CN111763446B

CN111763446B - Strippable hydrogel for removing surface pollutants

Info

Publication number: CN111763446B
Application number: CN202010630656.7A
Authority: CN
Inventors: 曹美文; 姚明宇; 沈阳; 位强; 田蓓; 杜洪龙; 张宇欣; 丁榛; 王生杰; 夏永清
Original assignee: China University of Petroleum East China
Current assignee: China University of Petroleum East China
Priority date: 2020-07-03
Filing date: 2020-07-03
Publication date: 2022-02-11
Anticipated expiration: 2040-07-03
Also published as: CN111763446A

Abstract

本发明公开了一种去除基材表面污染物的水凝胶的制备方法及应用，属于环境保护领域。将浓度为1–4wt％的海藻酸钠(SA)水溶液涂覆于被污染的基材表面，然后在表面均匀喷洒1–4wt％的氯化钙(CaCl₂)溶液，促使SA组分交联形成水凝胶膜。表面污染物可以通过溶解、吸附等方式进入到水凝胶膜中，随后将水凝胶膜从表面剥离，实现基材表面污染物的有效去除。同时，可以在上述SA溶液中添加氧化石墨烯(GO)或乙二胺四乙酸(EDTA)等活性吸附组分混合制备均一分散的稠溶液，然后进行表面涂覆并喷洒CaCl₂溶液诱导形成水凝胶膜，利用GO或EDTA提供的强吸附作用提高水凝胶膜对污染物的去除效果。The invention discloses a preparation method and application of a hydrogel for removing pollutants on the surface of a substrate, and belongs to the field of environmental protection. Aqueous solution of sodium alginate (SA) with a concentration of 1-4wt% was coated on the surface of the contaminated substrate, and then 1-4wt% calcium chloride (CaCl ₂ ) solution was evenly sprayed on the surface to promote the cross-linking of SA components A hydrogel film is formed. Surface contaminants can enter into the hydrogel film by means of dissolution, adsorption, etc., and then the hydrogel film is peeled off from the surface to achieve effective removal of contaminants on the surface of the substrate. At the same time, active adsorption components such as graphene oxide (GO) or ethylenediaminetetraacetic acid (EDTA) can be added to the above SA solution to prepare a uniformly dispersed thick solution, and then the surface is coated and sprayed with _CaCl2 solution to induce the formation of water. Gel film, using the strong adsorption provided by GO or EDTA to improve the removal effect of hydrogel film on pollutants.

Description

Strippable hydrogel for removing surface pollutants

Technical Field

The invention belongs to the technical field of environmental protection, and particularly relates to preparation of a strippable hydrogel and application of the strippable hydrogel in surface pollutant removal. Coating Sodium Alginate (SA) water solution with concentration of 1-4 wt% on the surface of the contaminated substrate, and uniformly spraying calcium chloride (CaCl) with concentration of 1-4 wt% on the surface₂) A solution to promote crosslinking of the SA component to form a hydrogel film. The surface pollutant can be dissolved and adsorbedAnd the like into the hydrogel film, and then peeling the hydrogel film from the surface, can effectively remove contaminants from the substrate surface. Meanwhile, active adsorption components such as Graphene Oxide (GO) or Ethylene Diamine Tetraacetic Acid (EDTA) and the like can be added into the SA solution to improve the removal effect of the hydrogel film on pollutants. The process utilizes the hydrophilicity of the SA and the complexing action, the hydrogen bond action, the electrostatic action, the pi-pi action and the like of the active adsorption component and the pollutants on the surface of the base material to dissolve and adsorb the pollutants, and then the hydrogel film is stripped from the surface of the base material, so that the pollutants on the surface of the base material can be conveniently and efficiently removed.

Background

In the last 80 th century, strippable coatings have been developed rapidly and their practical use has become more and more widespread. First, the strippable coatings can be used for instrument equipment protection, protecting surfaces from scratches, bruises, abrasions, and the like during shipping, storage, and assembly. Secondly, in the process of storing the equipment and instruments, the surfaces of the equipment and instruments are easily corroded by microorganisms, oil stains, moisture and the like, so that the surfaces are chemically corroded, the performance is reduced, even the equipment and instruments are failed to be discarded, and the strippable coating can play a good protection role. Furthermore, in hospitals, laboratories, pharmaceutical factories, nuclear facilities and the like, there are many contaminations on the surfaces of instruments and devices caused by the deposition of harmful substances, which are potential threats to practitioners. However, for various reasons, these surfaces are often not cleaned with large amounts of solution, resulting in difficult cleaning and time and labor consuming decontamination. For example, for precision electronic equipment, the removal of surface contaminants is a difficult problem, and the equipment is affected by improper methods and even damaged. Therefore, for such surface contamination, it is of great importance to develop a convenient and efficient decontamination method.

