Preparation Of Magnetic Polyvinyl Alcohol/sodium Polyacrylate Hydrogels And Theris Electrical Response Behavior

An intelligent hydrogel that electrically responds to the hydrogel's directional movement of ions inside and outside the gel under the action of an electric field,thus showing a reversible phase transition macroscopically.Among them,polyacrylic acid?PAA?hydrogels have good biocompatibility,low cost,and also have a pH response,which is very suitable for the most studied anionic hydrogels of the human body.However,due to the presence of a large number of strongly polar carboxylic acid groups,PAA hydrogels have poor mechanical properties,and the pure PAA hydrogels have a slow electrical response rate and poor practical applicability.To this end,the solution blending method is used to introduce the second component polyvinyl alcohol?PVA?to form a double network structure,which aims to improve the mechanical properties of PAAS hydrogels and other problems,and further through the physical doping into nano Fe₃O₄ magnetic particles To give the hydrogel a magnetic response,and for the first time to study the effect of magnetic nanoparticles on the electric field response of the hydrogel under the action of an alternating electromagnetic field.In terms of drug release,it is possible to realize the coordinated controlled release of the magnetic field and electric field,which may make the drug release more effective and has extremely important engineering significance.In this study,acrylic acid?AA?was neutralized to obtain sodium acrylate?AAS?,and then the AAS monomer and polyvinyl alcohol solution were blended uniformly,and then a series of different contents were prepared by free radical polymerization combined with freezing/thawing crosslinking PVA/PAAS composite hydrogel.Fourier transform infrared?FTIR?spectroscopy and scanning electron microscopy?SEM?confirmed that PVA was evenly dispersed in PAAS and formed a double network structure,resulting in the swelling rate and maximum swelling degree of the composite hydrogel with the increase of PVA content Reduced,while the tensile properties of pure PAAS hydrogels were significantly improved.The electrical response experiments show that PVA can increase the electrical response rate of hydrogels,and the most excellent PVA content is 21 wt%.In this study,Zn²⁺-doped nano-ferric oxide Fe₃O₄?referred to as ZFO?was prepared by chemical co-precipitation method,and modified with different modifiers to improve its dispersion in water.Nano-ZFO particles were introduced into the above composite hydrogel with PVA content of 21%by physical doping method,and magnetic composite water with nano-ZFO particles mass content of 0.5?3.0 wt%were prepared respectively gel.X-ray diffraction?XRD?,FTIR and projection electron microscopy?TEM?showed that the prepared nano-ZFO particles of the anti-spinel type with a particle size of about 5 nm,uniformly dispersed in water,and the hysteresis curve showed the doping of Zn²⁺can improve its magnetic properties.TEM photographs of magnetic nanoparticles and hydrogels showed that the nanoparticles were evenly dispersed in the hydrogel.The swelling experiment showed that the introduction of nano?ZFO can significantly improve the swelling performance of the hydrogel,and the swelling properties of the hydrogel increase with the increase of pH and decrease with the increase of the concentration of the electrolyte solution.Tensile experiments showed that nano?ZFO particles can significantly improve the tensile properties of hydrogels.Thermogravimetric analysis?TGA?showed that nanoparticles have a catalytic effect on the thermal decomposition of hydrogels.The application of alternating electromagnetic fields has a certain effect on the hydrogel swelling performance and electrical response rate.