Search results for: nano emulsion

Authors: Neeraj Kumar Verma

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Lanthanum hydroxide and manganese oxide nanocomposite are synthesized by chemical routes. Physical characterization is done by TEM to look at the size and dispersion of the nanoparticles in the composite. Chemical characterization is done by X-ray diffraction technique and FTIR to ascertain the attachment of the functionalities and bond stretching. Further thermal analysis is done by thermogravimetric analysis to find the tendency of the thermal decomposition in the elevated temperature range of 0-1000°C. Proper analysis and correlation of the various results obtained suggested the controlled growth of crystalline without agglomeration and good stability in the various temperature ranges of the composite.

Keywords: nanoparticles, XRD, TEM, lanthanum hydroxide, manganese oxide

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Authors: Sarathlal Koyiloth Vayalil, Stephan V. Roth, Gonzalo Santoro, Peng Zhang, Matthias Schwartzkopf, Bjoern Beyersdorff

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Nanostructured magnetic thin films have gained significant relevance due to its applications in magnetic storage and recording media. Self-organized arrays of nanoparticles and nanowires can be produced by depositing metal thin films on nano-rippled substrates. The substrate topography strongly affects the film growth giving rise to anisotropic properties (optical, magnetic, electronic transport). Ion-beam erosion (IBE) method can provide large-area patterned substrates with the valuable possibility to widely modify pattern length scale by simply acting on ion beam parameters (i.e. energy, ions, geometry, etc.). In this work, investigation of the growth mechanism of Permalloy thin films on such nano-rippled Si (100) substrates using in situ grazing incidence small angle x-ray scattering measurements (GISAXS) have been done. In situ GISAXS measurements during the deposition of thin films have been carried out at the P03/MiNaXS beam line of PETRA III storage ring of DESY, Hamburg. Nanorippled Si substrates prepared by low energy ion beam sputtering with an average wavelength of 33 nm and 1 nm have been used as templates. It has been found that the film replicates the morphology up to larger thickness regimes and also the growth is highly anisotropic along and normal to the ripple wave vectors. Various growth regimes have been observed. Further, magnetic measurements have been done using magneto-optical Kerr effect by rotating the sample in the azimuthal direction. Strong uniaxial magnetic anisotropy with its easy axis in a direction normal to the ripple wave vector has been observed. The strength of the magnetic anisotropy is found to be decreasing with increasing thin film thickness values. The mechanism of the observed strong uniaxial magnetic anisotropy and its depends on the thickness of the film has been explained by correlating it with the GISAXS results. In conclusion, we have done a detailed growth analysis of Permalloy thin films deposited on nanorippled Si templates and tried to explain the correlation between structure, morphology to the observed magnetic properties.

Keywords: grazing incidence small angle x-ray scattering, magnetic thin films, magnetic anisotropy, nanoripples

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Authors: H. Soltani, J. Hadfield, M. Redmond, D. S. Nobes

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The passage of oil droplets through a vertical mini-slot were investigated in this study. Oil-in-water emulsion can undergo coalescence of finer oil droplets forming droplets of a size that need to be considered individually. This occurs in a number of industrial processes and has important consequences at a scale where both body and surfaces forces are relevant. In the study, two droplet diameters of smaller than the slot width and a relatively larger diameter where the oil droplet can interact directly with the slot wall were generated. To monitor fluid motion, a particle shadow velocimetry (PSV) imaging technique was used to study fluid flow motion inside and around a single oil droplet rising in a net co-flow. The droplet was a transparent canola oil and the surrounding working fluid was glycerol, adjusted to allow a matching of refractive index between the two fluids. Particles seeded in both fluids were observed with the PSV system allowing the capture of the velocity field both within the droplet and in the surrounds. The effect of droplet size on the droplet internal circulation was observed. Part of the study was related the potential generation of flow structures, such as von Karman vortex shedding already observed in rising droplets in infinite reservoirs and their interaction with the mini-channel. Results show that two counter-rotating vortices exist inside the droplets as they pass through slot. The vorticity map analysis shows that the droplet of relatively larger size has a stronger internal circulation.

Keywords: rising droplet, rectangular orifice, particle shadow velocimetry, match refractive index

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Authors: Tamer El-Messery, Teresa Sanchez-Moya, Ruben Lopez-Nicolas, Gaspar Ros, Esmat Aly

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Olive leaves (OLs), the main by-product of the olive oil industry, have a considerable amount of phenolic compounds. The exploitation of these compounds represents the current trend in food processing. In this study, OLs polyphenols were microencapsulated with polycaprolactone (PCL) and utilized in formulating novel functional yoghurt. PCL-microcapsules were characterized by scanning electron microscopy, and Fourier transform infrared spectrometry analysis. Their total phenolic (TPC), total flavonoid (TFC) contents, and antioxidant activities (DPPH, FRAP, ABTS), and polyphenols bioaccessibility were measured after oral, gastric, and intestinal steps of in vitro digestion. The four yoghurt formulations (containing 0, 25, 50, and 75 mg of PCL-microsphere/100g yoghurt) were evaluated for their pH, acidity, syneresis viscosity, and color during storage. In vitro digestion significantly affected the phenolic composition in non-encapsulated extract while had a lower impact on encapsulated phenolics. Higher protection was provided for encapsulated OLs extract, and their higher release was observed at the intestinal phase. Yoghurt with PCL-microsphere had lower viscosity, syneresis, and color parameters, as compared to control yoghurt. Thus, OLs represent a valuable and cheap source of polyphenols which can be successfully applied, in microencapsulated form, to formulate functional yoghurt.