At present, various methods for treating pollutants on the surface of an object exist, but most methods have small application range and higher cost, and are not suitable for large-scale application. The adsorption method is an effective pollutant treatment method and is widely used for treating pollutants in water, but the research on removing the pollutants on the surface of an object is less, and the method is mainly limited by the preparation of a suitable strippable surface adsorption film.

The invention mainly provides a preparation method and application of a strippable surface decontamination hydrogel. The method comprises coating SA solution or SA mixed solution added with active adsorption component GO or EDTA on the surface, and spraying CaCl on the surface₂The solution induces the cross-linking of SA molecules to form a hydrogel film in situ, and the hydrogel film is peeled from the surface of the substrate after the surface pollutants are dissolved and adsorbed in the hydrogel film, so that the convenient and efficient removal of the pollutants on the surface of the substrate is realized.

The invention has the following outstanding advantages: (1) the materials used in the invention are environment-friendly and nontoxic, and have high safety; (2) the invention coats the surface to form a film in a solution mode, the fluidity of the solution enables the surface shape to have self-adaptability, and the invention can well cover the uneven surface to form a hydrogel film which is tightly attached; (3) the invention has the outstanding advantages of fast film forming, easy stripping and low cost; (4) the invention utilizes the hydrophilicity of SA and the interaction of active adsorption components and surface pollutants to dissolve and adsorb the pollutants, concentrates the pollutants on the surface of an object into hydrogel under the action similar to 'enrichment', and has good decontamination effect; (5) the hydrogel film can be completely stripped from the surface and collected in a centralized manner, so that the next step of unified treatment of pollutants is facilitated. In conclusion, the invention can realize quick decontamination, has the characteristics of strong adaptability, small harm to the environment and the like, and is a novel material with wide application prospect.

Disclosure of Invention

The invention provides a preparation method of a strippable hydrogel and application thereof in removing surface pollutants, which comprises the following steps:

(1) preparing an SA solution or an SA thick solution added with an active adsorption component GO or EDTA, wherein the concentrations of various components in the prepared solution are respectively as follows: GO is 0.1-1.5 mg/mL (or EDTA is 1-25 mg/mL), and sodium alginate is 1-4 wt%.

(2) Coating the solution on the surface of a polluted substrate, and spraying the prepared CaCl with a certain concentration (1-4 wt%) (in parts by weight)₂Solution, forming a peelable film, drying after film formationThe contaminants on the surface of the substrate can be removed by drying and stripping.

Preferably, the GO in the step (1) has a concentration of 0.2-1.0 mg/mL, an EDTA concentration of 5-15 mg/mL and an SA concentration of 2-3 wt%, and GO is uniformly dispersed by using vortex ultrasound.

Preferably, CaCl is used in the step (2)₂The concentration of the solution is 2-3 wt%.

Preferably, in the step (2), the GO (or EDTA)/SA mixed thick solution is coated on the surface of the substrate, and then CaCl is added₂The solution is sprayed on the surface of the coating to form a film.

Preferably, the film in the step (2) is peeled after being dried.

The strippable decontamination hydrogel is used for removing pollutants on the surface of a base material and has high removal efficiency. Compared with the prior art, the invention has the following advantages: (1) the invention has the characteristics of high film forming speed, easy peeling, good decontamination effect and the like; (2) the material used by the invention is safe, nontoxic and environment-friendly; (3) the method for removing the pollutants on the surface of the base material has simple process, strong operability and high efficiency; (4) the invention coats the surface to form a film in a solution mode, the fluidity of the solution enables the surface shape to have self-adaptability, and the polluted surface can be uniformly coated, so that the surface can be well jointed without depending on the shape of a substrate; (5) the invention has universality and can treat organic matter pollution, radioactive nuclide and heavy metal ion pollution on the surfaces of plastics, glass, metal materials and the like. .

Drawings

FIG. 1 is a standard curve of rhodamine B in example 1 of the present invention.

FIG. 2 is a UV absorption spectrum of the concentration of rhodamine B on the substrate surface in example 1 of the present invention.

FIG. 3 shows the peeling of the peelable films prepared on the surfaces of different substrates in example 1 of the present invention

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

(1) preparing 50.0mg/L rhodamine B standard stock solution.

(2) Drawing a rhodamine B standard curve: preparing a standard solution of rhodamine B with the concentration of 0, 1, 2, 4, 6, 10, 12, 15 and 25mg/L, measuring the absorbance of the standard solution at 554nm by using an ultraviolet spectrophotometer, and drawing a standard curve.

(3) 15mL of rhodamine B solution with the concentration of 50.0mg/L is accurately sucked into the culture dish by a pipette gun, and the rhodamine B solution is poured into a plastic culture dish to be dried to simulate pollutants on the surface of the substrate.

(4) Uniformly coating a 3 wt% SA solution doped with 1mg/mL GO in a culture dish with pollutants on the surface, and spraying 3 wt% CaCl₂The solution is placed on the GO/SA mixed solution, and is kept stand for 12 hours after film formation.

