Novel Method For Preparation Research Articles

Preparation of water-soluble melanin from squid ink using ultrasound-assisted degradation and its anti-oxidant activity.

Water-soluble squid melanin fractions were firstly prepared using ultrasound-assistant degradation method under alkaline condition, which is optimized by response surface methodology. The processing melanin fractions were divided into different molecular weight (Mw) fractions by membrane separation (below 10kDa, among 10-50kDa and over 50kDa). The AFM image and particle-size analysis showed monomer units of the melanin were destroyed, and huge polymers were degraded into smaller soluble particles after ultrasound. While, UV, IR and solid (13)C NMR spectra indicated that the basic structure of melanin fraction was still retained after ultrasound process. Further analysis showed soluble melanin fractions obtained in 0.5 and 1M NaOH, with Mw above 10kDa exhibited much higher in vitro antioxidant potency. The IC50 of these fractions (IC50 among 19-80μg) on scavenging O 2 ∙¯ is more efficient than carnosine (IC50 = 355μg/ml.), a commercialized antioxidant. They (IC50 mong 115-180μg/ml) are as efficient as carnosine (IC50 = 110μg/ml) on scavenging ∙OH. Our research has reported a novel method for preparation of water-soluble melanin fractions from squid ink, which could be a promising free radical scavenger from nature resource.

A novel method for preparation of a platinum catalyst at low temperatures

Uniformly distributed Pt nano-particles with excellent adhesion were deposited on conductive substrates by coating the substrate with a Pt complex precursor and its subsequent reduction with a gaseous reducing agent at temperatures as low as 100 °C. This novel two-step method enables excellent control over the particle size and distribution since it is dependent only upon the deposition of the precursor solution, and there is little to no agglomeration or movement of Pt nano-particles during the reduction process. The good adhesion was the result of the reaction at the solid–gas interface, where the solid precursor was chemically converted to metallic Pt. XPS confirmed that 100% of Pt was in the metallic state. The electrochemical catalytic properties of the Pt nano-particles were tested using cyclic voltammetry in an iodide electrolyte. The prepared samples were also used to assemble dye-sensitised solar cells that achieved a light to electricity conversion efficiency of 5.1% under AM 1.5 illumination.

A Novel Method for Preparation of Zn-Doped CuInS2Solar Cells and Their Photovoltaic Performance

In this study, a novel method was proposed to synthesize high quality Zn-doped CuInS2 nanocrystals under high frequency magnetic field at ambient conditions. The magnetic Zn-doping gave superparamagnetic heating of the resulting nanocrystals via magnetic induction, causing an accelerating growth rate of the doped CuInS2 under ambient conditions faster than conventional autoclave synthesis. Shape evolution of the Zn-doped CuInS2 nanocrystals from initially spherical to pyramidal, to cubic, and finally to a bar geometry was detected as a function of time of exposure to magnetic induction. These colloidal solvents with different shaped nanocrystals were further used as “nanoink” to fabricate a simple thin film solar device; the best efficiency we obtained of these crystals was 1.01% with a 1.012 μm thickness absorber layer (bar geometry). The efficiency could be promoted to 1.44% after the absorber was thickened to 2.132 μm.

Microwave-Assisted Preparation and Physical Characterisation of Iron Oxyhydroxides Adsorbents for Arsenic Removal from Aqueous Solutions

A novel method for preparation of iron oxyhydroxide materials, involving aqueous precipitation followed by microwave assisted aging is investigated. The produced materials are characterized by XRD, SEM, EDX and TEM spectroscopy and BET analysis. The materials show physical characteristics dependent on preparation procedure. The adsorptive properties of the materials for arsenic are studied by batch adsorption techniques. It is found that the rate of arsenic upload depends strongly on the degree of crystallinity of the materials. The adsorption capacity is approximately 55 mg/g. The physical characterization of the arsenic loaded adsorbents show that the adsorption process modifies the morphology of the materials. Over 4% of arsenic atoms are incorporated into the particle matrix.

