CN114805812B - A kind of ladder-shaped phenyl polysilsesquioxane, polycaprolactone/ladder-shaped phenyl polysilsesquioxane blend film and its preparation method - Google Patents

Abstract

The invention discloses a ladder-shaped phenyl polysilsesquioxane, a polycaprolactone/ladder-shaped phenyl polysilsesquioxane blend film and a preparation method thereof. In a nitrogen atmosphere, phenyltrimethoxysilane is The hydrolysis reaction is carried out in the presence of an organic solvent and hydrochloric acid to obtain silanol; the silanol is reacted in the presence of an alkali solution at room temperature and nitrogen atmosphere to obtain a trapezoidal phenyl polysilsesquioxane. Dissolve polycaprolactone and trapezoidal phenyl polysilsesquioxane in an organic solvent to obtain a precursor solution, and then use an electrospinning device to electrospin the precursor solution to obtain polycaprolactone/trapezoidal phenyl Polysilsesquioxane blend film. The construction of the "roughened" structure on the fiber surface makes the composite fiber membrane have good superhydrophobicity, the contact angle can reach 158°±0.1°, and the adhesion force is only 111.916μN.

Description

A ladder-shaped phenyl polysilsesquioxane, polycaprolactone/ladder-shaped phenyl polysilsesquioxane Alkane blend film and preparation method thereof

technical field

The invention belongs to oil-water separation technology, in particular to a polycaprolactone/trapezoidal phenyl polysilsesquioxane blended electrostatic spinning membrane and a preparation method thereof.

Background technique

Common oil-water separation methods include chemical methods (in-situ combustion method, chemical demulsification method), biological methods (biodegradation method) and physical methods (air flotation method, centrifugation method, membrane separation method) [Zuo J, Liu Z, Zhou C, et al. A durable superwetting clusters-inlayed mesh with high efficiency and flux for emulsion separation[J]. Journal of Hazardous Materials, 2020, 403: 123620], in which membrane separation technology is favored for its high efficiency, low cost and environmental protection been widely concerned. Membranes used for oil-water separation usually have special wettability, such as hydrophilic-oleophobic or hydrophobic-oleophilic, when a mixture of oil and water comes into contact with the membrane, one liquid can permeate through while the other liquid does not. will be blocked [Tian Y, Ma H. Solvent-free green preparation of reusable EG-PVDF foam for efficient oil-water separation[J]. Separation and Purification Technology, 2020, 253: 117506]. Surface modification (coating, grafting, copolymerization) and blending with other substances (polymers, copolymers, nanoparticles) are usually used to prepare membranes with special wettability [Cui J, Li F, Wang Y , et al. Electrospun nanofiber membranes for wastewater treatment applications[J]. Separation and Purification Technology, 2020, 250: 117116]. Compared with surface modification methods which are cumbersome, harsh conditions and high cost, blending is favored by many people because of its simple operation and low cost. He et al[He L, Lei W, Liu D. One-step facile fabrication of mechanicalstrong porous boron nitride nanosheets-polymer electrospun nanofibrousmembranes for repeatable emulsified oil/water separation[J]. Separation and Purification Technology, 2021, 264: 11 8446] by electrostatic A novel porous hydrophilic boron nitride nanosheet/polyacrylonitrile (BNNS/PAN) nanofiber membrane was prepared by spinning method, which has good mechanical properties, with a mechanical strength of 19.9 Mpa and a Young's modulus of 139.6 MPa. Du et al. mixed polyvinylidene fluoride (PVDF), polyvinylidene fluoride pyrrolidone (PVP) and inorganic titanium dioxide (TiO ₂ ) nanoparticles, and then electrospun to prepare a hydrophilic and oleophobic film with a layered rough structure. A facile and ingenious approach to reusable functional separation membranes. Polycaprolactone (PCL) has attracted extensive attention because of its good biocompatibility, biodegradability and film-forming properties. Although the PCL spinning membrane itself is hydrophobic, it still has certain limitations.

Contents of the invention

The present invention prepares PCL/ph-LPSQ composite fiber membrane by blending electrospinning method, and characterizes its element composition, wettability, thermal performance, etc. field applications.

