Preparation Of Cellulose-based Conductive Gels And Their Application In The Field Of Electrical Sensing

Hydrogel is a three-dimensional network structure containing a large amount of water,which can absorb a large amount of water without breaking.It can absorb water,retain water,and conduct electricity.It is a multifunctional polymer.Cellulose and its derivatives are a kind of green,environment-friendly and degradable biomass resource.Since cellulose itself is not easily soluble in water,we modified cellulose into water-soluble cellulose acetate（WSCA）which is easily soluble in water and added it to the hydrogel to enhance the mechanical properties of the hydrogel and improve the hydrogel’s breakability specialty.In this paper,water-soluble cellulose acetate（WSCA）was used as raw material to add it to three different hydrogels,and its structure and properties were studied.The details are as follows:（1）Select water-soluble cellulose acetate（WSCA）prepared by modifying cellulose,monomer acrylamide（AM）,ion lithium chloride（Li Cl）,initiator ammonium persulfate（APS）,crosslinking agent N’N-methylenebisacrylamide（MBA）was prepared as a double network PAM/Li Cl/WSCA hydrogel electrolyte by a one-pot preparation method.We explored the microstructure,composition and mechanical properties of hydrogels through electron microscopy,infrared,and Raman universal tensile machines.A supercapacitor was assembled using the prepared hydrogel as a solid electrolyte,and a series of tests were performed on the electrochemical performance of the capacitor.The results show that PAM/Li Cl/WSCA hydrogel can form hydrogel rapidly and has good mechanical properties,and the stress is 143 KPa when the concentration of WSCA is 0.5%.The formed hydrogel also has excellent freeze resistance and can maintain a transparent and soft state even at-80°C.The assembled capacitors are not only resistant to freezing,but can maintain 64%of the original capacitance at-40°C.It is also anti-folding and excellent stability,and still maintains 91%of the capacitance capacity after 1000 charging and discharging.The PAM/Li Cl/WSCA hydrogel electrolyte is not only easy to prepare,but also has good frost resistance and excellent electrochemical performance.（2）Select water-soluble cellulose acetate（WSCA）and tannic acid to mix,make tannic acid and WSCA molecular chain complex,add monomer acrylic acid（AA）,ion aluminum hexahydrate（Al Cl₃.6H₂O）initiator ammonium persulfate（APS）,catalyst N’N’N’N-tetramethylethylenediamine（TEMED）,and hydrogels were prepared by a simple method.Subsequently,the prepared hydrogel was soaked in a mixed solution of ethylene glycol and water to obtain frost resistance.We tested the infrared,electron microscopy,mechanical properties,and frost resistance of the prepared hydrogel,and tested the anti-folding and stability of the assembled supercapacitor.The results show that the prepared TA@WSCA-Al³⁺-PAA has excellent mechanical properties.With the increase of TA@WSCA content,the stress gradually increases.When the TA@WSCA content is 1.5%,the stress of the hydrogel can be It reaches 932.2 KPa.The TA@WSCA-Al³⁺-PAA hydrogel also exhibits good electrical conductivity,self-healing and freeze resistance,and can maintain a soft state even at-40°C.The voltage window of the assembled supercapacitor can reach 1.2 V.After calculation,the capacity of the hydrogel capacitor can reach 234 F/g.（3）Use ethylene glycol as the hydrogen donor and zinc chloride as the hydrogen acceptor to prepare an anhydrous deep eutectic solvent（DES）by mixing them in different proportions,and then prepare the prepared water-soluble cellulose acetate（WSCA）as a single The deep eutectic solvent hydrogel DES-WSCA was prepared by a one-pot method using bulk acrylamide（AM）,initiator ammonium persulfate（APS）,and crosslinker N’N-methylenebisacrylamide（MBA）.The prepared DES-WSCA hydrogel was tested by infrared,electron microscopy,Raman,etc.,and various performance tests were carried out on the assembled DES-WSCA hydrogel solid supercapacitor.The results show that the DES-WSCA hydrogel electrolyte has good freezing resistance at-80°C and good mechanical properties,and its stress will become larger with the increase of WSCA content.After being assembled into a supercapacitor,the DES-WSCA hydrogel capacitor has a large voltage window up to2.2 V and a capacitance capacity of 371.5 F/g.The assembled supercapacitors can be combined in a variety of ways to meet different needs.The DES-WSCA hydrogel supercapacitor also has good stability,and the capacitance retention rate can be maintained above 91%after 10,000 charges and discharges.