There have been a number of theoretical and experimental studies on tensile properties of carbon nanotubes (CNT), reporting the Young's modulus of the individual CNT up to 1 TPa. Although CNT shows the promise to be used as reinforcement in a high modulus/strength composite material, it exhibits quite disappointing in terms of modulus or strength. Along with recent advance in CNT growth technique, we will be able to directly measure tensile properties of millimeter-long MWCNTs. This study firstly tackles the direct measurement of the tensile properties of millimeter-long MWCNTs that can be used as reinforcement in a composite system. A carefully designed tensile testing technique for the MWCNTs is developed, which allows us to obtain more accurate and reliable measured values. The average tensile strength and Young's modulus of the CNTs investigated in this study are measured to be 0.85 GPa and 34.65 GPa, respectively. Also, this work statistically investigates the effect of the CNT dimensions including length, diameter and volume on the tensile properties. To the best of our knowledge, this is the very first report on the tensile properties of macroscopically long and continuous CNTs.Since its discovery, carbon nanotube (CNT) is believed to be the strongest and stiffest materials because it may be thought as a rolled-up sheet of graphite. Theoretical predictions and experimental observations have been carried out on the tensile properties of CNTs 1-8 . For instance, J. R. Xiao et al. predicted that the tensile strength of single-walled CNTs (SWCNTs) is 94-126 GPa by an analytical molecular structural mechanics model and M. Rossi, et al. reported that the Young's modulus of SWCNTs is around 0.915 TPa 9, 10 . As an evidence, R. S. Ruoff analyzed a single SWCNT using a tensile loaded rope between an atomic force microscope (AFM) tip and a SWCNT "paper", showing that the Young's modulus of SWCNT is around 1 TPa 11 . By the same method, Ruoff also investigated the tensile property of multi-walled CNTs (MWCNTs) which are attached between two AFM tips. It was observed that the tensile strength of an individual MWCNT is 63 GPa and its Young's modulus is 270-950 GPa 12 . It should be noted that the length of CNTs investigated in the aforementioned studies are found to be only at most several micron.Undesirably, for the CNT reinforced composites, the outstanding mechanical properties of individual CNTs have not been translated into the nanocomposites 13 . Certainly it attributes the dispersion and waviness of the CNTs in a matrix to the poor modulus and strength of composites. Although the contributions might be significant, this could be also an indication of the poor mechanical properties of the CNT as reinforcement in a composite system. In fact, due to the nanoscale dimensions and the corresponding unavoidable assumptions in measurement, it always presents significant challenges to accurately measure and determine the mechanical properties. Often, the theoretical values of the Young's modulus and tensile strength don...

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The effect of a hydrophilic layer of graphene oxide on polysulfone membranes was investigated to improve the antifouling properties of the membrane in ultrafiltration. Polysulfone membranes were obtained by the phase inversion method. Polyvinylpyrrolidone was added to generate pores in the membranes, and then a layer of graphene oxide was deposited on the prepared membranes using a vacuum-assisted filtration technique. This study investigated the cross-section/surface morphology, the water-contact angle, and the chemical structure of the prepared polysulfone/graphene oxide membranes. Due to the highly oxygenated structure of the graphene oxide, the surface hydrophilicity of the polysulfone membrane was significantly increased by applying a layer of graphene oxide. Moreover, the antifouling abilities of the membranes were evaluated by comparing the water-flux recovery ratio between the pure water flux before and after ultrafiltration.

Carbon fiber-synthetic foam core sandwich composites are widely used for many structural applications due to their superior mechanical performance and low weight. Unfortunately these structures typically have very poor acoustic performance. There is increasingly growing demand in mitigating this noise issue in sandwich composite structures. This study shows that marrying carbon fiber composites with natural cork in a sandwich structure provides a synergistic effect yielding a noise-free sandwich composite structure without the sacrifice of mechanical performance or weight. Moreover the cork-core sandwich composites boast a 250% improvement in damping performance, providing increased durability and lifetime operation. Additionally as the world seeks environmentally friendly materials, the harvesting of cork is a natural, renewable process which reduces subsequent carbon footprints. Such a transition from synthetic foam cores to natural cork cores could provide unprecedented improvements in acoustic and vibrational performance in applications such as aircraft cabins or wind turbine blades.