Carbonized electrospun polyacrylonitrile nanofibers as highly sensitive sensors in structural health monitoring of composite structures

Abstract

Electrospun polyacrylonitrile (PAN) nanofibers were stabilized at 2808C for 1 h in an ambient condition, and then carbonized at 8508C in inert argon gas for additional 1 h in order to fabricate highly pure carbonous nanofibers for the development of highly sensitive sensors in structural health monitoring (SHM) of composite aircraft and wind turbines. This study manifests the real-time strain response of the carbonized PAN nanofibers under various tensile loadings. The prepared carbon nanofibers were placed on top of the carbon fiber pre-preg composite as a single layer. Using a hand lay-up method, and then co-cured with the prepreg composites in a vacuum oven following the curing cycle of the composite. The electric wires were connected to the top surface of the composite panels where the cohesively bonded conductive nanofibers were placed prior to the tensile and compression loadings in the grips of the tensile unit. The test results clearly showed that the carbonized electrospun PAN nanofibers on the carbon fiber composites were remarkably performed well. Even the small strain rates (e.g., 0.020% strain) on the composite panels were easily detected through voltage and resistance changes of the panels. The change in voltage can be mainly attributed to the breakage/ deformation of the conductive network of the carbonized PAN nanofibers under the loadings. The primary goal of the present study is to develop a cost-effective, lightweight, and flexible strain sensor for the SHM of composite aircraft and wind turbines. V C 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43235.

Stabilization of palladium nanoparticles inside chitosan derived N‐doped carbon nanofibers for Heck reaction

“…Herein, Heck reaction was used to evaluate the catalytic performance of Pd@Carbon nanofibers. The optimized reaction condition was first adopted from our previous report 29 . As shown in Figure 8, the catalytic activity decreased in the order of Pd@Carbon‐800 > Pd@Carbon‐600 > Pd@Carbon‐400.…”

“…The optimized reaction condition was first adopted from our previous report. 29 As shown in Figure 8, the catalytic activity decreased in the order of Pd@Carbon-800 > Pd@Carbon-600 > Pd@Carbon-400. Pore size analysis and PALS result have demonstrated that the mesopores and defect holes inside carbon nanofibers were enlarged at high carbonization temperature.…”

“…25,26 Among the carbon materials, carbon nanofibers are ideal supporting materials for catalytic metal nanoparticles for their fascinating fibrous structure and electrical/ mechanical properties. [27][28][29] Beside the similar physicochemical properties with ordinary carbon materials, they exhibited larger surface areas, well-defined fibrous structures and easily tuned mesoporous properties. Carbon nanofibers can display unusual behaviors compared to classical carbon supports, especially for liquid-phase reaction.…”

Highly Hydrophilic Electrospun Polyacrylonitrile/ Polyvinypyrro-lidone Nanofibers Incorporated with Gentamicin as Filter Medium for Dam Water and Wastewater Treatment

“…Recently, electrospinning procedure has been used to produce polymer nanofibers embedded with additives such as anti-bacterial materials for water treatment and separation. Nanofibers have been gaining considerable attention due to their unique properties [43][44][45][46]. They are generally referred to as ultra fine fibers, possess some unique features, such as nanoscaled dimension in the cross-sectional area and macroscopic length on the axis of fibers.…”

“…They are generally referred to as ultra fine fibers, possess some unique features, such as nanoscaled dimension in the cross-sectional area and macroscopic length on the axis of fibers. There fibers possess high surface area, flexibility and porous structure which allow much higher sites for separation processes [43][44][45][46].…”