Sharif Digital Repository

The diffusion and deposition of TiO2 nanoparticles in EOR application was investigated in this paper. TEM image of nanoparticles showed that the particles are elongated with average long and short axis sizes of 54 and 15 nm. Water flooding tests showed that the recovery factor can be improved from 49% to 80% using TiO2 nanoparticles. Viscosity and interfacial tension measurements showed that by using TiO2 nanoparticles the viscosity of injected fluid and interfacial tension do not change significantly and can not explain the change in recovery factor. Contact angle measurements showed that nanoparticles deposition changed the wettability of the rock surface from oil-wet to water-wet. SEM... 

Although application of nanoparticles in enhanced oil recovery has been reported, understanding the transport and retention of nanoparticles in the oilfield reservoir is still a crucial issue. In this research, behavior of low concentration of TiO2 nanoparticles in core plug porous media and the mechanism of increasing oil recovery were investigated. Flooding test with a concentration of 0.01% TiO2 nanoparticles showed improvement in sweeping heavy oil from 41% to 55%. Inductively coupled plasma results on the exiting effluent of the flooding test with a concentration of 0.05% TiO2 nanoparticles showed the presence of only 0.5% of injected nanoparticles, which indicates high affinity of the... 

New membrane materials and processes have been extensively developed due to urgent needs for much more economic separation processes. Recently, graphene has been confirmed to be an excellent separation membrane. As there is no support in the obtained three-dimensional (3D) architecture constructed from tubular graphene network, it is possible to take full advantage of the large surface of graphene. In this study 3D graphene aerogels were synthesized by a simple method and modified to adjust hydrophilicity of the samples to achieve high liquid volumetric rate. Modified samples were used for the filtration of the enzymes including amylase, cellulase, lipase and protease. Slightly differently... 

Anatase and amorphous TiO2 nanoparticles were used to improve recovery of heavy oil from sandstone cores. Before performing core floods, the stability of nanoparticles at different salinities was tested using ζ potential and ultraviolet-visible (UV-vis) methods. While water recovered only 49% of the oil in the core flood experiments, 0.01% anatase structure solution recovered 80% of the oil after injecting two pore volumes at optimum conditions. To understand the mechanism responsible for improved recovery, contact angle measurements were performed on the rock surface before and after treatment with the nanoparticle solution. Contact angle measurements showed that the rock wettability... 

In the past few years, most studies have focused on smart substances that can respond to changes in the environment, as they can be appropriately applied in different fields, including biosensing, biotechnology, and drug delivery. Here, new fluorescent carbon dots (CDs) are synthesized by Terebinth by designing a simple and single-stage hydrothermal path, which facilitates the manufacture of CDs with no need for boring artificial methods, or using poisonous/costly solvents and starting substances. The method is used to concurrently form CDs and passivate their surface, which results in inherently emitted fluorescence. The study of the structure and optical features of the resulting CDs...