木质素交联共聚的抗紫外抗菌导电水凝胶及其压力传感性能

Anti-UV antibacterial conductive lignin-copolymerized hydrogel for pressure sensing

木质素作为植物中第二丰富的大分子,具有廉价易得、环境友好、生物相容性好、抗紫外和抗氧化等优异的特性。但是木质素作为造纸工业的副产品通常被当作废物丢弃或低值燃料处理,大大降低了木质素的利用价值,而利用木质素开发具有抗紫外、抗菌和导电特性的水凝胶却具有重要的研究价值。利用烯丙基缩水甘油醚将木质素进行醚化反应引入双键,合成可交联共聚的3-烯丙氧基-2-羟基丙基木质素(Lignin_(AHP)),再将Lignin_(AHP)与丙烯酸(AA)和两性离子单体甲基丙烯酸磺基甜菜碱(SBMA)进行交联共聚,构筑了具有抗氧化、抗紫外和抗菌性能的P(AA-co-Lignin_(AHP)-co-SBMA)水凝胶。研究了水凝胶的形貌、黏附性、导电性、抗紫外、抗氧化、抗菌等性能,探讨了其压力传感性能。研究表明,水凝胶的溶胀率随着SBMA含量的增加而提高,可达到360%;SBMA含量为2.24%质量分数水凝胶的压缩应力强度达到1.45 MPa,对木材的胶黏强度可达到3.5 MPa;SBMA含量为3.68%质量分数水凝胶的导电率达到22.5×10-4S/cm;水凝胶具有优异的抗氧化活性和紫外屏蔽性能,能遮挡住纸币的防伪标志;水凝胶拥有良好的生物相容性(95%),有利于NIH 3T3细胞吸附在水凝胶表面,促进细胞的附着和增殖,同时水凝胶对大肠杆菌和金黄色葡萄球菌呈现优异的抗菌性能;水凝胶对压力具有较好的灵敏度,能将手指和手肘运动信号转换成稳定的电信号,作为传感器以监测人体实时的运动情况,可将其应用于电子皮肤和可穿戴传感器等领域。

Hydrogel is a three-dimensional polymeric network with high water content,which has great potential for the applications in wearable devices,electronic skin,and tissue engineering.However,conventional hydrogels have drawbacks of weak anti-UV,antioxidant,and antibacterial properties.As the second abundant macromolecule in nature,lignin has excellent advantages of low cost,wide availability,environmentally friendliness,biocompatibility,UV resistance and antioxidation.As a by-product of the paper industry,lignin is usually discarded as wastes or disposed as low-value fuel,which greatly reduces the utilization values of lignin.It is desired to use lignin for preparing antibacterial,anti-UV and antioxidant hydrogels.In this paper,the 3-allyloxy-2-hydroxypropyl lignin(Lignin _(AHP)) was synthesized by the etherification of lignin using allyl glycidyl ether(AGE).Lignin_(AHP) was copolymerized with acrylic acid(AA)and sulfobetaine methacrylate(SBMA)to prepare P(AA-co-Lignin_(AHP)-co-SBMA)hydrogels with antioxidant,anti-UV and anti-bacterial properties.The morphology,adhesion,conductivity,anti-UV,anti-oxidation,and antibacterial properties of the hydrogels were studied,and its pressure sensing performance was explored.The FTIR results showed that lignin and SBMA were incorporated into hydrogels.The SEM images displayed that the hydrogels exhibited honeycomb porous structure.The swelling ratio of the hydrogels increased with the increase of SBMA content and could reach 360%.The hydrogels with SBMA content of 2.24%had good compressive strength of 1.45 MPa.The hydrogels can closely adhere to various substrates,such as to bone,glass,and wood.The adhesion strength to wood reached 3.5 MPa.The conductivity of the hydrogel with SBMA content of 3.68%was 22.5×10^(-4)S/cm.The hydrogel exhibited excellent antioxidant activity and UV shielding properties,which can block the anti-counterfeiting marks of banknotes.The hydrogels possessed strong biocompatibility(95%),which is conducive to the NIH 3T3 cells being attached on the surface of hydrogel to promote the proliferation of cells.The developed hydrogels showed excellent antibacterial properties against Escherichia coli and Staphylococcus aureus.The hydrogels have good pressure sensitivity and can convert the motion signals of fingers and elbows into stable electrical signals.The lignin-copolymerized hydrogels with anti-UV,antibacterial,conductive properties can monitor the real-time movement of human body,which can be applied to electronic skin and wearable sensors.