26 research outputs found
Carbon nanotube (CNT) incorporated cementitious composites for functional construction materials: The state of the art
No full textCarbon nanotube (CNT) is one of the most promising nanomaterials, which has remarkable mechanical, electrical, thermal properties and chemical stability. Since the incorporation of CNT may dramatically improve the mechanical, electrical, thermal properties of composites, numerous studies on the fabrication and characterization of cementitious composites with CNT have been extensively conducted by researchers. Especially, the studies on the development of functional cementitious composites utilizing CNT have attracted much attention in the construction field. This paper introduces the state of art studies on the fabrication technologies of CNT-incorporated cementitious composites and provides in-depth information on the functional characteristics of the composites. Specifically, various dispersion techniques of CNT particles in cementitious materials are revisited to conclude on the pros and cons of those techniques. Furthermore, the mechanical properties, electromagnetic shielding and sensing performances, and heat generation characteristics of cementitious composites with CNT are extensively reviewed.
Bio-inspired incorporation of functionalized graphene oxide into carbon nanotube fibers for their efficient mechanical reinforcement
No full textAn efficient strategy for the enhancement of mechanical properties of carbon nanotube (CNT) fibers is developed using functionalized graphene oxide with a quaternary ammonium (QA) group (QA-FGO). QA-FGO is designed to induce the p-cation interaction, one of the strongest interactions in living systems, with CNT fibers. Based on the strategy, the tensile strength (58 MPa), specific strength (0.49 N/tex), modulus (2.5 GPa) and toughness (1.1 MJ/m(3)) of CNT fibers are enhanced to 409 MPa, 0.65 N/tex, 13.4 GPa, and 10.1 MJ/m(3), respectively. The reinforcement mechanism is systematically demonstrated with experimental and theoretical approaches.
Observations of Device Orientation Decisions on Mobile Videos
No full textA sensor-rich mobile video represents a new type of videos acquired from modern smart phones. During video recording, it is also recorded various amounts of sensor data collected from embedded sensors. Unlike the conventional videos acquired from proprietary capturing devices, these videos allow enriched reconstruction of their surrounding environments, while enabling users to record them handily. In this paper, we examine the robustness of existing device orientation detection method, by analyzing the motion sensor samples that are publicly available from the sensor-rich mobile video hosting website, and discuss our observation results and potential problems when computing device orientation of georeferential mobile videos
Effect of silica aerogel incorporation on electrical characteristics and strain-sensing capability of nano-porous CNT/PDMS sensors
No full textThe present study focuses on investigating the effect of incorporating silica aerogel on the electrical characteristics and sensing capabilities of carbon nanotube (CNT)-embedded PDMS nanocomposites. Initially, the concept of developing nanohybrid clusters composed of CNT and silica aerogel was introduced, followed by comprehensive evaluations of their formation including zeta potential, Raman spectra and FT-IR spectrum. Subsequently, the nanocomposites with varied silica aerogel contents from 0.5 to 2 % by polymer mass were assessed for their sensing capability. It is observed that porosity has exerts perceptible influence on the overall effective electrical conductivity of the sensor below the percolation thresholds, while it does not have any impact beyond this threshold. In addition, the effective medium proposition theory has been modified to analyze both the effective electrical conductivity and the piezoelectric properties of the sensors fabricated. Based on the theoretical and experimental results, the developed CNT@aerogel nanohybrid clusters displayed the potential to enhance sensing sensitivity and increase linearity during stretching condition