The present invention adopts following technical scheme:

A trapezoidal phenyl polysilsesquioxane has the following chemical structural formula:

In the present invention, phenyltrimethoxysilane (PTMS) is hydrolyzed under acidic conditions to generate silanol; the latter undergoes dehydration condensation between silanols under alkaline conditions to generate the target product with a Si-O-Si main chain structure, Thus, a trapezoidal phenyl polysilsesquioxane was prepared. Specifically, in a nitrogen atmosphere, phenyltrimethoxysilane undergoes a hydrolysis reaction in the presence of an organic solvent and hydrochloric acid to obtain silanol. Preferably, after the hydrolysis reaction is completed, the reaction solution is left to stand for layers, and the upper layer solution is taken and washed with water. To neutrality, silanol is obtained, which exists in the form of solution. The hydrolyzed silanol solution obtained in the previous step was reacted in the presence of an alkali solution at room temperature and a nitrogen atmosphere. After the reaction was completed, it was washed with water to neutrality, and then evaporated and dried to obtain a white solid product. Silsesquioxane (ph-LPSQ).

A polycaprolactone/ladder-shaped phenyl polysilsesquioxane blend film prepared from the above-mentioned ladder-shaped phenyl polysilsesquioxane and PCL, preferably, the above-mentioned ladder-shaped phenyl polysilsesquioxane It is prepared by electrospinning with PCL; specifically, a certain proportion of PCL and ph-LPSQ are dissolved in an organic solvent to obtain a precursor solution, and then an electrospinning device is used to electrospin the precursor solution to obtain polyhexene Lactone/Ladder Phenyl Polysilsesquioxane Blend Film.

In the present invention, the concentration of the precursor solution is 6wt% ~ 20wt%, preferably 10wt% ~ 14wt%; the organic solvent is chloroform; the mass ratio of PCL and ph-LPSQ is 1: (0.1 ~ 1), preferably 1: (0.2 ~0.4).

The present invention adopts sol-gel method to prepare trapezoidal phenyl polysilsesquioxane, and uses FT-IR and ²⁹ Si-NMR to characterize the target product structure. The synthesized product was blended with PCL, and a uniform PCL/ph-LPSQ nanofibrous membrane was prepared by one-step electrospinning method by controlling process parameters such as solution concentration, solvent blending ratio, and solute blending ratio. The chemical composition, structure, morphology, hydrophobicity and thermal properties of the fiber membrane were characterized by ATR-IR, XPS, EDS, WCA, AFM, TGA, etc. Some potential applications of fibrous membranes in the fields of self-cleaning, antifouling, oil absorption, and oil-water separation are discussed.

The invention uses PTMS as a raw material, fully hydrolyzes under the action of dilute hydrochloric acid to generate silanol, and then catalyzes with potassium hydroxide to undergo dehydration condensation between hydroxyl groups. During the process, the addition amount of solvent toluene, the reaction temperature, the amount of catalyst, etc. are controlled to prepare trapezoidal phenyl polysilsesquioxane with good regularity. The structure of the target product was characterized by ²⁹ Si-NMR and FT-IR. The spinning process was determined as follows: solvent: chloroform, concentration: 14%, receiving distance: 20 cm, voltage: 12 kV, flow rate: 1 mL/h, temperature: 27.5±0.5℃, humidity: 85±5%. On the basis of the process conditions, PCL and ph-LPSQ were blended, and the composite PCL/ph-LPSQ nanofibers were obtained by adjusting the mass blending ratio. The nanofibrous membrane prepared by the blend ratio of PCL and ph-LPSQ at 1.0:0.2 was selected for subsequent experiments. The chemical composition of the fiber membrane surface was analyzed by EDS, XPS and ATR-IR, and the rough morphology of the fiber membrane surface was observed and characterized by SEM and AFM. The wettability and thermal properties of the PCL/ph-LPSQ fiber membrane were characterized by WCA, TG, adhesion, etc. The results show that the formation of "roughened" morphology on the fiber surface endows the nanofiber membrane with superhydrophobicity, the contact angle can reach 158°±0.1°, and the adhesion force is only 111 μN. Compared with the initial degradation temperature of 340°C for pure PCL membrane, it increased to 355°C after adding ph-LPSQ, and the composite fiber membrane was baked at 80°C for 24 h, and the weight loss rate was only 1.59%. The composite nanofiber membrane has excellent self-cleaning and anti-fouling properties. Its use in oil-water separation tests shows that after ten separation cycles, the separation efficiency can still reach more than 98%. After being treated for 24 h under the same conditions, it still maintains good hydrophobicity, showing excellent stability and cycling ability.

