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Two dimensional (2D) porous carbon nanosheets (CNS) have attracted tremendous research interests in energy storage and conversion, such as supercapacitors (SCs) and lithium-sulfur batteries, because of their unique micromorphology, chemical stability and high specific surface area (SSA). Rational design and facile scalable synthesis of

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A new composite flame retardant coating for cotton roving has been investigated. The proposed coating comprises natural lignin, pure carbon allotrope carbon nanotubes (CNTs) and non-toxic potassium carbonate (K2CO3). The series of complementary experiments, including thermogravimetric analysis, vertical burning in fire tube, limiting oxygen index (LOI) measurement and combustion in mass loss calorimeter enabled the formulation of an optimum composition including aqueous suspension with 1 wt% of CNTs, 1 wt% lignin (L) as well as 1 wt% of K2CO3. Applying L/CNT/K2CO3 on cotton roving increased LOI from 17.1 to 38.5%, decreased final mass loss and temperature during vertical burning from 100 to 78% and 457 to 190 °C, respectively. Moreover, peak heat release rate and total heat released dropped from 97.5 to 70.4 kW/m2 and from 4.2 to 1.6 MJ/m2, respectively . The above experiments supported by scanning electron microscopy and Raman spectroscopy allowed also the explanation of the complementary mechanisms responsible for the overall fire retardant effect.

Experimental studies reveal that the simultaneous addition of zinc dialkyl dithiophosphates (ZDDPs) and multi-wall carbon nanotubes (MWCNTs) to a poly-alpha-olefin base oil strongly reduces wear. In this paper, it is shown that MWCNTs promote the formation of an anti-wear (AW) layer on the metal surface that is much thicker than what ZDDPs can create as a sole additive. More importantly, the nanotubes’ action is indirect, i.e., MWCNTs neither mechanically nor structurally strengthen the AW film. A new mechanism for this effect is also proposed, which is supported by detailed tribometer results, friction track 3D-topography measurements, electron diffraction spectroscopy (EDS), and Raman spectroscopy. In this mechanism, MWCNTs mediate the transfer of both thermal and electric energy released on the metal surface in the friction process. As a result, this energy penetrates more deeply into the oil volume, thus extending the spatial range of tribochemical reactions involving ZDDPs.

Ultrasonic homogenization is the method of choice for producing and dispersing graphene. In this paper, we show that sp3 hybridization defects introduced by long high-power sonication cause a significant decrease in electrical conductivity. In order to show this, two turbostratic graphene (TG) dispersions were sonicated at two power settings of the tip sonifier at 20 W and 60 W, and for different periods varying from 1 min to 180 min. Afterwards, TG thin films were prepared by the Langmuir technique and transferred onto a quartz substrate by the Langmuir-Schaefer method. The thin films were investigated by electrical conductivity measurement, UV-VIS, Raman spectroscopy and scanning electron microscopy. We found that the relative performance of the TG thin films in terms of transparency and sheet resistance was higher than that for similarly prepared pristine graphene flakes, reported in our previous work. Moreover, despite the increase in transmittance, the electrical conductance significantly decreases with the time of sonication, especially for the 60 W sonication power. The results of Raman spectroscopy indicate that this particular behavior can be explained by the introduction of sp3 hybridization defects into the TG flakes during high power sonication.