• Smart Structures and Systems
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• v.12 no.1
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• pp.73-95
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• 2013

Nine deoxyribonucleic acid (DNA) sequences were used to functionalize single-walled carbon nanotube (SWNT) sensors to detect the trace amount of methanol, acetone, and HCl in vapor. DNA 24 Ma (24 randomly arranged nitrogenous bases with one amine at each end of it) decorated SWNT sensor and DNA 24 A (only adenine (A) base with a length of 24) decorated SWNT sensor have demonstrated the largest sensing responses towards acetone and HCl, respectively. On the other hand, for the DNA GT decorated SWNT sensors with different sequence lengths, the optimum DNA sequence length for acetone and HCl sensing is 32 and 8, separately. The detection of methanol, acetone, and HCl have identified that DNA functionalized SWNT sensors exhibit great selectivity, sensitivity, and repeatability with an accuracy of more than 90%. Further, a sensor array composed of SWNT functionalized with various DNA sequences was utilized to identify acetone and HCl through pattern recognition. The sensor array is a combination of four different DNA functionalized SWNT sensors and two bare SWNT sensors (work as reference). This wireless sensing system has enabled real-time gas monitoring and air quality assurance for safety and security.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.29-30
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• 2003

Several forms of nanonetworked carbon materials were synthesized by high pressure and high temperature treatments of fullerene C$\_$60/ and single-walled carbon nanotube bundles. Structural properties (e.g. thermal expansion coefficients and compressibilities) of the synthesized materials were investigated by XRD measurements using synchrotron X-ray. Their formation mechanisms are also discussed.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.165-168
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• 2004

Carbon nanotube is a geometrical frame-like structure and the primary bonds between two nearest-neighboring atoms act like beam members, whereas an individual atom acts as the joint of the related beam members. The sectional property parameters of these beam members are obtained from molecular mechanics. Computations of the elastic deformation of single-walled carbon nanotubes reveal that the Young's moduli of carbon nanotubes vary with the tube diameter and are affected by their helicity. With increasing tube diameter, the Young's moduli of carbon nanotubes approach the Young's modulus of graphite.

• Structural Engineering and Mechanics
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• v.66 no.5
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• pp.621-629
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• 2018

By employing the nonlocal continuum field theory of Eringen and Von Karman nonlinear strains, this paper presents an analytical model for linear and nonlinear dynamics analysis of single-walled carbon nanotubes (SWNTs) conveying fluid with different boundary conditions. In the linear analysis the natural frequencies and critical flow velocities of SWNTs are computed. However, in the nonlinear analysis the effect of nonlocal parameter on nonlinear dynamics of cantilevered SWNTs conveying fluid is investigated by using bifurcation diagram, phase plane and Poincare map. Numerical results confirm existence of chaos as well as a period-doubling transition to chaos.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.122-123
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• 2005

단층벽 탄소나노튜브(Single-walled carbon nanotube)를 성장시키고 성장된 탄소나노튜브를 여러 단계의 여과과정이 필요 없는 단순한 정제과정을 통하여 비정질 탄소 찌꺼기, 촉매 금속 등의 불순물을 제거하였다. 성장 온도가 증가함에 따라 수율이 증가하고 불순물의 함유량이 적은 탄소나노튜브가 성장이 되었으며 전반적으로 0.41-2.0 nm의 균일한 직경을 가진 SWNT가 합성이 되었으며 정제 후 96% 이상의 순도를 가진 SWNT를 얻을 수 있었다. 전반적으로 실험결과에 대한 물질의 특성 은 field emission scanning electron microscopy (FESEM)와 X-ray diffraction (XRD) 그리고 Raman spectroscopy로 조사하였다.

• Computers and Concrete
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• v.26 no.2
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• pp.137-150
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• 2020

In this paper, the bending behavior of single-walled carbon nanotube-reinforced composite (CNTRC) laminated plates is studied using various shear deformation plate theories. Several types of reinforcement material distributions, a uniform distribution (UD) and three functionally graded distributions (FG), are inspected. A generalized higher-order deformation plate theory is utilized to derive the field equations of the CNTRC laminated plates where an analytical technique based on Navier's series is utilized to solve the static problem for simply-supported boundary conditions. A detailed numerical analysis is carried out to examine the influence of carbon nanotube volume fraction, laminated composite structure, side-to-thickness, and aspect ratios on stresses and deflection of the CNTRC laminated plates.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1387-1390
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• 2006

Several actuation mechanism for carton nanotubes has teen reported recently, including actuation by double-layer charge injection and ac voltages applyied to multiple electrodes. Carbon nanotube actuator based on double layer charge injection work well in electrolyte at low voltage. AC dielectrophoresis based on four electrode geometry demonstrated carton nanotubes in solution phase can be oriently manipulated by dielectrophoresis. From this point of view, and in regard to their performance, bucky paper actuator may alternate natural muscle. also, applied AC signal with appropriate magnitude and frequency together with four electrode arrangement has potential to realize nanotube electrokinetics.

• Composites Research
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• v.21 no.1
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• pp.8-15
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• 2008

Single-walled carbon nanotube networks(SWNT-networks) were uniformly formed on a glass substrate by the dip-coating method. The changes of electrical and optical properties of SWNT-networks were investigated with respect to processing variables including number of dip, concentration of SWNT-colloidal solution, withdrawal velocity. Consequently, the sheet resistance and transmittance of the SWNTs-networks were sensitively controlled by the processing variables. The networks have highly uniform sheet resistance and optically excellent transmittance within the range of visible ray.

• Advances in nano research
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• v.2 no.4
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• pp.199-210
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• 2014

Carbon nanotubes have exceptional mechanical, thermal and electrical properties, and are considered for high performance structural and multifunctional composites. In the present study, the natural frequencies of aligned single walled carbon nanotube (CNT) reinforced composite beams are obtained using shear deformable composite beam theories. The Ritz method with algebraic polynomial displacement functions is used to solve the free vibration problem of composite beams. The Mori-Tanaka method is applied to find the composite beam mechanical properties. The continuity conditions are satisfied among the layers by modifying the displacement field. Results are found for different CNT diameters, length to thickness ratio of the composite beam and different boundary conditions. It is found that the use of smaller CNT diameter in the reinforcement element gives higher fundamental frequency for the composite beam.

• Structural Engineering and Mechanics
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• v.57 no.3
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• pp.441-456
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• 2016

This work reports wave propagation in the nanocomposite cylinders that reinforced by straight single-walled carbon nanotubes based on a mesh-free method. Moving least square shape functions have been used for approximation of displacement field in weak form of motion equation. The straight carbon nanotubes (CNTs) are assumed to be oriented in specific or random directions or locally aggregated into some clusters. In this simulation, an axisymmetric model is used and also the volume fractions of the CNTs and clusters are assumed to be functionally graded along the thickness. So, material properties of the carbon nanotube reinforced composite cylinders are variable and estimated based on the Eshelby-Mori-Tanaka approach. The effects of orientation, aggregation and volume fractions of the functionally graded clusters and CNTs on dynamic behavior of nanocomposite cylinders are studied. This study results show that orientation and aggregation of CNTs have significant effects on the effective stiffness and dynamic behaviors.