Chloride Sol Research Articles

Performance repair of building materials using alumina and silica composite nanomaterials with electrodynamic properties

Abstract In recent years, the service life of building materials has become the focus of attention. Among them, the service life of concrete and steel bars is particularly affected by the corrosion of external ions (such as Cl−) in the environment. To solve this problem, a new type of composite nanocolloid was prepared through a controllable preparation method. The composite nanocolloid is prepared from aluminum chloride sol and silica sol as raw materials. The prepared colloidal particles have a particle size distribution between 10.5 and 17.5 nm, exhibiting excellent stability and dispersibility. In order to verify the improvement effect of the composite nanocolloid on the properties of building materials, the influence of it on the porosity of concrete and the anti-corrosion performance of steel bars was experimentally studied. The results indicate that the moisture absorption and dehumidification speed of concrete treated with composite nano colloids is slower, and the pore size distribution is mainly concentrated in 100–1,000 nm, indicating that the colloids can effectively optimize the pore structure of concrete. In addition, the processed steel plate samples showed high AC impedance values and low corrosion current logarithmic values in electrochemical testing, indicating that composite nanocolloids have a significant protective effect on the corrosion of steel bars, which can effectively improve the performance of building materials and extend their service life.

Dark and UV-Enhanced Degradation of Dimethyl Methylphosphonate on Mesoporous CeO2 Aerogels

Our development of high surface-area mesoporous expressions of ceria (CeO2) is motivated by recent studies identifying CeO2 as one of the most reactive oxides for adsorbing and degrading toxic organophosphorus compounds, including chemical warfare simulants. We synthesize nanostructured CeO2 aerogels using a facile, scalable, and template-free sol–gel method to amplify the number of available and accessible surface sites for organophosphorus adsorption/degradation and then spectroscopically characterize the degradation of dimethyl methylphosphonate (DMMP) at the aerogel surface. The CeO2 aerogels retain high concentrations of surface-sited residual Cl from the chloride sol–gel precursors, which block DMMP binding sites and hinder the formation of surface hydroxyls (OH). We demonstrate that a simple alkaline soak removes surface-fouling Cl and creates a more OH-rich surface, thus unleashing the hydrolytic activity of the amplified CeO2 aerogel surfaces. Whereas the Cl-fouled CeO2 surface weakly and reversibly binds DMMP, the rinsed, OH-rich surface irreversibly binds DMMP and rapidly generates hydrolysis products. Exciting the CeO2 bandgap with UV light (390–400 nm) accelerates DMMP degradation and generates a higher proportion of mineralized POx products than the dark reaction. Our work marks the first-ever report of photodegradation of a chemical warfare simulant at CeO2 as well as the first report of mineralized POx formation at CeO2 at room temperature. The high surface-area CeO2 aerogels exhibit higher capacity than non-networked, nanoparticulate CeO2, thus highlighting the potential applicability of nanocrystalline CeO2 aerogels for protection against organophosphorus compounds.

Hypothetical Mechanism of Skin Argyria

Introduction. Argyria is an acquired skin condition that appears after the exposure or consumption of silver, leading to blue or grey coloration of the skin and mucosa. The aim of the present work was to draw researchers’ attention to two aspects of the argyria that until now have not received enough consideration. They are: (1) the process of delivering silver compound from the gastrointestinal tract to the skin and (2) the possibility for silver chloride to participate in this process along with the silver proteinates. Methodology. Illustrative experiments included the observation of color change (visual and using UV-Vis spectrometry) under different light exposure conditions of silver chloride sol in a sweat-simulating solution, in vials and under pig skin (in direct contact). Results and Discussion. A hypothetical mechanism based on a perspiration system for delivering the silver compounds from the gastrointestinal tract to the skin for argyria was proposed. It was also proposed not to completely exclude the partial participation of silver chloride along with the silver proteinates in this process.

Comparative analysis of SERS-active colloidal silver solutions of various type and prospects of their applications

Raman spectroscopy is a promising method for optical vibrational spectroscopy. Nowadays, Raman spectroscopy finds many applications, in particular, in biological and medical diagnostics. However, the Raman scattering can be enhanced using the Surface-enhanced Raman scattering method. Colloidal solutions of noble metals are used as SERS-active systems. In this work, the enhancing factors were estimated for colloidal silver solutions of three different types (citrate, borohydride, chloride) with two substances (phenylalanine, cytochrome C). Phenylalanine is a widely used model substance for Raman and Surface-enhanced Raman spectroscopy. Cytochrome C is one of the most researched proteins. It involves in the electron transport chain of the mitochondrial inner membrane and provides cellular respiration. Borohydride, citrate and chloride sols with phenylalanine gave an enhancement about 50, 200 and 30 times, respectively, and with cytochrome C about 30, 160 and 20, respectively. A comparative analysis of active and inactive sols by SERS and absorption spectroscopy was also performed. The absorption spectra of active sols have characteristic maxima in the region of 400 nm. Both the SERS method of model substances and absorption spectroscopy can be used to assess the enhancing properties.

