PH sensitive type nanofiber hydrogel felt and preparation method thereof

文档序号：1291107 发布日期：2020-08-07 浏览：18次中文

阅读说明：本技术 pH敏感型纳米纤维水凝胶毡及其制备方法 (PH sensitive type nanofiber hydrogel felt and preparation method thereof ) 是由张彩丹于 2020-06-03 设计创作，主要内容包括：本发明公开了一种pH敏感型纳米纤维水凝胶毡及其制备方法,涉及响应型纳米水凝胶材料技术领域。本发明提供的一种pH敏感型纳米纤维水凝胶毡及其制备方法,通过采用聚天冬氨酸的中间体聚琥珀酰亚胺和聚丙烯腈溶于溶剂中进行静电纺丝,得到聚琥珀酰亚胺/聚丙烯腈纳米纤维毡；再分别用热交联法对聚琥珀酰亚胺/聚丙烯腈纳米纤维毡中聚丙烯腈组分进行交联,用交联剂对聚琥珀亚酰胺组分进行交联；将交联后的聚琥珀酰亚胺/聚丙烯腈纳米纤维毡进行水解,洗涤干燥,得到pH敏感型纳米纤维水凝胶毡。本发明提供的纳米水凝胶毡在具备较强pH敏感性的同时、兼具较强机械性能和吸水性能,且溶胀速率高,在药物缓释、传感器、驱动器等领域具有广泛的应用前景。(The invention discloses a pH sensitive type nanofiber hydrogel felt and a preparation method thereof, and relates to the technical field of response type nanofiber hydrogel materials. The invention provides a pH sensitive nanofiber hydrogel felt and a preparation method thereof.A polysuccinimide/polyacrylonitrile nanofiber felt is obtained by dissolving polysuccinimide, which is an intermediate of polyaspartic acid, and polyacrylonitrile in a solvent for electrostatic spinning; respectively crosslinking the polyacrylonitrile component in the polysuccinimide/polyacrylonitrile nano fiber felt by a thermal crosslinking method, and crosslinking the polysuccinimide component by a crosslinking agent; and hydrolyzing the crosslinked polysuccinimide/polyacrylonitrile nanofiber felt, washing and drying to obtain the pH sensitive nanofiber hydrogel felt. The nano hydrogel felt provided by the invention has strong pH sensitivity, strong mechanical property and water absorption property, high swelling rate and wide application prospect in the fields of drug slow release, sensors, drivers and the like.)

1. A method for preparing a pH-sensitive nanofiber hydrogel mat, comprising:

(1) dissolving polysuccinimide and polyacrylonitrile in a solvent according to a preset mass ratio, stirring, standing, defoaming to obtain a spinning solution, adding the spinning solution into a solution storage device, and applying high voltage to carry out electrostatic spinning to prepare a polysuccinimide/polyacrylonitrile nano-fiber felt;

(2) placing the polysuccinimide/polyacrylonitrile nano fiber felt in a heating device at the temperature of 150-300 ℃ for heating for 0.4-4h to ensure that the polyacrylonitrile component in the polysuccinimide/polyacrylonitrile nano fiber felt is subjected to thermal crosslinking, and then placing the polysuccinimide/polyacrylonitrile nano fiber felt in a crosslinking agent to ensure that the polyacrylonitrile component in the polysuccinimide/polyacrylonitrile nano fiber felt is subjected to crosslinking of the crosslinking agent;

(3) and hydrolyzing the crosslinked polysuccinimide/polyacrylonitrile nanofiber felt, washing the hydrolyzed polysuccinimide/polyacrylonitrile nanofiber felt to be neutral by using deionized water, and performing freeze drying treatment to obtain the pH-sensitive nanofiber hydrogel felt.

2. The method according to claim 1, wherein the mass ratio of the polysuccinimide to the polyacrylonitrile is 1:99 to 99: 1.

3. The method according to claim 1, wherein the solvent is at least one of dimethylformamide, dimethylacetamide and dimethylsulfoxide.

4. The method of claim 1, wherein the gas in the heating device is air or nitrogen.

5. The method according to claim 1, wherein the crosslinking agent is a diamine compound, and the crosslinking step is carried out by steam crosslinking or solution crosslinking.

