Study On Preparation And Properties Of Self-healing And Pressure Sensitive Polyvinyl Alcohol Composite Hydrogel

In recent years,hydrogel materials have been widely used in sensors,human tissu es,medical beauty,and the like due to their water retention and flexibility.Therefore,this paper prepares hydrogels based on polyvinyl alcohol?PVA?initiated by different metal ions by chemical and physical methods,and tests the related properties of the three hydrogels.The experimental samples were characterized by FTIR,SEM,XRD and other test methods.The self-healing properties,mechanical properties,water retention properties,antibacterial properties and pressure sensitivity properties of the experimental samples were tested.The novel PAA-Fe³⁺-Al³⁺hydrogel with triple network structure?TN?was synthesized via bimetallic ions synergistic cross-linking strategy.As-synthesized samples were characterized by scanning electron microscope?SEM?,Fourier Transform Infrared analysis?FTIR?and X-ray diffractometer?XRD?.Simultaneously,the relatively rapid self-healing of PAA-Fe³⁺-Al³⁺polymer can be obtained through the coordination of metal ions with the–COO-in PAA and the oxygen of agar in the TN hydrogel system.And the prepared hydrogels demonstrate excellent mechanical properties—high tensile strength and large elasticity.Especially,the antimicrobial activity of the novel hydrogel against Staphylococcus aureus?S.aureus?and Escherichia coli?E.coli?bacteria was investigated using the inhibition zone method,showing remarkable antibacterial activity.The skin sensor was successfully fabricated by constructing a sandwich structure,and PDMS?polydimethylsiloxane?was used as a water retaining layer to introduce flexible water prepared by sodium dodecylbenzenesulfonate?SDBS?and bimetallic ions(Fe³⁺,Al³⁺).In this work,we successfully fabricated a skin sensor by constructed a sandwich structure to introduce a PDMS?polydimethylsiloxane?as water-retaining layer into sodium dodecylbenzene sulfonate?SDBS?and Bimetallic ion(Fe³⁺,Al³⁺)prepared flexible hydrogel to maintain moisture.More importantly,the addition of SDBS results in a graded porous structure of the hydrogel,which facilitates the transport of ions and thus achieves pressure-sensitive behavior such as pulse rhythm,sound vibration and joint bending.Additionally,the hydrogel fabricated by the bimetallic ion as a crosslinking agent has high mechanical strength and self-healing properties that can self-heal within 2s without any stimulation,wherein the self-healing efficiency is 95%.The new flexible skin sensors are prepared from silver nanowires,graphene and biomineral hydrogels to improve pressure sensitivity and surface roughness recognition.the prepared flexible skin has a wide range of high sensitivities including high pressure sensitivity and low pressure sensitivity,which can detect the pressure of the rice size.Since graphene loaded with silver nanowires easily forms the sheet structure,it can undergo slight changes in pressure such as sphygmus rhythm,sound vibration,and joint bending.The flexible skin detects changes in electrical resistance caused by dynamic interaction between the sensor and the surface of the material being tested,distinguishing various fruit surfaces.It is worth mentioning that the flexible artificial skin containing silver nanowires has obvious antibacterial properties against E.coli and S.aureus.Furthermore,the prepared flexible artificial skin can be applied to various fields such as artificial intelligence,tactile perception,personal medical equipment,etc.,demonstrating its great potential in smart skin.