Ion Liberation Research Articles

Geochemical effects of carbonated water on reservoir and caprock minerals for carbon capture and storage

CO2 can be safely stored in geological formations, such as deep saline aquifers and depleted oil or gas reservoirs. However, knowledge about caprock and storing bed integrity is essential for safe storage in sedimentary porous rocks. In this study typical carbonate and sandstone minerals present in the reservoir and caprocks have been exposed to carbonated water above supercritical conditions of CO2 for short time periods (7 days) to investigate the CO2-brine-rock interactions and their effects on mineral stability. After exposure, the equilibrated brine composition was determined and any changes to the mineral samples were examined by SEM, EDX and XRD analyses. The solubility of CO2 in brines was low, increasing with pressure and decreasing with salinity, and no significant increase in CO2 solubility was observed above critical pressure and temperature for CO2. Quartz and clay minerals were the least reactive sandstone minerals, while ion exchange reactions were observed for the feldspar minerals. For calcite minerals, calcium ion liberation was observed accompanied by a pH increase, which is linked to mineral dissolution. SEM, EDX and XRD analyses did not detect any changes on the surfaces of silicate and carbonate minerals exposed to the carbonated water. The overall results confirm minimal effects on silicate and carbonate minerals after short-term exposure to carbonated water above supercritical conditions of CO2.

Calcium bioaccessibility as affected by strontium. Temperature effect on citrate binding to strontium and calcium alone and in combination

Strontium as a bone health promoter was found to increase the bioaccessibility of essential calcium from solid calcium citrate tetrahydrate in aqueous suspensions. This is unexpected since calcium citrate binds calcium stronger than strontium with ΔH0ass,c = 5.07 kJ⋅mol−1, ΔS0ass,c = 78.0 J⋅mol−1⋅K−1 for 1:1 Ca-Citrate complex formation and ΔH0ass,c = 1.67 kJ⋅mol−1, ΔS0ass,c = 58.3 J⋅mol−1⋅K−1 for 1:1 Sr-Citrate complex formation as determined both electrochemically and by isothermal titration calorimetry. Calcium citrate tetrahydrate has reverse solubility around physiological temperature in contrast to strontium citrate pentahydrate. This difference results in opposite effect of strontium upon calcium ion liberation from calcium citrate suspensions at both low and high temperature compared to physiological temperature, for which strontium was found to stabilize solid calcium citrate tetrahydrate. This effect, confirmed by quantum mechanical calculation and by comparison of spontaneous aqueous supersaturation of calcium citrate and strontium citrate, is suggested to be involved in the positive effect of strontium on bone and teeth health. The conclusions provide a theoretical foundation for the research of molecular mechanisms among calcium, strontium, and citrate ions in relation to bone and teeth health.

Ammonium release in synthetic and human urine by a urease immobilized nanoconstruct.

In this work, we have studied the ability of urease immobilized on glutaraldehyde crosslinked chitosan coated magnetic iron oxide nanoparticles (Urease/GA/CS/MIONPs), for the hitherto unreported comparative hydrolysis of urea in synthetic (SUr) and real human urine (HUr). The prepared Urease/GA/CS/MIONPs were characterized by a combination of Fourier transform infrared spectroscopy (FTIR), field emission-scanning-electron-microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX) and dynamic light scattering (DLS). The nanoconstructs display the highest ammonium ion liberation post-urea hydrolysis in 1/20 or 1/24-fold dilutions of SUr and HUr, respectively. The optimum activity of immobilized urease is observed at pH 7, and the nanoconstructs facilitate efficient urea-hydrolysis till at least 45 °C. Kinetic analysis of the immobilized urease shows km and vmax of 14.81 mM, 12.36 mM, and 18.55 μM min-1 and 10.10 μM min-1, towards SUr and HUr, respectively. The magnetization of the immobilized urease is suitable for reuse across multiple cycles of urea hydrolysis in SUr and HUr. The robust performance of Urease/GA/CS/MIONPs in SUr and HUr is promising for generating ammonium as a useable source of nitrogen from human urine, and underscores the suitability of SUr as a urine mimic for such interventions.

Investigating Electrosprayed Droplets Using Particle-into-Liquid Sampling for Nanoliter Electrochemical Reactions

Electrospray ionization (ESI) is a powerful ionization technique that can generate charged solvent droplets and bare analyte ions from sample solutions. Despite seeing extensive use in mass spectrometry due in part to the low internal energy deposited into the ions formed during ionization, some unknowns persist regarding the exact dynamics of droplet breakup and molecule behavior during spray, and research is still underway regarding how various types of molecules acquire charge during the ESI process. Previously, the authors introduced a novel aerosol measurement technique, particle-into-liquid sampling for nanoliter electrochemical reactions (PILSNER). The current work introduces a new method utilizing PILSNER for the examination of the particles generated during ESI using simple analysis techniques with a commercially available potentiostat. This technique is applied in this work for the detection of charges on electrosprayed droplets, including the estimation of the number of charges on individual ESI droplets using a fluorescent proxy. This technique provides an additional tool for the exploration of the complex process of droplet generation and ion liberation during ESI.

