PBO materials possess super mechanical properties and high thermal and chemical resistance due to their special rigid-rod backbones with heterocyclie chemical structure and supermolecular microstrueture. But these str...PBO materials possess super mechanical properties and high thermal and chemical resistance due to their special rigid-rod backbones with heterocyclie chemical structure and supermolecular microstrueture. But these structures may be affected by a series of preparing technologies, among which the coagulant is even more important. In this paper the chemical and microstrueture changes of PBO materials coagulated with different solvents were investigated. Analyses of molecular weight and chemical structure of PBO coagulated indicate that the heteroeyclie ring of PBO will experience cleavage in coagulation and in this stage water plays an important role. The final structure of PBO materials may involve several intermediate structures lying between benzoxazole a,d the open ring. Wide-angle X-ray diffraction （WAXD） 20 scans and scanning probe microscope （ SPM ） show that the microstrueture of PBO materials eoagulated in solvents with different properties will change a lot and those coagulants with the smaller rate of diffusion like methanol can cause more ordered molecule alignment containing fewer voids.展开更多
In this work, the surface modification of poly （1, 4-phenylene-cis-benzobisoxazole） （PBO） fibers by O 2 /Ar coaxial atmospheric dielectric barrier discharge was investigated, as well as the interfacial adhesion pr...In this work, the surface modification of poly （1, 4-phenylene-cis-benzobisoxazole） （PBO） fibers by O 2 /Ar coaxial atmospheric dielectric barrier discharge was investigated, as well as the interfacial adhesion properties of modified PBO fibers/epoxy composites. The results indicated that the contact angle decreased remarkably from 84.7 to 63.5 after 3 min O 2 /Ar plasma treatment. SEM and AFM images showed that the surface of the treated PBO fibers became rather rough. In addition, XPS results suggested that the polar functional group （O=C- O） was introduced on the surface of the treated PBO fiber. The interfacial adhesion test showed that the interfacial shear strength （IFSS） and the interlaminar shear strength （ILSS） increased significantly by 63.54% and 130%, respectively. Moreover, the excellent tensile property of the PBO fibres was well preserved.展开更多
Conventional firefighting clothing and fire masks can protect firemen’s safety to a certain extent,whereas cannot perceive environmental hazards and monitor their physical status in real time.Herein,we fabricated two...Conventional firefighting clothing and fire masks can protect firemen’s safety to a certain extent,whereas cannot perceive environmental hazards and monitor their physical status in real time.Herein,we fabricated two kinds of Janus graphene/poly(pphenylene benzobisoxazole)(PBO)fabrics by laser direct writing approach and evaluated their performance as intelligent firefighting clothes and fire masks.The results showed that the Janus graphene/PBO fabrics were virtually non-combustible and achieved the highest thermal protection time of 18.91 s ever reported in flame,which is due to the intrinsic flame-retardant nature of PBO fibers.The graphene/PBO woven fabrics-based sensor showed good repeatability and stability in human motion monitoring and NO_(2)gas detection.Furthermore,the piezoelectric fire mask was assembled with graphene/PBO nonwoven fabric as electrode layer and polyvinylidene fluoride(PVDF)electrostatic direct writing film as piezoelectric layer.The filtration efficiency of the fire mask reaches 95%for PM_(2.5)and 100%for PM_(3.0),indicating its effective filtration capability for smoke particles in fires.The respiratory resistance of the piezoelectric fire mask(46.8 Pa)was lower than that of commercial masks(49 Pa),showing that it has good wearing comfort.Besides,the piezoelectric fire mask can be sensitive to the speed and intensity of human breathing,which is essential for indirectly reflecting the health of the human body.Consequently,this work provides a facile approach to fabricate next-generation intrinsic flame-retardant smart textiles for smart firefighting.展开更多
基金Sponsored by the National High Technology Research and Development Program of China(Grant No. 2002AA305109) and Innovational Project in Space Flight Science and Technology(Grant No.2409035).
