Sharif Digital Repository

Niosomes, as a kind of drug delivery system, is widely used for the topical delivery of lipophilic drugs. Optimization of niosomes plays an essential role in enhancing their therapeutic efficiencies. This study aims to prepare an optimized niosomal formulation of simvastatin (nSIM), a lipophilic member of statins, through the experiment (Response Surface methodology). Optimized niosomes were characterized in size, polydispersity index (PDI), entrapment efficiency (EE), stability, releasing pattern, and antimicrobial activity. The different molar ratio of surfactant and cholesterol were applied to prepare various formulation of simvastatin loaded niosome. Mean particle size and size... 

In this study, an attempt has been made using different concentrations of rare-earth (RE) elements Yb, Gd in Ni–Zn spinel ferrite to examine the magneto-optical and electrical conductivity analysis of the prepared samples. RE doped Ni–Zn ferrite with composition Ni0.5Zn0.5YbxGdxFe2-xO4 (where, x = 0.00, 0.20, 0.40, 0. 60, 0.80 and 1.00) were prepared by one step sol-gel self-ignition approach. XRD and FESEM were used to examine the formation of a single-phase and variations in the grain size with the increasing contents of RE elements in Ni–Zn ferrite NPs. FTIR confirmed the vibrational studies of the RE doped spinel ferrite. The saturation magnetization, remanence, and coercivity elucidated... 

In this research, a facile, two-step synthesis of Fe3O4–LCysteine–graphene quantum dots (GQDs) nanocomposite is reported. This synthesis method comprises the preparation of GQDs via hydrothermal route, which should be conjugated to the LCysteine functionalized core–shell magnetic structure with the core of about 7.5-nm iron oxide nanoparticle and 3.5-nm LCysteine shell. LCysteine, as a biocompatible natural amino acid, was used to link magnetite nanoparticles (MNPs) with GQDs. X-ray powder diffraction, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, energy dispersive X-ray were used to investigate the presence and formation of MNPs, L Cysteine functionalized MNPs,... 

Stimulated devices are highly demanded for actuators and artificial muscles in the recent era but susceptible to low deformation at an applied voltage. In the present work, ionic liquids (ILs) based gel films were prepared from the polyvinyl chloride (PVC), dibutyl adipate (DBA), 1-butyl, 3-methimidazolium chloride, and 1-pentyl-3-methylimidazolium hexafluorophosphate by a simple solvent evaporation method. The structural, morphological, optical, and mechanical properties of the composite PVC/ILs gel were characterized by Fourier-transform infrared spectroscopy (FTIR), Large Angle X-ray scattering (LAXS), UV–visible (UV–vis) absorption spectroscopy, scanning electron micrpscopy (SEM) and... 

Carbonaceous materials (CMs) have been applied extensively for enhancing the catalytic performance of environmental catalysts, however, the self-catalytic mechanism of CMs for groundwater remediation is rarely investigated. Herein, we unveiled the catalytic ability of various CMs via Fe(III) reduction through polyvinyl alcohol-coated calcium peroxide nanoparticles (PVA@nCP) for trichloroethylene (TCE) removal. Among selected CMs (graphite (G), biochar (BC) and activated carbon (AC)), BC and AC showed enhancement of TCE removal of 89% and 98% via both adsorption and catalytic degradation. BET and SEM analyses showed a higher adsorption capacity of AC (27.8%) than others. The generation of... 

This study demonstrated the prolonged benefits of polyvinyl-coated calcium peroxide (PVA@CP) in Fe(II)/nFeS mediated Fenton-like reaction. PVA@CP was prepared by a coating of PVA on calcium peroxide (CP) and synthesized nano-sized iron sulfide (nFeS) was characterized by scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM) with energy dispersive spectroscopy (EDS) elemental mapping, X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma optical emission spectroscopy (ICP-OES) and Fourier transmission infrared (FTIR) techniques. Trichloroethylene (TCE) degradation in various oxic environments (H2O2, CP, or... 

