阅读说明：本技术 一种水凝胶光纤包层的制备方法 (Preparation method of hydrogel optical fiber cladding ) 是由 初凤红 张露 郭资 于 2019-09-10 设计创作，主要内容包括：本发明涉及一种水凝胶光纤包层的制备方法,包括以下步骤：S1通过水凝胶单体、光引发剂和去离子水配制获得前驱体溶液A和前驱体溶液B,其中前驱体溶液A中水凝胶单体的浓度高于前驱体溶液B中水凝胶单体的浓度；S2将前驱体溶液A注入模具中,用紫外灯照射,发生光交联固化,挤出,得到水凝胶光纤的纤芯；S3：将S2中得到的纤芯浸入前驱体溶液B中,之后由前驱体溶液B中浸渍提拉出,用紫外灯照射,发生光交联固化,得到包层后的光纤；S4通过显微镜观测S3中包层后的光纤是否达到目标直径。与现有技术相比,本发明技术方案制得的水凝胶光纤包层与水凝胶纤芯契合良好；显著降低了光纤使用过程中的信号损耗；所制光纤包层折射率和厚度可控。(The invention relates to a preparation method of a hydrogel optical fiber cladding, which comprises the following steps: s1, preparing a precursor solution A and a precursor solution B by using a hydrogel monomer, a photoinitiator and deionized water, wherein the concentration of the hydrogel monomer in the precursor solution A is higher than that in the precursor solution B; s2, injecting the precursor solution A into a mold, irradiating by an ultraviolet lamp, carrying out photocrosslinking curing, and extruding to obtain a fiber core of the hydrogel optical fiber; s3: immersing the fiber core obtained in the step S2 in the precursor solution B, then immersing and pulling out the fiber core from the precursor solution B, irradiating the fiber core by using an ultraviolet lamp, and carrying out photocrosslinking and curing to obtain a clad optical fiber; s4 is observed by a microscope whether the optical fiber after cladding in S3 has reached the target diameter. Compared with the prior art, the hydrogel optical fiber cladding prepared by the technical scheme of the invention has good fit with the hydrogel fiber core; the signal loss in the use process of the optical fiber is obviously reduced; the refractive index and thickness of the prepared optical fiber cladding are controllable.)

1. A method for preparing a hydrogel optical fiber cladding is characterized by comprising the following steps:

s1: preparing a precursor solution A and a precursor solution B by using a hydrogel monomer, a photoinitiator and deionized water, wherein the concentration of the hydrogel monomer in the precursor solution A is higher than that of the hydrogel monomer in the precursor solution B;

s2: injecting the precursor solution A into a mold, carrying out ultraviolet irradiation for 1-8 min to carry out photocrosslinking curing, and then extruding from the mold to obtain a fiber core of the hydrogel optical fiber;

s3: immersing the fiber core obtained in the step S2 into the precursor solution B, waiting for 1-7S, pulling out the fiber core from the precursor solution B, irradiating the fiber core by using an ultraviolet lamp, and carrying out photo-crosslinking curing to obtain a clad optical fiber;

s4: observing whether the optical fiber after cladding reaches the target diameter in S3 through a microscope, and if not, repeating the step S3 until the target diameter is reached.

2. The method of claim 1, wherein the hydrogel monomer is one or more selected from the group consisting of polyethylene glycol diacrylate, sodium alginate, polymethyl methacrylate, and polyvinyl alcohol.

3. The method according to claim 1, wherein the concentration of the hydrogel monomer in the precursor solution A is 0.5-0.9 g/ml.

4. The method according to claim 1, wherein the concentration of the hydrogel monomer in the precursor solution B is 0.4-0.8 g/ml.

5. The method of claim 1, wherein the hydrogel optical fiber cladding is prepared in S3 by dip-draw method, and then is cured by hanging the hydrogel optical fiber cladding vertically under an ultraviolet lamp.

6. The method of claim 1, wherein the UV irradiation time in S3 is 3-7 min.

7. The method of claim 1, wherein the thickness of the fiber cladding after two S3 steps is 20-89 μm.

8. The method of claim 5, wherein the thickness of the hydrogel optical fiber cladding formed by a single dip-draw is controlled by the concentration of the hydrogel monomer in the precursor solution B.

9. The method according to claim 1, wherein the refractive index of the hydrogel optical fiber cladding is controlled by the concentration of the hydrogel monomer in the precursor solution B.

Technical Field

The invention relates to the technical field of optical fiber sensing, in particular to a preparation method of a hydrogel optical fiber cladding.

Background

The conventional silica optical fiber and plastic optical fiber are hard in texture and poor in biocompatibility, and are severely limited in the biomedical field. The hydrogel is a hydrophilic reticular polymer swelling body which can swell in water, absorb and retain a large amount of water and can not be dissolved in water. Hydrogels are the subject of extensive research and are widely used in tissue engineering, drug delivery and wound dressings due to their excellent biocompatibility, soft texture and other good properties. In recent years, efforts have been made to integrate photonic functionality into hydrogel materials for new biomedical applications, including functional fibers for light transmission and monitoring of blood oxygen levels in biological tissues, hydrogel implants containing cells for toxicity detection and optogenetic therapy, and nanoparticle-embedded hydrogels for detection of biochemical analysis.

