CN-119978439-B - Preparation method of polyvinyl alcohol-based electromagnetic shielding conductive hydrogel

Abstract

The invention discloses a preparation method of a polyvinyl alcohol-based electromagnetic shielding conductive hydrogel, which comprises the following steps of (1) preparing a high-concentration dimethyl sulfoxide aqueous solution, adding polyvinyl alcohol into the dimethyl sulfoxide aqueous solution, heating and stirring to completely dissolve the polyvinyl alcohol to obtain a mixed solution, (2) placing the mixed solution after standing in a mold and freezing at a low temperature to obtain PVA gel, (3) preparing an electrolyte salt solution, wherein the electrolyte salt solution contains low-concentration dimethyl sulfoxide, and placing the PVA gel in the electrolyte salt solution to obtain the polyvinyl alcohol-based electromagnetic shielding conductive hydrogel after ion exchange. The polyvinyl alcohol-based electromagnetic shielding conductive hydrogel prepared by the method has high transparency, strength and ion conductivity, the light transmittance is up to 75.2%, the compression strength is up to 2.97MPa when the strain is 80%, the ion conductivity can be up to 10.34mS/cm, and meanwhile, the effective electromagnetic shielding effectiveness (> 30 dB) can be still maintained at the low temperature of-60 ℃ for more than 60 hours.

Inventors

• GU WEIHUA
• WANG JIAN
• Ding Shuoshuo
• ZHAO YAWEN
• XIA YUSEN
• CHENG HENGYU
• MA JUNWEI

Assignees

• 安徽工业大学

Dates

Publication Date

20260508

Application Date

20250227

Claims (1)

1. 1. The preparation method of the polyvinyl alcohol-based electromagnetic shielding conductive hydrogel is characterized by comprising the following steps of: (1) Mixing and stirring 12mL of DMSO and 8mL of deionized water at a rotating speed of 700r/min for 10min to obtain a DMSO aqueous solution; (2) Adding 1.5g of PVA into the DMSO aqueous solution in the step (1), heating and stirring for 50min at 90 ℃, and then standing for 10min to obtain a mixed solution in which the PVA is completely dissolved and no redundant bubbles exist; (3) Placing the mixed solution in the step (2) into a polytetrafluoroethylene mould, and then placing the polytetrafluoroethylene mould filled with the mixed solution into a freezing layer of a refrigerator for freezing for 10 hours to carry out gel, thereby obtaining a gel product; (4) Mixing and stirring 2.8g of NaCl and 50mL of deionized water for 10min to obtain a solution A, mixing and stirring 30mL of DMSO and 8mL of deionized water for 10min to obtain a solution B, mixing and stirring the solution A and the solution B for 10min, and preparing to obtain an electrolyte salt solution; (5) Placing the gel product in the step (3) in the electrolyte salt solution in the step (4) for 12 hours, and obtaining the polyvinyl alcohol-based electromagnetic shielding conductive hydrogel after ion exchange balance is achieved; The light transmittance of the polyvinyl alcohol-based electromagnetic shielding conductive hydrogel obtained by the method reaches 75.2%, the compressive strength at 80% strain reaches 2.97MPa, the electromagnetic shielding effectiveness at normal temperature is 41.21dB when the thickness of the hydrogel is 2mm, and the electromagnetic shielding effectiveness at 60h at-60 ℃ is 34.28dB.

