木质素荧光碳点-聚乙烯醇薄膜湿度传感器的制备及性能  

Preparation and properties of lignin fluorescent CDs-PVA film humidity sensor

作　　者：刘凯 胡妙言 高诗雨 孙天懿 徐丽 连海兰 徐长妍 LIU Kai;HU Miaoyan;GAO Shiyu;SUN Tianyi;XU Li;LIAN Hailan;XU Changyan(College of Materials Science and Engineering,Jiangsu Co-Innovation Centre of Efficient Processing and Utilization of Forest Products,Jiangsu Province Key Laboratory of Green Biomass-based Fuels and Chemicals,Nanjing Forestry University,Nanjing 210037,China;2019 Jiangsu graduate workstation:Jingjiang Guolin Wood Industry Co.Ltd.,Jingjiang 214500,China)

机构地区：[1]南京林业大学材料科学与工程学院,南京林业大学江苏省林产品高效加工利用联合创新中心,南京林业大学绿色生物质燃料与化学品江苏省重点实验室,南京210037 [2]2019年江苏省研究生工作站:靖江国林木业有限公司,靖江214500

出　　处：《林业工程学报》2023年第3期114-122,共9页Journal of Forestry Engineering

基　　金：国家自然科学基金(32071703)。

摘　　要：实现家居环境中湿度监测和预警对人体健康具有重要意义,但基于碳点的湿度研究尚在初级阶段。以木质素为碳源,以间苯二胺、盐酸为掺杂剂,采用一锅水热法在水热反应温度为200℃,反应时间为10 h时获得碳点(carbon dots,CDs),并结合红外光谱、X射线光电子能谱、透射电镜和荧光分光光度计等进行测试分析。结果表明,该碳点的荧光量子产率达14.81%,在水溶液中表现出明显的紫外光区吸收特性,而且当激发波长为440 nm时,其荧光强度最高,并发出绿色荧光(发射波长为512 nm)。采用该碳点与聚乙烯醇构建的薄膜湿度传感器不仅表现出良好的湿敏性,而且具有良好的荧光性能和拉伸性能:当相对湿度从50%增加到90%时,传感器呈现明显的颜色变化,即该传感器在不同湿度下产生不同的响应;加入CDs后聚乙烯醇薄膜在365 nm的紫外光下产生明亮的绿光发射,其拉伸强度从58.36 MPa提升到92.46 MPa,断裂伸长率从237.15%提高到279.17%。该木质素荧光碳点-聚乙烯醇薄膜湿度传感器在家居环境中具有良好的应用潜力。Monitoring the humidity in the home environment plays an important role in improving the living condition.However,the existing humidity sensors have some drawbacks,such as complex operation,high cost,long response time,etc.It is still a challenge to synthesize a simple visual fluorescent humidity sensor.As an emerging zero-dimensional nanomaterial,carbon dots(CDs)have gained wide attention in recent years in the fields of the bioimaging,sen-sing,photocatalysis,anti-counterfeiting and drug delivery due to their good water solubility,abundant precursors,stable photoluminescence properties,low toxicity,and excellent biocompatibility.However,limited studies have been reported on the application of CDs in the field of humidity sensing,which cannot meet the range of environmental humidity detection required by the industrial production and daily life.In this study,using lignin as carbon source,MPDA as nitrogen source and HCl as dopant,CDs were obtained by the one-pot hydrothermal method with a hydrothermal reaction temperature of 200℃and reaction time of 10 h.After the hydrothermal reactor had cooled to room temperature,the mixed solution was removed,and unreacted impurities were removed using a filter with a pore size of 0.22μm.The filtered reaction solution was centrifuged at 10000 r/min for 15 min.The supernatant after the centrifugation was dialyzed for 48 h using a dialysis bag with a molecular weight of 1000 to further remove unreacted impurities.After the dialysis treatment,the remaining solution in the dialysis bag was the original solution of lignin fluorescent CDs.Further vacuum freeze-drying for 72 h resulted in a solid powder of lignin fluorescent CDs.The fluorescence quantum yield of the carbon dots was 14.81%,and it was shown obvious ultraviolet absorption characteristics in the aqueous solution.When the excitation wavelength was 440 nm,its fluorescence intensity was the highest,and it emitted green fluorescence(the emission wavelength was 512 nm).In addition,the CDs-PVA film humidity sensor prepared w

关 键 词：木质素 碳点 光致发光 薄膜湿度传感器 湿敏性 拉伸性能 

分 类 号：O482.31[理学—固体物理]