高可拉伸性、自愈合、自黏附性POSS/聚丙烯酸钠导电复合水凝胶的制备与性能

Preparation and properties of POSS/sodium polyacrylate conductive composite hydrogels with high stretchability,self-healable and self-adhesive properties

导电水凝胶在柔性可穿戴设备、电子皮肤和生物电极等方面具有很大的应用潜力。然而,复杂多变的应用场景对导电水凝胶在可拉伸性、自愈合性、自黏附性和生物相容性等方面提出了更高的要求。利用水溶性多面体低聚倍半硅氧烷(POSS)与聚丙烯酸钠(PAA-Na)之间的非共价键交联设计了一种具有高可拉伸性、自愈合、自黏附性和良好生物相容性的导电复合水凝胶(OCAPS/PAA-Na)。OCAPS/PAA-Na水凝胶的断裂伸长率为2537.0%~4056.1%;POSS的加入提高了水凝胶的力学性能,拉伸强度由10.5 kPa提高到23.8 kPa,拉伸模量由7.1 kPa提高到27.8 kPa,断裂能由3.7 kJ·m^(-2)提高到6.8 kJ·m^(-2)。OCAPS/PAA-Na水凝胶具有优异的自愈合性能,自愈合效率达97.8%。该水凝胶对有机材料和无机材料均具有良好的黏附性,黏附强度最高分别达到19.6 kPa和18.2 kPa。细胞毒性试验和溶血试验表明,水凝胶具有优异的生物相容性。制备过程中原位生成的NaCl晶体,提高了水凝胶的电导率(由0.165 S·m^(-1)增加到0.290 S·m^(-1))。OCAPS/PAA-Na水凝胶可作为应变式电阻传感器材料精确地检测一些细微的人体动作,传感灵敏系数值达5.17,在柔性智能可穿戴设备和电子皮肤领域具有良好的应用前景。

Conductive hydrogels have great potential applications in flexible wearable devices,electronic skin and biological electrodes.However,the complex and changing application scenarios put forward higher requirements on the stretchability,self-healable,self-adhesive and biocompatibility of conductive hydrogels.In this paper,a conductive composite hydrogel(OCAPS/PAA-Na)with high extensibility,self-healable,self-adhesive and excellent biocompatibility was designed by the non-covalent cross-linking between a water-soluble polyhedral oligomeric silsesquioxane(POSS)and sodium polyacrylate(PAA-Na).The elongation at break of OCAPS/PAA-Na hydrogel is 2537.0%-4056.1%.The addition of POSS improves the mechanical properties of hydrogels:The tensile strength increases from 10.5 kPa to 23.8 kPa;The tensile modulus increases from 7.1 kPa to 27.8 kPa;The fracture energy increases from 3.7 kJ·m^(−2)to 6.8 kJ·m^(−2).OCAPS/PAA-Na hydrogel has excellent self-healable property,and the selfhealable efficiency is up to 97.8%.The hydrogel shows good adhesion to both organic and inorganic materials,with the highest adhesive strength of 19.6 kPa and 18.2 kPa,respectively.Cytotoxicity test and hemolysis test show that the hydrogel has excellent biocompatibility.The conductivity of the hydrogel increases from 0.165 to 0.290 S·m^(−1)with NaCl crystals is generated in situ during the preparation.OCAPS/PAA-Na hydrogel can be used as a strain resistance sensor material to accurately detect some subtle human actions and the gauge factor value can reach 5.17,which has a good application prospect in the field of flexible intelligent wearable devices and electronic skin.