A new micromechanical approach for the preparation of graphene nanoplatelets deposited on polyethylene

Abstract

An advantageous micromechanical technique to deposit large area graphene nanoplatelet (GNP) thin films on a low-density polyethylene substrate is proposed. This method is based on the application of shear-stress and friction forces to a graphite platelets/ethanol paste on the surface of a polymeric substrate; it allows us to obtain a continuous film of superimposed nanoplatelets mainly made of 13-30 graphene layers. X-ray diffraction (XRD), atomic force and transmission electron microscopy (TEM) measurements support the occurrence of a partial exfoliation of the graphite platelets due to shear-stress and friction forces applied during film formation. Scanning electron microscopy (SEM) observations point out that the surface of the polymer is uniformly coated by the overlap of GNPs, and TEM analysis reveals the tendency of the nanoplatelets to align parallel to the interface plane. It has been found that the deposited samples, under white light illumination, exhibit a negative photoconductivity and a linear photoresponse as a function of the applied voltage and the optical power density in the -120 ÷ 120 mV and 20.9 ÷ 286.2 mW cm ranges, respectively.

Effect of photonic flash annealing with subsequent compression rolling on the topography, microstructure and electrical performance of carbon-based inks

“…To counteract this disruption, Arapov et al used compression rolling to improve the structural integrity of the prints, as well as provide further improvements to resistivity, down to 20 X h -1 , along with a reduction in film thickness and surface roughness from 6 lm and 0.945 lm, respectively, after thermal drying to 1.7 lm and 0.065 lm, respectively, after photonic annealing followed by compression rolling [26]. Compression rolling alone has also been investigated as a possible postprocessing method for a range of applications including radio frequency identification (RFID) antenna and other graphene-based prints and coatings, which in these cases were binder-free, where it produced improvements in the electrical and thermal conductivity of the devices due to better flake alignment [26][27][28][29]. There are also reports of compression rolling leading to improvements in the electrochemical performance of screen-printed lithium-ion batteries with electrodes consisting of graphite [30][31][32] and amorphous carbon [33].…”

Thermoresistive Properties of Graphite Platelet Films Supported by Different Substrates

“…Furthermore, the surfaces of polymers such as poly (methyl methacrylate), polyethylene terephthalate and low-density polyethylene (LDPE) have been made conductive by depositing graphite or graphene layers onto them for the fabrication of printed radio frequency devices [18], electrically conductive paths [19], piezoresistive sensors [20], and strain gauges [9]. These layers can be deposited by chemical vapor deposition [21], casting and drying inks [18], micromechanical techniques based on spreading an alcoholic suspension of graphite nanoplatelets [22,23] and spraying conductive composites [9]. In particular, this last technique is easy, inexpensive, and industrially scalable for the fabrication of large area films.…”

Wavy graphene sheets from electrochemical sewing of corannulene

“…S25 and S26, ESI † ). 35 The inter-layer distance was obtained by Fast Fourier Transform (FFT) of the layered regions evidenced in the insets, providing value of 10.2 ± 0.2 Å, Fig. 4b ( vide infra ).…”