Tribocorrosion Evaluation of Nb2O5, TiO2, and Nb2O5 + TiO2 Coatings for Medical Applications

Materials used in biomedicine for purposes of long-time stay inside the body presents diverse sort of problems like cytotoxicity, wear, biocompatibility, and ion liberation along time. This paper presents the characterization of corrosion-wear combined phenomena on Nb2O5, TiO2, and Nb2O5 + TiO2 coatings with future applications as biomaterials. After the films’ production process using magnetron sputtering technique, they were characterized through an optic, scanning electron, and atomic force microscopy to evaluate their morphology, structure, and surface damage suffered by the synergy between wear and corrosion phenomena. The life in service of the implant was evaluated in terms of the coating behavior against inside body conditions like charge, wear, and electrochemical degradation. This test was made with electrochemical measurements in simulated biological fluid combined with the wear characterization implementing a potentiostat and a tribometer in a linear wear configuration with a bone pin. As a result, the different electrochemical responses of the films were evidenced by polarization curves and equivalent circuits of the systems. The coefficient of friction and surface degradation were also obtained and evaluated. Comparing the properties of the systems, we conclude that TiO2 coatings have better behavior in terms of the wear-corrosion synergy phenomena while the systems with Nb present pitting corrosion.

Origin of Degradation in Perovskite Solar Cells by Intensity Modulated Photovoltage Spectroscopy Measurement (IMVS)

Perovskite solar cells (PSCs) based on lead halide perovskite have attracted much attention owing to the fast development of their power conversion efficiency (PCE) from 3.8% to 25%. Various factors play important roles in affecting the conversion efficiency of PSCs, such as charge carrier generation, transport, recombination, and collection. In addition, the presence of interfacial defects has also a crucial effect in charge carrier transfer and recombination processes. However, the origin and mechanism of interfacial charge recombinations in PSCs are still not comprehensively investigated. For that purpose, we have performed intensity-modulated photovoltage spectroscopy (IMVS) and transient photovoltage (TPV) measurements of PSCs, which were fabricated with FTO/c-TiO2/mp-TiO2/Perovskite/PTAA/Au cell structure. The solar cell (J-V) characteristics of the PSCs on the day-1, day-2, day-3, and day-6 after the cell fabrication, indicating a significant degradation of the cell with time. The Nyquist plots of IMVS measurement on the same day as the J-V measurement seem to be composed of two semicircles at a lower frequency range and a higher frequency range. The semicircle at the lower frequency range enlarged on the day-6 measurement, but the semicircle at higher frequency decreased. The change of this Nyquist plot is in agreement with a significant decrease in the J-V curves. The semicircle at lower frequency may be assigned to the ion diffusion or migration. Therefore, cell degradation may be caused by the liberation of ions (including iodide) from the surface of the perovskite crystal structure. It then increases recombination loss due to back charge transfer from TiO2 to perovskite as indicated by the changing of the semicircle at high frequency into a smaller semicircle. Therefore, the present results reemphasize that the improvement of PSC stability needs the prevention of ions liberations from the surface by introducing passivation substances. In addition, the results also show the practical usefulness of IMVS for inspecting PSC degradation due to such an ion liberation process.

Silver, copper, and copper hydroxy salt decorated fumed silica hybrid composites as antibacterial agents

Decoration of matrices such as silicates, graphene, etc. is an efficient technique in order to develop multifunctional materials with enhanced properties, which are of use for microbial control. Consequently, it leads to an increased search for alternative matrices and synthesis methods for decoration. Herein, decoration of a fumed silica is proposed, with structures that consisted of silver (Ag@FS), copper hydroxy salt (CuHS@FS), and copper (Cu@FS), for antibacterial applications. With the simple combination of the metal precursor salt, the appropriate solvent, and the fumed silica, the composites were obtained by one-pot solvothermal (200 °C for 1 h), rapid (2 min) microwave assisted precipitation, and by ascorbic acid chemical reduction, respectively. Characterization by powder X-ray diffraction (XRD), thermogravimetric analysis (TGA), and field emission scanning electron microscopy (FE-SEM) proved the successful decoration of the fumed silica with layered copper hydroxy salt (90 width x 970 length nm) and round-like metallic Ag (210 nm) and Cu (370 nm) particles. Fourier transformed infrared (FTIR) and Raman spectroscopy evidenced the presence of SiOMetal interactions. The antibacterial activity was evaluated against the Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, giving inhibition and bactericidal values between 3−12 mg/ mL and 12−24 mg/ mL, respectively, with a maximum ion liberation ratio of 1.4 %. The application of the fumed silica presented here, is an attractive alternative to existing matrices, in order to fabricate multifunctional materials, as it is ready-to-use and feasible for large-scale production. Moreover, the applied synthesis routes provide rapid approaches for decoration, creating composites useful for antibacterial applications.

