Carbon nanotubes exhibit many unique intrinsic physical and chemical properties and have been intensively explored for biological and biomedical applications in the past few years.In this comprehensive review,we summa...Carbon nanotubes exhibit many unique intrinsic physical and chemical properties and have been intensively explored for biological and biomedical applications in the past few years.In this comprehensive review,we summarize the main results from our and other groups in this field and clarify that surface functionalization is critical to the behavior of carbon nanotubes in biological systems.Ultrasensitive detection of biological species with carbon nanotubes can be realized after surface passivation to inhibit the non-specific binding of biomolecules on the hydrophobic nanotube surface.Electrical nanosensors based on nanotubes provide a label-free approach to biological detection.Surface-enhanced Raman spectroscopy of carbon nanotubes opens up a method of protein microarray with detection sensitivity down to 1 fmol/L.In vitro and in vivo toxicity studies reveal that highly water soluble and serum stable nanotubes are biocompatible,nontoxic,and potentially useful for biomedical applications.In vivo biodistributions vary with the functionalization and possibly also size of nanotubes,with a tendency to accumulate in the reticuloendothelial system(RES),including the liver and spleen,after intravenous administration.If well functionalized,nanotubes may be excreted mainly through the biliary pathway in feces.Carbon nanotube-based drug delivery has shown promise in various In vitro and in vivo experiments including delivery of small interfering RNA(siRNA),paclitaxel and doxorubicin.Moreover,single-walled carbon nanotubes with various interesting intrinsic optical properties have been used as novel photoluminescence,Raman,and photoacoustic contrast agents for imaging of cells and animals.Further multidisciplinary explorations in this field may bring new opportunities in the realm of biomedicine.展开更多
Microwave absorbing materials have received considerable interest over the years for their applications in stealth,communications,and information processing technologies.These materials often require functionalization...Microwave absorbing materials have received considerable interest over the years for their applications in stealth,communications,and information processing technologies.These materials often require functionalization at the nanoscale so to achieve desirable dielectric and magnetic properties which induce interaction with incident electromagnetic radiation.This article presents a comprehensive review on the recent research progress of nanomaterials for microwave absorption,including the basic mechanism of microwave absorption(e.g.,dielectric loss,magnetic loss,dielectric/magnetic loss coupling),measurement principle(e.g.,fundamentals of analysis,performance evaluation,common interaction pathways:Debye relaxation,Eddy current loss,natural resonance,size and shape factors),and the advances and performance review in microwave absorption(e.g.,absorption bandwidth,reflection loss values,absorption peak position)using various nanomaterials,such as carbon nanotubes,carbon fibers,graphenes,oxides,sulfides,phosphides,carbides,polymers and metal organic frameworks.Overall,this article not only provides an introduction on the fundamentals of microwave absorption research,but also presents a timely update on the research progress of the microwave absorption performance of various nanomaterials.展开更多
As the rapid development of portable and wearable devices,different electromagnetic interference(EMI)shielding materials with high efficiency have been desired to eliminate the resulting radiation pollution.However,li...As the rapid development of portable and wearable devices,different electromagnetic interference(EMI)shielding materials with high efficiency have been desired to eliminate the resulting radiation pollution.However,limited EMI shielding materials are successfully used in practical applications,due to the heavy thickness and absence of sufficient strength or flexibility.Herein,an ultrathin and flexible carbon nanotubes/MXene/cellulose nanofibrils composite paper with gradient and sandwich structure is constructed for EMI shielding application via a facile alternating vacuum-assisted filtration process.The composite paper exhibits outstanding mechanical properties with a tensile strength of 97.9±5.0 MPa and a fracture strain of 4.6±0.2%.Particularly,the paper shows a high electrical conductivity of 2506.6 S m?1 and EMI shielding effectiveness(EMI SE)of 38.4 dB due to the sandwich structure in improving EMI SE,and the gradient structure on regulating the contributions from reflection and absorption.This strategy is of great significance in fabricating ultrathin and flexible composite paper for highly efficient EMI shielding performance and in broadening the practical applications of MXene-based composite materials.展开更多
In this study, atomic force microscope (AFM) tips are used as tools to cut and manipulate carbon nanotubes on various surfaces. The lateral forces acting on AFM tips during manipulation are also recorded and analyzed ...In this study, atomic force microscope (AFM) tips are used as tools to cut and manipulate carbon nanotubes on various surfaces. The lateral forces acting on AFM tips during manipulation are also recorded and analyzed from the perspective of micro-mechanics. It is found that differences in surface conditions can lead to obvious increase in micro-friction between nanotube and substrate. And also due to rehybridization, carbon nanotubes present excellent resilience when undergoing different degrees of strain. Finally, carbon nanotubes can complexly deform from elastic stage to plastic stage before complete rupture.展开更多
A route combining powder metallurgy and subsequent friction stir processing was utilized to fabricate carbon nanotube （CNT） reinforced AI （CNT/AI） and 6061AI （CNT/6061AI） composites. Microstructural observations...A route combining powder metallurgy and subsequent friction stir processing was utilized to fabricate carbon nanotube （CNT） reinforced AI （CNT/AI） and 6061AI （CNT/6061AI） composites. Microstructural observations indicated that CNTs were uniformly dispersed in the matrix in both CNT/AI and CNT/6061AI composites. Mg and Si elements tended to segregate at CNT-AI interfaces in the CNT/6061AI composite during artificial aging treatment. The tensile properties of both the AI and 6061AI were increased by CNT incorporation. The electrical conductivity of CNT/AI was decreased by CNT addition, while CNT/6061AI exhibited an increase in electrical conductivity due to the Mg and Si segregation.展开更多
