阅读说明：本技术 一种纳米纤维材料、其制备方法及其在化工废水硝基苯监测中的应用 (Nanofiber material, preparation method thereof and application of nanofiber material in nitrobenzene monitoring of chemical wastewater ) 是由 杨宇斐 于 2018-06-21 设计创作，主要内容包括：本发明涉及一种纳米纤维材料,其包括聚合物基质和荧光剂。本发明还涉及一种所述纳米纤维材料的制备方法,通过电纺丝技术制备新型纳米纤维材料,该方法简单易行、快速高效、成本较低,具有较好的普适性。制备得到的新型纳米纤维材料具有新颖独特的纳米纤维形貌,用于废水中硝基苯监测对硝基苯的检测限很低,对废水中硝基苯的响应时间短,所述材料再生性能优良,可重复利用。(The present invention relates to a nanofiber material comprising a polymer matrix and a fluorescent agent. The invention also relates to a preparation method of the nanofiber material, which is used for preparing the novel nanofiber material by an electrospinning technology, and the method is simple, easy, rapid, efficient, low in cost and good in universality. The prepared novel nanofiber material has a novel and unique nanofiber shape, the detection limit of monitoring p-nitrobenzene in wastewater is very low, the response time of monitoring p-nitrobenzene in wastewater is short, and the material has excellent regeneration performance and can be recycled.)

1. A nanofiber material comprising a polymer matrix and a fluorescent agent.

2. The nanofiber material of claim 1 wherein the nanofiber material has a one-dimensional nanofiber morphology; the diameter of the nanofiber is 200-600 nm; preferably, the fluorescent agent is contained in an amount of 5 to 10 parts by weight, preferably 6 to 8 parts by weight, based on 100 parts by weight of the polymer matrix.

3. The nanofiber material according to claim 1 or 2, wherein the polymer matrix comprises a cellulose organic acid ester; preferably, the polymer matrix comprises at least one of cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate phthalate and cellulose acetate succinate.

4. The nanofiber material of any one of claims 1-3 wherein the fluorescer comprises an anthracene-based fluorescer; preferably, the phosphor comprises at least one of 9-chloroanthracene, 9-anthracenal, 9-anthracenemethanol, 9-methylanthracene, 9-acetylanthracene, 9-bromoanthracene, and 9-vinylanthracene.

5. A method of preparing a nanofibrous material according to any of claims 1-4 comprising the steps of:

s1, mixing the polymer matrix, the fluorescent agent and the solvent to prepare an electrospinning stock solution;

s2, preparing the electrospinning stock solution into electrospinning nanofibers through electrospinning;

and S3, removing the solvent in the electrospun nanofiber to obtain the nanofiber material.

6. The production method according to claim 5, wherein the solvent comprises a mixed solvent composed of a solvent I and a solvent II; preferably, the solvent I comprises an amide polar solvent, and the solvent II comprises a ketone solvent; more preferably, the solvent I comprises at least one of N, N dimethylacetamide, N dimethylformamide, N-dimethylpropionamide, N-diethylacetamide, N-methylacetamide or N-ethylacetamide, and the solvent II comprises at least one of acetone, cyclohexanone, methyl ethyl ketone or methyl isobutyl ketone.

7. The production method according to claim 5 or 6, characterized in that, in the electrospinning dope, based on 100 parts by weight of the polymer matrix, the content of the fluorescent agent is 5 to 10 parts by weight, preferably 6 to 8 parts by weight, the content of the solvent is 400-1000 parts by weight, preferably 500-800 parts by weight; and/or

The mass ratio of the solvent I to the solvent II in the solvent is 1 (1-4), preferably 1 (1.5-3).

8. The preparation method according to any one of claims 5 to 7, wherein in step S2, the electrospinning device comprises a syringe and a receiver, the syringe is pushed at a speed of 0.8-1.5mL/h, and the receiver is rotated at a speed of 500-; the distance between the needle of the injector and the receiver is 12-18cm, the voltage of the electrospinning is 10-20kV, and the electrospinning time is 8-10 min.

