Electric Charge Properties Research Articles

Tuneable ion transport by electrically responsive membranes under electrical assistance

The conventional membrane technology provides an effective solution for ion separation. However, the traditional membrane is not able to tune the permselectivity during operation, and has inherent drawbacks of permeance and selectivity trade-off. In view of this, the purpose of this project is to realize controllable ion transport without impeding water filtration through electrically responsive membrane (ERMs) under electrical assistance. To achieve this, we developed electrically responsive membranes with different electrical conductivities and surface charge properties by incorporating multi-walled carbon nanotubes (CNTs) and different acids doped polyaniline (PANI). The external potential was supplied to create tuneable electrostatic interactions between surface charged ERMs and ions, which was expected to regulate and control ion transport. It was found that the developed ERMs exhibited improved rejection without decreasing the water permeance under applied potential. The responsiveness of ion rejection to the electrical potential was affected by the combined effect of charge density and electrical conductivity. The calculations based on the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory suggested that imposing an external voltage increased the surface potential of ERMs and thus improved the electrostatic repulsive force between ERMs and ions, resulting in improved ion rejection. It is believed that this simple and feasible strategy for fabrication of ERMs has a potential for practical applications in tunable ion separation.

Analysis of the electric charge properties of biofilm for the development of biofilm matrices as biosorbents for water pollutant

Analysis of the electric charge properties of biofilm for the development of biofilm matrices as biosorbents for water pollutant

Synthesis and analysis of structural, compositional, morphological, magnetic, electrical and surface charge properties of Zn-doped nickel ferrite nanoparticles

Zn-doped nickel ferrite nanoparticles (ZnxNi(1-x)Fe2O4) were synthesized using the co-precipitation technique. The structural and compositional studies of the ZnxNi(1-x)Fe2O4 nanoparticles revealed their face-centred cubic spinel structure and an appropriate amount of Zn doping in nickel ferrite nanoparticles, respectively. The morphological analysis had been carried out to obtain the particle size of the synthesized nanoparticles. The magnetic studies revealed the superparamagnetic nature of the ZnxNi(1-x)Fe2O4 nanoparticles, and the maximum magnetization of 30 emu/g for the Zn0.2N0.8Fe2O4 sample. The M − H curves were fitted with the Langevin function to obtain the magnetic particle diameter of ZnxNi(1-x)Fe2O4 nanoparticles. The electrical conduction in ZnxNi(1-x)Fe2O4 nanoparticles was explained through the Verway hopping mechanism. The Zn0.2N0.8Fe2O4 nanoparticle exhibited a higher electrical conductivity of 42 μS/cm and surface charge of −29/7 mV due to the enhanced hopping of Fe3+ ions in the octahedral sites. Owing to this nature, they were identified as the suitable candidates in the applications such as thermoelectrics, hyperthermia, magnetic coating and for the preparation of conducting ferrofluids.

Synthesis and characterization of nanostructured copper and lanthanum co‐doped zirconia for voltammetric sensing of tumor biomarkers

AbstractNanostructured ZrO2‐based materials with their biocompatibility, excellent electrical, and surface charge properties became one of the best candidates for the electrochemical sensing applications. Here, synthesis of Zr1‐xCuxLaxO2 compounds was achieved in nanoscale and fully characterized using XRD, TEM, DRS, and cyclic voltammetry. A mixture of monoclinic and cubic phases was detected for the undoped ZrO2 (Z sample, x = 0). For the Cu‐doped compounds, (ZFW1, x = 0.05 and ZFW2, x = 0.1), a combination of cubic fluorite and monoclinic phase were detected. The intensity of the monoclinic phase for the Cu‐doped was higher than that of the undoped ZrO2 sample. Cu and La co‐doped samples (ZL1C1, x = 0.05 and ZL2C2, x = 0.1) were stabilized in a single cubic phase structure. Therefore, their band gap dropped from (4.8 eV) for the undoped ZrO2 to (1.49 eV) for the ZL1C1 sample and (2 eV) for the ZL2C2 sample. Voltammetric sensing of neurotransmitter metabolites (vanillylmandelic acid (VMA) and homovanillic acid (HVA)) was achieved using the modified electrodes due to their acquired high electrocatalytic and high electrochemical performance.