Keywords: yoghurt quality attributes, olive leaves, phenolic and flavonoids compounds, antioxidant activity, polycaprolactone as microencapsulant

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Authors: M. Cortés, E. Vera, M. Avella

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Corrosion is an imminent process in nature, which affects all types of materials. In sewerage systems, the corrosion process caused by microorganisms, also known as biogenic sulfuric acid attack, has been studied. This affects the structural integrity of the concrete drainage pipes and the sewage treatment plants. This article is a review of research which focuses on the study of how to reduce the production of hydrogen sulfide, how to improve the resistance of concrete through the use of additives and the implementation of antimicrobial techniques to reduce bacterial growth.

Keywords: bactericides, biogenic sulfuric acid, corrosion, concrete, hydrogen sulphide, nano materials, zeolites

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Authors: Van Tran Thi Thuy, Dukjoon Kim

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A series of pH- and thermosensitive poly(N-isopropyl acrylamide-co-acrylic acid) were synthesized by radical polymerization and grafted on poly succinimide backbones. The poly succinimide derivatives synthesized were coated on iron oxide magnetic nanoparticles for potential applications in drug delivery systems with theranostic and molecular imaging. The structure of polymer shell was confirmed by FT-IR, H-NMR spectroscopies. Its thermal behavior was tested by UV-Vis spectroscopy. The particle size and its distribution are measured by dynamic light scattering (DLS) and transmission electron microscope (TEM). The mean diameter of the core-shell structure is from 20 to 80 nm.

Keywords: magnetic, nano, PNIPAM, polysuccinimide

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Authors: Danielle Slomberg, Jerome Labille, Riccardo Catalano, Jean-Claude Hubaud, Alexandra Lopes, Alice Tagliati, Teresa Fernandes

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In the assessment and management of cosmetics and personal care products, sunscreens are of emerging concern regarding both human and environmental health. Organic UV blockers in many sunscreens have been evidenced to undergo rapid photodegradation, induce dermal allergic reactions due to skin penetration, and to cause adverse effects on marine systems. While mineral UV-blockers may offer a safer alternative, their fate and impact and resulting regulation are still under consideration, largely related to the potential influence of nanotechnology-based products on both consumers and the environment. Nanometric titanium dioxide (TiO₂) UV-blockers have many advantages in terms of sun protection and asthetics (i.e., transparency). These UV-blockers typically consist of rutile nanoparticles coated with a primary mineral layer (silica or alumina) aimed at blocking the nanomaterial photoactivity and can include a secondary organic coating (e.g., stearic acid, methicone) aimed at favouring dispersion of the nanomaterial in the sunscreen formulation. The nanomaterials contained in the sunscreen can leave the skin either through a bathing of everyday usage, with subsequent release into rivers, lakes, seashores, and/or sewage treatment plants. The nanomaterial behaviour, fate and impact in these different systems is largely determined by its surface properties, (e.g. the nanomaterial coating type) and lifetime. The present work aims to develop the eco-design of sunscreens through the minimisation of risks associated with nanomaterials incorporated into the formulation. All stages of the sunscreen’s life cycle must be considered in this aspect, from its manufacture to its end-of-life, through its use by the consumer to its impact on the exposed environment. Reducing the potential release and/or toxicity of the nanomaterial from the sunscreen is a decisive criterion for its eco-design. TiO₂ UV-blockers of varied size and surface coating (e.g., stearic acid and silica) have been selected for this study. Hydrophobic TiO₂ UV-blockers (i.e., stearic acid-coated) were incorporated into a typical water-in-oil (w/o) formulation while hydrophilic, silica-coated TiO₂ UV-blockers were dispersed into an oil-in-water (o/w) formulation. The resulting sunscreens were characterised in terms of nanomaterial localisation, sun protection factor, and photo-passivation. The risk to the direct aquatic environment was assessed by evaluating the release of nanomaterials from the sunscreen through a simulated laboratory aging procedure. The size distribution, surface charge, and degradation state of the nano-composite by-products, as well as their nanomaterial concentration and colloidal behaviour were determined in a variety of aqueous environments (e.g., seawater and freshwater). Release of the hydrophobic nanocomposites into the aqueous environment was driven by oil droplet formation while hydrophilic nano-composites were readily dispersed. Ecotoxicity of the sunscreen by-products (from both w/o and o/w formulations) and their risk to marine organisms were assessed using coral symbiotes and tropical corals, evaluating both lethal and sublethal toxicities. The data dissemination and provided risk knowledge from the present work will help guide regulation related to nanomaterials in sunscreen, provide better information for consumers, and allow for easier decision-making for manufacturers.

Keywords: alteration, environmental fate, sunscreens, titanium dioxide nanoparticles

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Authors: Sanjay Singh, Parameswara Rao Vuddanda

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The aim of the present study is study the factual benefit of nano size and surface coating of p-gp efflux inhibitor on enhancement of bioavailability of Berberine chloride (BBR); a p-gp substrate. In addition, 28 days sub acute oral toxicity study was also conducted to assess the toxicity of the formulation on chronic administration. BBR loaded polymeric nanoparticles (BBR-NP) were prepared by nanoprecipitation method. BBR NP were surface coated (BBR-SCNP) with the 1 % w/v of vitamin E TPGS. For bioavailability study, total five groups (n=6) of rat were treated as follows first; pure BBR, second; physical mixture of BBR, carrier and vitamin E TPGS, third; BBR-NP, fourth; BBR-SCNP and fifth; BBR and verapamil (widely used p-gp inhibitor). Blood was withdrawn at pre-set timing points in 24 hrs study and drug was quantified by HPLC method. In oral chronic toxicity study, total four groups (n=6) were treated as follows first (control); water, second; pure BBR, third; BBR surface coated nanoparticles and fourth; placebo BBR surface coated nanoparticles. Biochemical levels of liver (AST, ALP and ALT) and kidney (serum urea and creatinine) along with their histopathological studies were also examined (0-28 days). The AUC of BBR-SCNP was significantly 3.5 folds higher compared to all other groups. The AUC of BBR-NP was 3.23 and 1.52 folds higher compared to BBR solution and BBR with verapamil group, respectively. The physical mixture treated group showed slightly higher AUC than BBR solution treated group but significantly low compared to other groups. It indicates that encapsulation of BBR in nanosize form can circumvent P-gp efflux effect. BBR-NP showed pharmacokinetic parameters (Cmax and AUC) which are near to BBR-SCNP. However, the difference in values of T1/2 and clearance indicate that surface coating with vitamin E TPGS not only avoids the P-gp efflux at its absorption site (intestine) but also at organs which are responsible for metabolism and excretion (kidney and liver). It may be the reason for observed decrease in clearance of BBR-SCNP. No toxicity signs were observed either in biochemical or histopathological examination of liver and kidney during toxicity studies. The results indicate that administration of BBR in surface coated nanoformulation would be beneficial for enhancement of its bioavailability and longer retention in systemic circulation. Further, sub acute oral dose toxicity studies for 28 days such as evaluation of intestine, liver and kidney histopathology and biochemical estimations indicated that BBR-SCNP developed were safe for long use.