The objective of this work is to develop a new Preformed Particle Gel (PPG) suspension to enhance oil production and monitor water production in a porous medium on micromodel scale. To achieve the above goal, the following synthetic method was used. At the outset, the PPG samples were synthesized with polyethylene amine (PEI) as a crosslinker, 2,2′-Azobis (2-methylpropionamidine) dihydrochloride (AAPH) as initiator and acrylamide (AM) and 2-Acrylamido-2-methylpropanesulfonic acid (AMPS) monomers to improve the strength properties of PPGs by the radical polymerization method. Also, to characterize the micro and macro structural the samples, the scanning electron microscopy (SEM),... 

Protein aggregation, such as amyloid fibril formation, is molecular hallmark of many neurodegenerative disorders including Alzheimer's, Parkinson's, and Prion disease. Indole alkaloids are well-known as the compounds having the ability to inhibit protein fibrillation. In this study, we experimentally and computationally have investigated the anti-amyloid property of a derivative of a synthesized tetracyclic indole alkaloid (TCIA), possessing capable functional groups. The fibrillation reaction of Hen White Egg Lysozyme (HEWL) was performed in absence and presence of the indole alkaloid. For quantitative analysis, we used Thioflovin T binding assay which showed ~50% reduction in fibril... 

In the present study, an in-situ, two-step, highly controllable, fast, green, and facile strategy for fabricating the bimetallic cobalt-zinc-based metal-organic frameworks (MOFs) is employed for designing a non-enzymatic glucose sensing platform. The structural characterization, as well as the phase investigation of materials in each step, are assessed by X-ray diffraction, energy-dispersive X-ray spectroscopy, elemental mapping, field emission scanning electron microscopy, and Fourier transform infrared spectroscopy. Furthermore, the electrocatalytic activity of the CoZn-BTC/GC fabricated electrode toward the electro-oxidation of glucose is examined by various electrochemical techniques,... 

Commercial paints and coatings can serve as a protective barrier for metallic substrates in a corrosive environment. A considerable variety of nanostructures can be embedded in a polymeric coating to achieve both barrier and active protection. This research aims to elucidate the role of polyaniline (PANI) as an active polyelectrolyte modifier for the surface modification of mesoporous silica nanoparticles (MSNs) doped with zinc cations (Zn2+). To characterize the samples, we employed different techniques, including field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), N2 adsorption-desorption, Fourier transform infrared spectroscopy (FTIR), Raman... 

Cationic polymers such as poly-L-lysine (PLL) are able to interact electrostatically with DNA to produce polymeric systems with nanometric diameters due to the neutralization and accumulation of DNA. This study integrates the outstanding properties of carbon quantum dots (CQDs) with PLL to develop a novel gene delivery vehicle with a core-shell hybrid nanostructure. The CQD/PLL core-shell nanoparticles (NPs) were, therefore, synthesized in such a way that they had narrow size distribution and an average diameter under 10 nm, both of which were confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM). Fourier transform infrared (FTIR) spectroscopy exhibited that... 

A novel kappa-carrageenan (κC)-based superabsorbing hydrogel was synthesized through graft copolymerization of acrylamide (AAm) onto a κC substrate in the presence of a crosslinking agent. The crosslinked κC-poly(AAm) polymer graft was partially hydrolyzed in alkaline medium to yield a superabsorbent resin, H-carragPAM. The resin structure was confirmed using FTIR spectroscopy. The variables of graft copolymerization (monomer, initiator, polysaccharide and crosslinker concentration, reaction temperature and time as well as stirrer speed) that affected on the ultimate water-swelling capacity were optimized. The time-temperature variation of the copolymerization was investigated in terms of... 

Synergistic effects of Cyanex 272 mixed with D2EHPA and Cyanex 302 mixed with D2EHPA were investigated for the separation of cobalt and nickel from a dilute sulfate media with the aim of reducing the reagent cost. Selective extraction of cobalt over nickel improved with respect to D2EHPA, but worsened with respect to Cyanex 272. By the application of the slope analysis method, the stoichiometric coefficient of the extractant was found to be four for cobalt and five for nickel, in a mixture of D2EHPA with Cyanex 302. However, it was four for both cobalt and nickel in a mixture of D2EHPA with Cyanex 272. Fourier Transform Infrared Spectroscopy (FT-IR) was utilized to examine the... 

Tetraphenylthiophene diamine (TPTDA) was prepared through a modified three-step route to achieve an improved overall yield. TPTDA reacted with succinic, adipic, suberic, sebasic, and fumaric acids via the Yamazaki phosphorylation method to yield novel partially aromatic polyamides (TPT series). A counterpart polyamide series based on p-phenylene diamine (Ph series) was also synthesized under the same conditions. All of the polymers were characterized by means of spectrochemical (Fourier transform infrared spectroscopy. 1H-nuclear magnetic resonance (NMR), and 13C-NMR) and thermal (differential scanning calorimetry and thermogravimetric) methods of analysis. Solubility of TPT polyamides was... 

Silk fibroin (SF) has been broadly applied in wound dressing fabrication because of its proper features for wound healing. In this work, we developed a carboxymethyl cellulose (CMC)/gelatin blend film with different concentrations of glycerol, and modified the optimized film with an SF layer through electrospinning process. Tensile strength and cell viability evaluation of blend films demonstrated that the glycerol content of 3% could be suitable as the substrate layer for the two-layer wound dressing. The morphology of the blend film and electrospun nanofibers was obtained from scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). It concluded that... 

Photocatalytic membrane reactors (PMRs), coupling photocatalysts and membranes in a single system, have shown a considerable potential to reduce membrane fouling, which is one of the major drawbacks of using membranes to treat water and wastewater. In this study, the visible light-activated photocatalysts were incorporated into the polyacrylonitrile (PAN) casting solution to synthesize the photocatalytic composite membranes. The physicochemical properties and the morphology of the membranes and photocatalysts were characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction analysis (XRD), ultraviolet–visible diffuse reflectance... 

Asphaltenes, and their related issues, have been the focus of many literature investigations. However, in-depth analysis of asphaltenes structure and its relation to asphaltenes stability has been considered by fewer studies. In this research, extensive analysis of the structure of asphaltenes extracted from light, medium, and heavy oils is provided, together with analysis of three subfractions of the medium oil asphaltene having the least, intermediate, and highest solubilities. To this end, elemental analysis, EDX, mass spectroscopy, FTIR, NMR, XRD, and SEM results were collected. Higher hydrogen content and hydrogen/carbon atomic ratio, lower aromatic nature and olefinic entities were... 

Proteins possess a variety of nucleophiles, which can carry out different reactions in the functioning cells. Proteins endogenously and synthetically can be modified through their nucleophilic sites. The roles of these chemical modifications have not been completely revealed. These modifications can alter the protein folding process. Protein folding directly affects the function of proteins. If an error in protein folding occurs, it may cause protein malfunction leading to several neurodegenerative disorders such as Alzheimer's and Parkinson's. In this study, Hen Egg White Lysozyme (HEWL) and bovine insulin, as model proteins for studying the amyloid formation, were covalently attached with... 

Designing efficient and inexpensive catalysts toward the oxygen evolution reaction (OER) is vital for achieving sustainable and green hydrogen fuel production through water electrolysis. Herein, we have synthesized several bi- and trimetallic metal–organic frameworks (MOFs) composed of Co, Ni, and Mn metals and benzene-1,3,5-tricarboxylic acid linker. The MOFs were prepared via a simple hydrothermal method, and their electrocatalytic performances in alkaline OER were investigated. A battery of analytical techniques was employed to characterize the as-synthesized materials, including field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM),... 

In this study, the effects of unmodified calcium zinc phosphate (UCZP) and modified calcium zinc phosphate (MCZP) nanopigments (NPs) on the rheological, mechanical, and corrosion protection performance (CPP) of the epoxy (EP) coatings were investigated. Transmission electron microscopy (TEM) coupled with energy-dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) were used to study morphology and overall chemical structure of synthesized calcium zinc phosphate (CZP) NPs, respectively. The grafting of methyltriethoxysilane (MTES) molecules on the surface of CZP was assessed using Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and...