In the maritime industry, cost-effective and lightweight Fiber Reinforced Polymer (FRP) composites offer excellent mechanical properties, design flexibility, and corrosion resistance. However, their reliability in har...In the maritime industry, cost-effective and lightweight Fiber Reinforced Polymer (FRP) composites offer excellent mechanical properties, design flexibility, and corrosion resistance. However, their reliability in harsh seawater conditions is a concern. Researchers address this by exploring three approaches: coating fiber surfaces, hybridizing fibers and matrices with or without nanofillers, and interply rearrangement. This study focuses on evaluating the synergistic effects of interply rearrangement of glass/carbon fibers and hybrid nanofillers, specifically Multi-walled carbon nanotubes (MWCNT) and Halloysite nanotubes (HNT). The aim is to enhance impact properties by minimizing moisture absorption. Hybrid nanocomposites with equal-weight proportions of two nanofillers: 0 wt.%, 1 wt.%, and 2 wt.% were exposed to seawater for 90 days. Experimental data was subjected to modelling through the application of Predictive Fick’s Law. The study found that the hybrid composite containing 2 wt.% hybrid nanofillers exhibited a 22.10% increase in impact performance compared to non-modified counterparts. After 90 days of seawater aging, the material exhibited enhanced resistance to moisture absorption (15.74%) and minimal reduction in impact strength (8.52%) compared to its dry strength, with lower diffusion coefficients.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
A new type of sintered diamond reinforced by diamond MWCNTs composite fibers which were randomly orientated and even distributed in the diamond matrix was synthesized by using 3wt%mullti-walled carbon nanotubes（MWCNT...A new type of sintered diamond reinforced by diamond MWCNTs composite fibers which were randomly orientated and even distributed in the diamond matrix was synthesized by using 3wt%mullti-walled carbon nanotubes（MWCNTs） as starting additive under high pressure of 5.8 GPa at temperature of 1500℃for 1 min.A special polycrystalline diamond structure of direct bonding of both diamond to diamond and diamond to diamond-MWCNTs composite fiber was observed.The testing results show that it possesses not only high hardness（49～52 GPa） and Young’s modulus（878 GPa） but also high bending strength（1320～1540 GPa） and fracture toughness(9.0～9.2 MPa·m<sup>1/2</sup>) as it was theoretically predicted.The high performances of the composite were contributed by the fiber strengthening effect and the special structure which can offer more extensive diamond to diamond bonding.展开更多
This study investigated the effects of multi-walled carbon nanotubes(MWCNTs) and polycaprolactone(PCL) on the quasi-in vivo corrosion behavior of AZ31B Mg alloy treated by plasma electrolytic oxidation(PEO). Thin(~2 ...This study investigated the effects of multi-walled carbon nanotubes(MWCNTs) and polycaprolactone(PCL) on the quasi-in vivo corrosion behavior of AZ31B Mg alloy treated by plasma electrolytic oxidation(PEO). Thin(~2 μm, PCTPCL4) and thick(~60 μm, PCTPCL6) PCL layers were applied only onto the MWCNTs-PEO coating(PCT) as it showed better corrosion performance. Findings reveal that incorporation of MWCNTs induced several structural and functional modifications in the PEO coating, such as increased roughness, a thicker inner barrier layer, and reduced hydrophilicity.Quasi-in vivo corrosion testing was carried out under controlled temperature, p H, and fluid flow in simulated body fluid(SBF) by electrochemical impedance spectroscopy(EIS) and hydrogen evolution experiments. EIS results revealed that, after 48 h immersion, a diffusion process controlled hydration of the ceramic coatings. Comparison of the collected hydrogen after 15 days of immersion in the quasi-in vivo environment revealed that the PEO and PCT ceramic coatings decreased hydrogen generation by up to 74% and 91%, respectively, compared to non-coated alloy.PCTPCL6 coating exhibited the lowest amount of collected hydrogen(0.2 m L/cm^(2)). The thick PCL layer delayed the onset of substrate corrosion for at least 120 h, reducing the corrosion rate by 85% compared with the PCT.展开更多