Keywords: bioavailability, berberine nanoparticles, p-gp efflux inhibitor, nanoprecipitation method

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Authors: Indu Elizabeth

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Antimony/Multi Walled Carbon nano tube nanocomposite (Sb/MWCNT) is synthesized using ethylene glycol mediated reduction process. Binder free, self-supporting and flexible Sb/MWCNT nanocomposite paper has been prepared by employing the vacuum filtration technique. The samples are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy (RS), and thermal gravimetric analysis (TGA) to evaluate the structure of anode and tested for its performance in a Lithium rechargeable cell. Electrochemical measurements demonstrate that the Sb/MWCNT composite paper anode delivers a specific discharge capacity of ~400 mAh g-1 up to a current density of 100 mA g-1.

Keywords: antimony, lithium ion battery, multiwalled carbon nanotube, specific capacity

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Authors: Senthil Rajan Dharmalingam, Shamala Nadaraju, Srinivasan Ramamurthy

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Doxorubicin is the most widely used anticancer drugs in chemotherapy treatment. However, problems related to the development of multidrug resistance (MDR) and acute cardiotoxicity have led researchers to investigate alternative forms of administering doxorubicin for cancer therapy. Several methods have been attempted to overcome MDR, including the co-administration of a chemosensitizer inhibiting the efflux caused by ATP binding cassette transporters with anticancer drugs, and the bypass of the efflux mechanism. Co encapsulation of doxorubicin (Dox) and cyclosporine A (CSA) into poly (DL-lactide-co-glycolide) nanoparticles was emulsification-solvent evaporation method using polyvinyl alcohol as emulsion stabilizers. The Dox-CSA loaded nanoparticles were evaluated for particle size, zeta potential and PDI by light scattering analysis and thermal characterizations by differential scanning calorimetry (DSC). Loading efficiency (LE %) and in-vitro dissolution samples were evaluated by developed and validated HPLC method. The optimum particle size obtained is 298.6.8±39.4 nm and polydispersity index (PDI) is 0.098±0.092. Zeta potential is found to be -29.9±4.23. Optimum pH to increase Dox LE% was found 7.1 which gave 42.5% and 58.9% increase of LE% for pH 6.6 and pH 8.6 compared respectively. LE% achieved for Dox is 0.07±0.01 % and CSA is 0.09±0.03%. Increased volume of PVA and weight of PLGA shows increase in size of nanoparticles. DSC thermograms showed shift in the melting peak for the nanoparticles compared to Dox and CSA indicating encapsulation of drugs. In conclusion, these preliminary studies showed the feasibility of PLGA nanoparticles to entrap Dox and CSA and require future in-vivo studies to be performed to establish its potential.

Keywords: doxorubicin, cyclosporine, PLGA, nanoparticles

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Authors: Hafsi Khebab, Zirari Mounir, Mohamed Nadjib Bouaziz

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High Global Warming Potential refrigerants (HydroFluroCarbons) are one of the worst greenhouse gases used in a wide variety of applications, including refrigeration and air-conditioning. Nanotechnology is a promising field in sustainable energy to reduce energy and ecological resource consumption for HVACR (heat, ventilation, air conditioning, and refrigeration) systems. Most researchers reported an improvement in heat transfer coefficient, Coefficient of performance. In this report, a brief summary has been done on the performance enhancement of the Vapor Compression Refrigeration system using HFC134a with nano refrigerants.

Keywords: nanorefrigerant, HFCs, greenhouse gases, GWP, HVACR systems, energy saving

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Authors: Kunal Bhardwaj, Christine Browne

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With the increase in global awareness of the environmental impacts of plastic-based products, there has been a massive drive to reduce our use of these products. Use of plastic-based substrates in electronic circuits has been a matter of concern recently. Plastics provide a very smooth and cheap surface for printing high-performance electronics due to their non-permeability to ink and easy mouldability. In this research, we explore the use of nano cellulose (NC) films in electronics as they provide an advantage of being 100% recyclable and eco-friendly. The main hindrance in the mass adoption of NC film as a substitute for plastic is its higher surface roughness which leads to ink penetration, and dispersion in the channels on the film. This research was conducted to tune the RMS roughness of NC films to a range where they can replace plastics in electronics(310-470nm). We studied the dependence of the surface roughness of the NC film on the following tunable aspects: 1) composition by weight of the NC suspension that is sprayed on a silicon wafer 2) the width and the depth of the channels on the silicon wafer used as a base. Various silicon wafers with channel depths ranging from 6 to 18 um and channel widths ranging from 5 to 500um were used as a base. Spray coating method for NC film production was used and two solutions namely, 1.5wt% NC and a 50-50 NC-CNC (cellulose nanocrystal) mixture in distilled water, were sprayed through a Wagner sprayer system model 117 at an angle of 90 degrees. The silicon wafer was kept on a conveyor moving at a velocity of 1.3+-0.1 cm/sec. Once the suspension was uniformly sprayed, the mould was left to dry in an oven at 50°C overnight. The images of the films were taken with the help of an optical profilometer, Olympus OLS 5000. These images were converted into a ‘.lext’ format and analyzed using Gwyddion, a data and image analysis software. Lowest measured RMS roughness of 291nm was with a 50-50 CNC-NC mixture, sprayed on a silicon wafer with a channel width of 5 µm and a channel depth of 12 µm. Surface roughness values of 320+-17nm were achieved at lower (5 to 10 µm) channel widths on a silicon wafer. This research opened the possibility of the usage of 100% recyclable NC films with an additive (50% CNC) in high-performance electronics. Possibility of using additives like Carboxymethyl Cellulose (CMC) is also being explored due to the hypothesis that CMC would reduce friction amongst fibers, which in turn would lead to better conformations amongst the NC fibers. CMC addition would thus be able to help tune the surface roughness of the NC film to an even greater extent in future.