The transmission of light in the optical fiber is based on total reflection, and the light can be transmitted in the optical fiber to form total reflection as long as the direct refractive index of the fiber core is larger than the refractive index of the cladding. The optical fiber did not have a cladding in the early stage, but later use found that there was a difference in refractive index between the presence and absence of the stain on the surface of the fiber core. The change in refractive index is a fixed value when the core surface is free of contaminants. When stains exist, a layer of medium is added between the fiber core and the air, the refractive index change between the fiber core and the stains is a new condition for whether the light can be totally reflected or not, and a lot of waiting light can leak out from the spots of the stains, so that the existence of the optical fiber cladding is necessary. The presence of the fiber cladding not only allows a fixed refractive index difference between the core and the cladding, where light propagates producing stable total reflection. The cladding can effectively protect the surface of the optical fiber from being polluted by damp gas and stains and being scratched by external force, and the additional loss of the optical fiber microbend is reduced.

At present, a great deal of research experiments show that most of coatings of hydrogel optical fibers are calcium alginate coatings formed by impregnating fiber cores with sodium alginate and calcium chloride, but the coatings formed by the method are often uneven and easy to damage and fall off due to slight touch; the fiber core and the cladding are manufactured by using a prepared precursor solution to manufacture the cladding, using a coaxial double-cylinder and applying pressure to the coaxial double-cylinder by matching with an extrusion molding method or using a biomaterial 3D printer, but the cladding formed by the method is uneven in coverage, damaged and easy to fall off, and the whole operation process is complex.

Disclosure of Invention

The present invention is directed to a method for preparing a hydrogel optical fiber cladding, which overcomes the above-mentioned drawbacks of the prior art.

The purpose of the invention can be realized by the following technical scheme:

a method for preparing hydrogel optical fiber cladding comprises the following steps:

s1: preparing a precursor solution A and a precursor solution B by using a hydrogel monomer, a photoinitiator and deionized water, wherein the concentration of the hydrogel monomer in the precursor solution A is higher than that of the hydrogel monomer in the precursor solution B;

s2: injecting the precursor solution A into a mold, irradiating for 1-8 min by using an ultraviolet lamp to perform photocrosslinking curing, and then extruding from the mold to obtain a fiber core of the hydrogel optical fiber;

s3: immersing the fiber core obtained in the step S2 in the precursor solution B, waiting for 1-7S, then pulling out the fiber core from the precursor solution B, irradiating the fiber core by using an ultraviolet lamp, and carrying out photocrosslinking curing to obtain a clad optical fiber;

s4: observing whether the optical fiber after cladding reaches the target diameter in S3 through a microscope, and if not, repeating the step S3 until the target diameter is reached.

Further, the hydrogel monomer can be polyethylene glycol diacrylate, sodium alginate, polymethyl methacrylate, polyvinyl alcohol and the like. The optical fiber prepared in the technical scheme is mainly applied to the field of biomedicine, and the surface protein adhesion and cell adhesion of the hydrogel are very small, so that the hydrogel shows good biocompatibility when contacting with blood, body fluid and human tissues, and meanwhile, the hydrogel is soft and similar to organism tissues due to containing a large amount of water and can reduce adverse reactions when being used as a human implant. It is preferred to select it as the monomer material for the core and the cladding.

Furthermore, the concentration of the hydrogel monomer in the precursor solution A is 0.5-0.9 g/ml.

Further, the concentration of the hydrogel monomer in the precursor solution B is 0.4-0.8 g/ml.

Further, the dip-draw method is used in S2 to fabricate the hydrogel optical fiber cladding, and it is required to vertically hang and cure under an ultraviolet lamp.

Furthermore, the irradiation time of the ultraviolet lamp in S3 is 3-7 min.

Furthermore, the thickness of the cladding of the optical fiber after the two S3 steps is 20-89 μm.

Furthermore, the thickness of the hydrogel optical fiber cladding formed by one-time dip-draw can be controlled by the concentration of the hydrogel monomer in the precursor solution B.

Furthermore, the refractive index of the prepared hydrogel optical fiber cladding can be controlled by the concentration of the hydrogel monomer in the precursor solution B.

The precursor solution B adopted by the hydrogel optical fiber cladding prepared by the technical scheme is the same as the precursor solution A of the prepared hydrogel fiber core. On the one hand, the sodium alginate and the calcium chloride react to easily generate micelle, so that the cladding formed on the surface of the fiber core is very uneven and is easy to damage by touch, and the film forming thickness is not easy to control; on the other hand, the formed calcium alginate coating and the prepared hydrogel fiber core are two different substances, and the degree of fit is naturally not as good as that of the same substance and the same material and the adhesiveness of the same substance and the same material. The hydrogel optical fiber cladding prepared by the technical scheme of the invention is uniform, has good fit with the hydrogel fiber core, is not easy to generate gaps, and the formed cladding is flexible in texture and is not easy to damage and fall off when being touched.

Compared with the prior art, the invention has the following advantages:

1) according to the technical scheme, the precursor solution B which is the same as the material of the precursor solution A for manufacturing the fiber core but different in concentration is adopted, the precursor solution is thin, an even cladding is formed on the surface of the fiber core by a method of dipping, lifting and ultraviolet light cross-linking curing, the light transmittance is good, the degree of integrating with the fiber core is good, and the fiber core is firm and not prone to damage.

2) The integral preparation method is simple, the dipping process has the industrial production prospect of realizing automation, and the thickness of the cladding can be controlled by the dipping times, so that the integral process is flexible and controllable.

3) The refractive index of the optical fiber cladding can be controlled, and the refractive index of the cladding can be controlled by configuring precursor solutions B with different hydrogel monomer concentrations.

3) The signal loss in the use process of the optical fiber is remarkably reduced.

Drawings

FIG. 1 is a diagram: uncoated hydrogel cores (1061 μm diameter) under an optical microscope;

FIG. 2 is a diagram of: hydrogel optical fiber (diameter 1123 μm) with cladding under an optical microscope;

FIG. 3 is a diagram of: physical diagram of hydrogel optical fiber without cladding and with cladding.

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments.