144 research outputs found

    Synthesis and characterization of magnetite nano particles with high selectivity using in-situ precipitation method

    No full text
    In-situ precipitation method is widely used and reported in the literature for the synthesis of iron oxide nanoparticles based on their applications in many fields. However, the rate of reaction and rate constant for the production of Magnetite Phase of iron oxide did not study in depth. Reaction rates are required to design a scale-up of the process. In this study, Magnetite phase of iron oxide nanoparticles (Fe 3 O 4 ) are synthesized by the in-situ precipitation method, and the overall reaction rate is evaluated based on the concentration of Magnetite produced during the process. Further, X-ray diffraction, energy-dispersive X-ray spectroscopy and Raman spectroscopy are used to confirm the presence of a higher proportion of magnetite (Fe 3 O 4 ) in the final product, which is responsible for more top magnetic properties 74.615 emu. Changes in morphology of these nanoparticles at different intervals of the reaction are reported by transmission electron microscope. The results showed that spherical nanoparticles synthesized at different intervals of the reaction have a very narrow range of particle size, i.e. 9–15 nm. Detailed analysis reveals the presence of a higher share of maghemite (Fe 2 O 3 ) at the start of the reaction. However, maghemite eventually is converted to magnetite by the end of the reaction, thereby enhancing the magnetic strength of the nanoparticles

    Synthesis and characterization of magnetite nano particles with high selectivity using in-situ precipitation method

    Get PDF
    \u3cp\u3e In-situ precipitation method is widely used and reported in the literature for the synthesis of iron oxide nanoparticles based on their applications in many fields. However, the rate of reaction and rate constant for the production of Magnetite Phase of iron oxide did not study in depth. Reaction rates are required to design a scale-up of the process. In this study, Magnetite phase of iron oxide nanoparticles (Fe \u3csub\u3e3\u3c/sub\u3e O \u3csub\u3e4\u3c/sub\u3e ) are synthesized by the in-situ precipitation method, and the overall reaction rate is evaluated based on the concentration of Magnetite produced during the process. Further, X-ray diffraction, energy-dispersive X-ray spectroscopy and Raman spectroscopy are used to confirm the presence of a higher proportion of magnetite (Fe \u3csub\u3e3\u3c/sub\u3e O \u3csub\u3e4\u3c/sub\u3e ) in the final product, which is responsible for more top magnetic properties 74.615 emu. Changes in morphology of these nanoparticles at different intervals of the reaction are reported by transmission electron microscope. The results showed that spherical nanoparticles synthesized at different intervals of the reaction have a very narrow range of particle size, i.e. 9–15 nm. Detailed analysis reveals the presence of a higher share of maghemite (Fe \u3csub\u3e2\u3c/sub\u3e O \u3csub\u3e3\u3c/sub\u3e ) at the start of the reaction. However, maghemite eventually is converted to magnetite by the end of the reaction, thereby enhancing the magnetic strength of the nanoparticles. \u3c/p\u3

    Telescopic Synthesis of Azo Compounds via Stable Arenediazonium Tosylates by Using n-Butyl Nitrite as Diazotization Reagent

    No full text
    A multi-step catalyst-free synthesis of azo compounds by using n-butyl nitrite as a diazotization reagent and p-toluene sulfonic acid as a mild acidic agent in ethanol/water mixed solvent was investigated. In the combined one-pot synthesis process, no nitrous acid was produced during the diazotization. By controlling the conditions in a continuous process, a 62–88% yield was obtained. The current method has the following advantages: reduce waste by avoiding solvent for the purification of products in the diazotization step; save energy, time, and cost; work under environmentally benign conditions, and produce a good amount of products with potential use as azo-dyes, pigments, and therapeutic agents. © 2017, © 2017 Taylor & Francis Group, LLC

    Gelatin controversies in food, pharmaceuticals, and personal care products: Authentication methods, current status, and future challenges

    No full text
    Gelatin is a highly purified animal protein of pig, cow, and fish origins and is extensively used in food, pharmaceuticals, and personal care products. However, the acceptability of gelatin products greatly depends on the animal sources of the gelatin. Porcine and bovine gelatins have attractive features but limited acceptance because of religious prohibitions and potential zoonotic threats, whereas fish gelatin is welcomed in all religions and cultures. Thus, source authentication is a must for gelatin products but it is greatly challenging due to the breakdown of both protein and DNA biomarkers in processed gelatins. Therefore, several methods have been proposed for gelatin identification, but a comprehensive and systematic document that includes all of the techniques does not exist. This up-to-date review addresses this research gap and presents, in an accessible format, the major gelatin source authentication techniques, which are primarily nucleic acid and protein based. Instead of presenting these methods in paragraph form which needs much attention in reading, the major methods are schematically depicted, and their comparative features are tabulated. Future technologies are forecasted, and challenges are outlined. Overall, this review paper has the merit to serve as a reference guide for the production and application of gelatin in academia and industry and will act as a platform for the development of improved methods for gelatin authentication