9. The method according to any one of claims 5 to 8, wherein in step S3, the solvent is removed by drying at a temperature of 60 to 80 ℃ for 10 to 15 hours.

10. Use of a nanofibrous material according to any of claims 1-4 or obtained by the preparation method according to any of claims 5-9 for nitrobenzene monitoring in chemical wastewater comprising the following steps:

i) after the nanofiber material is immersed in chemical wastewater for 1-3 minutes, detecting a fluorescence emission signal of the nanofiber material at a 420nm position;

II) calculating the fluorescence quenching rate Q of nitrobenzene on the nanofiber material through a formula (I), and calculating the concentration c of nitrobenzene in the wastewater through a formula (II);

Q＝(F₀-F)/F₀ (I)

F₀/F＝Kc+b (II)；

wherein, F₀Is the initial fluorescence intensity of the nanofiber material itself; the K and b values were obtained by making a standard curve.

Technical Field

The invention belongs to the technical field of new materials and preparation thereof, and particularly relates to a nanofiber material, a preparation method thereof and application thereof in monitoring of nitrobenzene in chemical wastewater.

Background

In recent years, due to its superior properties and application value, one-dimensional nanomaterials are attracting much attention of researchers. A great deal of research is devoted to the preparation and construction of nano materials with various forms, such as nano fibers, nano tubes, nano rods, nano wires, nano rings and the like. Existing methods such as melt flutter, gas phase jet, nanolithography, self-assembly, etc. are often limited by narrow material range, fiber aggregation, high cost, low yield, etc. Among various methods for preparing one-dimensional nano materials, the electrospinning technology has become a practical and efficient method for preparing nano fiber materials. Compared with common mechanical drawing, electrostatic spinning also provides a continuous preparation process, and nanofibers with smaller diameters than those obtained by common mechanical drawing can be prepared through high voltage action different from mechanical drawing. The electrospinning technology can realize high-yield production, has simple equipment and low cost, and becomes a hot spot concerned by academic circles and industrial circles.

The electrospun fiber material essentially has an inherent three-dimensional porous structure and has the advantages of long length, high specific surface area, controllable size and the like. Therefore, the electrospinning technology can be widely applied to the fields of reinforcing materials, tissue engineering, separation technology, enzyme and catalyst immobilization, electronic devices and the like. The electrospun fiber membrane with the secondary porous structure comprises a core-shell, hollow and porous microstructure, and the structures enrich the secondary morphology of the electrospun fiber and further improve the specific surface area of the material, thereby becoming one of the research hotspots of the electrospinning technology.

Monitoring and treatment of nitrobenzene in waste water discharged by petrochemical enterprises are tasks and urgent research subjects of multiple petrochemical enterprises in China. Nitrobenzene compounds are widely used in the industrial fields of medicine, pesticide, dye, paper making, textile and the like, belong to refractory substances, and can be accumulated in the environment in large quantities to pollute surface water, underground water and soil. With the rapid development of fine chemical engineering, the increase of chemical enterprises for producing aniline substances and the enlargement of the scale thereof lead the demand of nitrobenzene substances to be obviously increased and the possibility of sudden environmental pollution accidents to be increased. Nitrobenzene has been listed as an organic pollutant detected in drinking water in the united states and a priority pollutant formulated by EPA, and is also listed as a black list of environmental pollutants in our country. The development of a rapid and sensitive detection technology for nitrobenzene is of great significance. Most of the existing nitrobenzene monitoring methods are methods of chromatography, chromatography-mass spectrometry and the like. However, this method is relatively time-consuming, cumbersome, bulky, complex to pre-process, expensive to implement and maintain, and not suitable for on-site monitoring. Patent CN105363394A reports a method for preparing magnetic molecularly imprinted microspheres and synthesizing micelles/polymers, which has relatively complicated synthesis reaction, modification and enrichment processes, high cost, and yet to improve detection sensitivity. The patent CN101382550A reports an enzyme-linked immunosorbent assay for measuring nitrobenzene, and the method has harsh storage conditions and needs to further reduce the detection limit. Patent CN103257138A reports an electrospinning material based on a color sensing mechanism, however, the enrichment and color development process is relatively tedious and time-consuming, and the response sensitivity needs to be improved.