Description of drawings

Figure 1 is the silicon NMR spectrum of ph-LPSQ.

Figure 2 is the infrared spectrum of ph-LPSQ.

Figure 3 is the SEM images of PCL fibers at different solution concentrations: (a1-a2): 6 wt%, (b1-b2): 8 wt%, (c1-c2): 10 wt%, (d1-d2): 12 wt%, (e1-e2): 14 wt%.

Figure 4 shows the diameter distribution and SEM images of PCL fibers under different solvent ratios: (a1-a3): 1:2 (V:V, N, N - dimethylformamide: chloroform), (e1-e3): Chloroform.

Figure 5 is the diameter distribution and SEM images of PCL/ph-LPSQ fibers under different blending ratios: (a1-a3): 1.0:0.2, (b1-b3): 1.0:0.4, (c1-c3): 1.0: 0.6, (d1-d3):1.0:0.8.

Figure 6 is the EDS spectrum of the PCL/ph-LPSQ nanofiber membrane.

Figure 7 is the infrared spectrum of PCL and PCL/ph-LPSQ nanofiber membrane (a); the XPS spectrum of PCL/ph-LPSQ nanofiber membrane: full spectrum (b), carbon spectrum (c), oxygen spectrum ( d), silicon spectrum (e).

Figure 8 is the image of PCL film (a-a') and PCL/ph-LPSQ nanofiber film (b-b') after baking at 80℃ for 4 h; TGA curve (c); thermal weight loss curve (d) of PCL/ph-LPSQ nanofibrous membrane baked at 80 °C for 24 h.

Figure 9 is the WCA diagram of the PCL membrane (a) and the PCL/ph-LPSQ nanofiber membrane (b).

Figure 10 is the PCL/ph-LPSQ nanofiber film adhesion-distance curve.

Figure 11 is the self-cleaning (methylene blue powder (a1-a3) and chalk powder (b1-b3)) and anti-fouling test (c1-c6) images of the PCL/ph-LPSQ nanofibrous membrane.

Figure 12 is a photo of the process of PCL/ph-LPSQ nanofiber membrane oil adsorption (a) and oil-water mixture separation (b).

Figure 13 shows the separation efficiency of the PCL/ph-LPSQ nanofiber membrane after 10 cycles of oil-water separation.

Figure 14 is the SEM and WCA images of the PCL/ph-LPSQ nanofibrous membrane at 80°C (a1, a2), 1M HCl (b1, b2), 1M NaOH (c1, c2) and 1M NaCl (d1, d2) .

Detailed ways

The invention uses phenyltrimethoxysilane as a raw material to prepare ph-LPSQ through a sol-gel method, and characterizes the structure of the target product by using silicon nuclear magnetic spectrum and infrared spectrum. Dissolve PCL and ph-LPSQ in chloroform, stir thoroughly to obtain a uniform spinning solution, control the concentration, solvent ratio and blending ratio and other process parameters to prepare a uniform composite nanofiber membrane. The surface chemical composition (ATR-IR, EDS, XPS) of the fiber membrane was analyzed, the wettability and thermal properties of the electrospun membrane were tested, the surface properties such as static contact angle and adhesion were tested, and the nanometer Self-cleaning and oil-water separation application properties of fiber membranes.