Description

Preparation method of polyvinyl alcohol-based electromagnetic shielding conductive hydrogel Technical Field The invention relates to a preparation method of polyvinyl alcohol-based electromagnetic shielding conductive hydrogel. Background With the advent of the 5G information age, various portable communication devices are increasingly used in life. Electronic components and complex circuits controlled by a wireless network inevitably generate a large amount of electromagnetic radiation and electromagnetic interference, and seriously influence the normal operation and human health of a sensitive electronic equipment system. In view of the rapid development of deformable, wearable electronic devices, there is an urgent need for efficient electromagnetic interference shielding materials having high transparency, good mechanical properties, and low temperature resistance stability. Hydrogels have excellent electrical conductivity, flexibility, compression resistance, and biocompatibility, have unique advantages and potential in the development of deformable, wearable electromagnetic shielding materials, and have become an important research goal in the academic and industrial industries. For example, the professor Liu Xiaofang and the professor Yu Ronghai of the university of aviation and aerospace in Beijing prepare an MXene organic hydrogel using MXene as a conductive network and using a water/glycerin binary solvent as an ion transmission channel, which has an excellent electromagnetic shielding function, and when the content of MXene is 1.1wt%, the maximum electromagnetic shielding effect of the MXene hydrogel is 33.6dB(Yu,Y.H.;Yi,P.;Xu,W.B.;Sun,X.;Deng,G.;Liu,X.F.;Shui,J.L.;Yu,R.H.Environmentally tough and stretchable MXene organohydrogel with exceptionally enhanced electromagnetic interference shielding performances,Nano-Micro Lett.14(2022)77)., which is research by He et al of university of eastern and south, to prepare a gas/organic/hydrogel with a gravity-induced asymmetric gradient structure, and the total electromagnetic shielding effect of the gas/organic/hydrogel is as high as 86.9dB(He,M.;Lv,X.L.;Li,Z.H.;Li,H.Y.;Qian,W.;Zhu,S.Y.;Zhou,Y.M.;Wang,Y.J.;Bu,X.H.Research on efficient electromagnetic shielding performance and modulation mechanism of aero/organo/hydrogels with gravity-induced asymmetric gradient structure,Small 20(2024)2403210)., although the hydrogel material has a good effect in electromagnetic shielding, along with the development of flexible electronics, communication technology and polar detection technology, the hydrogel material is used as a core protection material of high-end equipment, and needs to be applied to a multifunctional scene which has both environmental adaptability (low temperature) and intelligent interaction (transparent visualization). The hydrogel material is extremely fragile at low temperature, and it is difficult to maintain transparency to achieve maintenance of the screen display function, while maintaining electromagnetic shielding performance in an environment of-5 ℃ or less. Disclosure of Invention The invention aims to provide a preparation method of a polyvinyl alcohol-based electromagnetic shielding conductive hydrogel, which has high transparency, strength and ion conductivity and still has good electromagnetic shielding performance at an extremely low temperature (-60 ℃). The preparation method of the polyvinyl alcohol-based electromagnetic shielding conductive hydrogel comprises the following steps: (1) Adding polyvinyl alcohol (PVA) into the dimethyl sulfoxide aqueous solution, heating and stirring to completely dissolve the PVA to obtain a mixed solution, and standing the obtained mixed solution for a period of time to remove bubbles in the solution; (2) Placing the mixed solution after standing in a mould, and freezing at a low temperature to obtain PVA gel; (3) Preparing electrolyte salt solution containing DMSO, wherein the electrolyte salt solution contains low-concentration dimethyl sulfoxide, placing PVA gel into the electrolyte salt solution, and obtaining the polyvinyl alcohol-based electromagnetic shielding conductive hydrogel after ion exchange. In the step (1), the volume fraction of dimethyl sulfoxide in the dimethyl sulfoxide aqueous solution is 55-60% In the step (1), the mass-volume ratio of the polyvinyl alcohol to the dimethyl sulfoxide is 1.5 g:9-12 mL. In the step (1), the heating temperature is 90-95 ℃, the heating and stirring time is 50-60 min, and the standing time is 10-15 min. In the step (2), the freezing temperature is-20 to-25 ℃, and the freezing time is 10-12 hours. In the step (3), in the electrolyte salt solution, the electrolyte salt is one of NaCl, KCl or MgCl 2, and the mass concentration of the electrolyte salt is 3.15-3.2 mg/mL. In the step (3), the volume fraction of dimethyl sulfoxide in the electrolyte salt solution is 30-35%. In the step (3), the ion exchange time is 12-14 h. The electromagnetic shielding co