Parametric study of pulsed nanosecond laser interaction with carbon-nanotube composite bipolar plate for PEMFCs

Abstract

A laser processing technique is proposed for the processing of a 2.5 mm thick carbon nanotube (CNT) composite bipolar plate for proton exchange membrane fuel cells (PEMFCs). This study aims to understand laser interaction with the CNT composite plate experimentally using a pulsed nanosecond laser. Penetration depth, top width, spatter width, and overall physical morphologies are studied. Scanning electron microscope (SEM) and 3D Scanning Confocal Microscope were used for observation and measurements. Based on that, a parametric investigation is conducted and reported systematically. Most importantly, the pulse repetition rate presents a unique nature of interaction that resulted in a critical repetition rate distinguishing three operational regimes. The physical and chemical properties of the regimes are further analyzed by Vickers microhardness testing and energy dispersive X-ray (EDX) analyses performed on the surface and cross-section of each specimen. The results reveal that the pulse repetition rate introduces changes in mechanical properties and chemical compositions in the vicinity of the processed region. In conclusion, lower pulse repetition should be favored for less impact on mechanical properties, chemical composition, and morphological aspects.

Second harmonic generation on crystalline organic nanoclusters under extreme nanoconfinement in functionalized silica–benzil composites

“…In relevant technologies, the individual components can be altered and tailored in many ways aiming at utilizing their desired properties to the resultant nanocomposite structure as a whole. As heterogeneous multiphase formations, they can be fabricated combining appropriate organic and inorganic materials in various nanoscale morphologies such as e.g., carbon nanotubes 1 – 4 and nanoribbons 5 – 7 , graphene nanoplatelets 8 – 10 , carbon, perovskite and semiconductor quantum dots 11 – 13 , nanoparticles and nanospheres 14 – 16 , nanowires 17 – 21 , organic dyes 22 , nanocrystals 23 – 25 , isotropic liquids 26 or anisotropic liquid crystal materials 27 – 30 being incorporated into organic or inorganic liquids or host solid media such as e.g., polymers or inorganic nanoporous materials. Among the latter ones, mesoporous silica, p SiO (hereafter PS ) 31 , likewise the mesoporous silicon Si 32 – 34 and alumina p Al O (anodic aluminum oxide, AAO) 35 may be considered as most advanced host matrices for many nanocomposite technologies.…”

Structure and Properties of Carboxylated Carbon Nanotubes@Expanded Graphite/Polyethersulfone Composite Bipolar Plates for PEM

“…The addition of new conductive fillers can also improve the conductive properties of composite BPs without compromising flexural strength. A variety of fillers have been proven to be effective, such as conductive carbon black [ 33 ], carbon fibers [ 34 ], carbon nanotubes [ 35 ], graphene [ 36 ], etc. The preparation and performance of polypropylene/multi-walled carbon nanotubes/carbon nanofiber composite BPs were studied by C.A.…”