treat under 38-42kHz ultrasonic wave and -0.06~-0.10MPa negative pressure for 4-6min; The fabric liquid carrying rate was controlled to be 65±5%.

3. The low-temperature environmentally friendly soaping process for cotton knitted dyed fabric according to claim 1, characterized in that: The dynamic temperature-electric field coupled catalytic soaping in step 2 specifically includes: The working solution consists of: ZIF-8 immobilized laccase 0.5-0.8wt%, thermosensitive copolymer 5.8-7.2wt%, pH-responsive microspheres 0.3-0.5wt%, where the mass ratio of thermosensitive copolymer to nanozyme is (8-10):1; Execute three-stage temperature control: The first stage was 53-57°C / 4-6 min, with simultaneous application of a 90-110 Hz square wave electric field with a field strength of 4.5-5.5 V / cm; The second stage is 58-62℃ / 4-6min, the electric field frequency remains unchanged, and the field strength is reduced to 3.0-3.5V / cm; The third stage is 56-59℃ / 1-3min, switching to a DC electric field with a field strength of 0.8-1.2V / cm.

4. The low-temperature environmentally friendly soaping process for cotton knitted dyed fabric according to claim 1, characterized in that: The gradient countercurrent rinsing controlled by the electric field vector in step 3 specifically includes: First stage rinsing: water temperature 43-47°C, square wave electric field 2.8-3.2V / cm, water flow direction and the electric field direction of step 2 are at an angle of 0-30°, water flow speed 0.8-1.2m / s, rinsing time 3-5min Second stage rinsing: water temperature 38-42°C, DC electric field 0.9-1.1V / cm, water flow direction and the electric field direction of step 2 are at an angle of 150-180°, water flow speed 1.0-1.4m / s, rinsing time 2-4min Third stage rinsing: water temperature 33-37℃, pulse electric field 0.4-0.6V / cm, water flow direction and the electric field direction of step 2 are at an angle of 90-120°, water flow speed 1.2-1.6m / s, and rinsing time 1-3min.

5. The low-temperature environmentally friendly soaping process for cotton knitted dyed fabric according to claim 1, characterized in that: The membrane-electrolysis coupling process in step 4 specifically includes: Membrane separation: ceramic membrane components with a pore size of 50±5nm are used, the cross-flow velocity is 2.3-2.7m / s, the operating pressure is 0.38-0.42MPa, and the retained liquid-solid content is controlled at 12-18% before being discharged from the system Electrolytic regeneration: using boron-doped diamond anode, boron atomic content 1.2-1.8at%, current density 14-16mA / cm2, plate spacing 8-12mm, electrolysis time 7-9min, cell voltage 4.5-5.5V Recycled water control: Recycled water conductivity is 150-200μS / cm, turbidity is ≤5NTU, and the reuse ratio is 75-85%. It is given priority to be added to the third-level rinsing process.

6. The low-temperature environmentally friendly soaping process for cotton knitted dyed fabric according to claim 1, characterized in that: A transition process is provided between step 2 and step 3, and the process includes: The soaped fabric is rapidly cooled by gas-liquid two-phase flow, and the cooling medium is atomized water containing 0.1-0.3% nanobubbles; Apply a rotating magnetic field with a magnetic field strength of 50-80 mT and a rotation frequency of 2-4 Hz; Control the fabric surface temperature at 45±2℃ and proceed to step 3.

7. The low-temperature environmentally friendly soaping process for cotton knitted dyed fabric according to claim 1, characterized in that: The rinsing tank in step 3 is configured with a porous electrode structure, and the electrode has: Honeycomb through-holes, pore diameter 3-5mm, open porosity 60-70%; The surface is loaded with a MnO2-TiO2 composite catalytic layer with a loading of 2.5-3.5 mg / cm 2 ; The electrode spacing is dynamically adjustable, with an adjustment range of 8-12cm.

8. The low-temperature environmentally friendly soaping process for cotton knitted dyed fabric according to claim 1, characterized in that: A multi-stage pretreatment device is provided before the membrane separation unit in step 4, including: Cyclone separator: removes particles larger than 100 μm, cone angle 15-20°, feed speed 2.5-3.5 m / s; Electrocoagulation reactor: uses aluminum-iron composite electrodes, with alternating plates and an inter-electrode distance of 10-15 mm; Micro-nano aeration unit: bubble diameter 50-200nm, gas-liquid ratio 1: (8-12).

9. The low-temperature environmentally friendly soaping process for cotton knitted dyed fabric according to claim 1, characterized in that: The steps include a dye recovery subsystem comprising: A supercritical CO2 extraction device is used to extract the dye from the retentate in step 4, with a pressure of 25-30 MPa and a temperature of 45°C. A molecularly imprinted adsorption column is used for dye purification, with an imprinted cavity size of 1.2-1.8 nm; The recovered dyes are reused in the dyeing process, with a reuse rate of ≥85%.

10. The low-temperature environmentally friendly soaping process for cotton knitted dyed fabric according to claim 1, characterized in that: The catalytic soap washing tank in step 2 is configured with a double circulation system, including: Main circulation: axial flow circulation, flow rate 0.8-1.2m / s, promotes directional migration of catalyst; Secondary circulation: tangential flow circulation, flow rate 0.3-0.5m / s, to prevent the deposition of temperature-sensitive copolymers; The dual circulation flow ratio is controlled at (2.5-3.5):1.

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