ABSTRACT
In this work, UV-curable resin poly (ethylene glycol) diacrylate (PEGDA) was reinforced with three different types of nanofillers: pristine graphene (G), multiwalled carbon nanotubes (MWNTs), and a hybrid of MWNTs and graphene 70/30 in mass ratio (Hyb). PEGDA was mixed homogenously with the nanofiller oligomer by shear mixing and then photopolymerized, affording thin, stable films. The thermomechanical properties of the afforded nanocomposites indicated the superior reinforcing ability of pristine graphene compared with MWNTs and an intermediate behavior of the hybrid.
Subject(s)
Graphite , Nanocomposites , Nanotubes, Carbon , Polyethylene GlycolsABSTRACT
Graphene aerogel (GA) is a lightweight, porous, environmentally friendly, 3D structured material with interesting properties, such as electrical conductivity, a high surface area, and chemical stability, which make it a powerful tool in energy storage, sensing, catalyst support, or environmental applications. However, the poor mechanical stability that often characterizes graphene aerogels is a serious obstacle for their use in such applications. Therefore, we report here the successful mechanical reinforcement of GA with carbon fibers (CFs) by combining reduced graphene oxide (rGO) and CFs in a composite material. The surfaces of the CFs were first successfully desized and enriched with epoxy groups using epichloridrine. Epoxy-functionalized CFs (epoxy-CFs) were further covered by reduced graphene oxide (rGO) nanosheets, using triethylene tetramine (TETA) as a linker. The rGO-covered CFs were finally incorporated into the GA, affording a stiff monolithic aerogel composite. The as-prepared epoxy-CF-reinforced GA was characterized by spectroscopic and microscopic techniques and showed enhanced electrical conductivity and compressive strength. The improved electrical and mechanical properties of the GA-CFs composite could be used, among other things, as electrode material or strain sensor applications.
Subject(s)
Carbon Fiber/chemistry , Gels/chemistry , Graphite/chemistry , Compressive Strength , Electric Conductivity , Electric Power Supplies , Oxides/chemistry , PorosityABSTRACT
We present the preparation of disk-like graphene nanoflakes, highly dispersible in dimethylformamide (DMF), with uniform size and thickness. The preparation procedure includes an overnight mild sonication of natural graphite in DMF, followed by a purification step using ultra-centrifugation. The mean diameter of the as produced well defined round shaped graphene nanoflakes is about 100 nm and they consisted of less than twenty graphenic layers.