Cyclic voltammetry based on an electrochemical technique is one of the current methods that measure the developments of the electrochemical properties in biomaterial samples under conditions. Biomaterial structure was...Cyclic voltammetry based on an electrochemical technique is one of the current methods that measure the developments of the electrochemical properties in biomaterial samples under conditions. Biomaterial structure was changed by conductive material while these materials caused a connective network in whole of them and was able to transfer electrons inside of biomaterials. These changes in physical and chemical properties are investigated by analysis tools such as cyclic voltammetry (CV), X-radiation (XRF) and Ultraviolet-visible spectroscopy (UV-Vis). Bacterial cellulose is biodegradable, biosynthesis of A. xylinum which is a three-dimensional nano-network structure with a distinct tunnel and pore structure. In this study, the composite process produced electrically conducting bacterial cellulose pellicles containing well-dispersed and embedded multi-walled carbon nanotubes (MWCNTs) Ionic liquids (ILs), as observed in cyclic voltammetry (CV). For this purpose, we used a special tool, called OriginLab which is an industry-leading scientific graphing and data analysis software. The cyclic voltammetry graph presents the behavior of this composite which consists of a relationship between CNT dispersion, conductivity rate and changes in bacterial cellulose structure. The electrical conductivity of the cellulose/MWCNT composite was found different with respect to CNT dispersion. It was found that the incorporation process was a useful method not only for dispersing MWCNTs-ILs in an ultrafine fibrous network structure, but also for enhancing the electrical conductivity of the polymeric membranes.展开更多
采用均匀沉淀法制备纳米SnS/多壁碳纳米管(MWCNTs)复合物,利用场发射扫描电子显微镜(SEM)、X射线粉末衍射仪(XRD)和热重分析仪(TGA)对其形貌和组成进行表征。将纳米SnS/MWCNTs复合物10 mg超声分散在1.0 mL 5%(体积分数)全氟化树脂溶液中...采用均匀沉淀法制备纳米SnS/多壁碳纳米管(MWCNTs)复合物,利用场发射扫描电子显微镜(SEM)、X射线粉末衍射仪(XRD)和热重分析仪(TGA)对其形貌和组成进行表征。将纳米SnS/MWCNTs复合物10 mg超声分散在1.0 mL 5%(体积分数)全氟化树脂溶液中,分取8.0μL滴涂于处理好的玻碳电极(GCE)表面,得到修饰电极(纳米SnS/MWCNTs/GCE)。以纳米SnS/MWCNTs/GCE为工作电极,铂丝电极为对电极,饱和甘汞电极为参比电极,采用循环伏安法(CV)、电化学阻抗谱法(EIS)和差分脉冲伏安法(DPV)对纳米SnS/MWCNTs/GCE电化学性能进行考察,研究了2,4-二氯苯酚(2,4-DCP)在纳米SnS/MWCNTs/GCE上的电化学行为。结果表明:在pH 7.0的磷酸盐缓冲溶液中,纳米SnS/MWCNTs/GCE对2,4-DCP有明显的电催化作用和较高的选择性;2,4-DCP的浓度在0.05~3.00μmol·L^(-1)内与DPV响应的氧化峰电流呈线性关系,检出限(3S/N)为2.3×10^(-8)mol·L^(-1);按照标准加入法对水样进行回收试验,2,4-DCP回收率为92.0%~101%。展开更多
文摘In the maritime industry, cost-effective and lightweight Fiber Reinforced Polymer (FRP) composites offer excellent mechanical properties, design flexibility, and corrosion resistance. However, their reliability in harsh seawater conditions is a concern. Researchers address this by exploring three approaches: coating fiber surfaces, hybridizing fibers and matrices with or without nanofillers, and interply rearrangement. This study focuses on evaluating the synergistic effects of interply rearrangement of glass/carbon fibers and hybrid nanofillers, specifically Multi-walled carbon nanotubes (MWCNT) and Halloysite nanotubes (HNT). The aim is to enhance impact properties by minimizing moisture absorption. Hybrid nanocomposites with equal-weight proportions of two nanofillers: 0 wt.%, 1 wt.%, and 2 wt.% were exposed to seawater for 90 days. Experimental data was subjected to modelling through the application of Predictive Fick’s Law. The study found that the hybrid composite containing 2 wt.% hybrid nanofillers exhibited a 22.10% increase in impact performance compared to non-modified counterparts. After 90 days of seawater aging, the material exhibited enhanced resistance to moisture absorption (15.74%) and minimal reduction in impact strength (8.52%) compared to its dry strength, with lower diffusion coefficients.
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Supported by the National Natural Science Foundation of China(No.50342017)by the Natural Science Foundation of Beijing(No.2042019)
文摘A new type of sintered diamond reinforced by diamond MWCNTs composite fibers which were randomly orientated and even distributed in the diamond matrix was synthesized by using 3wt%mullti-walled carbon nanotubes（MWCNTs） as starting additive under high pressure of 5.8 GPa at temperature of 1500℃for 1 min.A special polycrystalline diamond structure of direct bonding of both diamond to diamond and diamond to diamond-MWCNTs composite fiber was observed.The testing results show that it possesses not only high hardness（49～52 GPa） and Young’s modulus（878 GPa） but also high bending strength（1320～1540 GPa） and fracture toughness(9.0～9.2 MPa·m<sup>1/2</sup>) as it was theoretically predicted.The high performances of the composite were contributed by the fiber strengthening effect and the special structure which can offer more extensive diamond to diamond bonding.