Keywords: nano cellulose films, electronic circuits, nanocrystals and surface roughness

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Authors: Zohreh Fallah, Edward P. L. Roberts

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One of the big challenges for produced water treatment is removing oil from water in the form of emulsified droplets which are not easily separated. An attractive approach is adsorption, as it is a simple and effective process. However, adsorbents must be regenerated in order to make the process cost effective. Several sorbents have been tested for treating oily wastewater. However, some issues such as high energy consumption for activated carbon thermal regeneration have been reported. Due to their significant electrical conductivity, Graphite Intercalation Compounds (GIC) were found to be suitable to be regenerated electrochemically. They are non-porous materials with low surface area and fast adsorptive capacity which are useful for removal of low concentration of organics. An innovative adsorption/regeneration process has been developed at the University of Manchester in which adsorption of organics are done by using a patented GIC adsorbent coupled with subsequent electrochemical regeneration. The oxidation of adsorbed organics enables 100% regeneration so that the adsorbent can be reused over multiple adsorption cycles. GIC adsorbents are capable of removing a wide range of organics and pollutants; however, no comparable report is available for removal of emulsified oil in produced water using abovementioned process. In this study the performance of this technology for the removal of emulsified oil in wastewater was evaluated. Batch experiments were carried out to determine the adsorption kinetics and equilibrium isotherm for both real produced water and model emulsions. The amount of oil in wastewater was measured by using the toluene extraction/fluorescence analysis before and after adsorption and electrochemical regeneration cycles. It was found that oil in water emulsion could be successfully treated by the treatment process and More than 70% of oil was removed.

Keywords: adsorption, electrochemical regeneration, emulsified oil, produced water

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Authors: S. Baississe, S. Godbane, A. Lekbir

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The objective of our work is to develop an ice cream from a fermented cream, skim milk and other ingredients and follow the evolution of its physicochemical properties, biochemical and microstructure of the products obtained. Our cream is aerated with the manufacturing steps start with a homogenizing follow different ingredients by heating to 40°C emulsion, the preparation is then subjected to a heat treatment at 65°C for 30 min, before being stored in the cold at 4°C for a few hours. This conservation promotes crystallization of the material during the globular stage of maturation of the cream. The emulsifying agent moves gradually absorbed on the surface of fat globules homogeneous, which results in reduced protein stability. During the expansion, the collusion of destabilizing fat globules in the aqueous phase favours their coalescence. During the expansion, the collusion of destabilized fat globules in the aqueous phase favours their coalescence. The stabilizing agent increases the viscosity of the aqueous phase and the drainage limit interaction with the proteins of the aqueous phase and the protein absorbed on fat globules. The cutting improved organoleptic property of our cream is made by the use of three dyes and aromas. The products obtained undergo physicochemical analyses (pH, conductivity and acidity), biochemical (moisture, % dry matter and fat in %), and finally in the microscopic observation of the microstructure and the results obtained by analysis of the image processing software. The results show a remarkable evolution of physicochemical properties (pH, conductivity and acidity), biochemical (moisture, fat and non-fat) and microstructure of the products developed in relation to the raw material (skim milk) and the intermediate product (fermented cream).

Keywords: ice cream, sour cream, physicochemical, biochemical, microstructure

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Authors: G. Roshan Deen, J. S. Pedersen

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Temperature-responsive poly(N-isopropyl acrylamide) PNIPAM microgels crosslinked with a new hydrophobic chemical crosslinker was prepared by surfactant-mediated precipitation emulsion polymerization. The temperature-responsive property of the microgel and the influence of the crosslinker on the swelling behaviour was studied systematically by light scattering and small-angle X-ray scattering (SAXS). The radius of gyration (Rg) and the hydrodynamic radius (Rh) of the microgels decreased with increase in temperature due to the volume phase transition from a swollen to a collapsed state. The ratio of Rg/Rh below the transition temperature was lower than that of hard-spheres due to the lower crosslinking density of the microgels. The SAXS data was analysed by a model in which the microgels were modelled as core-shell particles with a graded interface. The model at intermediate temperatures included a central core and a more diffuse outer layer describing pending polymer chains with a low crosslinking density. In the fully swollen state, the microgels were modelled with a single component with a broad graded surface. In the collapsed state they were modelled as homogeneous and relatively compact particles. The polymer volume fraction inside the microgel was also derived based on the model and was found to increase with increase in temperature as a result of collapse of the microgel to compact particles. The polymer volume fraction in the core of the microgel in the collapsed state was about 60% which is higher than that of similar microgels crosslinked with hydrophilic and flexible cross-linkers.

