Preparation And Performance Research Of Casein/Chitosan Composite Hydrogel

In the field of flexible electronic devices,traditional hydrogel materials could meet basic technical requirements.However,in some practical application scenarios,performances of hydrogel materials in terms of adhesion,toughness still insufficient.Bio-based materials often have unique functions and advantages in price,biocompatibility,and degradability.Therefore,hydrogel-based flexible electronic devices prepared by bio-based hydrogels have received extensive attention.Here,sodium caseinate(SC)and carboxymethyl chitosan(CC)were successfully introduced into polyacrylamide(PAAM)hydrogel system.Then hydrogel named PAAM-SC-CC hydrogel with high mechanical strength,stable adhesion and sensitive ion transport ability was successfully prepared,related sensitivities were also examined.Among them,micellar structure formed by SC could act as energy dissipation centers and formed dynamic bonding with CC and PAAM molecular chains which provided excellent mechanical properties for the system through efficient energy dissipation mechanism.It showed strong mechanical properties and excellent resilience,fracture strain and fracture stress up to 3366.93%,319.874 k Pa,respectively.In addition,based on multiple amino acid residues from SC,it could exhibit stable and reproducible adhesion behavior to various different substrates,with the maximum peel strength of 56.9 N/m to aluminum.Besides,due to certain amount of free ions,PAAM-SC-CC hydrogel could maintain stable and sensitive ionic conductivity properties which attaines as huigh as 0.351 m S/cm.Flexible wearable sensor assembled by PAAM-SC-CC hydrogel could monitor human motion in different strain ranges including throat flutter and joint extension.In general,Casein/Chitosan Composite Hydrogel prepared in this paper have achieved an effective combination of adhesion,toughness,and conductivity.The flexible hydrogel sensors with various properties assembled from it could accomplish wide range of types and wide range of applications,it is expected to broaden the application of hydrogels in the fields of bioelectrodes,human-machine interfaces,and personalized medicine,etc.