基金the financial support of the Iran National Science Foundation INSF (Grant No. 97014179)supported by RTI2018-096391-B-C33 (MCIU/AEI/FEDER, UE) and S2018/NMT4411 (Regional government of Madrid and EU Structural and Social Funds)+1 种基金the support of RYC-2017-21843financial support from the Spanish National Science Foundation (CSIC) and the Ministerio de Ciencia, Innovacióny Universidades (MINECO) grant number RTI2018-096328-B-I00。
文摘This study investigated the effects of multi-walled carbon nanotubes(MWCNTs) and polycaprolactone(PCL) on the quasi-in vivo corrosion behavior of AZ31B Mg alloy treated by plasma electrolytic oxidation(PEO). Thin(~2 μm, PCTPCL4) and thick(~60 μm, PCTPCL6) PCL layers were applied only onto the MWCNTs-PEO coating(PCT) as it showed better corrosion performance. Findings reveal that incorporation of MWCNTs induced several structural and functional modifications in the PEO coating, such as increased roughness, a thicker inner barrier layer, and reduced hydrophilicity.Quasi-in vivo corrosion testing was carried out under controlled temperature, p H, and fluid flow in simulated body fluid(SBF) by electrochemical impedance spectroscopy(EIS) and hydrogen evolution experiments. EIS results revealed that, after 48 h immersion, a diffusion process controlled hydration of the ceramic coatings. Comparison of the collected hydrogen after 15 days of immersion in the quasi-in vivo environment revealed that the PEO and PCT ceramic coatings decreased hydrogen generation by up to 74% and 91%, respectively, compared to non-coated alloy.PCTPCL6 coating exhibited the lowest amount of collected hydrogen(0.2 m L/cm^(2)). The thick PCL layer delayed the onset of substrate corrosion for at least 120 h, reducing the corrosion rate by 85% compared with the PCT.
文摘Cyclic voltammetry based on an electrochemical technique is one of the current methods that measure the developments of the electrochemical properties in biomaterial samples under conditions. Biomaterial structure was changed by conductive material while these materials caused a connective network in whole of them and was able to transfer electrons inside of biomaterials. These changes in physical and chemical properties are investigated by analysis tools such as cyclic voltammetry (CV), X-radiation (XRF) and Ultraviolet-visible spectroscopy (UV-Vis). Bacterial cellulose is biodegradable, biosynthesis of A. xylinum which is a three-dimensional nano-network structure with a distinct tunnel and pore structure. In this study, the composite process produced electrically conducting bacterial cellulose pellicles containing well-dispersed and embedded multi-walled carbon nanotubes (MWCNTs) Ionic liquids (ILs), as observed in cyclic voltammetry (CV). For this purpose, we used a special tool, called OriginLab which is an industry-leading scientific graphing and data analysis software. The cyclic voltammetry graph presents the behavior of this composite which consists of a relationship between CNT dispersion, conductivity rate and changes in bacterial cellulose structure. The electrical conductivity of the cellulose/MWCNT composite was found different with respect to CNT dispersion. It was found that the incorporation process was a useful method not only for dispersing MWCNTs-ILs in an ultrafine fibrous network structure, but also for enhancing the electrical conductivity of the polymeric membranes.
文摘采用均匀沉淀法制备纳米SnS/多壁碳纳米管(MWCNTs)复合物,利用场发射扫描电子显微镜(SEM)、X射线粉末衍射仪(XRD)和热重分析仪(TGA)对其形貌和组成进行表征。将纳米SnS/MWCNTs复合物10 mg超声分散在1.0 mL 5%(体积分数)全氟化树脂溶液中,分取8.0μL滴涂于处理好的玻碳电极(GCE)表面,得到修饰电极(纳米SnS/MWCNTs/GCE)。以纳米SnS/MWCNTs/GCE为工作电极,铂丝电极为对电极,饱和甘汞电极为参比电极,采用循环伏安法(CV)、电化学阻抗谱法(EIS)和差分脉冲伏安法(DPV)对纳米SnS/MWCNTs/GCE电化学性能进行考察,研究了2,4-二氯苯酚(2,4-DCP)在纳米SnS/MWCNTs/GCE上的电化学行为。结果表明:在pH 7.0的磷酸盐缓冲溶液中,纳米SnS/MWCNTs/GCE对2,4-DCP有明显的电催化作用和较高的选择性;2,4-DCP的浓度在0.05~3.00μmol·L^(-1)内与DPV响应的氧化峰电流呈线性关系,检出限(3S/N)为2.3×10^(-8)mol·L^(-1);按照标准加入法对水样进行回收试验,2,4-DCP回收率为92.0%~101%。