Keywords: microgels, SAXS, hydrophobic crosslinker, light scattering

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Authors: Jae-Yong Sim, Jung-Hun Kwon, Ji-Sung Park, Kee-Joe Lim

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One of the latest trends for insulation systems to improve the insulation performance is the use of eco-friendly hybrid insulation using compressed dry-air. Despite the excellent insulation performance of sulphurhexafluoride (SF6) gas, its use has been restricted due to the problems with significant global warming potential (GWP). Accordingly, lightning impulse performance of the hybrid insulation system covered with an aluminum trihydrate/silicone rubber (ATH/SIR) nanocomposite was examined in air at atmospheric pressure and in compressed air at pressures between 0.2 and 0.6 MPa. In the experiments, the most common breakdown path took place along the surface of the covered rod. The insulation reliability after several discharges should be guaranteed in hybrid insulation. On the other hand, the surface of the covered rod was carbonized after several discharges. Therefore, nanoscale ATH can be used as a reinforcement of covered dielectrics to inhibit carbonization on the surface of a covered rod. The results were analyzed in terms of the surface resistivity of the cover dielectrics.

Keywords: nanocomposite, hybrid insulation, ATH, dry-air

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Authors: Zina Saheb, Ezz El-Masry

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As CMOS technology scaling down, Silicon oxide thickness (SiO2) become very thin (few Nano meters). When SiO2 is less than 3nm, gate direct tunneling (DT) leakage current becomes a dormant problem that impacts the transistor performance. Floating gate MOSFET (FGMOSFET) has been used in many low-voltage and low-power applications. Most of the available simulation models of FGMOSFET for analog circuit design does not account for gate DT current and there is no accurate analysis for the gate DT. It is a crucial to use an accurate mode in order to get a realistic simulation result that account for that DT impact on FGMOSFET performance effectively.

Keywords: CMOS transistor, direct-tunneling current, floating-gate, gate-leakage current, simulation model

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Authors: Esma Hande Alıcı, Gülnur Arabacı

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Antioxidants are compounds or systems that can safely interact with free radicals and terminate the chain reaction before vital molecules are damaged. The anti-oxidative effectiveness of these compounds depends on their chemical characteristics and physical location within a food (proximity to membrane phospholipids, emulsion interfaces, or in the aqueous phase). Antioxidants (e.g., flavonoids, phenolic acids, tannins, vitamin C, vitamin E) have diverse biological properties, such as antiinflammatory, anti-carcinogenic and anti-atherosclerotic effects, reduce the incidence of coronary diseases and contribute to the maintenance of gut health by the modulation of the gut microbial balance. Plants are excellent sources of antioxidants especially with their high content of phenolic compounds. Raphanus raphanistrum L., the wild radish, is a flowering plant in the family Brassicaceae. It grows in Asia and Mediterranean region. It has been introduced into most parts of the world. It spreads rapidly, and is often found growing on roadsides or in other places where the ground has been disturbed. It is an edible plant, in Turkey its fresh aerial parts are mostly consumed as a salad with olive oil and lemon juice after boiled. The leaves of the plant are also used as anti-rheumatic in traditional medicine. In this study, we determined the antioxidant capacity of two different solvent fractions (methanol and ethyl acetate) obtained from Raphanus raphanistrum L. plant leaves. Antioxidant capacity of the plant was introduced by using three different methods: DPPH radical scavenging activity, CUPRAC (Cupric Ion Reducing Antioxidant Capacity) activity and Reducing power activity.

Keywords: antioxidant activity, antioxidant capacity, Raphanis raphanistrum L., wild radish

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Authors: M. Goliszek, M. Sobiesiak, O. Sevastyanova, B. Podkoscielna

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Lignin is one of three main constituents of biomass together with cellulose and hemicellulose. It is a complex biopolymer, which contains a large number of functional groups, including aliphatic and aromatic hydroxyl groups, carbohylic groups and methoxy groups in its structure, that is why it shows potential capacities for process of sorption. Lignin is a highly cross-linked polymer with a three-dimentional structure which can provide large surface area and pore volumes. It can also posses better dispersion, diffusion and mass transfer behavior in a field of the removal of, e.g., heavy-metal-ions or aromatic pollutions. In this work emulsion-suspension copolymerization method, to synthesize the porous microspheres of divinylbenzene (DVB), styrene (St) and lignin was used. There are also microspheres without the addition of lignin for comparison. Before the copolymerization, modification lignin with methacryloyl chloride, to improve its reactivity with other monomers was done. The physico-chemical properties of the obtained microspheres, e.g., pore structures (adsorption-desorption measurements), thermal properties (DSC), tendencies to swell and the actual shapes were also studied. Due to well-developed porous structure and the presence of functional groups our materials may have great potential in sorption processes. To estimate the sorption capabilities of the microspheres towards phenol and its chlorinated derivatives the off-line SPE (solid-phase extraction) method is going to be applied. This method has various advantages, including low-cost, easy to use and enables the rapid measurements for a large number of chemicals. The efficiency of the materials in removing phenols from aqueous solution and in desorption processes will be evaluated.

Keywords: microspheres, lignin, sorption, solid-phase extraction

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Authors: Piya Roychoudhury, Ruma Pal