Zingiber officinale Roscoe (Ginger) as a Complementary Option for Clinical Treatment of Endometriosis: An Experimental Study in Rats.

Endometriosis was induced (autotransplant) in Wistar rats. After 21 days, the rats were randomly divided into two groups (16 female rats each). Control group was forced-fed 0.9% sodium chloride solution, and the ginger group was forced-fed 0.5 mg/100 g of Zingiber officinale Roscoe fresh extract, both by gavage, for 14 days, in addition to their normal diet. After that, an anesthetic dose (ketamine/xylazine) was administered until euthanasia. Peritoneal lavage fluid was collected to evaluate tumor necrosis factor (TNF)-α and interleukin (IL)-6, and autotransplant was measured and excised to evaluate histology. The final mean volumes were larger in the control group (120.92 mm3 ± 78.91) than in the ginger group (40.50 mm3 ± 19.57) (P = .01). The endometriosis foci increased in the control group from 45.10 mm3 ± 29.96 at 21 days postimplantation to 120.92 mm3 ± 78.91 on the day of euthanasia (P = .02). In the ginger group, a slight increase was observed from 38.43 mm3 ± 19.96 to 40.50 mm3 ± 19.57, without statistical difference (P = .83). In addition, a greater increase in growth of the endometriosis foci was found when compared with the control (75.81 mm3 ± 58.95) and ginger groups (2.07 mm3 ± 18.87) (P = .004). No difference was found in TNF-α (P = .51) and in IL-6 (P = .12). The degree of lesion atrophy was higher in the ginger group (1 ± 0.92) than in the control group (2.25 ± 1.16) (P = .03). The ginger extract reduced and atrophied autotransplanted endometriosis foci, but did not reduce IL-6 and TNF-α in the peritoneal lavage fluid.

The Properties Difference of the Composites Based on the Float-Glass with the Bilateral Sol-Gel Films Studies

It has been determined the influence of the substrate from the float-glass parties on the composites with the bilateral nano film main optical characteristics (the refractive index and the reflectivity coefficient) and the nano film thickness as the nano photonics element. The composites and the nano films these characteristics dependences on the parties of the float-glass substrate (gas and tin) on which one or double-layers film was drawn at the speed values of 3.8, 5.8 and 17.3 mm/s have been studied. These studies show that the composites properties and the nano films thickness were sensitive both to the film drawing speed and to the float-glass parties (gas or tin) on which these nano films were drawn. These properties of the composites with the nano films drawn from the nitrate and chloride sols are different from each other.

Preparation of nanostructured activated alumina and hybrid alumina–silica by chemical precipitation for natural gas dehydration

In this study activated alumina nanostructure was prepared by precipitation method using aluminum chloride sol, aluminum nitrate and aluminum isobutanolate as a precursor at ambient temperature in the pH range of 10–11. The calcination of dried precipitation at 700°C for 3h produced activated gamma alumina with nanostructure (⩽10nm). The nitrogen isothermal adsorption method was applied to measure the BET specific surface area, total pore volume and pore diameter. Microstructure and morphological analyses were carried out using X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Humidity sorption capacity of adsorbents measured with aqueous saturated salt solutions. Maximum sorption capacity at 10% and 60% relative humidity obtained 7.7% and 18.1%, respectively.

A versatile synthesis of highly bactericidal Myramistin® stabilized silver nanoparticles

Silver nanoparticles stabilized by a well-known antibacterial surfactantbenzyldimethyl[3-(myristoylamino)propyl]ammonium chloride(Myramistin®) were produced for the first time by borohydride reduction of silver chloride sol in water.Stable aqueous dispersions of silver nanoparticles without evident precipitationfor several months could be obtained. In vitro bactericidal tests showed thatMyramistin® capped silver NPs exhibited notable activity against six differentmicroorganisms—gram-positive and gram-negative bacteria, yeasts and fungi.The activity was up to 20 times higher (against E. coli) compared toMyramistin® at the same concentrations and on average 2 times higher if compared with citrate-stabilizedNPs.