文摘PBO materials possess super mechanical properties and high thermal and chemical resistance due to their special rigid-rod backbones with heterocyclie chemical structure and supermolecular microstrueture. But these structures may be affected by a series of preparing technologies, among which the coagulant is even more important. In this paper the chemical and microstrueture changes of PBO materials coagulated with different solvents were investigated. Analyses of molecular weight and chemical structure of PBO coagulated indicate that the heteroeyclie ring of PBO will experience cleavage in coagulation and in this stage water plays an important role. The final structure of PBO materials may involve several intermediate structures lying between benzoxazole a,d the open ring. Wide-angle X-ray diffraction （WAXD） 20 scans and scanning probe microscope （ SPM ） show that the microstrueture of PBO materials eoagulated in solvents with different properties will change a lot and those coagulants with the smaller rate of diffusion like methanol can cause more ordered molecule alignment containing fewer voids.
基金supported by Shanghai Composite Company and partially by National Natural Science Foundation of China (No.10875146)
文摘In this work, the surface modification of poly （1, 4-phenylene-cis-benzobisoxazole） （PBO） fibers by O 2 /Ar coaxial atmospheric dielectric barrier discharge was investigated, as well as the interfacial adhesion properties of modified PBO fibers/epoxy composites. The results indicated that the contact angle decreased remarkably from 84.7 to 63.5 after 3 min O 2 /Ar plasma treatment. SEM and AFM images showed that the surface of the treated PBO fibers became rather rough. In addition, XPS results suggested that the polar functional group （O=C- O） was introduced on the surface of the treated PBO fiber. The interfacial adhesion test showed that the interfacial shear strength （IFSS） and the interlaminar shear strength （ILSS） increased significantly by 63.54% and 130%, respectively. Moreover, the excellent tensile property of the PBO fibres was well preserved.
基金the National Natural Science Foundation of China(Nos.52073224 and 52202111)the Textile Vision Basic Research Program of China(No.J202110)+4 种基金the Key Research and Development Program of Xianyang Science and Technology Bureau,China(No.2021ZDYF-GY-0035)the Key Research and Development Program of Shaanxi Province,China(No.2022SF-470)the Key Research and Development Program of Shaanxi Province,China(No.2022GY-377)the Natural Science Foundation of Shaanxi Province(No.2021JQ-685)the Scientific Research Project of Shaanxi Provincial Education Department,China(No.22JC035).
文摘Conventional firefighting clothing and fire masks can protect firemen’s safety to a certain extent,whereas cannot perceive environmental hazards and monitor their physical status in real time.Herein,we fabricated two kinds of Janus graphene/poly(pphenylene benzobisoxazole)(PBO)fabrics by laser direct writing approach and evaluated their performance as intelligent firefighting clothes and fire masks.The results showed that the Janus graphene/PBO fabrics were virtually non-combustible and achieved the highest thermal protection time of 18.91 s ever reported in flame,which is due to the intrinsic flame-retardant nature of PBO fibers.The graphene/PBO woven fabrics-based sensor showed good repeatability and stability in human motion monitoring and NO_(2)gas detection.Furthermore,the piezoelectric fire mask was assembled with graphene/PBO nonwoven fabric as electrode layer and polyvinylidene fluoride(PVDF)electrostatic direct writing film as piezoelectric layer.The filtration efficiency of the fire mask reaches 95%for PM_(2.5)and 100%for PM_(3.0),indicating its effective filtration capability for smoke particles in fires.The respiratory resistance of the piezoelectric fire mask(46.8 Pa)was lower than that of commercial masks(49 Pa),showing that it has good wearing comfort.Besides,the piezoelectric fire mask can be sensitive to the speed and intensity of human breathing,which is essential for indirectly reflecting the health of the human body.Consequently,this work provides a facile approach to fabricate next-generation intrinsic flame-retardant smart textiles for smart firefighting.