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Cyanobacteria, commonly known as blue green algae were found to be an effective bioreagent for nanoparticle synthesis. Nowadays silver nanoparticles (AgNPs) are very popular due to their antimicrobial and anti-proliferative activity. To exploit these characters in different biotechnological fields, it is very essential to synthesize more stable, non-toxic nano-silver. For this reason silver-gold alloy (Ag-AuNPs) nanoparticles are of great interest as they are more stable, harder and more effective than single metal nanoparticles. In the present communication we described a simple technique for rapid synthesis of biocompatible AgNP and Ag-AuNP employing cyanobacteria, Leptolyngbya and Lyngbya respectively. For synthesis of AgNP the biomass of Leptolyngbya valderiana (200 mg Fresh weight) was exposed to 9 mM AgNO3 solution (pH 4). For synthesis of Ag-AuNP Lyngbya majuscula (200 mg Fresh weight) was exposed to equimolar solution of hydrogen tetra-auro chlorate and silver nitrate (1mM, pH 4). After 72 hrs of exposure thallus of Leptolyngyba turned brown in color and filaments of Lyngbya turned pink in color that indicated synthesis of nanoparticles. The produced particles were extracted from the cyanobacterial biomass using nano-capping agent, sodium citrate. Firstly, extracted brown and pink suspensions were taken for Energy Dispersive X-ray (EDAX) analysis to confirm the presence of silver in brown suspension and presence of both gold and silver in pink suspension. Extracted nanoparticles showed a distinct single plasmon band (AgNP at 411 nm; Ag-Au NP at 481 nm) in Uv-vis spectroscopy. It was revealed from Transmission electron microscopy (TEM) that all the synthesized particles were spherical in nature with a size range of ~2-25 nm. In X-ray powder diffraction (XRD) analysis four intense peaks appeared at 38.2°, 44.5°, 64.8°and 77.8° which confirmed the crystallographic nature of synthesized particles. Presence of different functional groups viz. N-H, C=C, C–O, C=O on the surface of nanoparticles were recorded by Fourier transform infrared spectroscopy (FTIR). Scanning Electron microscopy (SEM) images showed the surface topography of metal treated filaments of cyanobacteria. The stability of the particles was observed by Zeta potential study. Antibiotic property of synthesized particles was tested by Agar well diffusion method against gram negative bacteria Pseudomonas aeruginosa. Overall, this green-technique requires low energy, less manufacturing cost and produces rapidly eco-friendly metal nanoparticles.

Keywords: cyanobacteria, silver nanoparticles, silver-gold alloy nanoparticles, spectroscopy

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Authors: Amir Razmjou, Elika Karbassi Yazdi

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Several direct lithium extraction (DLE) technologies have been developed for Li extraction from different brines. Although laboratory studies showed that they can technically recover Li to 90%, challenges still remain in developing a sustainable process that can serve as a foundation for the lithium dependent low-carbon economy. There is a continuing quest for DLE technologies that do not need extensive pre-treatments, fewer materials, and have simplified extraction processes with high Li selectivity. Here, an overview of DLE technologies will be provided with an emphasis on the basic principles of the materials’ design for the development of membranes with nanochannels and nanopores with Li ion selectivity. We have used a variety of building blocks such as nano-clay, organic frameworks, Graphene/oxide, MXene, etc., to fabricate the membranes. Molecular dynamic simulation (MD) and density functional theory (DFT) were used to reveal new mechanisms by which high Li selectivity was obtained.

Keywords: lithium recovery, membrane, lithium selectivity, decarbonization

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Authors: Haythem Barrak, Gaetan Laroche, Adel M’nif, Ahmed Hichem Hamzaoui

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The use of semiconductor oxides, as chemical or biological, requires their functionalization with appropriate dependent molecules of the substance to be detected. generally, the support materials used are TiO2 and SiO2. In the present work, we used zinc oxide (ZnO) known for its interesting physical properties. The synthesis of nano scale ZnO was performed by co-precipitation at low temperature (60 ° C).To our knowledge, the obtaining of this material at this temperature was carried out for the first time. This shows the low cost of this operation. On the other hand, the surface functionalization of ZnO was performed with (3-aminopropyl) triethoxysilane (APTES) by using a specific method using ethanol for the first time. In addition, the duration of this stage is very low compared to literature. The samples obtained were analyzed by XRD, TEM, DLS, FTIR, and TGA shows that XPS that the operation of grafting of APTES on our support was carried out with success.

Keywords: functionalization, nanoparticle, ZnO, APTES, caractérisation

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Authors: Kirit Siddhapara, Dimple Shah

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In this research, we have studied the doping behaviors of two transition metal ion dopants on the crystal phase, particle sizes, XRD patterns, EDAX spectra, and photoreactivity of TiO2 nanoparticles. The crystalline size of TiO2 is close to 4 nm Calculated from (1 0 1) peak by using FWHM method in Scherrer’s equation. Test metal ion concentrations ranged from 1% to 4 at.%, we report the growth of [Fe, Mn]xTiO2 nanocrystals prepared by Sol-Gel technique, followed by freeze-drying treatment at -30°C temperature for 12hrs. The obtained Gel was thermally treated at different temperature like 200°C, 400°C, 600°C, 800°C. Thermal gravimetric analysis (TGA) shows that dopant concentration affects thermal decomposition. The photoreactivities of transition metal ion-doped TiO2 nanoparticles under UV irradiation were quantified by the degradation of formaldehyde.

Keywords: growth from solution, sol-gel method, nanomaterials, oxides, magnetic materials, titanium compounds

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Authors: Maryam Atapour

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Chemical pesticides, which are widely used in agriculture, cause problems such as soil and water pollution, reducing biodiversity and creating pest resistance. These problems have led to increased attention to alternative and more sustainable methods such as natural-based pesticides. Herbal pesticides have been developed based on essential oils or extracts from different parts of plants, such as leaves, roots, and flowers. Herbal pesticides are compatible with the environment and can be used in integrated pest management programs. Despite the many benefits, herbal pesticides, especially essential oil-based compounds, have low durability in the environment, and their production costs are high, so the use of herbal extracts with appropriate formulations is more justified in all aspects. In the current study and based on the results of previous studies, aqueous and 70% ethanolic extract of Artemisia absinthium L. was prepared by the percolation method and formulated as an emulsion and water-soluble powder. To produce powder formulation, 20% maltodextrin was used with the spray-dryer method. Different concentrations of these compounds were sprayed on bushes infected with rose aphid Macrosiphum rosae (L.). Sampling was done randomly and the percentage of aphids’ mortality was checked. The results showed that the use of different concentrations of ethanolic extracts created a significant difference in the mortality rate of aphids, while water-soluble powder formulation caused less mortality. The current results showed that the extract of this plant has practical usability to control aphids, and with the appropriate formulation, it can be used as a good alternative to chemical pesticides.

