The interlaminar shear property of composites remains a serious concern in application. In this article, five different multiwalled carbon nanotubes （MWCNTs） are tried to improve the interlaminar shear property of c...The interlaminar shear property of composites remains a serious concern in application. In this article, five different multiwalled carbon nanotubes （MWCNTs） are tried to improve the interlaminar shear property of composites, including two MWCNTs （MWCNTs-A and MWCNTs-B） different with diameters and lengths, an orientated MWCNTs （MWCNTs-C）, a film-shaped MWCNTs-A （MWCNTs-D）, and a surface-treated MWCNTs-B （MWCNTs-E）, The interlaminar shear strength （ILSS） of the composites, filled with one of the above-mentioned materials as a constituent is investigated. The best ILSS increases by 8.16% from 24,5 MPa to 26.5 MPa with MWCNTs-E. In addition, the dispersion of MWCNTs in a glass fiber-reinforced polymer （GFRP） is researched by a scanning electron microscopy （SEM） in association with the ILSS results.展开更多
High-performance microwave absorption(MA) materials must be studied immediately since electromagnetic pollution has become a problem that cannot be disregarded. A straightforward composite material, comprising hollow ...High-performance microwave absorption(MA) materials must be studied immediately since electromagnetic pollution has become a problem that cannot be disregarded. A straightforward composite material, comprising hollow MXene spheres loaded with C–Co frameworks, was prepared to develop multiwalled carbon nanotubes(MWCNTs). A high impedance and suitable morphology were guaranteed by the C–Co exoskeleton, the attenuation ability was provided by the MWCNTs endoskeleton, and the material performance was greatly enhanced by the layered core–shell structure. When the thickness was only 2.04 mm, the effective absorption bandwidth was 5.67 GHz, and the minimum reflection loss(RLmin) was-70.70 d B. At a thickness of 1.861 mm, the sample calcined at 700 ℃ had a RLmin of-63.25 d B. All samples performed well with a reduced filler ratio of 15 wt%. This paper provides a method for making lightweight core–shell composite MA materials with magnetoelectric synergy.展开更多
Over the past decade,the interest in aluminum composites reinforced with carbon nanotubes has grown significantly.Studies have been carried out to overcome problems with uniform dispersion,interfacial bonding,void for...Over the past decade,the interest in aluminum composites reinforced with carbon nanotubes has grown significantly.Studies have been carried out to overcome problems with uniform dispersion,interfacial bonding,void formation and carbide formation of the composites.In the present work,multi-wall carbon nanotubes(MWCNTs) aluminum composites were produced.High-energy ball milling with the aim at developing well-dispersed MWCNTs Al composites was followed by cold compaction,sintering,and hot extrusion at 500 ℃.Different amounts of stearic acid as processing control agent(PCA) is used in order to minimize cold welding of the Al particles,and to produce finer particles.Differential scanning calorimetry(DSC),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray diffraction(XRD) were employed to analyze the MWCNTs,the aluminum powder,and the composites’ microstructural behavior.The hardness and tensile properties of the composites are also evaluated.The results showed 500% increase in yield stress after the addition of 1 wt% MWCNTs in Al-MWCNTs based composite.The ball-milling time of 4 h is found to be sufficient as excessive milling time destroys a vast number of MWCNTs.展开更多
A regrown composite fiber was synthesized during the sintering of diamond under high pressure 5.8 GPa and high temperature 1500℃for 1 min,using 3wt%MWCNTs as additive.SEM observation of the fiber after alkali and aci...A regrown composite fiber was synthesized during the sintering of diamond under high pressure 5.8 GPa and high temperature 1500℃for 1 min,using 3wt%MWCNTs as additive.SEM observation of the fiber after alkali and acid treatment revealed that the outer layer of the fiber is composed of nano-polycrystalline diamond.EDS,XPS,XRD and Raman spectrum analysis further identified that the fiber is composed of MWCNTs in the inner part and nano-polycrystalline diamond in the out layer.It is proposed that the untransformed MWCNTs may act as a template for the regrown outer layer of nano diamond fiber under high pressure and high temperature.展开更多
Nanomedicine is an emerging field concerned with the use of precision engineered nanomaterials, which leads to the development of novel remedial and diagnostic modalities for human use. In this study, Cu(NO_3)_2 and A...Nanomedicine is an emerging field concerned with the use of precision engineered nanomaterials, which leads to the development of novel remedial and diagnostic modalities for human use. In this study, Cu(NO_3)_2 and Ag NO_3 precursors were reduced to copper nanoparticles(Cu NPs) and silver nanoparticles(Ag NPs) using Terminalia arjuna bark extracts under microwave irradiation in the presence of well-dispersed multi-walled carbon nanotubes(MWCNTs) in aqueous medium. The formation of Cu NPs or Ag NPs and their functionalization with MWCNTs via bioactive molecules of plant extract were evidenced from UV–Vis spectra, XRD, FTIR, FESEM, EDX, and TEM images. The phytochemically functionalized Cu-MWCNTs and Ag-MWCNTs nanomaterials showed enhanced biocide activity, and the inhibitory activity for bacteria was higher than that of fungus. Furthermore, these biohybrid nanomaterials are non-toxic to normal epithelial cells(Vero), whereas they are highly toxic for tested human cancer cells of MDA-MB-231, He La, Si Ha, and Hep-G2. The cell viability was found to decrease with the increasing dose from 10 to 50 lg m L^(-1), as well as incubation time from 24 to 72 h. For instance, the cell viability was found to be *91 % for normal Vero cells and *76 % for cancer cells for lower dose of 10 lg m L^(-1).展开更多
文摘The interlaminar shear property of composites remains a serious concern in application. In this article, five different multiwalled carbon nanotubes （MWCNTs） are tried to improve the interlaminar shear property of composites, including two MWCNTs （MWCNTs-A and MWCNTs-B） different with diameters and lengths, an orientated MWCNTs （MWCNTs-C）, a film-shaped MWCNTs-A （MWCNTs-D）, and a surface-treated MWCNTs-B （MWCNTs-E）, The interlaminar shear strength （ILSS） of the composites, filled with one of the above-mentioned materials as a constituent is investigated. The best ILSS increases by 8.16% from 24,5 MPa to 26.5 MPa with MWCNTs-E. In addition, the dispersion of MWCNTs in a glass fiber-reinforced polymer （GFRP） is researched by a scanning electron microscopy （SEM） in association with the ILSS results.
