采用吸附-化学沉淀法合成了磷酸铵锌/埃洛石纳米管(ZAP/HNT)复合材料,并将ZAP/HNT和Exolit○R OP 1230膨胀型阻燃剂一起用于阻燃环氧树脂(EP)。采用红外光谱(FT-IR)和扫描电子显微镜(SEM)对合成的ZAP/HNT及其环氧树脂复合物(EP/ZAP/HNT...采用吸附-化学沉淀法合成了磷酸铵锌/埃洛石纳米管(ZAP/HNT)复合材料,并将ZAP/HNT和Exolit○R OP 1230膨胀型阻燃剂一起用于阻燃环氧树脂(EP)。采用红外光谱(FT-IR)和扫描电子显微镜(SEM)对合成的ZAP/HNT及其环氧树脂复合物(EP/ZAP/HNT)进行了表征,ZAP/HNT中ZAP的粒径约为20~50 nm,表面的-OH与环氧基发生了作用,在EP中分散均匀。热分析(TG)表明,ZAP/HNT在加热过程中脱水、脱氨,600℃时总质量损失约11.34%。790℃时,EP/ZAP/HNT的残炭量为26%,具有良好的成炭性能。用微尺度燃烧量热法(MCC)和UL-94等方法分析了复合材料的阻燃性能,与EP相比,EP/ZAP/HNT(25%)的HRR下降幅度可达到58.82%。ZAP/HNT与OP 1230具有明显的协同阻燃性能。对炭渣用能谱仪(EDS)和SEM进行了分析,P、Al、Si、Zn主要分布在残渣外层,说明燃烧中阻燃剂在气体的作用下迁移到表面,形成由焦磷酸盐、碳、Al 2Si 2O 5等金属氧化物组成的稳定炭层。展开更多
Flexible, lightweight, robust and versatile properties are essential for the next generation of wearable as well as intelligent electromagnetic interference(EMI) shielding materials. In this work, multilayered films c...Flexible, lightweight, robust and versatile properties are essential for the next generation of wearable as well as intelligent electromagnetic interference(EMI) shielding materials. In this work, multilayered films containing cellulose nanofiber(CNF) layers, CNF/MXene layers, and CNF/silver nanowires(CNF/Ag NWs)layers were fabricated by an efficient and easy-to-use vacuum filtration method. Compared with a uniformly mixed film, the resultant layered composite films that loaded with a low MXene and AgNWs content exhibit superior mechanical properties with a tensile strength of 137 MPa, a strain at break of 5.7%, excellent EMI shielding effectiveness(EMI SE) of 61.9 d B, and higher EMI SE/t of 20,653 d B cm^(-1).This is attributed to the high-performance CNF substrate, the highly efficient layered structures, and extensive hydrogen-bonding interactions. In particular, a high degree of ohmic loss of multiple interfaces and polarization relaxation of local defects, as well as an abundance of terminal groups, favor the loss of electromagnetic waves(EMW) within the material. In addition, the prepared multifunctional layered composite films also show good antibacterial properties. As a result, the obtained new kind of flexible layered structure EMI shielding composite films with excellent EMI shielding performance, and mechanical properties present promising application prospects in the fields of EMI shielding and protection for aerospace, portable, and wearable flexible electronic devices.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51773167,52102303,52103095)the China Postdoctoral Science Foundation(No.2019M650268)+1 种基金the Opening Project of State Key Laboratory of Polymer Materials Engineering(Sichuan University)(No.sklpme2021-05-09)Foundation of Education Department of Shaanxi Province(No.20JK0805)。
文摘Flexible, lightweight, robust and versatile properties are essential for the next generation of wearable as well as intelligent electromagnetic interference(EMI) shielding materials. In this work, multilayered films containing cellulose nanofiber(CNF) layers, CNF/MXene layers, and CNF/silver nanowires(CNF/Ag NWs)layers were fabricated by an efficient and easy-to-use vacuum filtration method. Compared with a uniformly mixed film, the resultant layered composite films that loaded with a low MXene and AgNWs content exhibit superior mechanical properties with a tensile strength of 137 MPa, a strain at break of 5.7%, excellent EMI shielding effectiveness(EMI SE) of 61.9 d B, and higher EMI SE/t of 20,653 d B cm^(-1).This is attributed to the high-performance CNF substrate, the highly efficient layered structures, and extensive hydrogen-bonding interactions. In particular, a high degree of ohmic loss of multiple interfaces and polarization relaxation of local defects, as well as an abundance of terminal groups, favor the loss of electromagnetic waves(EMW) within the material. In addition, the prepared multifunctional layered composite films also show good antibacterial properties. As a result, the obtained new kind of flexible layered structure EMI shielding composite films with excellent EMI shielding performance, and mechanical properties present promising application prospects in the fields of EMI shielding and protection for aerospace, portable, and wearable flexible electronic devices.