The existing electrospinning fiber fluorescent material is mainly constructed by covalent modification and electrostatic layer-by-layer self-assembly. The construction methods have the defects of long preparation period, complicated synthesis steps, leakage of fluorescent agents and the like. The development of a new construction mode, the improvement of the stability, the reproducibility and the reproducibility of the material, and the development of a new detection material with high sensitivity and high selectivity is the development direction of the electrospun fiber fluorescent sensing material.

Therefore, there is a need to develop a nanofiber material with fluorescence sensing function and good stability, reproducibility and reproducibility, and high sensitivity and selectivity, and a preparation method thereof.

Disclosure of Invention

The invention aims to solve the technical problem of providing a novel nanofiber material and a preparation method thereof, aiming at the defects of the prior art, the method prepares raw materials into electrospinning stock solution, prepares a nanofiber film material by an electrospinning technology, is simple and quick, has good universality, and has the characteristics of good stability, reproducibility and reproducibility of the prepared nanofiber material, and high sensitivity and selectivity when used for monitoring nitrobenzene in chemical wastewater.

To this end, a first aspect of the invention provides a nanofibrous material comprising a polymer matrix and a fluorescent agent.

According to the nanofiber material disclosed by the invention, the nanofiber material has a one-dimensional nanofiber morphology.

According to the nanofiber material provided by the invention, the diameter of the nanofiber is 200-600 nm.

The nanofiber material according to the present invention, the content of the fluorescent agent is 5-10 parts by weight based on 100 parts by weight of the polymer matrix.

In some preferred embodiments of the present invention, the fluorescent agent is present in an amount of 6 to 8 parts by weight, based on 100 parts by weight of the polymer matrix.

According to the nanofibrous material of the invention, the polymer matrix comprises a cellulose organic acid ester.

In some preferred embodiments of the invention, the polymer matrix comprises at least one of cellulose acetate, cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate phthalate, or cellulose acetate butyrate.

According to the nanofiber material of the present invention, the fluorescent agent comprises an anthracene-based fluorescent agent.

In some preferred embodiments of the present invention, the fluorescer comprises at least one of 9-chloroanthracene, 9-anthracenal, 9-anthracenemethanol, 9-methylanthracene, 9-acetylanthracene, 9-bromoanthracene, or 9-vinylanthracene.

In a second aspect, the present invention provides a method for preparing a nanofiber material according to the first aspect of the present invention, which comprises the following steps:

s1, mixing the polymer matrix, the fluorescent agent and the solvent to prepare an electrospinning stock solution;

s2, preparing the electrospinning stock solution into electrospinning nanofibers through electrospinning;

and S3, removing the solvent in the electrospun nanofiber to obtain the nanofiber material.

According to the preparation method of the nanofiber material, the solvent comprises a mixed solvent consisting of a solvent I and a solvent II; the solvent I comprises an amide polar solvent, and the solvent II comprises a ketone solvent.

In some preferred embodiments of the invention, the solvent I comprises at least one of N, N dimethylacetamide, N dimethylformamide, N-dimethylpropionamide, N-diethylacetamide, N-methylacetamide or N-ethylacetamide.

In some preferred embodiments of the present invention, the solvent II comprises at least one of acetone, cyclohexanone, methyl ethyl ketone, or methyl isobutyl ketone.

According to the preparation method of the nanofiber material, the content of the fluorescent agent in the electrospinning stock solution is 5-10 parts by weight based on 100 parts by weight of the polymer matrix; the content of the solvent is 400-1000 parts by weight.

In some preferred embodiments of the present invention, the amount of fluorescer in the electrospinning dope is 6 to 8 parts by weight based on 100 parts by weight of the polymer matrix; the content of the solvent is 500-800 parts by weight.

In some preferred embodiments of the present invention, the mass ratio of the solvent I to the solvent II in the solvent is 1 (1-4).