基金This work was financially supported by the National Natural Science Foundation of China(52130510,62071120,52075097,52205454,52375413)the Natural Science Foundation of Jiangsu Province(BE2022066,BZ2023043,BK20202006,BK20211562)Science and Technology Program of Suzhou,Jiangsu Province,China(SYG202302).
文摘High-performance microwave absorption(MA) materials must be studied immediately since electromagnetic pollution has become a problem that cannot be disregarded. A straightforward composite material, comprising hollow MXene spheres loaded with C–Co frameworks, was prepared to develop multiwalled carbon nanotubes(MWCNTs). A high impedance and suitable morphology were guaranteed by the C–Co exoskeleton, the attenuation ability was provided by the MWCNTs endoskeleton, and the material performance was greatly enhanced by the layered core–shell structure. When the thickness was only 2.04 mm, the effective absorption bandwidth was 5.67 GHz, and the minimum reflection loss(RLmin) was-70.70 d B. At a thickness of 1.861 mm, the sample calcined at 700 ℃ had a RLmin of-63.25 d B. All samples performed well with a reduced filler ratio of 15 wt%. This paper provides a method for making lightweight core–shell composite MA materials with magnetoelectric synergy.
文摘Over the past decade,the interest in aluminum composites reinforced with carbon nanotubes has grown significantly.Studies have been carried out to overcome problems with uniform dispersion,interfacial bonding,void formation and carbide formation of the composites.In the present work,multi-wall carbon nanotubes(MWCNTs) aluminum composites were produced.High-energy ball milling with the aim at developing well-dispersed MWCNTs Al composites was followed by cold compaction,sintering,and hot extrusion at 500 ℃.Different amounts of stearic acid as processing control agent(PCA) is used in order to minimize cold welding of the Al particles,and to produce finer particles.Differential scanning calorimetry(DSC),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray diffraction(XRD) were employed to analyze the MWCNTs,the aluminum powder,and the composites’ microstructural behavior.The hardness and tensile properties of the composites are also evaluated.The results showed 500% increase in yield stress after the addition of 1 wt% MWCNTs in Al-MWCNTs based composite.The ball-milling time of 4 h is found to be sufficient as excessive milling time destroys a vast number of MWCNTs.
基金Supported by the National Natural Science Foundation of China(No.50342017)by the Natural Science Foundation of Beijing(No.2042019)
文摘A regrown composite fiber was synthesized during the sintering of diamond under high pressure 5.8 GPa and high temperature 1500℃for 1 min,using 3wt%MWCNTs as additive.SEM observation of the fiber after alkali and acid treatment revealed that the outer layer of the fiber is composed of nano-polycrystalline diamond.EDS,XPS,XRD and Raman spectrum analysis further identified that the fiber is composed of MWCNTs in the inner part and nano-polycrystalline diamond in the out layer.It is proposed that the untransformed MWCNTs may act as a template for the regrown outer layer of nano diamond fiber under high pressure and high temperature.
基金financial support for his Ph.D.degree from Kuvempu University
文摘Nanomedicine is an emerging field concerned with the use of precision engineered nanomaterials, which leads to the development of novel remedial and diagnostic modalities for human use. In this study, Cu(NO_3)_2 and Ag NO_3 precursors were reduced to copper nanoparticles(Cu NPs) and silver nanoparticles(Ag NPs) using Terminalia arjuna bark extracts under microwave irradiation in the presence of well-dispersed multi-walled carbon nanotubes(MWCNTs) in aqueous medium. The formation of Cu NPs or Ag NPs and their functionalization with MWCNTs via bioactive molecules of plant extract were evidenced from UV–Vis spectra, XRD, FTIR, FESEM, EDX, and TEM images. The phytochemically functionalized Cu-MWCNTs and Ag-MWCNTs nanomaterials showed enhanced biocide activity, and the inhibitory activity for bacteria was higher than that of fungus. Furthermore, these biohybrid nanomaterials are non-toxic to normal epithelial cells(Vero), whereas they are highly toxic for tested human cancer cells of MDA-MB-231, He La, Si Ha, and Hep-G2. The cell viability was found to decrease with the increasing dose from 10 to 50 lg m L^(-1), as well as incubation time from 24 to 72 h. For instance, the cell viability was found to be *91 % for normal Vero cells and *76 % for cancer cells for lower dose of 10 lg m L^(-1).