Phenyltrimethoxysilane (high purity, ≥98%) was purchased from Shanghai Anaiji Chemical Technology Co., Ltd. Toluene, anhydrous methanol, hydrochloric acid, potassium hydroxide, chloroform, and N,N- dimethylformamide were all purchased from Jiangsu Qiangsheng Functional Chemicals Co., Ltd., and all of them were of analytical grade (AR). Polycaprolactone (PCL, M _n ≈ 80000 g/mol) was purchased from Shanghai Sigma-Aldrich Trading Co., Ltd. Distilled water was self-made in the laboratory, and the above reagents were used directly without further purification. Aluminum foil paper (30 cm × 20 cm), polytetrafluoroethylene tube (18 S, inner diameter 1.07 mm, outer diameter 1.87 mm), single-axis needle (18G, inner diameter 0.84 mm, outer diameter 1.27 mm) were purchased from Beijing Lanjieke Technology Co., Ltd., Shenzhen Wall Nuclear Material Co., Ltd. and Shanghai Jinrong Chemical Technology Co., Ltd.

The obtained samples were tested by a Thermo Scientific Nicolet iS5 infrared spectrometer. The synthesized product was analyzed by silicon NMR spectrometer by solid wide cavity superconducting NMR spectrometer (AVANCEIII/WB-400). The morphology of the samples was characterized by a cold field emission scanning electron microscope (SU8100). The content and distribution of elements on the surface of the fiber membrane were tested by using a desktop scanning electron microscope (TM-3030) with energy dispersive X-ray energy spectroscopy. A ThermoScientific Nexsa X-ray photoelectron spectrometer was used to test the fiber membrane for surface element analysis, using Mono AlKa rays (hν=1486.6 eV) as monochromatic light, the working pressure in the cabin was 4.0×10 ^-9 Pa, and the incident angle was 45 °, based on the binding energy of carbon in saturated hydrocarbons (284.6 eV). The thermal properties of the fiber membranes were analyzed using a thermogravimetric instrument (Diamond 5700). The wettability of the fiber membrane surface was characterized by an automatic microscopic droplet wettability tester (OCA40). The fiber membrane was fixed on a glass slide with double-sided tape, and 3 μL of deionized water was used as a test droplet, and measured at any five points on the sample, and the average value was taken. The surface morphology and three-dimensional structure of the fiber membrane were characterized by atomic force microscopy (VEECO Multimode 8). The surface interfacial tension instrument (DCAT11) was used to measure the interfacial tension of the fiber membrane surface. Use double-sided tape to stick the sample on the glass slide and place it on the stage. Then pipette 4 μL of deionized water, transfer it to the metal test ring above the sample, and keep the droplet in a spherical shape. After the loading platform was raised to a suitable height, the program was run, and the ring carrying the water droplets approached the surface of the fiber membrane at a speed of 0.1 mm/s. The maximum value of the force curve generated by the ring from contacting to leaving the surface of the fiber membrane was Adhesion value.

Embodiment one

The synthetic route of trapezoidal phenyl polysilsesquioxane (ph-LPSQ) is as follows:

Among them, phenyltrimethoxysilane (PTMS) is completely hydrolyzed under acidic conditions to generate silanols; the latter undergoes dehydration condensation between silanols under alkaline conditions to generate the target product with a Si-O-Si main chain structure, and obtains White solid product ladder-shaped phenyl polysilsesquioxane (ph-LPSQ), molecular weight 1000-1300.

(1) Hydrolysis of PTMS monomer

In a nitrogen atmosphere, 10 mL of phenyltrimethoxysilane and 60 mL of toluene were added to a 500 mL three-neck flask equipped with electromagnetic stirring, and the reaction system was placed in an ice bath at -10 °C. The prepared dilute hydrochloric acid (20 mL, 0.1 mol/L) was added dropwise to the mixture within 30 min. After the dropwise addition, the reaction was stirred for 24 h. After the hydrolysis reaction was completed, the reaction solution was placed in a separatory funnel, and the upper layer solution was taken and washed 5 times with 150 mL deionized water until neutral.