6. The method of claim 5, wherein the crosslinking agent is ethylenediamine or hexamethylenediamine.

7. The method of claim 1, wherein the hydrolyzing the polysuccinimide/polyacrylonitrile nanofiber mat after crosslinking comprises:

placing the crosslinked polysuccinimide/polyacrylonitrile nano-fiber felt in an alkaline solution for heating and hydrolysis; or the like, or, alternatively,

and putting the crosslinked polysuccinimide/polyacrylonitrile nano-fiber felt into an acidic solution, heating for hydrolysis, and then putting the crosslinked polysuccinimide/polyacrylonitrile nano-fiber felt into an alkaline solution for hydrolysis at normal temperature.

8. The method of claim 1, wherein the parameters of the electrospinning process include a syringe pump advancing speed of 0.3 to 0.4m L/h, a voltage of 15 to 18kV, and a spinning distance of 18 cm.

9. A pH-sensitive nanofiber hydrogel mat, which is prepared by the method for preparing the pH-sensitive nanofiber hydrogel mat according to any one of claims 1 to 8, wherein the pH-sensitive nanofiber hydrogel mat has a network interpenetrating structure.

Technical Field

The invention relates to the technical field of response type nano hydrogel materials, in particular to a pH sensitive type nano fiber hydrogel felt and a preparation method thereof.

Background

The intellectualization of the material is one of the important directions for the development of modern high-technology new materials, and the response type hydrogel serving as an intelligent soft material not only has the characteristics of softness and humidity similar to biological tissues, but also can generate swelling or contraction behaviors under the stimulation of external environment, such as pH, temperature, electric field, light and the like, so the response type hydrogel has great application prospect in the fields of intelligent robots, microfluidic valves, biomedicine, sensors and the like. In recent years, the use of responsive hydrogels has made great progress. However, the conventional hydrogel has a slow response speed, and usually takes several minutes or even several hours to complete the response behavior, which seriously hinders the application of the responsive hydrogel. Therefore, the construction of the hydrogel with the rapid response characteristic has important significance.

In recent years, the electrostatic spinning technology can be applied to the field of hydrogel preparation due to the advantages of capability of preparing nanofibers with small diameters, simple method, controllable process and the like. Abundant through-hole structures inside the electrospun nanofiber membrane form a water molecule diffusion channel, so that the response speed of the hydrogel can be greatly improved. At present, researches on constructing a temperature, pH, electric field and other stimulus response type nanofiber hydrogel felt by an electrospinning method have been reported.

In the process of implementing the invention, the inventor finds that the related art has at least the following problems:

the nanofiber hydrogel felt is formed by depositing nanofibers, in the nanofiber hydrogel felt prepared by the prior art, cohesive force among the nanofibers is weak, and the orientation degree of macromolecular chains in the nanofibers is poor, so that the mechanical performance of the nanofiber hydrogel felt is generally poor, and particularly the mechanical performance of the nanofiber hydrogel felt is further weakened after the nanofiber hydrogel felt swells.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a pH sensitive nanofiber hydrogel felt and a preparation method thereof, and the pH sensitive nanofiber hydrogel felt is prepared by improving the preparation process, adopting polyacrylonitrile and polysuccinimide to carry out solution blending, carrying out electrostatic spinning molding to obtain a composite nanofiber membrane, carrying out heat treatment on the composite nanofiber membrane to crosslink the polyacrylonitrile, and then placing the composite nanofiber membrane in a crosslinking agent to crosslink the polysuccinimide; and finally, hydrolyzing the uncrosslinked parts of the two components to obtain the pH sensitive nanofiber hydrogel felt, wherein the obtained pH sensitive nanofiber hydrogel felt has high mechanical property and high pH response speed. The technical scheme of the invention is as follows:

according to a first aspect of embodiments of the present invention, there is provided a method for preparing a pH-sensitive nanofiber hydrogel mat, the method comprising:

In a preferred embodiment, the mass ratio of the polysuccinimide to the polyacrylonitrile is 1:99 to 99: 1.

In a preferred embodiment, the solvent is at least one of dimethylformamide, dimethylacetamide and dimethylsulfoxide.

In a preferred embodiment, the gas in the heating device is air or nitrogen.

In a preferred embodiment, the crosslinking agent is a diamine compound, and the crosslinking process is performed by steam crosslinking or solution crosslinking.

In a preferred embodiment, the crosslinking agent is ethylenediamine or hexamethylenediamine.

