Buckypaper/环氧复合材料加压滤渗浸渍法制备工艺研究

Buckypaper/聚合物复合材料中碳纳米管团聚较少,且含量较高,使得碳纳米管的优异性能得以更加充分的发挥,显著提升了复合材料的各项性能。由于Buckypaper结构紧密,传统的滤渗浸渍方法不能满足制备高质量Buckypaper/环氧复合材料的要求。为提高环氧树脂在Buckypaper中的浸渍效率和质量,开发了Buckypaper的"加压滤渗"浸渍工艺,将环氧树脂溶液通过Buckypaper进行加压过滤,实现对Buckypaper的有效、均匀和完全浸渍。Buckypaper/环氧复合材料微观形貌表征结果表明,"加压滤渗"浸渍工艺制备的Buckypaper/环氧复合材料表面质量良好,且环氧树脂在Buckypaper内部充分浸渍,且分布均匀。与溶液浸渍法制备的Buckypaper/环氧复合材料对比,"加压滤渗"浸渍工艺制备的复合材料具有更加优异的力学性能,更加充分地发挥了Buckypaper的增强效率。

Ultrathin, Lightweight, and Flexible CNT Buckypaper Enhanced Using MXenes for Electromagnetic Interference Shielding

Lightweight,flexibility,and low thickness are urgent requirements for next-generation high-performance electromagnetic interference(EMI)shielding materials for catering to the demand for smart and wearable electronic devices.Although several efforts have focused on constructing porous and flexible conductive films or aerogels,few studies have achieved a balance in terms of density,thickness,flexibility,and EMI shielding effectiveness(SE).Herein,an ultrathin,lightweight,and flexible carbon nanotube(CNT)buckypaper enhanced using MXenes(Ti3C2Tx)for high-performance EMI shielding is synthesized through a facile electrophoretic deposition process.The obtained Ti3C2Tx@CNT hybrid buckypaper exhibits an outstanding EMI SE of 60.5 dB in the X-band at 100μm.The hybrid buckypaper with an MXene content of 49.4 wt%exhibits an EMI SE of 50.4 dB in the X-band with a thickness of only 15μm,which is 105%higher than that of pristine CNT buckypaper.Furthermore,an average specific SE value of 5.7×10^(4) dB cm^(2) g^(−1) is exhibited in the 5-μm hybrid buckypaper.Thus,this assembly process proves promising for the construction of ultrathin,flexible,and high-performance EMI shielding films for application in electronic devices and wireless communications.

Growth of Carbon Nanocoils by Porous α-Fe2O3/SnO2 Catalyst and Its Buckypaper for High Efficient Adsorption

High-purity(99%)carbon nanocoils(CNCs)have been synthesized by using porousα-Fe2O3/SnO2 catalyst.The yield of CNCs reaches 9,098%after a 6 h growth.This value is much higher than the previously reported data,indicating that this method is promising to synthesize high-purity CNCs on a large scale.It is considered that an appropriate proportion of Fe and Sn,proper particle size distribution,and a loose-porous aggregate structure of the catalyst are the key points to the high-purity growth of CNCs.Benefiting from the high-purity preparation,a CNC Buckypaper was successfully prepared and the electrical,mechanical,and electrochemical properties were investigated comprehensively.Furthermore,as one of the practical applications,the CNC Buckypaper was successfully utilized as an efficient adsorbent for the removal of methylene blue dye from wastewater with an adsorption efficiency of 90.9%.This study provides a facile and economical route for preparing high-purity CNCs,which is suitable for large-quantity production.Furthermore,the fabrication of macroscopic CNC Buckypaper provides promising alternative of adsorbent or other practical applications.

Electrodeposited Sulfur and CoxS Electrocatalyst on Buckypaper as High-Performance Cathode for Li-S Batteries

Lithium-sulfur batteries(LSBs)are considered as the next generation of advanced rechargeable batteries because of their high energy density.In this study,sulfur and CoxS electrocatalyst are deposited on carbon nanotube buckypaper(S/CoxS/BP)by a facile electrodeposition method and are used as a binder-free high-performance cathode for LSBs.Elemental sulfur is deposited on buckypaper by electrooxidation of a polysulfide solution(-S6^2-).This approach substantially increased the current and time efficiency of sulfur electrochemical deposition on conductive material for LSBs.S/CoxS/BP cathode could deliver an initial discharge capacity as high as 1650 mAh g^-1 at 0.1 C,which is close to the theoretical capacity of sulfur.At current rate of 0.5 C,the S/CoxS/BP has a capacity of 1420 mAh g^-1 at the first cycle and 715 mAh g^-1 after 500 cycles with a fading rate of 0.099%per cycle.The high capacity of S/CoxS/BP is attributed to both the homogeneous dispersion of nanosized sulfur within BP and the presence of CoxS catalyst.The sodium dodecyl sulfate(SDS)pretreatment of BP renders it polarity to bind polysulfides and thus facilitates the good dispersibility of nanosized sulfur within BP.CoxS catalyst accelerates the kinetics of polysulfide conversion and reduces the presence of polysulfide in the cathode,which suppresses the polysulfide diffusion to anode,i.e.,the shuttle effect.The mitigation of the active material loss improves not only the capacity but also the cyclability of S/CoxS/BP.

Vibration monitoring for composite structures using buckypaper sensors arrayed by flexible printed circuit

Fiber-reinforced resin-based plastics are widely used in structural composites for aerospace and automotive applications,and they often face extreme load conditions in actual working environments.It is challenging to monitor the damage of the structure during the vibration process.This study was aimed at using buckypaper(BP)sensors to monitor the structural health status of composite structures under ambient vibrations.First,the feasibility of flexible printed circuit instead of wire is verified by the tensile experiment.Then the vibration monitoring experiment of the composite cantilever beam is carried out by using BP sensors systematically.The sweep frequency experiment determines the excitation frequency of the cantilever beam.Low-period vibration fatigue cycle and high-period vibration fatigue cycle experiments are designed to verify the vibration monitoring method using BP sensors.Besides,the signal response of BP sensors in the vibration experiment is analyzed,and the relationship betweenΔR/R0 and vibration acceleration is obtained.Finally,through the change law ofΔR/R0 of the sensor,the cumulative damage caused by vibration fatigue is visualized.It is demonstrated that the monitoring method based on BP sensors can be applied to study the damage behavior of composite structure under the vibration environment.