Sharif Digital Repository

ZSM-5 (Seolite Sconoy Mobil) aluminosilicate zeolites synthesized by the hydrothermal method were incorporated into the hydrophobic ethyl cellulose (EC) nanofibrous membrane. The performance of synthesized nanofibers was investigated for a gravity driven oil–water separation. The synthesized ZSM-5 nanozeolites and EC/ZSM-5 composite nanofibers were characterized using XRD, FESEM, XPS, FTIR and AFM analysis. The permeability of EC/ZSM-5 5 wt% for oil in water mixture was in order of n-hexane (5170 ± 60 L/m2 h) > n-heptane (4600 ± 50 L/m2 h) > cyclohexane (4350 ± 35 L/m2 h) > pump oil (3780 ± 28 L/m2 h) > lubricating oil (3200 ± 25 L/m2 h) > motor oil (2980 ± 20 L/m2 h) with a separation... 

The contribution of electrospun nanofibrous membranes (e.NFMs) in the biosensing platforms opens up a new prospect for the invention of faster and more sensitive analytical devices. In this paper, we utilized e.NFM of polyethersulfone (PES) as a solid substrate for the protein immobilization through two different approaches: physical and covalent. Scanning electron microscopy (SEM) and Fourier-transform-infrared (FTIR) tests were performed to study the effect of plasma treatment on protein immobilization efficacy. Moreover, taking advantage of ELISA technique, the influence of different parameters, namely, nanofibers diameter, membrane thickness, plasma treatment time, an incubation time of... 

The UiO-66 NH2 and ZIF-8 metal organic framework nanoparticles (NMOFs) were incorporated into the polyvinylidene fluoride (PVDF) nanofibrous membrane. Then, the chitosan nanofibers were coated on the PVDF nanofibers to produce the PVDF/chitosan nanofibers. The performance of synthesized PVDF/NMOFs single layer and PVDF/chitosan/NMOFs two layers nanofibrous membranes was investigated for BSA protein molecules and Cr(VI) ions separation via ultrafiltration membrane process. The potential of synthesized nanofibers was also examined for BSA and Cr(VI) adsorption in a batch system. The characteristics of synthesized nanofibrous membranes were determined using SEM, EDX, TGA, BET, porosity and... 

Protein capturing on polymeric substrate of microfluidic devices is a key factor for the fabrication of immunoassay with high sensitivity. In this work, simple and versatile technique of electrospinning was used to produce electrospun nanofibrous membranes (e.NFMs) with high surface area as a substrate for microfluidic-based immunoassay to increase sensitivity. It was found that the simultaneous use of e.NFM and 1-Ethylethyl-3-(3-dimethylaminopropyl)-carbodiimide/N-Hydroxysuccinimide hydroxysuccinimide as coupling agent has synergic effect on antigen immobilization onto the microchannels. It was found that the oxygen plasma technique for the creation of oxygen containing functional group... 

In this study, superhydrophobic dual layer membranes with highly porous structure were fabricated using electrospinning and electrospraying techniques. Electrospinning method was used to produce the support nanofibrous layer using polyvinylidene fluoride-co-hexafluoropropylene (PH) as the polymer and a mixed solvent system of N,N-Dimetylformamide (DMF) and acetone. Afterwards, hydrophobic, functionalized TiO2 nanoparticles were deposited on the surface of the support layer using the electrospraying technique. TiO2 chemical functionalization and their deposition on the support layer were investigated by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy. The... 

Nanofiber membranes were fabricated by electrospinning poly(vinylidene fluoride). The electrospun nanofiber membranes were further modified by grafting of acrylic acid (AA) and methacrylic acid (MAA) over the surfaces of the membranes. Plasma AA graft was attempted only, and the results indicated the partial membrane pore filling with grafted AA. For MAA grafting, chemically induced polymerization using benzoyl peroxide and hydrogen peroxide was attempted. The combination of plasma and chemically induced MAA graft polymerization was also attempted. The membranes were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and static contact angle (SCA)... 

