Experimental investigation of the mechanical grinding effect on graphene structure

Abstract

Graphene has been proven to be a promising material for various applications due to its outstanding chemical, physical, optical as well as mechanical properties. To further improve these properties of graphene, here we apply a grinding method with various speeds (100–600 rpm) of a planetary ball mill under wet conditions in graphene based aqueous solution. Therefore, the improvements in dispersion and thermal characteristics of the graphene–water solution were investigated based on the morphological and structural changes. The best dispersibility and highest thermal conductivity of graphene–water solution were observed for a grinding speed of 500 rpm. As a result, the grinding speed of 500 rpm is found as the optimum condition of planetary ball milling in the case study. The reason for the grinding speed of 500 rpm revealing the best condition is attributed to the reduced ratio (ID/IG = 0.221) of the D band and the G band in Raman spectroscopy. We believe that structurally upgraded graphene in this study would greatly improve the performance of the graphene based devices.

Synthesis, characterization, and performance analysis of carbon molecular sieve‐embedded polyethersulfone mixed‐matrix membranes for the removal of dissolved ions

“…The reason for this range is thought to be the mechanical grinding process. Similar observations have been made by many researchers where grinding of filler particles resulted in micron size particles (Li, Sui, Li, Cai, & Jin, 2014; Myekhlai et al, 2014; Palaniandy, Azizli, Hussin, & Hashim, 2007).…”

Electrical Conductivity Measurement of Transparent Conductive Films Based on Carbon Nanoparticles

“…The XRD patterns of the pristine GN, AgNPs, MWCNT and of their hybrids, are displayed in Figure 5. The crystalline plane peaks (002), (101), (004), (110) and (112) of GN were depicted at 2θ = 26.5°, 44.6°, 54.6°, 77.6° and 83.8° in the XRD pattern of the pristine GN, respectively [53], while the crystalline plane peaks (002) and (100) of the MWCNTs were depicted at 2θ = 25° and 43° [57,58]. In addition, the crystalline plane peaks (110), (200), (220), (311) and (222) of the AgNPs were identified at 2θ = 38.3°, 44.4°, 63.5°, 77.7° and 81.6°, respectively [59,60].…”

“…This grinding method is an effective way for making a wide surface area, thereby significantly reducing the agglomeration of the nanopowder [52]. However, there is no need to describe the details of the grinding process because it can be referred to from many other studies [53,54].…”

“…Garg et al [55] reported that the maximum thermal conductivity enhancement was obtained by applying ultrasonic excitation for 40 min; interestingly, the thermal conductivity of the nanofluid was decreased by prolonging the treatment over 40 min. In previous studies [53,54], the ground nanopowder was dispersed into pure water; then, in order to split the coalesced particles in the liquid, the resulting nanofluid was processed with an ultrasonic exciter for 40 min. Our hybrid nanofluid was instead prepared by mixing the base liquid, carbon particles, and metal particles, using an Ag wire with a diameter of 0.2 mm (Nano Technology Inc., Daejeon, South Korea).…”

Photovoltaic Characteristics of Multiwalled Carbon Nanotube Counter-Electrode Materials for Dye-Sensitized Solar Cells Produced by Chemical Treatment and Addition of Dispersant

“…In order to increase the specific surface area, flattening and fine planetary ball milling (Haji Engineering, Seoul, Korea) was performed. It should be noted that this grinding method is an effective way to increase the surface area, and thereby, significantly reduce the agglomeration of the MWCNTs [44]. Spherical zirconia balls (3.0 mm) were used as the collision medium.…”