Phosphorylated polyvinyl alcohol membranes for redox Fe3+/H2 flow cells

A novel method for preparation of phosphorylated polyvinyl alcohol (p-PVA) membranes was developed and used to synthesize a series of membranes with different degree of phosphorylation (4–9 wt % of phosphorus). The optimal mass ratio of PVA:H3PO2 was found to be 4.0:1.0, while the optimal curing time was 3 h at a temperature of 120 °C. The membranes possessed good mechanical robustness and chemical stability in acidic media. The possible pathway of PVA phosphorylation leading to formation of P–C bonds was suggested based on IR-spectra of the membranes. The water flux (6.08 × 10−2 g cm−2 h−1) and permeability of ferric ions (3.5 × 10−5 cm2 min−1) were comparable to those of commercial Nafion 117 membrane. The dependence of the proton conductivity on the concentration of H2SO4 at 22 °C was studied that allowed us to predict the intrinsic proton conductivity of the p-PVA membrane (5.5 × 10−3 S cm−1). The partial charges on oxygen atoms in the proposed structural units were calculated and the results permitted to suggest a mechanism of proton transport. The performance of the p-PVA membrane was tested in a Fe3+/H2 redox fuel cell showing power density of 71 mW cm−2 at 200 mA cm−2.

Novel method for preparation of cyclodextrin polymers: physico-chemical characterization and cytotoxicity

The objective of this work was to optimize the synthesis procedure of soluble cyclodextrin polymers developed by Weltrowski et al. The use of the parameters indicated by the latter in our laboratory led to a lower result, which did not exceed 15 % (w/w). The new method resulted simultaneously in two fractions, a water soluble one and an insoluble one with a yield of 40 and 85 % (w/w), respectively. Only soluble cyclodextrin polymers were characterized along with the cytotoxicity study. The optimized soluble polymers were characterized by Fourier-Transform Infrared Spectrophotometer, Thermogravimetric Analyzer, Differential Scanning Calorimetry, Powder X-Ray Diffraction Analysis and Size Exclusion Chromatography. In vitro cytotoxicity against peritoneal macrophage cells of female CD1 mice showed that soluble poly-α-CD and poly-γ-CD were less cytotoxic than soluble poly-β-CD at small dose and the opposite was true at higher dose. In conclusion, temperature and time could be used to optimize the yield of polymer cyclodextrins, which will have a broad use in the drug delivery system.

An innovative method for preparation of nanometal hydroxide superabsorbent hydrogel

A novel method for preparation of a conducting nanometal hydroxide hydrogel was undertaken. In situ accommodation of metal hydroxide nanoparticles within swollen hydrogel networks is developed. Thus, poly(acrylic acid/acrylate) hydrogel (PAAc/AC) was prepared by simultaneous polymerization of acrylic acid/acrylate (AAc/AC). Electrodeposition hydroxide of nanoiron and nanocopper into (PAAc/AC) hydrogel was performed. Swelling behaviour and swelling kinetics of prepared hydrogel were evaluated in media having different pH values. The conductivity of both PAAc/AC/nanocopper hydroxide and PAAc/AC/nanoiron hydroxide were measured in comparison with that for PAAc/AC hydrogel. An amelioration in conductance of PAAc/AC hydrogel having 0.8×103μS after being incorporated with nanocopper hydroxide and nanoiron hydroxide to be 1.5×103μS and 2.6×103μS, respectively has been achieved. Distribution of the metal hydroxide nanoparticles penetrated within the hydrogel networks using transmission electron microscopy has been thoroughly elucidated.