The Effect of An Aqueous Electricidal Solution on General Well Being

Solution4USA’s dietary supplement, referred to here as “ELECTROCIDE™,” is a new type of aqueous nutraceutical which is antipathogenic in nature due to pathogen specific electrical charge properties. Thousands of people have been treated with this product when delivered through an existing network of medical professionals validating its efficacy and safety. Using FDA guidelines, “ELECTROCIDE™” was evaluated for wellness benefits as a potential investigational drug under medical supervision using 52 volunteers (Group1: 15 and Group2: 37) in an institutional setting (The Lovelady Center (TLC) in Birmingham, Alabama) using quantitative measurements of vital signs along with two qualitative self-reported questionnaires. The results indicate a highly significant improvement in vital signs and a significant reduction in various physiological and emotional conditions.

Pharmacologically Active Vanadium Species: Distribution in Biological Media and Interaction with Molecular Targets.

Biospeciation of some of the most studied vanadium (symbol V) complexes with biological or medicinal activity is discussed in this review in order to emphasize the importance of the distribution of V species in biological media. The exact knowledge of the chemical species present in blood or cells may provide essential information regarding the biological effect of V potential drugs. In blood serum, vanadium species can interact with low (citrate, lactate, oxalate, amino acids, etc., indicated with bL) and high molecular mass (proteins like transferrin, albumin, immunoglobulins, etc.) components, while the interaction with red blood cells can interfere with the transport of these drugs towards the target cells. The interaction of bLs and proteins is discussed through the analysis of instrumental and computational data. The fate of the active V species, when these are in the real serum samples and when they reach and cross cell membranes, is also discussed. The differences in the V complexes selected in this review (donor atoms, stability, coordination geometry, electric charge, hydrolipophilicity balance, substituents and redox properties) cover all the possible modes of interaction with bLs and proteins, allowing for the biodistribution of the studied compounds to be predicted. This approach could be applied to newly synthesized potential V drugs.

Diclofenac removal from water by photocatalysis- assisted filtration using activated carbon modified with N-doped TiO2

The aim of this study was to develop powdered and granular activated carbon modified with N doped TiO2, namely PAC-TiO2N and respective, GAC-TiO2N by sol-gel method, starting from commercial activated carbon, for the removal from water of diclofenac (DCF), an emerging pollutant. The synthesized materials were characterized systematically and morphostructural, light absorption and electrical charge properties were determined. The sorption and photocatalytic capacities of both materials were determined by batch experiments based on the kinetic models and the effect of operational parameters. GAC-TiO2N was selected for further testing in fixed bed-column experiments envisaging its potential integration with real drinking water treatment technology. The GAC-TiO2N tested in UV irradiation-assisted fixed bed-column filtration for DCF removal exhibited a great potential for practical application, by testing in simulated coexisting DCF and humic acids (HAs) and real surface water spiked with DCF (Bega River, Timisoara city, Romania). About 80% removal efficiency was noticed for both DCF and HAs and about 70% of the organic matter was removed (expressed as total organic carbon- TOC indicator). UV irradiation during filtration allowed the activation of the GAC-TiO2N filtration layer without TiO2 loss, which led to longer life-times due to the potential “self-cleaning” effect and its good stability.

A Surfactant-Free Synthesis Technique of Coral-Like Zno Hierarchical Structures for Photocatalytic Degradation of Resorcinol under UV Irradiation

Hierarchical coral-like ZnO structures were successfully prepared by a surfactant-free wet chemical method. Various characterization tests were carried out to analyze the as-prepared ZnO samples. The coral-like ZnO was used to degrade resorcinol at three different solution pH values (pH 5.0, pH 8.0 and pH 11.0). It was observed that the resorcinol adsorption onto the ZnO was strongly dependent on the electrical charge properties of both photocatalyst and resorcinol. Photocatalytic degradation of resorcinol reached the highest at pH 11.0 due to high concentration of hydroxyl ions for hydroxyl radicals generation.

Characteristics of Alcian-blue Dye Adsorption of Natural Biofilm Matrix

In this study, natural biofilm matrices formed on stones have been used for the adsorption of Alcian blue dye. Alcian blue is a member of polyvalent basic dyes that largely used from laboratory until industrial dying purposes. The adsorption of the dye onto the biofilm matrix has been carried out at different experimental conditions such as adsorption isotherm and kinetic of adsorption. The electric charge properties of biofilm matrix and its changes related to the adsorption of Alcian blue have been also investigated. Moreover, the results of Alcian blue adsorption to the biofilm were compared to those onto the acidic and neutral resin. The kinetics of adsorption result showed that the adsorption of the Alcian blue dye reached to a maximum adsorption amount within 60 minutes. The adsorption amount of Alcian blue to biofilm increased monotonously, and the maximum adsorption amount was greater compared to the resins. On the contrary, Alcian blue did not attach to the neutral resin having no electric charge. It seems that Alcian blue attached to the acidic resins due to electrostatic attractive force, and the same seems to be the case for adsorption of Alcian blue to biofilm. The adsorption of Alcian blue to the biofilm and acidic resins fitted to Langmuir type indicates that the binding of Alcian blue to the biofilm and acidic resins occurred in a monolayer like form. The maximum adsorption amount of Alcian blue on the biofilm (0.24 mmol/dry-g) was greater than those of acidic resin (0.025 mmol/dry-g). This indicates that the biofilm has many more sites for Alcian blue attachment than acidic resins. According to the result of this study, the biofilm matrix can be a good adsorbent for dye such as Alcian blue or other dyes that causing hazards in nature.

