Synthesis and Characterization of Some Graphene Oxide Powders Used as Additives in Hydraulic Mortars

Abstract

Various powders of graphene oxide (GO), GO with silver (GO-Ag) and zinc oxide (GO-ZnO) were obtained. The powders were silanized with (3-aminopropyl) triethoxysilane (APTES) aiming to be used, in a future stage, as additives in the hydraulic lime mortars composition. The powders were characterized by Fourier Transform Infrared Spectrometry (FTIR) and Scanning Electron Microscopy (SEM) before and after the silanization process. GO, GO-Ag, GO-Ag-APTES, GO-ZnO and GO-ZnO-APTES powders were also investigated by Thermogravimetric Analysis (TG/DTA) and Ultraviolet–Visible Spectroscopy (UV-Vis). Likewise, the antibacterial effect of powders against five bacterial strains was evaluated. The peaks associated to the functional groups from GO, GO-APTES, GO-Ag, GO-Ag-APTES, GO-ZnO and GO-ZnO-APTES powders were identified by FTIR analysis. The mass losses of powders, analyzed by TG/DTA were lower than those recorded for GO. By UV-VIS analysis, maxima corresponding to the electronic π-π * and n-π * transitions were recorded. SEM images highlighted the lamellar and layered structure of GO, but also the presence of Ag and Zn nanoparticles on the surface of graphene sheets. All these results confirm the presence of Ag/ZnO/APTES on the GO. The antibacterial effect evaluated by recording the diameter of the inhibition zone ranged between 12–22 mm.

Enhanced photocatalytic activity and diode performance of ZnO‐GO nanocomposites via doping with aluminum

“…The band at 1530 cm −1 pointed out the skeletal vibration of the graphene sheets 66 . The peak at 1360 cm −1 is assigned to O‐H deformations of the C‐OH 66 . The band at 1055 could refer to the alkoxy group vibrations 68 .…”

“…The broad band at 3400 cm À1 is attributed to -OH (hydroxyl group) stretching vibration which arose from the vibration of hydroxyl groups, 65 indicating the hydrophilic feature of synthesized nanopowder, which was highly observed in prior reports. 66 The fine structure at 2930 is attributed to the C-H stretching vibration 67 from the alkane group. The band at 1530 cm À1 pointed out the skeletal vibration of the graphene sheets.…”

High-Throughput Preparation of Uncontaminated Graphene-Oxide Aqueous Dispersions with Antioxidant Properties by Semi-Automated Diffusion Dialysis

“…Several peculiarities deal with absorption bands at 1729 and 1619 cm −1 , which are distinctive features of any GO sample. There is some ambiguity in the interpretation of the band at 1619 cm −1 , which could be assigned to C=C [ 107 , 108 , 109 ]. However, this band corresponds to the absorption of water molecules embedded in graphite layers, proven by isotopic exchange with D 2 O [ 110 , 111 , 112 ].…”

Properties Evolution of Some Hydraulic Mortars Incorporating Graphene Oxides

“…It could be attributed to the stretching vibrations of the hydroxyl group from Ca(OH) 2 . The wide band at 3436 cm −1 corresponds to the stretching vibrations of the O-H bond, which can also be attributed to the oxygen groups found both on the surface and at the edge of the GO sheets [8,33]. The third band could be assigned to the carbonatite phases, while the fourth one corresponds to the Si-O stretching vibrations.…”

“…Recently, it was found that various nanomaterials, such as nano-TiO 2 [6,7] and graphene [8,9] could be successfully used to improve the mechanical properties and durability of the mortars [10][11][12]. Nano-TiO 2 has been also proved an excellent photocatalytic material that imparts biocidal, self-cleaning, and smog-abating functionalities when added to cement-based materials [13,14].…”