(2) Polycondensation of hydrolyzate

The hydrolyzate obtained in the previous step was transferred to a 250 mL three-necked flask equipped with a reflux condenser, and 3 mL of KOH solution (1 g/L) was added dropwise to the reaction liquid through a syringe at room temperature and under a nitrogen atmosphere. After the dropwise addition, the reaction temperature was set to 80 °C, and the reaction was refluxed for 24 h. After the reaction was finished, it was washed to neutrality with 200 mL of deionized water, then rotary evaporated and vacuum-dried to obtain a white solid product ph-LPSQ with a number average molecular weight of 1200.

Figure 1 is the silicon nuclear magnetic spectrum and infrared spectrum of ph-LPSQ. ²⁹ Si-NMR has been widely used as one of the most effective methods to characterize the structure of ladder-like polysilsesquioxanes. There are two characteristic peaks in the silicon NMR spectrum. The peak and weak peaks represent the chemical shifts of the silicon atoms located in the ladder-like backbone and the ends of the molecular chains, respectively. The half-width of the characteristic peaks of silicon atoms on the main chain is usually used to characterize the regularity of ladder polymers. This is because the smaller the half-width, the more monotonous the chemical environment of silicon atoms, and the higher the regularity. The half-peak width of the sample prepared in the present invention is 4.25, showing better regularity.

The infrared spectrum results of ph-LPSQ are shown in Figure 2. The characteristic peaks of the benzene ring observed around 3072, 3052 and 3010 cm ^-1 belong to the typical stretching vibration of CH, and the characteristic peaks observed around 1596 and 1434 cm ^-1 The peak belongs to C=C. The peaks at 1133 and 3626 cm ^-1 belong to the characteristic peaks of Si-O-Si bond and Si-OH bond, respectively. The peaks at 694 and 737 cm ^-1 correspond to the characteristic peaks of Si-C bonds.

The above results indicated that ph-LPSQ has been successfully synthesized.

Example 2 Preparation of PCL nanofiber membrane

The preparation process of the precursor solution for electrospinning is as follows: a certain proportion of PCL is dissolved in the solvent. Stir thoroughly with a magnetic stirrer for 4 h at room temperature to prepare a transparent and homogeneous solution, and then sonicate for 30 min to remove air bubbles. The precursor solution was electrospun using an electrospinning device (JDF05), which consisted of a high-voltage power supply, a propulsion pump, a syringe, and a receiving device. When the push pump pushes the solution out of the needle, a Taylor cone is formed at the needle under the action of an electric field. As the voltage increases, the electrostatic field force on the solution overcomes the tension and viscous resistance of the fluid surface, resulting in the formation of nanofibers that are collected on an aluminum foil collector.

In the case of receiving distance (20 cm), voltage (12 kV), flow rate (1 mL/h), temperature (27.5±0.5°C) and humidity (85±5%), different precursor solution concentrations were used (wt%, 6%-14%, the change interval is 2%, chloroform) for electrospinning, the results are shown in Figure 3.

Under the condition of constant solution concentration (14%), receiving distance (20 cm), voltage (12 kV), flow rate (1 mL/h), temperature (27.5±0.5°C) and humidity (85±5%), Different solvents ( N,N -dimethylformamide/chloroform 1:2 volume ratio, chloroform) were used for electrospinning, and the results are shown in Figure 4; the nanofiber membrane prepared by chloroform was selected for subsequent research.

Example 2 Preparation of PCL/ph-LPSQ nanofiber membrane

The precursor solution for electrospinning was prepared as follows: a certain proportion of PCL and ph-LPSQ were dissolved in chloroform. Fully stir with a magnetic stirrer at room temperature for 4 h to prepare a transparent and homogeneous solution, and then sonicate for 30 min to remove air bubbles to obtain a precursor solution, PCL and ph-LPSQ as solutes with a concentration of 14 wt%, using an electrospinning device ( JDF05) Electrospinning the precursor solution, the electrospinning device consists of a high voltage power supply, a propulsion pump, a syringe and a receiving device. When the push pump pushes the solution out of the needle, a Taylor cone is formed at the needle under the action of an electric field. As the voltage increases, the electrostatic field force on the solution overcomes the tension and viscous resistance of the fluid surface, resulting in the formation of nanofibers that are collected on an aluminum foil collector.