Electrostatic blocking barrier as an effective strategy to inhibit electron recombination in DSSCs

The concept of negatively charged electrostatic blocking barrier is demonstrated using benzotriazole (btzH) as ancillary ligands in a new ruthenium-dicarboxybipyridine photosensitizer, [Ru(dcbpyH)2(btzH)2], which was deprotonated in a stepwise manner generating the (Bu4N)2[Ru(dcbpy)2(btzH)2], (Bu4N)3[Ru(dcbpy)2(btzH)(btz)] and (Bu4N)4[Ru(dcbpy)2(btz)2] acid-base conjugates. All compounds were isolated as solids and used for the preparation of DSSCs with structurally similar TiO2/dye interface but distinct electric charge properties. The results revealed that the negative charges at the TiO2 surface, generated by deprotonation of the dcbpyH ligands, are less effective than those generated by deprotonation of the ancillary ligands located much farther from the surface. This peripheral electrostatic field probably is more effective in inhibiting the approach of the negatively charged hole transporter I3−, and consequently the electron recombination, thus enhancing the overall cell performance. This hypothesis was confirmed by measuring the interfacial resistance and capacitance of running cells, and simulating the respective impedance spectroscopy data using the transmission line model.

Effects of source and seasonal variations of natural organic matters on the fate and transport of CeO2 nanoparticles in the environment

Natural organic matter (NOM) affects the stability and transport of nanoparticles (NPs) in natural waters by modifying their physiochemical properties. Source location, and seasonal variations, influence their molecular, physical and electrical charge properties. To understand the variations of NOM on the mobilization of NPs, large volumes of water were collected from the Ohio River (OR) over winter and summer seasons and dissolved NOMs were concentrated. The chemical and structural differences of these NOMs were compared with the Suwannee River humic acid (SRHA) SRHA using 1H and 13C nuclear magnetic resonance spectroscopy, and Fourier transforms infrared (FTIR) spectroscopy. Thermal analysis and FTIR confirmed that differences in composition, structure, and functional groups are a result of SRHA fractionation compared to whole molecule OR-NOM. The influence of OR-NOMs on the surface charge of CeO2 NPs and the effects on the transport and retention in a three-phase (deposition-rinse-re-entrainment) sand-packed columns were investigated at CeO2 NPs initial concertation of 10ppm, pH6.8, increasing ionic strength (3, 5, and 10mM), retention time of 1min, and increasing NOM concentration (1, 5, and 10ppm). The summer OR-NOM showed higher stabilization and mobilization effect on the CeO2 than the winter NOM; while their effect was very different form the SRHA. The stabilization of NPs is attributed to both electrostatic and steric effects. The differences in the chemical structure of the complex and heterogeneous NOMs showed disparate reactivity and direct impact on CeO2-NPs stability. Using SRHA to study the effect of NOM for drinking water related assessment does not sufficiently represent the natural conditions of the environment.

Electric Charge Characteristics of Biofilms Formed on Various Surfaces

Biofilm is predominant habitats of microbes in aquatic environments. Biofilm forms when microbes attach on surfaces and produce extracellular polymeric substances. Biofilm matrix has been showed to have high sorption capacity to accumulate various ions including nutrient ions. The main driving force of the accumulation of the ions is supposed to be an electrostatic interaction between the nutrient and the biofilm polymer. Hence, the understanding of electric charge properties of biofilm polymer is critically important to understand the accumulation process. The present study aimed to investigate the characteristics of electric charge properties of biofilm polymer from biofilms formed on various surfaces (stone, wood, glass bottle, teflon, rubber, and stainless steel). The electric charge properties of biofilm polymers were investigated by measuring the electrophoretic mobility of the biofilms in various pHs (range from pH 2 to pH 9) and titrated HCl and NaOH aqueous solution to the biofilm suspension. The results indicated that biofilm matrices seemed to have both negatively and positively charged sites as a result of ionization of functional groups existed in biofilm polymers. According to the results of this study, there is a universal characteristic of electric charge properties of biofilms regardless of the kind of substrate.