Interfacial structure of annealed alumina – zirconia – silicate nanoceramics

An alumina – zirconia nanocomposite has been produced using the chloride sol – gel method and embedded into a silicate matrix by dispersing the nanocomposite into a powdered silica glass and subsequent annealing. The resultant nanoceramic was subjected to 27Al magic angle spinning (MAS) NMR, small angle X-ray scattering (SAXS), and X-ray photoelectron spectroscopy (XPS), leading to a core-shell type model of the interfacial region. Initially the particles are agglomerated with the shell containing mainly atoms of octahedral coordination and the core aluminium atoms of tetrahedral coordination. Upon annealing the agglomerates break up, causing a change in the coordination of the aluminium atoms. As the atoms diffuse into the matrix, the ones that were initially in the shell change to be tetrahedrally coordinated, and therefore increase the overall population of tetrahedrally coordinated aluminium atoms within the interface.

Electrocatalytic reactions of phenolic compounds at ferric ion co-doped SnO2:Sb5+ electrodes

The anodic voltammetric responses for some phenolic compounds (phenol, p-chlorophenol, p-nitrophenol, p-aminophenol, p-methoxyphenol and hydroquinone) can be significantly enhanced at the Sb5+ and Fe3+ co-doped SnO2 electrodes as compared to those at the Sb5+ doped SnO2 electrodes. Tin dioxide based electrodes, Sb5+ and smaller amounts of Fe3+ ion co-doped SnO2 electrodes, are prepared on Ti substrates by a thermal decomposition method from the chloride sol. The electrocatalytic activities of SnO2:Sb5+,Fe3+ electrodes are sensitive to the content of the co-doped Fe3+ ion as well as that of Sb5+ion, and the maximum activity for the anodic oxidation of phenolic compounds has been found at the SnO2:Sb5+(5%),Fe3+(0.5%) electrode. The larger response at the SnO2:Sb5+(5%),Fe3+(0.5%) electrode is demonstrated to result from increased values of the apparent heterogeneous rate constants (kapp) for the corresponding anodic reactions at the electrode surfaces, which is caused by the enhanced adsorption of the phenolic compounds at Sb-sites at the electrode surface via the non-bonded electron pairs of the hydroxyl group in acidic media. The electrocatalytic benefit of the SnO2:Sb5+(5%),Fe3+(0.5%) electrode is anticipated to be a result of the increased number of Sb5+ sites in the lattices due to the charge compensation by Fe3+ ion.

Electrocatalytic reactions of phenolic compounds at ferric ion co-doped SnO 2:Sb 5+ electrodes

The anodic voltammetric responses for some phenolic compounds (phenol, p-chlorophenol, p-nitrophenol, p-aminophenol, p-methoxyphenol and hydroquinone) can be significantly enhanced at the Sb 5+ and Fe 3+ co-doped SnO 2 electrodes as compared to those at the Sb 5+ doped SnO 2 electrodes. Tin dioxide based electrodes, Sb 5+ and smaller amounts of Fe 3+ ion co-doped SnO 2 electrodes, are prepared on Ti substrates by a thermal decomposition method from the chloride sol. The electrocatalytic activities of SnO 2:Sb 5+,Fe 3+ electrodes are sensitive to the content of the co-doped Fe 3+ ion as well as that of Sb 5+ion, and the maximum activity for the anodic oxidation of phenolic compounds has been found at the SnO 2:Sb 5+(5%),Fe 3+(0.5%) electrode. The larger response at the SnO 2:Sb 5+(5%),Fe 3+(0.5%) electrode is demonstrated to result from increased values of the apparent heterogeneous rate constants ( k app) for the corresponding anodic reactions at the electrode surfaces, which is caused by the enhanced adsorption of the phenolic compounds at Sb-sites at the electrode surface via the non-bonded electron pairs of the hydroxyl group in acidic media. The electrocatalytic benefit of the SnO 2:Sb 5+(5%),Fe 3+(0.5%) electrode is anticipated to be a result of the increased number of Sb 5+ sites in the lattices due to the charge compensation by Fe 3+ ion.

Surface-Enhanced Resonance Raman Scattering Study on Adsorption of Spectral Sensitizing Dyes on Silver Chloride Sols

In this paper, the Surface-enhanced Resonance Raman Scattering (SERRS), spectra of 1-ethyl-3-methylthia-2-cyanine iodide (D-1), 1,1'-diethyl-2,2'-cyanine iodide (D-2) and crystal violet (CV) adsorbed on the surface of silver chloride colloids are recorded and discussed

SERS of dimethyl sulphoxide on silver electrodes and on silver chloride sol

The surface enhanced Raman spectra of dimethyl sulphoxide were observed on polycrystalline silver electrodes. Spectra of similar intensities were recorded for electrode surfaces activated by the oxidation-reduction cycle and by scanning only within the range of more negative potentials. The micrographs obtained by scanning electron microscopy indicated that both surfaces are rough. In the case of an anodized silver electrode in a chloride medium, the SERS spectrum could be superimposed on the bulk DMSO spectrum enhanced by interaction with particles of silver chloride sol produced during the oxidation-reduction cycle.