Thermal properties of Si(Al)/diamond composites prepared by in situ reactive sintering

This article described a novel method of preparation of diamond–silicon matrix composites via in situ reaction by spark plasma sintering (SPS). Thermal properties of samples sintered under two conditions (vacuum and argon) were evaluated and the effect of Al-addition to Si matrix was demonstrated. The results presented that Si/diamond composite (sintered in argon) yielded a thermal conductivity (TC) of 346.2W/mK, higher than that of the sample sintered in vacuum, along with a coefficient of thermal expansion (CTE) of 1.455×10−6K. Microstructures of these materials were studied by scanning electron microscopy and X-ray diffraction. As a result of reaction between diamond and silicon, SiC phase formed. The research showed that the addition of Al could not give any benefit to the thermal conductivity of composite, although it contributed to the relative packing density of 99.6% with a volume fraction of 55% of diamond particles. Additionally, the influence of interface on thermal properties of Si(Al)/diamond composites was specifically discussed.

Preparation of Si–diamond–SiC composites by in-situ reactive sintering and their thermal properties

This article described a novel method of preparation of Si–diamond–SiC composites by in-situ reactive spark plasma sintering (SPS) process. The relative packing density of Si–diamond–SiC composite was 98.5% or higher in a volume fraction range of diamond between 20% and 60%. Si–diamond–SiC composites containing 60vol% diamond particles yielded a thermal conductivity of 392W/mK, higher than 95% the theoretical thermal conductivity calculated by Maxwell–Eucken's equation. Coefficients of thermal expansion (CTEs) of the composites are lower than the values of theoretical models, indicating strong bonding between the diamond particle and the Si matrix in the composite. The microstructures of these materials were studied by field emission scanning electron microscope (FE-SEM) and X-ray diffraction (XRD). As a result of reaction between diamond and silicon, SiC phase formed.

A method to break charge transfer complex of polyimide: A study on solution behavior

AbstractCharge transfer complex strongly affects the optical transparency of polyimide film. Here, solution behavior of a polyimide derived from 3,3′,4,4′ biphenyltetracarboxylic dianhydride and 1,4‐bis(3‐aminopropyl)piperazine in acetic acid, chloroform, and their mixed solvents is investigated in detail by light scattering. It is found that the polyimide existed as single chains in acetic acid owing to the acid‐base interaction. However, association is observed in chloroform solution because of the charge transfer complex and enhanced by increasing the solution concentration. To break the charge transfer interaction and clear the association, only a small amount of acetic acid is required to add into the chloroform solution owing to the protonation of the diamine groups, confirmed by the zeta potential measurements. Simultaneously, the associates disappear quickly after addition of acetic acid. This study will provide a novel method for preparation of high optical transparent polyimide film by simply tuning the solvent. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Preparation and characterisation of acephate nano-encapsulated complex

Acephate is the most widely used organophosphorous insecticide in Indian subcontinent. In order to prepare ecofriendly and hydrophilic formulation of acephate, nanotechnology-based research is necessary. Here, we report a novel method of preparation and subsequent characterisation of the acephate nano-encapsulation complex. Nanoparticles of the encapsulation complex were characterised by dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared (FTIR) spectroscopy. The TEM image reveals the size of particles in the range 90–120 nm. This method would be very useful for industries for making farmer-friendly pesticide formulations.

A novel method for preparation of interconnected pore-gradient ceramic foams by gelcasting

A novel approach was introduced to prepare pore-gradient Al2O3 ceramic foams with association of gelcasting process and polymer sphere template. This approach allows the design of pore connectivity and gradient height of ceramic foams by the appropriate selection of sphere sizes and numbers. The limitation of ceramic foams fabricated by polymeric sponge process on sponge carrier can be resolved by this approach. Epispastic polystyrene (EPS) spheres with different sizes were employed to array ordered templates. Influence of solid content and dispersant on the viscosity of Al2O3 slurry was studied. EPS spheres modified by oxygen plasma to increase the hydrophilicity of surfaces and influence of pre-removal of EPS template on the integrity of networks were investigated. Results showed that 55 vol.% Al2O3 slurries with 0.5 wt% dispersant kept good fluidity for casting and permeability in template. Water contact angle of EPS surface decreased from 95.2° to 20°. Some defects in green bodies such as edge-delamination and micropores disappeared after surface modification. The perfect structure and morphology of the ceramic foams were ascribed to the pre-removal of template by solvent. The hierarchical pore structure was fabricated with EPS spheres of 2.1, 2.6 and 3.2 mm diameters. Porosity and compressive strength of the pore-gradient Al2O3 ceramic foam were 68.5% and 3.06 MPa at 1,500 °C, respectively.