PEO coatings design for Mg-Ca alloy for cardiovascular stent and bone regeneration applications.

Four bioactive PEO (plasma electrolytic oxidation) coatings were generated on Mg0.8Ca alloy using a Ca/P-based electrolyte and adding Si or Fas necessary. Surface characteristics, chemical composition and ion liberation of the coatings were characterized using SEM/EDS (Scanning Electron Microscopy/Energy Dispersive X-ray spectroscopy), X-ray diffraction, optical profilometry and ICP-OES (inductively coupled plasma optical emission spectrometry). Direct biocompatibility studies were performed by seeding premyoblastic, endothelial and preosteoblastic cell lines over the coatings. Biocompatibility of the coatings was also evaluated with respect to murine endothelial, preosteoblastic, preosteoclastic and premyoblastic cell cultures using extracts obtained by the immersion degradation of the PEO-coated specimens. The coatings reduced the degradation of magnesium alloy and released Mg Ca, P, Si and F. Of all the studied compositions, the Si-containing PEO coating exhibited the optimal characteristics for use in all potential applications, including bone regeneration and cardiovascular applications. Coatings with high F content negatively influenced the endothelial cells. RAW 264.7, MC3T3 and co-culture differentiation studies using extracts of PEO coated Mg0.8Ca demonstrated improved osteoclastogenesis and osteoblastogenesis processes compared to bare alloy.

Bonding durability, antibacterial activity and biofilm pH of novel adhesive containing antibacterial monomer and nanoparticles of amorphous calcium phosphate

ObjectivesThe dentin bonding often fails over time, leading to secondary caries and restoration failure. The objectives of this study were to develop an adhesive with dimethylaminohexadecyl methacrylate (DMAHDM) and nanoparticles of amorphous calcium phosphate (NACP), and investigate the effects of storage in artificial saliva for six months on the bonding durability, antibacterial activity, ion release and biofilm pH properties for the first time. MethodsDMAHDM was added at 5% (by mass) to Scotchbond Primer and Adhesive (SBMP). NACP was added at 10%, 20%, and 30% to SBMP adhesive. Dentin bonding durability, antibacterial activity against Streptococcus mutans biofilms, and calcium (Ca) and phosphate (P) ion liberation properties were investigated after 1 day and 6months of storage in artificial saliva. ResultsDentin bond strength (n = 50) had 25% loss after 6 months of aging for SBMP control. However, SBMP + DMAHDM+10NACP and SBMP + DMAHDM+20NACP showed no loss in bond strength after storage in artificial saliva for 6 months. The DMAHDM + NACP incorporation method dramatically reduced the biofilm metabolic activity and acid production, and decreased the biofilm CFU by four orders of magnitude, compared to SBMP control, even after 6 months of aging (p < 0.05). DMAHDM + NACP had long-lasting Ca and P ion releases, and raised the biofilm pH to 6.8, while the control group had a cariogenic biofilm pH of 4.5. ConclusionsIncorporating DMAHDM + NACP in bonding agent yielded potent and long-lasting antibacterial activity and ions liberation ability, and much higher long-term dentin bond strength after 6-month of aging. The new bonding agent is promising to inhibit caries at the restoration margins and increase the resin-dentin bonding longevity. Clinical significanceThe novel bioactive adhesive is promising to protect tooth structures from biofilm acids and secondary caries. NACP and DMAHDM have great potential for applications to a wide range of dental materials to reduce plaque and achieve therapeutic effects.

Bioactive multi-elemental PEO-coatings on titanium for dental implant applications

Bioactive PEO (Plasma Electrolytic Oxidation) coatings were generated on Grade I commercially pure titanium for dentistry applications using a Ca/P-based electrolyte with added Si, Mg, Zn or F species. Surface characteristics, chemical composition and ion liberation of the coatings were characterized using SEM/EDS, X-ray diffraction, optical profilometry, contact angle and ICP-OES. Corrosion resistance (OCP and DC polarization) was evaluated in SBF. Osteoblastogenesis and osteoclastogenesis processes on PEO-coated Ti and non-coated Ti controls were assessed after 7 days and 5 days of cell culture, respectively. Monolayer formation and metabolic activity were evaluated for the MC3T3 preosteoblastic cell line. All PEO coatings favoured differentiation processes over proliferation and presented three times greater quantity of secreted collagen than non-coated Ti control. All coating enabled osteoclast differentiation, with differences in number and size of the osteoclasts between the materials.

