Search

• In situ modification of sawdust was done and magnetized sawdust is obtained. • The effect of magnetorheological properties on absorption capacity was studied. • Highly hydrophobic and oleophilic properties was revealed due to surface modification with polymer. • Magnetorheological behavior of the fluid (oil + modified sawdust) was modeled with Bingham plastic model. • The effect of magnetic field on the formation of parallel web of magnetic particles was studied. Protecting the environment is important for its impact on the life of humans and organisms. Oil pollution is one of the most important factors affecting the life of creatures. Here we are looking for the way to magnetize oil contamination by modified sawdust. The iron oxide nanoparticles were coated in situ on the sawdust using co-precipitation method, which magnetized the sawdust. Subsequently, the magnetic sawdust was successfully functionalized with a saline coupling agent to form a highly hydrophobic and oleophilic surface. FE-SEM, FTIR, EDXA, VSM, WCA and optical microscopy were performed to complete characterization of the products. In addition, a new magnetorheological (MR) fluid based on the crude oil and magnetized sawdust was developed and its rheological properties studied by a rheometer furnished with a magnetic field generator. The results were completely fitted using Bingham model. The strong MR response induced in the crude oil by adding the modified sawdust could exhibit a high crude oil removal capacity of about 47 times the modified sawdust weight. [ABSTRACT FROM AUTHOR]

• Polymer/fiber composite membrane was presented for gas separation. • Capillary condensation mechanism occurred for CO 2 transport in polymer/fiber interface. • Composite membranes showed simultaneous enhancements in CO 2 permeability and CO 2 /CH 4 ideal selectivity. One of the most important shortcomings of the polymeric membranes in comparison with inorganic membranes is the trade-off between permeability and selectivity. Gas permeability in inorganic membranes follows different mechanisms including capillary condensation mechanism. The aim of present study was improving the polymeric membranes performance by introducing capillary condensation mechanism for the gas transport similar to that observed in the inorganic membranes. Capillary condensation of gases needs a continuous diffusion pathway, therefore in the present study short glass wool fibers (with a micro size in diameter and millimeter size in length) were chosen as a proper alternative instead of nanoparticles. Short glass wool fibers present proper dispersion in the Pebax matrix as a result of its good compatibility with polymer segments. Gas permeability behavior in such composite membranes was assisted using pure CO 2 , CH 4 and N 2 gases. Obtained results demonstrated that gas permeability behavior in the short fiber reinforced composite membranes is depends on the fiber content. At lower content of the fiber, such reinforcement causes simultaneous increment in gas permeabilities in a way that 62.37%, 32.12% and 50.71% increase in permeability was observed for CO 2 , CH 4 , and N 2 respectively. But at higher content due to formation of more continuous interface, capillary condensation was appeared for more condensable gas (CO 2) which results in 17.65% reduction in its permeability. Based on the results the using of short fiber instead of nanoparticles in polymeric membranes can be more beneficial in performance and economic point of view. [ABSTRACT FROM AUTHOR]