Uniform Droplets Generation Using a Direct-Mode Jet Pulse Spray System

A novel method of preparation of uniform droplets using a direct-mode jet pulse spray system has been developed. By means of the periodical switch-on between a membrane-like rotating distribution exit and a micronozzle, a fluid stream was stimulated to be disintegrated into monodisperse droplets. The effects of the rotational speed (n) and thickness (H) of the distribution exit and flow rate of the dispersed phase (Q) on droplet characteristics were investigated. It was found that the uniformity of droplets would be enhanced with increased rotational speed and decreased thickness of the distribution exit, even for a relatively high flow rate of the dispersed phase. A relatively steady value of the coefficient of variation in size less than 10% could be obtained under the conditions of n = 350 rpm and H = 3 mm at Q = 7.5–8.7 mL/min. The influence of vortices was characterized by the Taylor number and parameter K, showing that the parameter K is capable of more precisely predicting the turbulence transition. Therefore, the system has effectively attained an improvement not only in uniformity but also in productivity of droplets generation.

A Novel Method for Preparation of Antimicrobial Cellulose Textile by Surface Carbamatization and N-Chlorination

Surface carbamatization of cellulose fabric was accomplished through co-heating with urea. The carbamate group on textile surface was transformed to N-chlorocarbamate after exposure to sodium hypochlorite solution. Effect of carbamatization temperature, time on Nitrogen content of fabrics was investigated, and the effect of bleach technology on chlorine content on fabrics was also studied. Using shake flask method antimicrobial activities against E. coli and S. aureus were studied. The results showed that when carbamatization temperature was 138°C and the time was 3 hours, nitrogen content of cellulose fabric was the highest: 1.47%. Antibacterial ability of cellulose fabrics with 0.81mg/g chlorine against E. coli and S. aureus was 99.9999% and 100%, respectively.

A novel method for preparation of pure Bi 2SiO 5 crystals

Pure Bi 2SiO 5 crystals were firstly prepared by a novel method of melt-cooling process with Bi 2O 3 and SiO 2 as starting materials. In this study, the preparation and properties of the samples were characterized by thermo gravimetric (TG), differential scanning calorimeter (DSC), field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The results showed several endothermic valleys at 579.6 °C, 744.3 °C, 829.3 °C and 879.2 °C during heating process; and a distinct exothermic peak at 805.3 °C during the melt cooling process. XRD and SEM images revealed highly-ordered lamellar pure Bi 2SiO 5 crystals with coarse grains can be achieved by 2 h heating at 805.3 °C.

Effect of pulsed electric field on the secondary structure and thermal properties of soy protein isolate

Changes of structure and thermal stability of soy protein isolate after pulsed electric field treatment were analyzed by Fourier transform infrared spectroscopy and differential scanning calorimetry (DSC). When the applied pulsed electric field (PEF) treatment intensity was over 35 kV/cm, the amino acid side chain, anti-parallel β-sheets, β-turn as well as β-sheets in soy protein isolate (SPI) secondary structure were significantly changed, which suggested that PEF treatment might be a new processing method for SPI; the dipole moments of some bonds, such as C=O, C–O, and C–O–C were partially polarized, accompanying with complete denaturation of β-conglycinin and glycinin obtained from DSC. Furthermore, self-reassembly from β-turn to α-helix in SPI structure abruptly happened under intense PEF treatment condition, which suggested that the PEF treatment had induced change of the orientation of α-helix dipole moment to stabilize α-helix. This observation implies that PEF treatment technique may be a novel method for preparation of protein nanotube.