Surface-enhanced Raman scattering and enhanced fluorescence of dyes on silver chloride sols

The enhanced fluorescence and enhanced Raman spectra of dye-1555 molecules adsorbed on silver chloride sols are detected for the first time. The enhanced fluorescence is attributed to the double resonance effect proposed by Chew and Wang. The enhanced Raman spectra indirectly support the energy-transfer model of spectral sensitization of dyes, one of two competing mechanisms of spectral sensitization in the photographic process.

Glass capillary columns for gas chromatography coated with non-extractable films of cyanosilicone rubbers

A procedure for the preparation of glass capillary columns using a bonded cyanosilicone rubber as stationary phase is presented. Two types of cyanosilicone pre-polymer were synthesized, with 25% and 100% cyano-substitution, respectively. Glass capillaries that had been leached with HCl or treated with a sodium chloride sol were coated with the pre-polymer, and a rubber was formed situ. Such columns show very good thermal stability up to 300°C; further, activity is low and the efficiency good. The utility of these thermally stable polar columns is demonstrated by the analysis of aldononitrile derivatives prepared from sugars and also polynuclear aromatics (PNAs), especially aza-PNAs.

The Halide Conversion of Silver Chloride and of Silver Bromide: a Kinetic Study

AbstractThe conversions of silver chloride sols into silver bromide and of silver bromide sols into silver iodide have been Studied potentiometrically. Both reactions follow the same kinetics and have activation energies of 11.1 ±1.5 and 9.5±0.6 kcal. mole–1 respectively. The addition of gelatin to the sols retards the reactions and increases their apparent activation energies to 22.7 ±0.7 and 23.3 ±0.6 kcal.mole–1, respectively. Also, P.V.A. retards the conversion of silver bromide and raises the activation energy of this reaction to 18.1 ±0.6 kcal.mole–1

Stability of polyvinyl chloride latex: III. Effects of simple electrolytes

The stability and electrophoretic mobility of a polyvinyl chloride sol at various concentrations of sodium and magnesium salts was studied as a function of the surface concentration of an anionic surfactant, the dodecyl sulfate. The adsorption isotherm of the latter was determined spectrophotometrically as a function of the sol concentration and the electrolyte concentration in the medium. Stability results were found to compare favorably with DLVO theory predictions. The mobility study showed electrophoretically derived surface concentrations to be poor indicators of sol stability. In addition, the presence of a permanent particle surface charge, attributed to catalyst fragments, was established.

Water Structure around Silver Iodide Sol Particles

IN order to explain lower values of differential capacity at the negative silver iodide/solution interface than at the mercury/solution interface, Lyklema1 proposed that the Stern layer in the former may be of icelike (tetrahedral) structure, and pointed out that this would also explain the greater specificity of cations in the silver iodide case. More recently Levine and Bell2 have commented that such structure would tend to remove the distinction between inner and outer Helmholtz planes so that the fluctuation potential would become small, this making the maximum in the outer Helmholtz plane potential much less marked. This effect would then explain the relative constancy of the flocculation concentration for silver iodide sols at high (negative) potentials3,4 compared with those of silver bromide and silver chloride sols, which have been reported5 to decrease at high negative potentials. The hypothesis is supported by the well-known epitaxis of ice on silver iodide which is more effective near the zero point of charge6.

The formation, growth, and stability of silver chloride sols

A mechanistic investigation of sol formation by precipitation from homogeneous solution has been performed by interpretation of conductivity data. Initiation of growth occurred by heterogeneous nucleation upon impurity particles of approximate average radius 20 a and continued by a surface controlled process. In the later stages of growth, sedimentation and changes in colloidal stability affected the growth rate and the concentration of silver and chloride ions producing zero point charge in supersaturated solutions could readily be calculated.

Association phenomena. I. The growth of particles of silver chloride and the higher-order tyndall effect

1. 1. Monodispcrscd silver chloride sols were prepared which were stable for various periods of time depending on the initial concentrations. 2. 2. The higher order Tyndall light given off by such silver chloride sols was investigated. 3. 3. The transmittance of silver chloride sols was studied as a function of time.