High-tensile transparent conductive sodium alginate gel substrate and preparation method thereof
A highly stretchable transparent conductive sodium alginate gel substrate was prepared by crosslinking polyols and CaCl2, which solved the problem of insufficient transparency and stretchability of transparent conductive substrates in flexible electronic devices. This method achieves environmentally friendly and efficient conductivity, making it suitable for multifunctional sensors and optoelectronic devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-05-24
- Publication Date
- 2026-04-17
AI Technical Summary
Existing transparent conductive substrates are difficult to simultaneously possess high stretchability and transparency in flexible and stretchable electronic devices, and the preparation process often uses toxic synthetic compounds, resulting in poor environmental performance.
A highly tensile, transparent, and conductive sodium alginate gel substrate was prepared by crosslinking sodium alginate with a polyol and CaCl2 coagulation bath. This method avoids the use of expensive equipment and toxic raw materials.
Sodium alginate gel substrates with high tensile strength, excellent transparency, and good ionic conductivity were prepared, which are suitable for flexible sensors and optoelectronic devices, and have high reliability and multiple sensitivity properties.
Smart Images
Figure CN121873383A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of gel substrates, and more specifically to a highly tensile, transparent, conductive sodium alginate gel substrate and its preparation method. Background Technology
[0002] Transparent conductive gel substrates can be applied to flexible sensors or optoelectronic devices. In particular, transparent stretchable substrates based on natural polymers will promote the development of environmental sustainability. Currently, a series of substrates based on natural polymers have been studied for use in organic solar cells, flexible optoelectronic devices, touch screens, etc. However, the tensile strain of natural polymer-based substrates is almost no more than 35%. In addition, as a key component of flexible and stretchable electronic devices, the substrate not only needs to have high stretchability, but also appropriate conductivity. The main strategy for preparing conductive substrates is to coat the substrate with a metal layer or embed conductive fillers, but there are many problems, such as decreased transparency and abrupt hard-soft interface changes, which will inevitably lead to insufficient optical transparency and stretchability.
[0003] To overcome these problems, researchers have made some efforts in preparing transparent conductive substrates, but some limitations remain: transparent conductive substrates, usually made of ionic liquids or synthetic compounds, are not environmentally friendly, and it is difficult to obtain transparent conductive substrates that simultaneously possess high tensile strain and strength. Therefore, integrating high tensile strength and transparency into multifunctional sensors and devices remains a significant challenge. Summary of the Invention
[0004] This invention aims to overcome at least one of the defects of the prior art and provide a method for preparing a highly stretchable, transparent, conductive sodium alginate gel substrate. The entire process requires no expensive experimental equipment or toxic or synthetic experimental raw materials, making it completely environmentally friendly. Another objective of this invention is to provide a highly stretchable, transparent, conductive sodium alginate gel substrate prepared by the aforementioned method. This prepared substrate possesses high stretchability, excellent transparency, and good ionic conductivity, while also exhibiting high reliability, a wide sensing range, and multiple sensitivity to external stimuli. Furthermore, this invention also provides the application of the highly stretchable, transparent, conductive sodium alginate gel substrate in flexible sensors or optoelectronic devices.
[0005] To achieve the above objectives, the present invention provides the following technical solution:
[0006] Preferably, after centrifuging to remove bubbles from a uniform, transparent polyol / sodium alginate / ultrapure water mixed solution, the solution is spread evenly on a plastic plate and then immersed in a CaCl2 coagulation bath for 0.5–8 minutes to obtain a hydrogel. The amount of polyol used is 5–40% of the sodium alginate solution, and the concentration of the sodium alginate solution is 1.5–4.5%. More preferably, the amount of polyol used is 15–30% of the sodium alginate solution, and the concentration of the sodium alginate solution is 3–4%.
[0007] Preferably, the hydrogel is equilibrated at room temperature for 6 to 48 hours, then fixed onto a plastic plate and dried at 30 to 65°C for a certain period of time to obtain a highly tensile, transparent, conductive sodium alginate gel substrate.
[0008] This technical solution develops a simple soaking and drying strategy for preparing conductive gel substrates, achieving both high tensile strength and excellent transparency. Furthermore, the prepared conductive gel substrates not only exhibit good ionic conductivity but also high reliability, a wide sensing range, and multi-sensitivity to external stimuli. More importantly, these conductive gel substrates have been successfully used as green substrates in the fabrication of flexible and imaging optoelectronic devices. These remarkable properties are largely attributed to the introduction of a certain amount of polyol and the use of a CaCl2 coagulation bath, which respectively induces physical and ionic crosslinking with sodium alginate. After drying, the polyol imparts liquid-like transport properties to the film, while the free CaCl2 portion provides excellent ionic conductivity. This strategy will open up new methods for constructing highly stretchable, transparent, and ionicly conductive substrates for multifunctional sensors and devices.
[0009] The experiment also revealed that the amount of polyol used and the concentration of sodium alginate solution both had a significant impact on the performance of the prepared gel substrate.