Novel Method of Preparation of Gold‐Nanoparticle‐Doped TiO2 and SiO2 Plasmonic Thin Films: Optical Characterization and Comparison with Maxwell–Garnett Modeling

AbstractSiO2 and TiO2 thin films with gold nanoparticles (NPs) are of particular interest as photovoltaic materials. A novel method for the preparation of spin‐coated SiO2–Au and TiO2–Au nanocomposites is presented. This fast and inexpensive method, which includes three separate stages, is based on the in situ synthesis of both the metal‐oxide matrix and the Au NPs during a baking process at relatively low temperature. It allows the formation of nanocomposite thin films with a higher concentration of Au NPs than other methods. High‐resolution transmission electron microscopy studies revealed a homogeneous distribution of NPs over the film volume along with their narrow size distribution. The optical manifestation of localized surface plasmon resonance was studied in more detail for TiO2‐based Au‐doped nanocomposite films deposited on glass (in absorption and transmittance) and silicon (in specular reflectance). Maxwell–Garnett effective‐medium theory applied to such metal‐doped nanocomposite films describes the peculiarities of the experimental spectra, including modification of the antireflective properties of bare TiO2 films deposited on silicon by varying the concentration of metal NPs. The antireflective capabilities of the film are increased after a wet etching process.

Preparation of composite magnetic microspheres by reactive blending

A novel method for preparation of polymer-based magnetic microspheres was proposed by utilizing melt reactive blending, which was based on selective location of Fe3O4 nanoparticles in PA6 domains of polystyrene (PS)/polyamide 6 (PA6) immiscible blends. The morphology of PA6/Fe3O4 composite magnetic microspheres was studied by scanning electronic microscopy (SEM). The composite magnetic microspheres were spherical with a diameter range of 0.5–8 μm; the diameter was sharply decreased with a very narrow distribution by adding terminal maleic anhydride functionalized polystyrenes (FPS) for reactive blending. Transmission electron microscopy (TEM) and thermogravimetry analysis (TGA) results showed that most of Fe3O4 was located in the PA6 microspheres. Magnetization data revealed the magnetite content of PA6/Fe3O4 microspheres was about 32 wt% and the saturation magnetization could be up to 17.2 Am2/kg.

Structure and Magnetic Properties of Sm-Fe-N Prepared by Nitriding High Purity Sm<sub>2</sub>Fe<sub>17</sub> Grown from Sm-Rich Melt

We report on a novel method for preparation of high purity Sm2Fe17 phase by removing the liquid impurity phase from the Sm-rich precursor at high temperatures. With decreasing Sm addition, the percentage of liquid phase left as impurity is decreasing. Nitrogen absorption to the Sm2Fe17 powders results in a complete formation of Sm2Fe17N3, which shows a weak disproportionation reaction at 773 K. The magnetic performance of the Sm2Fe17N3 from precursors with different Sm content is improving with decreasing Sm content.

A novel approach to prepare PA6/Fe3O4 microspheres for protein immobilization

AbstractA novel method for preparation of polymer‐based magnetic microspheres was proposed by utilizing melt reactive blending, which was based on selective location of Fe3O4 nanoparticles in PA6 domain of polystyrene (PS)/polyamide 6 (PA6) immiscible blends. The results showed that most of Fe3O4 was located in the PA6 microspheres. Magnetization data revealed the magnetite content of PA6/Fe3O4 microsphere could be up to 54 wt % with strong magnetic responsibility and high saturation magnetization. Carboxyl functional group, bonded with PA6/Fe3O4 microsphere by copolymerization of acrylic acid with PA6 chain in different concentration ethanoic acid (HAc) solution, was used as a ligand for protein adsorption. The amount of adsorbed bovine serum albumin (BSA) was optimized by changing the medium pH and the initial concentrations of BSA. The results denoted that the adsorption capacity of BSA reaches 215 mg/g microspheres, showing potentials to promising applications in bioseparation and biomedical fields. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.