    Optimization of the Synthesis of Superhydrophobic Carbon Nanomaterials by Chemical Vapor Deposition

    No full text
    Demand is increasing for superhydrophobic materials in many applications, such as membrane distillation, separation and special coating technologies. In this study, we report a chemical vapor deposition (CVD) process to fabricate superhydrophobic carbon nanomaterials (CNM) on nickel (Ni)-doped powder activated carbon (PAC). The reaction temperature, reaction time and H2/C2H2 gas ratio were optimized to achieve the optimum contact angle (CA) and carbon yield (CY). For the highest CY (380%) and CA (177°), the optimal reaction temperatures were 702 °C and 687 °C, respectively. However, both the reaction time (40 min) and gas ratio (1.0) were found to have similar effects on CY and CA. Based on the Field emission scanning electron microscopy and transmission electron microscopy images, the CNM could be categorized into two main groups: A) carbon spheres (CS) free carbon nanofibers (CNFs) and b) CS mixed with CNFs, which were formed at 650 and 750 °C, respectively. Raman spectroscopy and thermogravimetric analysis also support this finding. The hydrophobicity of the CNM, expressed by the CA, follows the trend of CS-mixed CNFs (CA: 177°) CSfree CNFs (CA: 167°) PAC/Ni (CA: 65°). This paves the way for future applications of synthesized CNM to fabricate water-repellent industrial-grade technologies

    Influence of Hydrophobicity of Acetylated Nanocellulose on the Mechanical Performance of Nitrile Butadiene Rubber (NBR) Composites

    No full text
    Novel acetylation process by substitution of acetic anhydride substitution with hydroxyl groups on nanocellulose (NCC) has been explored to increase its dispersion and interaction in nitrile butadiene (NBR) matrix. The crystallinity index was increased after modification when compared to unmodified NCC, but no significant different with increases of treatment time from 1 hour to 3 hours treatments proven by X-ray diffraction (XRD) results. The Fourier transform infra-red (FTIR) showed the existent of acetyl groups on surface of the NCC after treatment by existent of the peak 1736 cm-1 that attributed to carbonyl groups some peaks were observed at 1430, 1361 and 1248 cm-1 and confirmed on the acetylation process. The nuclear magnetic resonance (NMR) also show the present of acetyl groups by existent of the signal of proton methyl group at 1.90 ppm and new peaks at 5.42, 4.70 and 4.34 ppm, for all ACN samples. The thermal results by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC) showed that the acetylated NCCs were 10 % more thermally stable. Transmission electron microscopic (TEM) results showed that no significant changes were observed due to the acetylation process. The results also showed well distributed of individual NCC after acetylation, this improvement was primarily attributed to uniform dispersion of the ACN-NCC and less aggregated occurred. Due to its hydrophobic characteristics, highly crystalline and nano size, ACN-NCC brought a significant improvement up to 25 % on the mechanical properties of nitrile butadiene (NBR) rubber composites

    Treatment of Cotton by β-Cyclodextrin/Triclosan Inclusion Complex and Factors Affecting Antimicrobial Properties

    No full text
    The efficacy of antimicrobial treatment of cotton fabrics depends on various parameters of the coating process, such as the chemical nature and concentration of the antimicrobial agent, the composition of the crosslinking formulation, and the curing temperature. The inclusion complex of triclosan with β-cyclodextrin (βCD) was synthesized and characterized by FTIR, XRD, NMR, Raman, SEM, and TGA. The minimum inhibitory concentration and minimum bactericidal concentration of the complex against Klebsiella pneumoniae and Staphylococcus aureus were compared to those of its precursor. A multifactorial study included an evaluation of the effects of triclosan complexation with β-cyclodextrin, a comparison between the glyoxal and tetracarboxylic acid as crosslinkers, an investigation of the effect of crosslinker and catalyst concentrations, and a comparison of curing at 120°C and 180°C. The cotton was characterized by FTIR-ATR, the micrographs of treated samples were obtained by SEM and the weight add-on was calculated. The bactericidal properties were determined according to AATCC-147. The correlation between the coating process parameters and the antimicrobial efficacy was determined. The optimal combination leading to the highest weight add-on and the antimicrobial coating that was most durable to multiple detergent washes at an elevated temperature was the use of complexed triclosan grafted onto the cotton in the presence of tetracarboxylic acid, followed by curing at 180°C. The curing temperatures were 120°C (P=0.002) and 180°C (P=0.008), catalysts were 1 % and 2 % aluminium sulfate and sodium hypophosphite (P<0.001), and the crosslinkers were 5 % and 10 % glyoxal and butanetetracarboxylic acid (P<0.001); these parameters significantly enhanced the antimicrobial properties of the treated fabrics. The study showed that βCD did not have antimicrobial activity, while the βCD/triclosan-treated textile exhibited potential antimicrobial properties. Overall, the bactericidal activity of fabrics can be enhanced by using βCD/triclosan with 10 % butanetetracarboxylic acid as a cross-linker and 5 % sodium hypophosphite as a catalyst at a curing temperature of 180°C