Fixed solution concentration (14%), receiving distance (20 cm), voltage (12 kV), flow rate (1 mL/h), temperature (27.5±0.5°C) and humidity (85±5%) were constant, and different The blend ratio (m:m, PCL:ph-LPSQ) was electrospun, and the results are shown in Figure 5. With the increase of the amount of ph-LPSQ, the diameter of the fiber showed an increasing trend, but the standard deviation of the fiber diameter was from 1.22 μm increased to 4.48 μm, indicating that the uniformity of the fiber has decreased; the nanofiber membrane prepared by the mass blending ratio of PCL and ph-LPSQ of 1:0.2 was selected for subsequent research.

The chemical composition on the surface of the fiber membrane was analyzed by EDS energy spectroscopy. Figure 6 is the EDS element content and distribution diagram of the PCL/ph-LPSQ nanofiber membrane. The pure PCL nanofibrous membrane only contains two elements, C and O, and the Si element appears in the PCL/ph-LPSQ nanofibrous membrane, and its percentage content is 2.870%, which indicates that ph-LPSQ has been successfully blended with PCL. In order to further verify that ph-LPSQ has been successfully blended with PCL, the infrared spectrum and XPS spectrum of the PCL/ph-LPSQ nanofiber membrane were analyzed, as shown in Figure 7. According to the above EDS, ATR-IR, XPS spectral results, it shows that ph-LPSQ is uniformly dispersed in PCL.

As shown in Figure 8, after being baked in an oven at 80 °C for 4 h, the pure PCL nanofiber membrane melted, the nanofiber structure was destroyed, and the electrospun membrane was transformed into a smooth dense membrane. While under the same conditions, the morphology and structure of the PCL/ph-LPSQ nanofibrous membrane did not change significantly, and compared with the former, it showed better thermal stability. To further verify the previous results, the thermal properties of PCL and PCL/ph-LPSQ nanofibrous membranes were investigated by thermogravimetric analysis (TGA). With the addition of ph-LPSQ, the thermodynamic curves of PCL fiber membranes shifted slightly to the right The initial degradation temperature increased from 340°C to 355°C. And the carbon residue rate of PCL/ph-LPSQ fiber membrane is 11.61%, which is higher than that of pure PCL membrane. In addition, the baking time at 80°C was extended from 4 h to 24 h, and it was found that the weight of the PCL/ph-LPSQ fiber membrane decreased from 63 mg to 62 mg, and the weight loss rate was only 1.59%. The above results indicated that the PCL/ph-LPSQ nanofibrous membrane had better thermal performance.

The wettability of the PCL/ph-LPSQ nanofibrous membrane was evaluated by water contact angle and adhesion test. From Fig. 9(a), it can be seen that the initial water contact angles of PCL and PCL/ph-LPSQ nanofibrous membranes are 133.6°±0.2° and 158.0°±0.1°, respectively. After standing for 15 min, the contact angle of the PCL film decreased to 87.5°±0.6°, while the contact angle of the PCL/ph-LPSQ nanofiber film remained above 150°, as shown in Figure 9(b). This is because the two fibers have different surface structures and thus exhibit different water-repellent stability. As shown in Figure 10, after testing with the surface interfacial tension instrument, the measured adhesion force of the sample is 111.916 μN. The above results indicated that the PCL/ph-LPSQ nanofibrous membrane had good superhydrophobicity.

Superhydrophobic nanofiber membranes have certain application prospects in the fields of self-cleaning and oil-water separation. In order to study the self-cleaning performance of PCL/ph-LPSQ nanofiber membranes, methylene blue powder and chalk powder were used as pollutant reference samples. As shown in (a1-b3) in Figure 11, the sample film was fixed on the surface of the glass slide by double-sided adhesive tape and placed at an angle of 8°. As the water droplets fall, the pollutants distributed on the sample will be carried away from the surface of the sample with the rolling water droplets without leaving stains. In addition, the antifouling properties of the samples were also considered. As shown in Figure 11 (c1-c6), the sample was soaked in water stained with methylene blue. After taking it out, it can be observed that no blue stains are left on the surface of the sample film. The above results indicated that the ph-LPSQ nanofibrous membrane had good self-cleaning and antifouling properties.