In this research, poly(vinyl alcohol) (PVA)/chitosan electrospun nanofibrous membrane (ENM) was prepared by electrospinning method in order to investigate its dye removal ability from colored wastewater. The morphology and average fiber diameter of the membranes were investigated by scanning electron microscopy (SEM), image analysis and atomic force microscopy (AFM). The chemical characterization was studied by Fourier transform infrared spectroscopy (FTIR). The permeability of the membranes was evaluated by measuring pure water flux (PWF). In order to investigate the performance of the prepared membranes they were used in the batch adsorption and membrane separation for dye removal from... 

Nanofibrous structures that mimic the native extracellular matrix and promote cell adhesion have attracted considerable interest for biomedical applications. In this study, GO-modified nanofibrous biopolymers (GO) were prepared by electrospinning blended solutions of chitosan (80 vol%), polyvinyl pyrrolidone (15 vol%), polyethylene oxide (5 vol%) containing GO nanosheets (0–2 wt%). It is shown that GO nanosheets significantly change the conductivity and viscosity of highly concentrated chitosan solutions, so that ultrafine and uniform fibers with an average diameter of 60 nm are spinnable. The GO-reinforced nanofibers with controlled pore structure exhibit enhanced elastic modulus and... 

In the present study, dual layers mixed matrix membranes (MMMs) were prepared by incorporating aminated-Fe3O4 nanoparticles into the chitosan/polyvinyl alcohol nanofibers over the polyethersulfone (PES) membrane for the removal of Cr(VI) and Pb(II) ions in batch adsorption and membrane processes. The synthesized aminated-Fe3O4 nanoparticles were characterized using XRD, FESEM and FTIR analysis. The morphology and roughness of membranes were determined using SEM, TEM and AFM analysis. The effect of adsorption operating parameters such as pH (2–7), contact time (0–60 min), initial concentration of metal ions (20–1000 mgL−1) and temperature (30–50 °C) on the Cr(VI) and Pb(II) ions sorption was... 

In this study, novel chitosan/poly(vinyl alcohol) (PVA)/SiO2 nanocomposite ENMs were prepared to improve the mechanical strength and permeation properties of ENMs. The effect of various concentrations of SiO2 in the spinning solution (0, 0.5, 1.0 and 2.0 wt %) on the morphology, fiber diameter, porosity, thermomechanical properties, and permeability of the synthesized membranes was investigated. The prepared affinity membranes were utilized for the removal of dye from colored wastewater. Incorporating SiO2, as a reinforcing agent, was found to increase the compaction resistance of the nanocomposite ENMs. With the addition of 0.5 wt % of SiO2, the Young's modulus of the prepared membranes... 

Novel montmorillonite (Mt) chitosan/poly(vinyl alcohol) (PVA) nanocomposite electrospun nanofibrous membranes (ENM) were prepared and utilized for the treatment of colored wastewater. The Mt. with different mass percentages (0, 1.0, 2.0 and 3.0 mass%) was added to the membrane structure, and its effect on morphology, pore size, porosity, mechanical strength, and permeation properties of ENM were investigated. The fabricated membranes were used as affinity membranes for dye removal with ultrafast permeating adsorption. The results showed that incorporating Mt. as a reinforcing agent improved the nanocomposite ENM resistance to compaction. Young's modulus for the prepared membranes increased... 

Among polymers, polyaniline (PANi) has been introduced as a good candidate for muscle regeneration due to high conductivity and also biocompatibility. Herein, for the first time, we report the use of electrospun nanofibrous membrane of PAN-PANi as efficient scaffold for muscle regeneration. The prepared PAN-PANi electrospun nanofibrous membrane was characterized by scanning electron microscopy (SEM), Attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR) and tensile examination. The softer scaffolds of non-composite electrospun nanofibrous PAN govern a higher rate of cell growth in spite of lower differentiation value. On the other hand, PAN-PANi electrospun... 

In this paper we introduce novel strategy for antibody immobilization using high surface area electrospun nanofibrous membrane based on ethyl-3-(3-dimethylaminopropyl)-carbodiimide/N-hydroxysuccinimide (EDC/NHS) coupling chemistry. To present the high performance of proposed biosensors, anti-staphylococcus enterotoxin B (anti-SEB) was used as a model to demonstrate the utility of our proposed system. Polymer solution of polyethersolfone was used to fabricate fine nanofibrous membrane. Moreover, industrial polyvinylidene fluoride membrane and conventional microtiter plate were also used to compare the efficiency of antibody immobilization. Scanning electron microscopy images were taken to...