    Surface modification of reduced graphene oxide film by Ti ion implantation technique for high dye-sensitized solar cells performance

    No full text
    Titanium (Ti) ion implantation approach was used in the present study to modify the reduced graphene oxide nanosheet (rGO NS) by incorporating the Ti4+ ion (at various applied powers ranging from 50 to 250 W) onto the rGO NS to prepare photoanodes for Dye-Sensitized Solar Cell (DSSC). The surface morphologies, functional groups, optical properties and surface chemical states of the modified rGO based photoanode (rGO-TiO2 nanocomposite (NC)) were studied. Fourier transform infrared (FTIR) spectra coupled with the elemental/chemical states in X-ray photoelectron spectroscopy (XPS) analysis revealed the presence of Ti–O–C functional groups after the modification process. Besides, the average size of Ti ion was found to be 70–80 nm as incorporated with rGO NS. The spacing of anatase TiO2 onto rGO NS were reported as 0.35 nm and 0.34 nm under HRTEM analysis, respectively. Experimental result implied that 150 W was the optimum applied power for the surface modification to take place ascribed to the lowest possibility for the recombination to occur and the smallest energy band gap. On top of that, at 150 W, the electron transfer rate was also found to be the highest due to the highest availability of the carbon-atom vacancy holes for Ti4+ replacement. It was also discovered that the optimized power conversion efficiency (PCE) of 8.51% could be achieved in DSSC by implanting the Ti ion onto rGO NS-based photoanode using 150 W. Further increase of the applied power to 200 W or 250 W led to the undesirable recombination of the Ti ions and rGO NS due to the exceptional photocatalytic activity among N719 dye/rGO/TiO2 interfaces which interfered the charge transportation at the KI electrolyte/N719 dye/rGO/TiO2 interfaces

    Scalable bio-friendly method for production of homogeneous metal oxide nanoparticles using green bovine skin gelatin

    No full text
    The use of bovine skin gelatin in the synthesis of variety of nanostructures is a bio-friendly approach. In the current study, we investigated experimentally, for the first time, scalable process for production of homogeneous hexagonal zinc oxide nanoparticles (ZnO-NPs) not only with narrow size distribution and simple process but also cost effective and bio-friendly by green sol-gel method utilizing bovine skin gelatin (BSGB) matrix. Statistical analysis was done to evaluate the reliability of measuring the particle size using X-ray Diffraction analysis (XRD) and/or surface area (BET) instead of High Resolution Transmission Electron Microscope (HRTEM) and the following novel points are found. Impressively monodispersed ZnO-NPs with hexagonal structure were synthesized by adjusting the pH. All the samples exhibited hexagonal (wurtzite) crystal shape while the obtained morphology of the particles varies from hexagonal NPs to combination of hexagonal NPs and rod-like particles with reducing the pH from 6 to 2 due to the variation of bloom strength of the gelatin. Long chain gelatin contributed to suppressing the growth of nanoparticle and controlling the morphology. We discovered statistically that there was insignificant difference in measuring the particle size using XRD and HRTEM which can save time, energy, and cost at industrial aspect

    Porous 3D carbon decorated Fe3O4 nanocomposite electrode for highly symmetrical supercapacitor performance

    No full text
    In the present study, a hierarchical nanostructure of Fe3O4-porous hydrochar (p-Fe/HC) core shell nanocomposite was readily synthesized via a facile hydrothermal carbonization route followed by a KOH activation. In our new invention, hydrothermally formed core-shell nanoparticles underwent KOH activation to create micro- and mesopores forming porous hydrochar outer-shell on Fe3O4 nanoparticles core for improving capacitance performance. These porous structures eventually could act as potential electrolyte-accessible pathways which led to the contribution of pseudocapacitance connecting from the core (reaction at Fe3O4/electrolyte interface). Based on our electrochemical capacitive performance evaluation, p-Fe/HC nanocomposite electrode which comprised of 5 wt% Fe3O4 nanoparticles (±45 nm) could reach the specific capacitance of 259.3 F g-1 with a superior wide potential window of 1.8 V in 1 mol L-1 Na2SO4 aqueous electrolyte. By comparing KOH activation of pristine porous hydrochar and p-Fe/HC, an exceptionally high specific surface area (1712.8 m2 g-1) with bimodal type pores size distribution was observed. In addition, p-Fe/HC displayed a maximum energy density of 29.2 W h kg-1 at a power density of 1.2 kW kg-1, which is about 26% higher energy density than that of pristine porous hydrochar. In this manner, the synthesized porous hydrochar outer-shell could provide additional electrochemical stability to Fe3O4 core, preventing volume change at high current loading as well as conductive coating to enhance pseudocapacitance performance. Consequently, a symmetrical nanocomposite cell was successfully designed, with high capacitance retention of 95.1% after 5000 cycles
    corecore