RESUMO
The present study was set out to synthesize Mxene (Ti3C2Tx) and functionalized Mxene nanoparticles and fabricating Mxene coated stainless steel meshes using the dip-coating methodology to investigate the capability of Mxene nanoparticles in oil-water emulsion separation. O/W mixtures separation with extraordinary 100% of effectiveness and purity using designed grid was observed. Most specifically, Mxene fabricated mesh showed good resistance to corrosive solutions of HCl and NaOH and was used to separate O/W at harsh medium condition with a separation efficiency of more than after 96.0% replicated experiment, and its super-hydrophilicity persisted in spite of the air exposure condition, extreme fluids immersion, or abrasion. The XRD, FTIR, SEM, FESEM, AFM and DLS tests have been performed to characterize the Mxene coating and its effectiveness on the O/W separation. These analyzes confirm the fabricated tough super-hydrophilic stainless-steel mesh explored in this research can basically be utilized as a highly effective useful mesh for O/W fluid separation under different sever circumstances. The XRD pattern of the resulting powder shows a single phase formation of Mxene, the SEM and FESEM images confirms creation of coated mesh with approximately 30 µ pore size, AFM tests verify that structures (both in nm and µm sizes) formation with high RMS (Root Mean Square) roughness values of 0.18 µm and 0.22 µm for Mxene and carboxylic-Mxene coated mesh. The DLS tests prove the droplets size distribution of emulsion has been augmented after several O/W separation, which confirmed the coagulating mechanism of oil droplets once contacting with the Mxene and carboxylic Mxene coatings of the mesh.
Assuntos
Óleos , Água , Água/química , Propriedades de Superfície , Emulsões/química , Aço Inoxidável/químicaRESUMO
There is an increasing demand for the development of inexpensive and effective approaches for the oil-water separation due to the global concern in oil industries. The present study was conducted to fabricate graphitic carbon nitride/thermoplastic polyurethane (g-C3N4/TPU)-coated stainless steel meshes via the dip-coating method to investigate the capability of g-C3N4 nanosheets (CN-NS) in oil-water separation. CN-NS was synthesized using the polycondensation process followed by exfoliation with Hummer's method. We studied the effect of TPU and CN-NS concentration on wettability behavior to obtain an optimized coating solution. CN-NS-coated mesh showed superoleophilic/hydrophobic behavior at CN-NS:TPU ratio of 50:50, and it efficiently passed oil from the emulsified water-in-oil mixture (with 50 wt.% oil) with the efficiency of 99%. The wettability behavior of superhydrophilic/underwater superoleophobic was also obtained at CN-NS:TPU ratio of 80:20, and it was able to separate water from the emulsified water-in-oil mixture with the efficiency of 79% under gravity. Both filters were able to separate free water and oil mixtures with flux and efficiency of 6114 L.m-2.h-1 and ~ 99.99%, respectively. The mechanism of wettability behavior of the coating is mainly related to the functional groups on the edge of g-C3N4-NS, thus increasing the hydrophilic properties of the surface. In addition, the micro-nano hierarchical structure of the surface coating improves its roughness due to the presence of CN-NS, which is effectively embedded into the hydrophilic TPU. More importantly, commercially available TPU chemical and simple fabrication of g-C3N4 from an inexpensive precursor make the method reported herein as a significant alternative for large-scale application.
RESUMO
WO3 nanorods with average dimension about 23 x 145 nm have been synthesized in gram quantities by a hydrothermal method. Effect of various surfactants on the WO3 nanorods morphology was investigated. The results demonstrated that the application of suitable surfactant (such as Triton X-100), leads to obtain obviously individual morphology for WO3 nanorods (with average dimensions about 15 x 100 nm) and decrease the reaction time from 7 days to 3 days. With a very suitable and safe method, the as-prepared WO3 nanorods, will turn to WS2 nanoparticles by mixing them with Sulfur (S) powder, under reducing H2 atmosphere and high temperature. Therefore, application of the harmful and poisonous H2S gas was eliminated.
RESUMO
A facile and simple synthetic route was proposed for the synthesis of WS2 nanoparticles. The as-prepared WS2 nanoparticles can be characterized with X-ray diffraction spectrum (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). The average particle size of the product is about 85 nm that was calculated from XRD pattern by the Debye-Scherrer formula.