Molecular imprinting has become a powerful method for the preparation of robust materials that have the ability to recognize a specific chemical species. The stability,ease of preparation and low cost of these materia...Molecular imprinting has become a powerful method for the preparation of robust materials that have the ability to recognize a specific chemical species. The stability,ease of preparation and low cost of these materials have led to their assessment as substitutes for antibodies or enzymes in chemical sensors,catalysis and separations. The present techniques used to prepare molecular imprinting materials most often result in materials exhibiting a high affinity and selectivity but low capacity and poor site accessibility of the target molecules. In this study,we report a simple procedure for applying molecular imprinting functional groups to the inner surfaces of the AAO template-synthesized sol-gel nanotubes for biochemical separation of estrone. Using of nanotubes as the imprinted materials has the advantage of high affinity,selectivity,capacity and site accessibility for the target molecules. And it is important to emphasize that template route can be used to prepare imprinted nanotubes of nearly any materials. [WT5HZ]展开更多
Single-walled carbon nanotube(SWNT)thin film electrodes have been printed on flexible substrates and cloth fabrics by using SWNT inks and an off-the-shelf inkjet printer,with features of controlled pattern geometry(0....Single-walled carbon nanotube(SWNT)thin film electrodes have been printed on flexible substrates and cloth fabrics by using SWNT inks and an off-the-shelf inkjet printer,with features of controlled pattern geometry(0.4-6 cm^(2)),location,controllable thickness(20-200 nm),and tunable electrical conductivity.The as-printed SWNT films were then sandwiched together with a piece of printable polymer electrolyte to form flexible and wearable supercapacitors,which displayed good capacitive behavior even after 1,000 charge/discharge cycles.Furthermore,a simple and efficient route to produce ruthenium oxide(RuO_(2))nanowire/SWNT hybrid films has been developed,and it was found that the knee frequency of the hybrid thin film electrodes can reach 1,500 Hz,which is much higher than the knee frequency of the bare SWNT electrodes(~158 Hz).In addition,with the integration of RuO_(2) nanowires,the performance of the printed SWNT supercapacitor was significantly improved in terms of its specific capacitance of 138 F/g,power density of 96 kW/kg,and energy density of 18.8 Wh/kg.The results indicate the potential of printable energy storage devices and their significant promise for application in wearable energy storage devices.展开更多
文摘Carbon nanotubes exhibit many unique intrinsic physical and chemical properties and have been intensively explored for biological and biomedical applications in the past few years.In this comprehensive review,we summarize the main results from our and other groups in this field and clarify that surface functionalization is critical to the behavior of carbon nanotubes in biological systems.Ultrasensitive detection of biological species with carbon nanotubes can be realized after surface passivation to inhibit the non-specific binding of biomolecules on the hydrophobic nanotube surface.Electrical nanosensors based on nanotubes provide a label-free approach to biological detection.Surface-enhanced Raman spectroscopy of carbon nanotubes opens up a method of protein microarray with detection sensitivity down to 1 fmol/L.In vitro and in vivo toxicity studies reveal that highly water soluble and serum stable nanotubes are biocompatible,nontoxic,and potentially useful for biomedical applications.In vivo biodistributions vary with the functionalization and possibly also size of nanotubes,with a tendency to accumulate in the reticuloendothelial system(RES),including the liver and spleen,after intravenous administration.If well functionalized,nanotubes may be excreted mainly through the biliary pathway in feces.Carbon nanotube-based drug delivery has shown promise in various In vitro and in vivo experiments including delivery of small interfering RNA(siRNA),paclitaxel and doxorubicin.Moreover,single-walled carbon nanotubes with various interesting intrinsic optical properties have been used as novel photoluminescence,Raman,and photoacoustic contrast agents for imaging of cells and animals.Further multidisciplinary explorations in this field may bring new opportunities in the realm of biomedicine.
基金the support from the U.S.National Science Foundation(DMR-1609061),the School of Biological and Chemical Sciences and the College of Arts and Sciences,University of Missouri-Kansas City.
文摘Microwave absorbing materials have received considerable interest over the years for their applications in stealth,communications,and information processing technologies.These materials often require functionalization at the nanoscale so to achieve desirable dielectric and magnetic properties which induce interaction with incident electromagnetic radiation.This article presents a comprehensive review on the recent research progress of nanomaterials for microwave absorption,including the basic mechanism of microwave absorption(e.g.,dielectric loss,magnetic loss,dielectric/magnetic loss coupling),measurement principle(e.g.,fundamentals of analysis,performance evaluation,common interaction pathways:Debye relaxation,Eddy current loss,natural resonance,size and shape factors),and the advances and performance review in microwave absorption(e.g.,absorption bandwidth,reflection loss values,absorption peak position)using various nanomaterials,such as carbon nanotubes,carbon fibers,graphenes,oxides,sulfides,phosphides,carbides,polymers and metal organic frameworks.Overall,this article not only provides an introduction on the fundamentals of microwave absorption research,but also presents a timely update on the research progress of the microwave absorption performance of various nanomaterials.