(5) And (3) after drying, removing the film, putting 5mL of pure water into a plastic culture dish, dissolving the unadsorbed rhodamine B in the culture dish, measuring the light absorption value at 554nm by using an ultraviolet spectrophotometer, and calculating the adsorption quantity according to the previously measured rhodamine B standard curve.

Through detection, when the total content of rhodamine in a plastic culture dish is 750mg, after the rhodamine B is treated by using the strippable coating, the residual amount of rhodamine B on the surface of the base material is 3.9715mg, and the adsorption efficiency reaches 99.471%.

Example 2:

(1) preparing 50.0mg/L methylene blue standard stock solution.

(2) Drawing a methylene blue standard curve: preparing a standard solution of methylene blue with the concentration of 0, 1, 2, 3, 6, 8 and 10mg/L, measuring the absorbance of the standard solution at 664nm by using an ultraviolet spectrophotometer, and drawing a standard curve.

(3) 15mL of methylene blue solution with a concentration of 50.0mg/L was accurately pipetted into a petri dish using a pipette, and poured into a plastic petri dish to dry, simulating contaminants on the surface of the substrate.

(5) And (3) removing the film after drying, putting 5mL of pure water into a plastic culture dish, dissolving methylene blue which is not adsorbed in the culture dish, measuring the light absorption value of the culture dish at 664nm by using an ultraviolet spectrophotometer, and calculating the adsorption quantity according to the previously measured methylene blue standard curve.

(6) Through detection, when the total content of methylene blue in a plastic culture dish is 750mg, the residual amount of the methylene blue on the surface of the base material is 1.1428mg after the treatment by using the strippable coating, and the adsorption efficiency reaches 99.848%.

Example 3:

(1) preparing 50.0mg/L of malachite green standard stock solution.

(2) And (3) drawing a malachite green standard curve: preparing a standard solution of malachite green with the concentrations of 0, 1, 2.5, 5, 7.5 and 10mg/L, measuring the absorbance at 619nm by using an ultraviolet spectrophotometer, and drawing a standard curve.

(3) 15mL of malachite green solution with a concentration of 50.0mg/L is precisely sucked into the culture dish by a pipette, and the solution is poured into a plastic culture dish to be dried to simulate pollutants on the surface of the substrate.

(5) And (3) removing the film after drying, putting 5ml of pure water into a plastic culture dish, dissolving the malachite green which is not adsorbed in the culture dish, measuring the absorbance value at 619nm by using an ultraviolet spectrophotometer, and calculating the adsorption quantity according to the malachite green standard curve measured before.

(6) Through detection, when the total content of the malachite green in the plastic culture dish is 750mg, the residual amount of the malachite green on the surface of the base material is 8.1351mg after the treatment by the strippable coating, and the adsorption efficiency reaches 98.915%.

Example 4:

(1) preparing 1.0g/mL standard stock solution of the strontium ion mimic nuclide.

(2) The cover glass is cleaned by an ultrasonic cleaning machine and dried by nitrogen.

(3) Accurately sucking 50 μ L of 1.0g/mL strontium ion mimic nuclide solution onto a cover glass with a pipette, placing the cover glass into a culture dish, drying the mimic solution, and simulating pollutants on the surface of the substrate

(4) Uniformly coating a 3 wt% SA solution doped with 10mg/mL EDTA on a cover glass with pollutants on the surface, and spraying 3 wt% CaCl₂The solution was placed on the EDTA/SA mixed solution, and left to stand for 12 hours after film formation.

(5) And after drying, removing the film, putting the cover glass into a beaker filled with ultrapure water, performing ultrasonic treatment to dissolve the unadsorbed mimic nuclide in the water, measuring the concentration of strontium in the water by using atomic absorption spectroscopy, and calculating the adsorption quantity.

(6) Through detection, when the total content of the strontium ion mimic nuclide in the cover glass is 0.05mg, the residual amount of the strontium ion mimic nuclide on the surface of the base material is 0.00013mg after treatment by using the strippable coating, and the adsorption efficiency reaches 99.55%.

Claims

1. A method for removing contaminants from a surface of a substrate, comprising the steps of:

(1) preparing a sodium alginate thick solution added with an active adsorption component GO, wherein the prepared thick solution comprises the following components in concentration: 3 wt% of sodium alginate and 1mg/mL of GO;

(2) coating the thick solution on the surface of a polluted substrate, and then uniformly spraying 3 wt% of CaCl on the surface₂The solution is used for inducing in-situ crosslinking of sodium alginate to convert the solution into a hydrogel film, and the hydrogel is cured stably and surface pollutants are dissolved and adsorbed;

(3) and after drying, the hydrogel film is taken off from the surface of the base material, so that the pollutants on the surface of the base material can be conveniently removed.

2. A method for removing contaminants from the surface of a substrate according to claim 1, wherein the contaminants are heavy metal ions, organic contaminants.