细菌纤维素基CNFs/ZnO吸波材料的制备及性能  

Preparation and Properties of Bacterial Cellulose Based CNFs/ZnO Microwave Absorbing Materials

作　　者：刘平安[1] 林宝舜 丁会玲 肖亮 张志杰[1] LIU Pingan;LIN Baoshun;DING Huiling;XIAO Liang;ZHANG Zhijie(School of Materials Science and Engineering,South China University of Technology,Guangzhou 510640,Guangdong,China)

机构地区：[1]华南理工大学材料科学与工程学院,广东广州510640

出　　处：《华南理工大学学报（自然科学版）》2024年第8期138-145,共8页Journal of South China University of Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(52073106)。

摘　　要：随着电子信息技术的不断发展,电磁污染问题日益严重,高效吸波材料的研究受到越来越多的关注。该文以生物多孔材料细菌纤维素为碳源,采用碳化改性和水热法两步制备了细菌纤维素基CNFs/ZnO复合材料,研究了二水合醋酸锌的浓度对CNFs/ZnO复合材料吸波性能的影响。通过X射线衍射仪(XRD)、冷场发射扫描电子显微镜(FESEM)、矢量网络分析仪(VNA)对复合材料的结构、形貌和吸波性能进行表征。结果表明:CNFs/ZnO复合材料被成功制备,其中碳纳米纤维(CNFs)没有明显的衍射峰,呈无定形状态;碳化和改性CNFs均保持了细菌纤维素三维网络多孔架构的精细纳米纤维微观形貌,但是CNFs变得卷曲且直径明显减小;CNFs/ZnO复合材料中,ZnO被紧密吸引在CNFs表面或随机插入CNFs的空隙中。通过改变二水合醋酸锌的浓度可以控制ZnO在复合材料中的含量,进而调控复合材料的电磁参数,获得良好的阻抗匹配。当二水合醋酸锌的浓度为0.25 mol/L时,ZnO在CNFs上分散得最为均匀,此时CNFs和ZnO的电阻损耗、介电损耗和界面极化等协同作用于三维多孔网络结构上,增加了复合材料对电磁波的多次反射、散射和长程耗散作用。该条件下制备的CNFs/ZnO复合材料,在涂层厚度为2.8 mm、频率为15.1 GHz附近时,其最佳反射损耗为−57.5 dB,有效吸收带宽为7.1 GHz,是一种可靠的复合吸波材料。With the continuous development of electronic information technology,electromagnetic pollution is becoming increasingly serious,and the research of high-efficiency absorbing materials has received more and more attention.Using bacterial cellulose as carbon source,the study prepared CNFs/ZnO composites based on bacterial cellulose with carbonization-modification and hydrothermal two-step method,and studied the effects of zinc acetate dihydrate concentration on the microwave absorption properties of CNFs/ZnO composites.The structure,morphology and microwave absorption performance of the composites were characterized by X-ray diffraction(XRD),cold field emission scanning electron microscopy(FESEM)and vector network analysis(VNA).The results show that CNFs/ZnO composites are successfully prepared,and the carbon nanofibers(CNFs)show an amorphous state without obvious diffraction peaks.Both carbonized and modified CNFs maintain the fine microscopic morphology of nanofibers with a three-dimensional network and porous structure of bacterial cellulose,but CNFs become crimped and the diameter of the fibers decreases significantly.In CNFs/ZnO composites,ZnO is closely attracted to the surface of CNFs or randomly inserted into the gap of CNFs.By changing the concentration of zinc acetate hydrate,the content of ZnO in the composite can be controlled,which in turn regulates the electromagnetic parameters of the composite and obtains good impedance matching.When the concentration of zinc acetate hydrate is 0.25 mol/L,ZnO is most uniformly dispersed on CNFs.At this time,the resistance loss,dielectric loss and interface polarization of CNFs and ZnO are synergistic on the three-dimensional porous network structure,which increases the multiple reflection,scattering and long-range dissipation of electromagnetic waves.The CNFs/ZnO composite prepared under this condition is a reliable composite absorbing material with the best reflection loss of−57.5 dB and an effective absorption bandwidth of 7.1 GHz,at a coating thickness of 2.8 m

关 键 词：细菌纤维素 碳纳米纤维 ZNO 复合材料 吸波性能 

分 类 号：TB34[一般工业技术—材料科学与工程]