In some further preferred embodiments of the present invention, the mass ratio of the solvent I to the solvent II in the solvent is 1 (1.5-3).

In some preferred embodiments of the present invention, in step S2, the electrospinning device includes a syringe and a receiver, the syringe is pushed at a speed of 0.8-1.5mL/h, and the receiver is rotated at a speed of 500-; the distance between the needle of the injector and the receiver is 12-18cm, the voltage of the electrospinning is 10-20kV, and the electrospinning time is 8-10 min.

In some preferred embodiments of the present invention, in step S3, the solvent is removed by drying, wherein the temperature of drying is 60-80 ℃; the drying time is 10-15 hours.

In a third aspect, the invention provides an application of the nanofiber material according to the first aspect or the nanofiber material obtained by the preparation method according to the second aspect in nitrobenzene monitoring of chemical wastewater, which comprises the steps of immersing the nanofiber material in the chemical wastewater for 1-3 minutes, and detecting a fluorescence emission signal of the nanofiber material at 420 nm. And (3) calculating the fluorescence quenching rate of nitrobenzene on the nanofiber material through a formula (I), and calculating the concentration of nitrobenzene in the wastewater through a formula (II).

Q＝(F₀-F)/F₀ (I)

F₀/F＝Kc+b (II)

Wherein Q is fluorescence quenching rate, F is fluorescence intensity of the nanofiber material in the wastewater, and F is fluorescence intensity of the nanofiber material in the wastewater₀Is the initial fluorescence intensity of the nanofiber material itself; c is the concentration of nitrobenzene in the wastewater and the K and b values are obtained by making a standard curve.

The manufacturing method of the standard curve comprises the following steps: measuring the influence of nitrobenzene solutions with different concentrations on the fluorescence intensity of the nanofiber material as F₀and/F is a vertical coordinate, c is a horizontal coordinate, a standard curve is fitted through data processing, and a standard curve equation is obtained, wherein the slope of the equation is K, and the intercept is b.

Compared with the prior art, the invention has the following beneficial effects:

the novel nanofiber material with the fluorescence sensing function is prepared by an electrospinning technology, and the method is simple, easy, rapid, efficient, low in cost, good in universality and suitable for polymer matrixes and fluorescent agents of different types. The prepared novel nanofiber material has a novel and unique one-dimensional nanofiber shape, the detection limit of the material for monitoring p-nitrobenzene in wastewater is very low, and the detection can be realized by 0.2 mu g/L nitrobenzene in water; the response time to nitrobenzene in the wastewater is short, and the shortest time is only 1 min; the material has excellent regeneration performance, can be repeatedly used for more than 20 times, still keeps the fluorescence intensity at more than 96 percent, and can be repeatedly used.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings.

FIG. 1 is a scanning electron micrograph of a nanofiber material in example 1;

FIG. 2 is a transmission electron micrograph of the nanofiber material in example 1;

FIG. 3 is a standard curve chart for the calculation of nitrobenzene concentration in wastewater in test examples 1-7;

FIG. 4 is a graph depicting the reproducibility of the nanofiber material of example 1.

Detailed Description

In order that the invention may be more readily understood, the following detailed description of the invention is given, with reference to the accompanying examples and drawings, which are given by way of illustration only and are not intended to limit the scope of the invention.

In view of the problems that the method for monitoring nitrobenzene in the prior art has complicated process, higher cost and lower detection sensitivity and response sensitivity; the invention provides a method for preparing a nanofiber material with a fluorescence sensing function by using an electrospinning technology, which is simple and rapid, has good universality, and has the characteristics of good stability, reproducibility and reproducibility, and high sensitivity and selectivity when used for monitoring nitrobenzene in chemical wastewater. The present invention has been made based on the above findings.

The test instrument employed in the present invention was as follows:

scanning electron microscopy: obtaining by using a scanning electron microscope of type S570;

transmission electron microscopy: obtained by JEM-100CX type transmission electron microscope

Fluorescence emission signal: the measurement was carried out using a fluorescence spectrometer model F4500.