[0010] Preferably, the preparation method includes the following steps:
[0011] S1: Preparation of the mixed solution: Polyol, sodium alginate and ultrapure water are mixed to form a transparent and homogeneous solution; preferably, the polyol is polyethylene glycol, olive oil or glycerin; preferably, the polyol is glycerin.
[0012] S2: Preparation of hydrogel: After centrifuging and defoaming a uniform, transparent polyol / sodium alginate / ultrapure water mixture, pour it onto one end of a plastic plate with a plastic frame. Spread it evenly using a glass rod, remove the plastic frame, and quickly immerse the plastic plate horizontally in a CaCl2 coagulation bath. React for 0.5–8 minutes to obtain the hydrogel. The spreading thickness is 0.5–2 mm, the amount of CaCl2 solution used is 300–800 mL, and the concentration is 1.5–4.5%. Preferably, the reaction time is 1–5 minutes, the amount of CaCl2 solution used is 500–700 mL, and the concentration is 2–4%.
[0013] S3: Preparation of gel substrate: After the hydrogel is equilibrated at room temperature for 6 to 48 hours, it is fixed on a transparent plastic plate and dried at 40 to 85°C for 24 to 72 hours to obtain a highly tensile transparent conductive sodium alginate gel substrate; preferably, the hydrogel is equilibrated at room temperature for 12 to 24 hours and dried at 50 to 60°C for 24 to 48 hours.
[0014] Preferably, the preparation method further includes the step of dripping 0.5 ml of deionized water at each of the four corners where the plastic frame contacts the plastic plate to ensure a tight fit between the plastic frame and the plastic plate, and the thickness of the flat layer is controlled by the thickness of the plastic frame placed on the plastic plate.
[0015] Preferably, the tensile strain of the highly tensile transparent conductive sodium alginate gel substrate is 130% to 200%, and the tensile strength is 2.1 MPa to 25 MPa.
[0016] Preferably, the highly tensile, transparent, conductive sodium alginate gel substrate has a transparency of 88%–93% and an ionic conductivity of 1.6 mS / m. -1 ~10mS m -1 .
[0017] Preferably, the highly stretchable transparent conductive sodium alginate gel substrate is used in flexible sensors or optoelectronic devices. The highly stretchable transparent conductive sodium alginate gel substrate has high stretchability, excellent transparency, good ionic conductivity, high reliability, wide sensing range, and multiple sensitivity to external stimuli.
[0018] Preferably, the flexible sensor includes a wire and a highly tensile transparent conductive sodium alginate gel substrate.
[0019] Preferably, the optoelectronic device comprises a highly stretched transparent conductive sodium alginate gel substrate, a light-emitting layer, and a highly stretched transparent conductive sodium alginate gel substrate stacked sequentially.
[0020] Preferably, the light-emitting layer is a Zns:Cu / Dow Corning SYLGARD 184 light-emitting layer.
[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:
[0022] This invention develops a simple soaking and drying strategy for preparing conductive gel substrates. The entire process requires no expensive experimental equipment or toxic or synthetic experimental raw materials. The prepared sodium alginate gel substrate is environmentally friendly and biodegradable.
[0023] In this invention, highly stretchable, transparent, and conductive sodium alginate gel substrates were prepared using a simple soaking and drying strategy. These highly stretchable, transparent, and conductive sodium alginate gel substrates possess high stretchability, excellent transparency, and good ionic conductivity. They also exhibit high reliability, a wide sensing range, and multiple sensitivity to external stimuli. They have been successfully used in the construction of multifunctional sensors and optoelectronic devices, opening up new methods for constructing highly stretchable, transparent, and ionicly conductive substrates for multifunctional sensors and devices. Attached Figure Description
[0024] Figure 1 Data tables for sodium alginate solutions in Examples 1 to 6 of the present invention;
[0025] Figure 2 This is a comparative test data table for the present invention;
[0026] Figure 3 This is a diagram showing the fabrication process and performance of the light-emitting device based on the highly stretched transparent conductive sodium alginate gel substrate prepared in Example 3 of this invention.
[0027] Figure 4 This is a performance diagram of the strain sensor in this invention;
[0028] Figure 5 The image shows the appearance and flexibility characteristics of the highly tensile transparent conductive sodium alginate gel substrate prepared in Example 4 of this invention. Detailed Implementation
[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0030] This invention utilizes a polyol and a CaCl2 coagulation bath to generate physical and ionic crosslinks with sodium alginate, respectively. After drying, the polyol imparts liquid-like transport properties to the membrane, while the free CaCl2 portion gives the membrane excellent ionic conductivity, tensile properties, and transparency.