基金financial support from the National Natural Science Foundation of China(31771081,51472259)the Science and Technology Commission of Shanghai Municipality(18ZR1445100)Beijing Forestry University Outstanding Young Talent Cultivation Project(2019JQ03014).
文摘As the rapid development of portable and wearable devices,different electromagnetic interference(EMI)shielding materials with high efficiency have been desired to eliminate the resulting radiation pollution.However,limited EMI shielding materials are successfully used in practical applications,due to the heavy thickness and absence of sufficient strength or flexibility.Herein,an ultrathin and flexible carbon nanotubes/MXene/cellulose nanofibrils composite paper with gradient and sandwich structure is constructed for EMI shielding application via a facile alternating vacuum-assisted filtration process.The composite paper exhibits outstanding mechanical properties with a tensile strength of 97.9±5.0 MPa and a fracture strain of 4.6±0.2%.Particularly,the paper shows a high electrical conductivity of 2506.6 S m?1 and EMI shielding effectiveness(EMI SE)of 38.4 dB due to the sandwich structure in improving EMI SE,and the gradient structure on regulating the contributions from reflection and absorption.This strategy is of great significance in fabricating ultrathin and flexible composite paper for highly efficient EMI shielding performance and in broadening the practical applications of MXene-based composite materials.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.50135040 and 50173001).
文摘In this study, atomic force microscope (AFM) tips are used as tools to cut and manipulate carbon nanotubes on various surfaces. The lateral forces acting on AFM tips during manipulation are also recorded and analyzed from the perspective of micro-mechanics. It is found that differences in surface conditions can lead to obvious increase in micro-friction between nanotube and substrate. And also due to rehybridization, carbon nanotubes present excellent resilience when undergoing different degrees of strain. Finally, carbon nanotubes can complexly deform from elastic stage to plastic stage before complete rupture.
基金the support of the National Basic Research Program,China(Grant Nos.2011CB932603 and 2012CB619600)the National Natural Science Foundation, China(Grant No.51331008)
文摘A route combining powder metallurgy and subsequent friction stir processing was utilized to fabricate carbon nanotube （CNT） reinforced AI （CNT/AI） and 6061AI （CNT/6061AI） composites. Microstructural observations indicated that CNTs were uniformly dispersed in the matrix in both CNT/AI and CNT/6061AI composites. Mg and Si elements tended to segregate at CNT-AI interfaces in the CNT/6061AI composite during artificial aging treatment. The tensile properties of both the AI and 6061AI were increased by CNT incorporation. The electrical conductivity of CNT/AI was decreased by CNT addition, while CNT/6061AI exhibited an increase in electrical conductivity due to the Mg and Si segregation.
文摘Molecular imprinting has become a powerful method for the preparation of robust materials that have the ability to recognize a specific chemical species. The stability,ease of preparation and low cost of these materials have led to their assessment as substitutes for antibodies or enzymes in chemical sensors,catalysis and separations. The present techniques used to prepare molecular imprinting materials most often result in materials exhibiting a high affinity and selectivity but low capacity and poor site accessibility of the target molecules. In this study,we report a simple procedure for applying molecular imprinting functional groups to the inner surfaces of the AAO template-synthesized sol-gel nanotubes for biochemical separation of estrone. Using of nanotubes as the imprinted materials has the advantage of high affinity,selectivity,capacity and site accessibility for the target molecules. And it is important to emphasize that template route can be used to prepare imprinted nanotubes of nearly any materials. [WT5HZ]
基金We acknowledge financial support from the National Science Foundation(Nos.CCF 0726815 and CCF 0702204).
文摘Single-walled carbon nanotube(SWNT)thin film electrodes have been printed on flexible substrates and cloth fabrics by using SWNT inks and an off-the-shelf inkjet printer,with features of controlled pattern geometry(0.4-6 cm^(2)),location,controllable thickness(20-200 nm),and tunable electrical conductivity.The as-printed SWNT films were then sandwiched together with a piece of printable polymer electrolyte to form flexible and wearable supercapacitors,which displayed good capacitive behavior even after 1,000 charge/discharge cycles.Furthermore,a simple and efficient route to produce ruthenium oxide(RuO_(2))nanowire/SWNT hybrid films has been developed,and it was found that the knee frequency of the hybrid thin film electrodes can reach 1,500 Hz,which is much higher than the knee frequency of the bare SWNT electrodes(~158 Hz).In addition,with the integration of RuO_(2) nanowires,the performance of the printed SWNT supercapacitor was significantly improved in terms of its specific capacitance of 138 F/g,power density of 96 kW/kg,and energy density of 18.8 Wh/kg.The results indicate the potential of printable energy storage devices and their significant promise for application in wearable energy storage devices.