The oil absorption performance of the PCL/ph-LPSQ nanofibrous membrane is shown in Fig. 12(a). When the film came into contact with carbon tetrachloride, which was stained oily red at the bottom of the beaker, the oil droplets were quickly absorbed by the sample. This is because the prepared nanofibrous membrane has a porous and rough layered structure with a high specific surface area, so it has good oil absorption capacity, and the addition of ph-LPSQ promotes phase separation, which improves the surface roughness of the fiber, and the contact The angle reaches more than 150°. Therefore, the PCL/ph-LPSQ nanofibrous membrane was used to separate the oil-water mixture. Figure 12(b) shows the separation process of the PCL/ph-LPSQ nanofiber membrane for the oil-water mixture driven only by gravity. It can be seen that when an oil-water mixture containing 20 ml of methylene blue-stained deionized water and 20 ml of oil red-stained carbon tetrachloride was injected into a glass beaker, the oil droplets were rapidly absorbed and collected into the lower surface when it contacted the fiber membrane. In the beaker, while the water is impermeable, it remains on the top of the fibrous membrane, thus realizing the separation of the oil phase and the water phase. As shown in Figure 13, after 10 separation cycles, the sample membrane still has a high separation efficiency, which can reach 98%, showing good oil-water separation performance and circulation ability.

The stability of nanofibrous membranes plays a crucial role in its practical application. The present invention tests the stability of the PCL/ph-LPSQ nanofiber membrane in different pH solutions and at 80° C., and the results are shown in FIG. 14 . From Figure 14 (a1-d1), it can be seen that after soaking for 24 h, the fiber morphology remains stable without twisting or breaking. The contact angle test was carried out on the fiber membranes treated in different environments. The results are shown in Fig. 14 (a2-d2). After h, the WCA still remained above 150°. Although the WCA value decreased to 143.3° ± 0.2° in 1M NaOH solution, it still exhibited good hydrophobicity. This shows that the prepared nanofibrous membrane has good stability, and it can be seen that the composite of ph-LPSQ broadens the application range of the nanofibrous membrane in various environments.

Claims (7)

1. The polycaprolactone/trapezoidal phenyl polysilsesquioxane blend membrane is characterized by being prepared from trapezoidal phenyl polysilsesquioxane and PCL by adopting electrostatic spinning; the preparation method of the trapezoid phenyl polysilsesquioxane comprises the steps of hydrolyzing phenyl trimethoxy silane under an acidic condition to generate silanol; and dehydrating and condensing silanol under alkaline conditions to obtain trapezoidal phenyl polysilsesquioxane.

2. The polycaprolactone/trapezoidal phenyl polysilsesquioxane blend membrane of claim 1, wherein the trapezoidal phenyl polysilsesquioxane has a number average molecular weight of 800 to 1400.

3. The polycaprolactone/trapezoidal phenyl polysilsesquioxane blend membrane according to claim 1, wherein the phenyl trimethoxysilane undergoes hydrolysis in the presence of an organic solvent and hydrochloric acid in a nitrogen atmosphere to yield silanol; and (3) carrying out condensation reaction on silanol in the presence of alkali solution at room temperature under the condition of nitrogen atmosphere to obtain the trapezoid phenyl polysilsesquioxane.

4. The polycaprolactone/trapezoidal phenyl polysilsesquioxane blend membrane according to claim 3, wherein the volume ratio of phenyl trimethoxysilane, organic solvent and hydrochloric acid is 1: (5-7): (1-3); the hydrolysis reaction was carried out in an ice bath.

5. A polycaprolactone/trapezoidal phenyl polysilsesquioxane blend membrane according to claim 3, wherein the base solution is an inorganic base solution; the condensation reaction is reflux reaction for 20-30 h.

6. Use of the polycaprolactone/trapezoidal phenyl polysilsesquioxane blend membrane of claim 1 in the preparation of an oil-water separation material.

7. The use according to claim 6, wherein the oil-water is a mixture of an organic solvent and water.