[0031] Examples 1 to 6:
[0032] Please see Figures 1 to 5 This invention provides a technical solution: a highly tensile transparent conductive sodium alginate gel substrate and its preparation method, comprising the following steps:
[0033] S1: Preparation of the mixed solution: Glycerol, sodium alginate, and ultrapure water are mixed to form a transparent and homogeneous solution. The mass fraction of glycerol relative to the sodium alginate solution and the concentration of the sodium alginate solution are respectively shown in [reference needed]. Figure 1 ;
[0034] S2: Preparation of hydrogel: After centrifuging and defoaming a uniform and transparent glycerol / sodium alginate / ultrapure water mixture, pour it onto one end of a plastic plate with a plastic frame. Use a glass rod to spread it evenly, remove the plastic frame, and quickly immerse the plastic plate horizontally in a CaCl2 coagulation bath. React for 1 minute to obtain hydrogel; the spreading thickness is 1 mm, the amount of CaCl2 solution used is 600 ml, and the concentration is 2%;
[0035] S3: Preparation of gel substrate: After the hydrogel is equilibrated at room temperature for 24 hours, it is fixed on a transparent plastic plate and dried at 55°C for 48 hours to obtain a highly tensile transparent conductive sodium alginate gel substrate.
[0036] Example 7:
[0037] A highly tensile transparent conductive sodium alginate gel substrate is prepared in a manner similar to that of Example 3, except that the components of the mixed solution used are different, namely olive oil and sodium alginate.
[0038] Comparative Example 1:
[0039] The preparation process is basically the same as in Example 2, except that the amount of glycerol used in Comparative Example 1 is 0% of the mass of sodium alginate solution.
[0040] Comparative Example 2:
[0041] The preparation process is basically the same as in Example 3, except that the amount of CaCl2 coagulation bath used in Comparative Example 2 is 200 ml.
[0042] Comparative Example 3:
[0043] The preparation process is basically the same as in Example 3, except that the amount of glycerol used in this comparative example 3 is 0, and it does not go through the CaCl2 coagulation bath, but is prepared by coating and drying.
[0044] The performance of the products described in Examples 1 to 7, and Comparative Examples 1, 2, and 3 was tested, and the results are shown in the figure. Figure 2 .
[0045] like Figure 3 The figure shows the fabrication process and performance of the light-emitting device based on the highly stretched transparent conductive sodium alginate gel substrate prepared in Example 3. During the experiment, it was found that the highly stretched transparent conductive sodium alginate gel substrate can be cut into different shapes, so the light-emitting shape can be patterned. In addition, the light-emitting device also has flexibility.
[0046] like Figure 4 The image shows a highly tensile, transparent, conductive sodium alginate gel substrate used as a strain sensor. This substrate can stably and sensitively monitor the bending angle of a finger and can also be used to monitor handwriting.
[0047] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0048] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.
Claims
1. A highly tensile, transparent, conductive sodium alginate gel substrate and its preparation method, characterized in that, Includes the following steps: S1: Preparation of the mixed solution: Polyol, sodium alginate and ultrapure water are mixed to form a transparent and homogeneous solution; wherein, the polyol is polyethylene glycol, olive oil or glycerin, the amount of polyol used is 5-40% of the sodium alginate solution, and the concentration of the sodium alginate solution is 1.5-4.5%; S2: Preparation of hydrogel: After centrifuging and defoaming a uniform and transparent polyol / sodium alginate / ultrapure water mixture, pour it onto one end of a plastic plate with a plastic frame. Use a glass rod to spread it evenly. Remove the plastic frame and quickly immerse the plastic plate horizontally in a CaCl2 coagulation bath. React for 0.5–8 minutes to obtain the hydrogel. The thickness of the spread is 0.5–2 mm, the amount of CaCl2 solution used is 300–800 ml, and the concentration is 1.5–4.5%. S3: Preparation of gel substrate: After the hydrogel is equilibrated at room temperature for 6 to 48 hours, it is fixed on a transparent plastic plate and dried at 40 to 85°C for 24 to 72 hours to obtain a highly tensile transparent conductive sodium alginate gel substrate.
2. The highly tensile transparent conductive sodium alginate gel substrate and its preparation method according to claim 1, characterized in that, In step S2: 0.5 ml of deionized water is dripped at each of the four corners where the plastic frame contacts the plastic board to ensure a tight fit between the plastic frame and the plastic board; the thickness of the flat layer is controlled by the thickness of the plastic frame placed on the plastic board.
3. The highly tensile transparent conductive sodium alginate gel substrate and its preparation method according to claim 2, characterized in that: A highly tensile, transparent, conductive sodium alginate gel substrate was obtained through steps S1 to S3.
4. The highly tensile transparent conductive sodium alginate gel substrate and its preparation method according to claim 3, characterized in that: The fracture strain of the high-strength transparent conductive sodium alginate gel substrate is 120% to 200%, and the tensile strength is 2.0 MPa to 25 MPa.
5. The highly tensile transparent conductive sodium alginate gel substrate and its preparation method according to claim 4, characterized in that: The highly tensile, transparent, conductive sodium alginate gel substrate has a transparency of 88%–93% and an ionic conductivity of 1.5 mSm. -1 ~10mSm -1 .
6. The highly tensile transparent conductive sodium alginate gel substrate and its preparation method according to claim 5, characterized in that: Highly stretchable transparent conductive sodium alginate gel substrates can be used in flexible sensors or optoelectronic devices.