In a preferred embodiment, the hydrolyzing the polysuccinimide/polyacrylonitrile nanofiber mat after crosslinking comprises:

placing the crosslinked polysuccinimide/polyacrylonitrile nano-fiber felt in an alkaline solution for heating and hydrolysis; or the like, or, alternatively,

In a preferred embodiment, the parameters of the electrospinning process include a syringe pump advancing speed of 0.3 to 0.4m L/h, a voltage of 15 to 18kV, and a spinning distance of 18 cm.

According to a second aspect of the embodiments of the present invention, there is provided a pH-sensitive nanofiber hydrogel felt, wherein the pH-sensitive nanofiber hydrogel felt is prepared by any of the above methods for preparing a pH-sensitive nanofiber hydrogel felt, and the pH-sensitive nanofiber hydrogel felt has a network interpenetrating structure.

Compared with the prior art, the pH sensitive type nanofiber hydrogel felt and the preparation method thereof provided by the invention have the following advantages:

the invention provides a pH sensitive nanofiber hydrogel felt and a preparation method thereof.A polysuccinimide/polyacrylonitrile nanofiber felt is obtained by dissolving polysuccinimide, which is an intermediate of polyaspartic acid, and polyacrylonitrile in a solvent for electrostatic spinning; respectively crosslinking the polyacrylonitrile component in the polysuccinimide/polyacrylonitrile nano fiber felt by a thermal crosslinking method, and crosslinking the polysuccinimide component by a crosslinking agent; and hydrolyzing the crosslinked polysuccinimide/polyacrylonitrile nanofiber felt, washing and drying to obtain the pH sensitive nanofiber hydrogel felt. The nano hydrogel felt provided by the invention has strong pH sensitivity, strong mechanical property and water absorption property, high swelling rate and wide application prospect in the fields of drug slow release, intelligent switches, sensors, drivers and the like.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is a process flow diagram illustrating a method of making a pH sensitive nanofiber hydrogel mat according to an exemplary embodiment.

Fig. 2 is a scanning electron micrograph of a pH sensitive nanofiber hydrogel mat shown according to an exemplary embodiment.

FIG. 3 is a scanning electron micrograph of a prior art polysuccinimide/polyaspartic acid nanofiber mat prepared by electrostatic spinning.

Detailed Description

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a flow chart illustrating a method of manufacturing a pH-sensitive nanofiber hydrogel mat according to an exemplary embodiment, where the method of manufacturing the pH-sensitive nanofiber hydrogel mat, as shown in fig. 1, includes:

step 1: the preparation method comprises the steps of dissolving polysuccinimide and polyacrylonitrile in a solvent according to a preset mass ratio, stirring, standing, defoaming to obtain a spinning solution, adding the spinning solution into a solution storage device, and applying high voltage to carry out electrostatic spinning to obtain the polysuccinimide/polyacrylonitrile nano-fiber felt.

Step 2: and (2) heating the polysuccinimide/polyacrylonitrile nano fiber felt in a heating device at the temperature of 150-300 ℃ for 0.4-4h to thermally crosslink the polyacrylonitrile component in the polysuccinimide/polyacrylonitrile nano fiber felt, and then placing the polysuccinimide/polyacrylonitrile nano fiber felt in a crosslinking agent to crosslink the polyacrylonitrile component in the polysuccinimide/polyacrylonitrile nano fiber felt by the crosslinking agent.

The invention selects polysuccinimide and polyacrylonitrile as raw materials for electrostatic spinning, wherein the polyacrylonitrile is a pH response type polyacrylonitrile-based hydrogel precursor, and can form a network after being subjected to heat treatment and crosslinking, and can also be hydrolyzed to generate a pH response group carboxyl; polysuccinimide is a polyaspartic hydrogel precursor, can form a network through chemical crosslinking, and can also be hydrolyzed to generate a pH response group carboxyl.

And step 3: and hydrolyzing the crosslinked polysuccinimide/polyacrylonitrile nanofiber felt, washing the hydrolyzed polysuccinimide/polyacrylonitrile nanofiber felt to be neutral by using deionized water, and performing freeze drying treatment to obtain the pH-sensitive nanofiber hydrogel felt.

According to the invention, through a double-crosslinking means, the finally prepared pH-sensitive nanofiber hydrogel felt has a network interpenetrating structure, so that the mechanical properties of the polysuccinimide/polyacrylonitrile nanofiber felt are greatly improved, and the two selected materials have pH response performance after crosslinking and hydrolysis, so that the mechanical properties of the polysuccinimide/polyacrylonitrile nanofiber felt are improved, and meanwhile, the pH response speed is high.