Keywords: contact toxicity, formulation, extract, aphid, Artemisia absinthium.

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Authors: Paramita Banerjee, K. R. S. Chandrakumar, G. P. Das

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Bulk MgH2 has drawn much attention for the purpose of hydrogen storage because of its high hydrogen storage capacity (~7.7 wt %) as well as low cost and abundant availability. However, its practical usage has been hindered because of its high hydrogen desorption enthalpy (~0.8 eV/H2 molecule), which results in an undesirable desorption temperature of 3000C at 1 bar H2 pressure. To surmount the limitations of bulk MgH2 for the purpose of hydrogen storage, a detailed first-principles density functional theory (DFT) based study on the structure and stability of neutral (Mgm) and positively charged (Mgm+) Mg nanoclusters of different sizes (m = 2, 4, 8 and 12), as well as their interaction with molecular hydrogen (H2), is reported here. It has been found that due to the absence of d-electrons within the Mg atoms, hydrogen remained in molecular form even after its interaction with neutral and charged Mg nanoclusters. Interestingly, the H2 molecules do not enter into the interstitial positions of the nanoclusters. Rather, they remain on the surface by ornamenting these nanoclusters and forming new structures with a gravimetric density higher than 15 wt %. Our observation is that the inclusion of Grimme’s DFT-D3 dispersion correction in this weakly interacting system has a significant effect on binding of the H2 molecules with these nanoclusters. The dispersion corrected interaction energy (IE) values (0.1-0.14 eV/H2 molecule) fall in the right energy window, that is ideal for hydrogen storage. These IE values are further verified by using high-level coupled-cluster calculations with non-iterative triples corrections i.e. CCSD(T), (which has been considered to be a highly accurate quantum chemical method) and thereby confirming the accuracy of our ‘dispersion correction’ incorporated DFT calculations. The significance of the polarization and dispersion energy in binding of the H2 molecules are confirmed by performing energy decomposition analysis (EDA). A total of 16, 24, 32 and 36 H2 molecules can be attached to the neutral and charged nanoclusters of size m = 2, 4, 8 and 12 respectively. Ab-initio molecular dynamics (AIMD) simulation shows that the outermost H2 molecules are desorbed at a rather low temperature viz. 150 K (-1230C) which is expected. However, complete dehydrogenation of these nanoclusters occur at around 1000C. Most importantly, the host nanoclusters remain stable up to ~500 K (2270C). All these results on the adsorption and desorption of molecular hydrogen with neutral and charged Mg nanocluster systems indicate towards the possibility of reducing the dehydrogenation temperature of bulk MgH2 by designing new Mg-based nano materials which will be able to adsorb molecular hydrogen via this weak Mg-H2 interaction, rather than the strong Mg-H bonding. Notwithstanding the fact that in practical applications, these interactions will be further complicated by the effect of substrates as well as interactions with other clusters, the present study has implications on our fundamental understanding to this problem.

Keywords: density functional theory, DFT, hydrogen storage, molecular dynamics, molecular hydrogen adsorption, nanoclusters, physisorption

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Authors: A. D'Alessandro, F. Ubertini, A. L. Materazzi

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In the field of civil engineering, Structural Health Monitoring is a topic of growing interest. Effective monitoring instruments permit the control of the working conditions of structures and infrastructures, through the identification of behavioral anomalies due to incipient damages, especially in areas of high environmental hazards as earthquakes. While traditional sensors can be applied only in a limited number of points, providing a partial information for a structural diagnosis, novel transducers may allow a diffuse sensing. Thanks to the new tools and materials provided by nanotechnology, new types of multifunctional sensors are developing in the scientific panorama. In particular, cement-matrix composite materials capable of diagnosing their own state of strain and tension, could be originated by the addition of specific conductive nanofillers. Because of the nature of the material they are made of, these new cementitious nano-modified transducers can be inserted within the concrete elements, transforming the same structures in sets of widespread sensors. This paper is aimed at presenting the results of a research about a new self-sensing nanocomposite and about the implementation of smart sensors for Structural Health Monitoring. The developed nanocomposite has been obtained by inserting multi walled carbon nanotubes within a cementitious matrix. The insertion of such conductive carbon nanofillers provides the base material with piezoresistive characteristics and peculiar sensitivity to mechanical modifications. The self-sensing ability is achieved by correlating the variation of the external stress or strain with the variation of some electrical properties, such as the electrical resistance or conductivity. Through the measurement of such electrical characteristics, the performance and the working conditions of an element or a structure can be monitored. Among conductive carbon nanofillers, carbon nanotubes seem to be particularly promising for the realization of self-sensing cement-matrix materials. Some issues related to the nanofiller dispersion or to the influence of the nano-inclusions amount in the cement matrix need to be carefully investigated: the strain sensitivity of the resulting sensors is influenced by such factors. This work analyzes the dispersion of the carbon nanofillers, the physical properties of the fresh dough, the electrical properties of the hardened composites and the sensing properties of the realized sensors. The experimental campaign focuses specifically on their dynamic characterization and their applicability to the monitoring of full-scale elements. The results of the electromechanical tests with both slow varying and dynamic loads show that the developed nanocomposite sensors can be effectively used for the health monitoring of structures.