Enhanced the Negative Charges of <i>Antheraea pernyi</i> Silk Fibroin by Methylglyoxal Modification

Antheraea pernyi silk fibroin has favorable biocompatibility, good bioactivity and controllable biodegradability, meeting the basic requirements of controlled drug release carriers. Enhancing the negative charge of silk fibroin could further increase the encapsulation and loading efficiency of positively charged drugs. In this study, Antheraea pernyi silk fibroin was chemically modified by methylglyoxal in aqueous solution. The electric charge properties of Antheraea pernyi silk fibroin were examined to characterize the modification, the results indicated that the isoelectric point of Antheraea pernyi silk fibroin decreased from 4.5 to 3.9, and the zeta potential reduced from-11.7 mV to-12.8 mV. Amino acid analysis and 1H-NMR spectra showed that arginine residue of Antheraea pernyi silk fibroin side chain was modified by methylglyoxal for enhancing negative charge of silk fibroin. These results suggested that methylglyoxal-modified Antheraea pernyi silk fibroin could be considered as a potential starting material in loading positively charged drugs.

Electrical properties of extended defects in III-nitrides

Electrical and structural properties of extended defects including threading dislocations/V-defects and nanopipes in unintentionally doped GaN, InGaN (50nm)/GaN and AlInN (33nm)/AlN(1nm)/GaN heterostructures have been investigated by means of various scanning probe (Kelvin probe and conductive-Atomic Force Microscopy) and electron beam (electron beam induced current and transmission electron microscopy) microscopy methods. Due to low energy measurements of Kelvin probe force microscopy, charge state of the dislocations have been correctly identified where threading dislocations (TDs) with screw-component are negatively charged, while pure-edge type TDs are neutral in InGaN/GaN. It is explained how various factors such as indium segregation, surface termination, presence of vacancies and/or impurities affect the electrical charge, conductivity and recombination properties of the extended defects. They are found to be strongly correlated to the type of dislocations as identified from TEM.

Superparamagnetic iron oxide nanoparticles: promote neuronal regenerative capacity?

Currently, we know that neuronal outgrowth during development and regeneration requires a complex interaction of intra- and extracellular molecules such as growth factors, neurotransmitters and extracellular matrix proteins (O’Donnell et al., 2009). Furthermore, the discovery of a broad spectrum of growth-promoting cues has led to novel concepts for therapeutic strategies. However, although our understanding of the molecular mechanisms underlying neuronal regeneration is constantly growing, there is still no therapy for the treatment of brain or spinal cord injuries (SCI) (Filli and Schwab, 2012). Recent attempts have been made to influence regeneration using nano-scaled particles that specifically act at the molecular level (Polak and Shefi, 2015).

The synthesis of styrene acrylate emulsion and its application in xerographic paper

Abstract During xerographic printing processes, the electric charge properties of the paper surface are essential to obtain effective toner transfer and high image quality. Surface and volume resistance are indispensable to the accumulation of the surface charge and different resistance values generate different electrical fields with optical drum, and have a significant effect on toner transfer efficiency. In this paper, surface sizing was investigated to improve the surface properties for better toner transfer and image quality. Styrene acrylate emulsion (SAE) latex was successfully synthesized and fully characterized with a Fourier transform infrared (FT-IR) spectrometer, a laser particle analyzer and a scanning electron microscope (SEM). The results showed that under the conditions of emulsifier dosage at 3 wt%, initiator concentration at 0.5 wt% and the reaction temperature at 80°C, the monomer conversion can reach 80%. The effects of various factors including initiator dosage, emulsifier dosage and monomer ratio on the sizing performance were studied. The effects of different ratios of SAE to starch on surface and volume resistance of paper were also systematically investigated. The differences in electric properties of various paper samples were quantified and their influence on paper-toner adhesion and print quality was clarified. Relationships between electrical properties of paper and paper-toner adhesion force, and thus print quality were established. Strategies to improve printing performance through effective control of paper electrical properties were also developed. It is concluded that the best printing quality and toner adhesion were achieved when the ratio of SAE to starch is between 1:10 and 2:10.

