The present work describes the fabrication of superhydrophobic and superoleophilic reduced graphene oxide-coated cotton (rGO@cotton) by a facile one-step hydrothermal used method for oil-water separation. Results from X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FESEM) analysis show the formation of a composite structure with the presence of an ultrathin coating of rGO on the cotton fibers. The contact angle (CA) between a static water droplet and the rGO@cotton surface in air was measured ~ 162.9°, which suggests the formation of a superhydrophobic surface on the synthesized product. Moreover, the rGO@cotton showed excellent absorption capacity for oils where 1 g of rGO@cotton was able to remove ~ 30-40 g of various oils in the first cycle from oil-water mixtures. The flexible rGO@cotton was reusable and demonstrated oil retention up to ~ 35-50% at the tenth cycle using simple sorption-mechanical squeezing test. Overall, the present work identifies that the rGO@cotton is an efficient absorbent for effective separation of oil from oil-water mixtures.

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Energetic thin films with high mass loadings of nanosized components have been recently fabricated using electrospray deposition. These films are composed of aluminum nanoparticles (nAl) homogeneously dispersed in an energetic fluoropolymer binder, poly(vinylidene fluoride) (PVDF). The nascent oxide shell of the nAl has been previously shown to undergo a preignition reaction (PIR) with fluoropolymers such as polytetrafluoroethylene (PTFE). This work examines the PIR between alumina and PVDF to further explain the reaction mechanism of the Al/PVDF system. Temperature jump (T-jump) ignition experiments in air, argon, and vacuum environments showed that the nAl is fluorinated by gas phase species due to a decrease in reactivity in a vacuum. Thermogravimetric analysis coupled with differential scanning calorimetry (TGA/DSC) was used to confirm the occurrence of a PIR, and gas phase products during the PIR and fluorination of nAl were investigated with temperature jump time-of-flight mass spectrometry (T-jump TOFMS). Results show a direct correlation between the amount of alumina in the PVDF film and the relative signal intensity of hydrogen fluoride release (HF). Although the PIR between alumina and PVDF plays an important role in the Al/PVDF reaction mechanism, burn speeds of Al/PVDF films containing additional pure alumina particles showed no burn speed enhancement.