Keywords: carbon nanotubes, self-sensing nanocomposites, smart cement-matrix sensors, structural health monitoring

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Authors: Ram Mohan, Mahendran Samykano, Shyam Aravamudhan

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Metallic nanowires with sub-micron and hundreds of nanometer diameter have a diversity of applications in nano/micro-electromechanical systems (NEMS/MEMS). Characterizing the mechanical properties of such sub-micron and nano-scale metallic nanowires are tedious; require sophisticated and careful experimentation to be performed within high-powered microscopy systems (scanning electron microscope (SEM), atomic force microscope (AFM)). Also, needed are nanoscale devices for placing the nanowires; loading them with the intended conditions; obtaining the data for load–deflection during the deformation within the high-powered microscopy environment poses significant challenges. Even picking the grown nanowires and placing them correctly within a nanoscale loading device is not an easy task. Mechanical characterizations through experimental methods for such nanowires are still very limited. Various techniques at different levels of fidelity, resolution, and induced errors have been attempted by material science and nanomaterial researchers. The methods for determining the load, deflection within the nanoscale devices also pose a significant problem. The state of the art is thus still at its infancy. All these factors result and is seen in the wide differences in the characterization curves and the reported properties in the current literature. In this paper, we discuss and present our experimental method, results, and discussions of uniaxial tensile loading and the development of subsequent stress–strain characteristics curves for Nickel nanowires. Nickel nanowires in the diameter range of 220–270 nm were obtained in our laboratory via an electrodeposition method, which is a solution based, template method followed in our present work for growing 1-D Nickel nanowires. Process variables such as the presence of magnetic field, its intensity; and varying electrical current density during the electrodeposition process were found to influence the morphological and physical characteristics including crystal orientation, size of the grown nanowires1. To further understand the correlation and influence of electrodeposition process variables, associated formed structural features of our grown Nickel nanowires to their mechanical properties, careful experiments within scanning electron microscope (SEM) were conducted. Details of the uniaxial tensile characterization, testing methodology, nanoscale testing device, load–deflection characteristics, microscopy images of failure progression, and the subsequent stress–strain curves are discussed and presented.

Keywords: uniaxial tensile characterization, nanowires, electrodeposition, stress-strain, nickel

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Authors: Jaromír Marek, Jakub Wiener, Yan Wang

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The main goal of this study was to find simple and industrially applicable production of ion exchangers based on nanofibrous polystyrene matrix and characterization of prepared material. Starting polystyrene nanofibers were sulfonated and crosslinked under appropriate conditions at the same time by sulfuric acid. Strongly acidic cation exchanger was obtained in such a way. The polymer matrix was made from polystyrene nanofibers prepared by Nanospider technology. Various types postpolymerization reactions and other methods of crosslinking were studied. Greatly different behavior between nano and microsize materials was observed. The final nanofibrous material was characterized and compared to common granular ion exchangers and available microfibrous ion exchangers. The sorption properties of nanofibrous ion exchangers were compared with the granular ion exchangers. For nanofibrous ion exchangers of comparable ion exchange capacity was observed considerably faster adsorption kinetics.

Keywords: electrospinning, ion exchangers, nanofibers, polystyrene

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Authors: Onuoha Gideon

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The preliminary studies on the potentials of Bambara nut and pigeon pea as imitation milk were investigated. Bambara nut and Pigeon pea milk were produced from two separate unit operations; Bambara nut seed was cooked, dehulled, milled and strained to milk (BCM) and another batch was toasted at moderate temperature, dehulled, milled and strained to milk (BTM). Pigeon pea seed was cooked, dehulled, milled and strained to milk (PCM) and another batch was toasted at moderate temperature, dehulled, milled and strained to milk (PTM). The result of the proximate analysis on the milk samples on wet basis showed that the protein content ranged from 28.56 – 26.77, the crude fibre ranged from 6.28 – 1.85, the ash content ranged from 5.22 – 1.17, the fat content ranged from 2.71 – 1.12, the moisture content ranged from 95.93 – 93.83, the carbohydrate content ranged from 67.62 – 58.83. The functional analysis on the milk samples showed that emulsification capacity ranged from 43.21 – 38.66, emulsion stability ranged from 34.10 – 25.00, the specific gravity ranged from 997.50 – 945.00, the foaming capacity ranged from 3,500 to 2,250, the measurement of viscosity ranged from 0.017 – 0.007, the pH range from 5.55 – 5.25, the measurement of dispersibility range from 11.00 – 7.00, the total soluble solid ranged from 4.00 to 1.75, the total titratable acidity ranged from 0.314 – 0.328. The sensory evaluation report showed that in terms of flavor, sample BCM and PCM value were significantly different from sample BTM and PTM. In terms of colour, sample BCM showed a significant difference from samples BTM, PCM and PTM. In term of texture, sample BCM was significantly different from samples BTM, PCM and PTM. The general acceptability shows that sample BCM was significantly different from other the samples and was the most accepted. The microbial analysis indicated that the microbial load increases with time. Bacterial count ranged from 1.3 x 105 – 1.20 x 106 to 1.6 x 105 – 1.06 x 106, fungal count ranged from 4.0 x 105 – 8.0 x 105 to 4.0 x 105 – 7.0 x 105. The studies showed that BCM was the most preferred.

Keywords: imitation milk, Bambara nut, Pigeon pea, proximate composition

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Authors: Roshank Haghighat, Laleh Maleknia

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In this study, electrospun TiO2/nylon-6 nanofiber mats were successfully prepared. The nanofiber mats were characterized by SEM, FE-SEM, TEM, XRD, WCA, and EDX analyses. The results revealed that fibers in different distinct sizes (nano and subnano scale) were obtained with the electrospinning parameters. The presence of a small amount of TiO2 in nylon-6 solution was found to improve the hydrophilicity (antifouling effect), mechanical strength, antimicrobial and UV protecting ability of electrospun mats. The resultant nylon-6/TiO2 antimicrobial spider-net like composite mat with antifouling effect may be a potential candidate for future water filter applications, and its improved UV blocking ability will also make it a potential candidate for protective clothing.

Keywords: electrospinning, hydrophilicity, antimicrobial, nanocomposite, nylon-6/TiO2

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