Characterization of the semi-interpenetrated network based on collagen and poly(N-isopropyl acrylamide-co-diethylene glycol diacrylate)

The study is devoted to the characterization of the semi-interpenetrating polymeric network (semi-IPN) structures, prepared as dual sensitive networks, based on poly(N-isopropyl acrylamide-co-diethylene glycol diacrylate) inserted into a collagen porous membrane with potential biomedical-applications. The pharmaceutical applications are related to the possibility of using the semi-synthetic networks for inclusion, retention, transportation and release of drug molecules. The insertion and the homogeneity distribution of the drug into the polymeric network were evaluated by near infrared-chemical imaging (NIR-CI) technique. The drug release was investigated from the kinetically viewpoint in simulated biological environment by using UV-vis spectrophotometric technique. The zeta potential measurement results showed meaningful change of the electric potential of the network surface at the interfacial double layer with the environment in the interdependence with the network composition and environment characteristics. The biodegradable character of the semi-synthetic network, also presented, undergoes with tissue engineering request for achievement of tissue substituents. Texture analysis of the semi-IPN was realized in order to evidence the potential applications of the prepared compounds in tissue engineering. The adhesion properties reveal the possibility to control the surface adhesion by: network composition, the ratio between the polymer types, and the crosslinking degree of polymeric networks. The evaluation of the semi-IPN characteristics in medical terms, concerned the surface electrical charge, the loading, retention and release properties of an active compound, the adhesion properties and the effect of collagenase enzyme over the collagen fibres as component in semi-IPN, and from the pharmaceutical terms emphasizes the potential applications of the new polymeric semi-IPN networks.

Electric charge trapping, residual stresses and properties of ceramics after metal/ceramics bonding

Abstract The use of ceramic components in electrical engineering and mechanical applications is rapidly increasing. Most of these applications require the use of ceramics bonded with metal. In this paper, we have studied the role of residual stresses occurring after joining between an industrial alumina ceramic (Al 2 O 3 ) and Ni-based super-alloy, on the dielectric behaviour of ceramics. The electric charging phenomenon i.e. trapping–detrapping or diffusion of electric charges is studied by Scanning Electron Microscope Mirror Effect (SEMME) coupled with the Induced Current Method (ICM). Knowing that localized trapped charges in ceramics is a source of damage, the correlation between residual stress intensity, apparent-toughness of ceramics and ability to trap charges near the interface was demonstrated: the SEMME and ICM measurements of the quantities of trapped charges near the interface, highlighted the changes in the ceramic properties related to residual stresses due to both thermo-mechanical effect and diffusion of metallic species in the ceramics, during the bonding process.

LATTICE BOLTZMANN STUDY OF ELECTROHYDRODYNAMIC DROP DEFORMATION WITH LARGE DENSITY RATIO

The lattice Boltzmann method (LBM) has been applied to electrohydrodynamics (EHD) in recent years. In this paper, Shan–Chen (SC) single-component multiphase LBM is developed to study large-density-ratio EHD problems. The deformation/motion of a droplet suspended in a viscous liquid under an applied external electric field is studied with three different electric field models. The three models are leaky dielectric model, perfect dielectric model and constant surface charge model. They are used to investigate the effects of the electric field, electric properties of liquids and electric charges. The leaky dielectric model and the perfect dielectric model are validated by the comparison of LBM results with theoretical analysis and available numerical data. It shows that the SC LBM coupled with these electric field models is able to predict the droplet deformation under an external electric field. When net charges are present on the droplet surface and an electric field is applied, both droplet deformation and motion are reasonably predicted. The current numerical method may be an effective approach to analyze more complex EHD problems.

Impact of strange quark matter nuggets on pycnonuclear reaction rates in the crusts of neutron stars

This article presents an investigation into the pycnonuclear reaction rates in dense crustal matter of neutron stars contaminated with strange quark matter nuggets. The presence of such nuggets in the crustal matter of neutron stars would be a natural consequence if Witten's strange quark matter hypothesis is correct. The methodology presented in this article is a recreation of a recent representation of nuclear force interactions embedded within pycnonuclear reaction processes. The study then extends the methodology to incorporate distinctive theoretical characteristics of strange quark matter nuggets, like their low charge-per-baryon ratio, and then assesses their effects on the pycnonuclear reaction rates. Particular emphasis is put on the impact of color superconductivity on the reaction rates. Depending on whether quark nuggets are in this novel state of matter, their electric charge properties vary drastically, which turns out to have a dramatic effect on the pycnonuclear reaction rates. Future nuclear fusion network calculations may thus have the potential to shed light on the existence of strange quark matter nuggets and on whether they are in a color superconducting state, as suggested by QCD.