Effect of ultrasonic activation on calcium ion quantification, smear layer removal, and canal cleaning efficacy of demineralizing irrigants.

Background:Effective removal of smear layer ensures better penetration of irrigants ensuring root canal disinfection and has the potential of sealing dentinal tubules during obturation.Aim:The aim of this study is to evaluate the canal cleaning efficacy and calcium ion liberation with the use of demineralizing irrigants, namely, 17% ethylenediaminetetraacetic acid (EDTA), 7% maleic acid, and 10% citric acid with or without ultrasonic (US) activation.Materials and Methods:Crowns of 62 extracted maxillary central incisors were decoronated and root canals prepared. Based on the final irrigant teeth were divided into following groups (n = 10), namely, 10% citric acid, 7% maleic acid, 17% EDTA, and 10% citric acid with US activation, 7% maleic acid with US activation, and 17% EDTA with US activation. Irrigants were subjected to inductively coupled plasma–atomic emission spectroscopy followed by debris scoring and scanning electron microscope analysis.Statistical Analysis:One-way analysis of variance with the Bonferroni's correction for multiple testing was employed.Results:About 10% citric acid with US activation liberated the highest calcium ions and removed the maximum smear layer.Conclusions:Citric acid with US activation is a potentially effective irrigation regimen with sodium hypochlorite.

An optimised spectrophotometric assay for convenient and accurate quantitation of intracellular iron from iron oxide nanoparticles

We report the development and optimisation of an assay for quantitating iron from iron oxide nanoparticles in biological matrices by using ferene-s, a chromogenic compound. The method is accurate, reliable and can be performed with basic equipment common to many laboratories making it convenient and inexpensive. The assay we have developed is suited for quantitation of iron in cell culture studies with iron oxide nanoparticles, which tend to manifest low levels of iron. The assay was validated with standard reference materials and with inductively coupled plasma-mass spectrometry (ICP-MS) to accurately measure iron concentrations ∼1 × 10−6 g in about 1 × 106 cells (∼1 × 10−12 g Fe per cell). The assay requires preparation and use of a working solution to which samples can be directly added without further processing. After overnight incubation, the absorbance can be measured with a standard UV/Vis spectrophotometer to provide iron concentration. Alternatively, for expedited processing, samples can be digested with concentrated nitric acid before addition to the working solution. Optimization studies demonstrated significant deviations accompany variable digestion times, highlighting the importance to ensure complete iron ion liberation from the nanoparticle or sample matrix to avoid underestimating iron concentration. When performed correctly, this method yields reliable iron ion concentration measurements to ∼2 × 10−6 M (1 × 10−7 g/ml sample).

In-Spray Supercharging of Peptides and Proteins in Electrospray Ionization Mass Spectrometry

Enhanced charging, or supercharging, of analytes in electrospray ionization mass spectrometry (ESI MS) facilitates high resolution MS by reducing an ion mass-to-charge (m/z) ratio, increasing tandem mass spectrometry (MS/MS) efficiency. ESI MS supercharging is usually achieved by adding a supercharging reagent to the electrospray solution. Addition of these supercharging reagents to the mobile phase in liquid chromatography (LC)-MS/MS increases the average charge of enzymatically derived peptides and improves peptide and protein identification in large-scale bottom-up proteomics applications but disrupts chromatographic separation. Here, we demonstrate the average charge state of selected peptides and proteins increases by introducing the supercharging reagents directly into the ESI Taylor cone (in-spray supercharging) using a dual-sprayer ESI microchip. The results are comparable to those obtained by the addition of supercharging reagents directly into the analyte solution or LC mobile phase. Therefore, supercharging reaction can be accomplished on a time-scale of ion liberation from a droplet in the ESI ion source.

Particulate gold as an anti‐inflammatory mediator in bone allograft—An animal study

Morselized allograft is widely used when increased bone stock is needed in implant surgery. Gold ions liberated from metallic gold surfaces act in an anti-inflammatory manner by inhibiting cellular NF-κB-DNA binding and suppressing I-κ B-kinase activation. This study investigated the effect of 45-63 μm sized gold particles mixed in morselized allograft. It was hypothesized that bio-released gold ions would influence allograft reabsorption, increase mechanical stability, and further stimulate osseointegration. A pair of 10 mm long implants surrounded by a 2.5-mm gap was inserted in proximal part of each humerus in 10 sheep. Each gap was filled with morselized allograft with 1.29 mg gold particles or nothing. Observation time was 12 weeks. The gold ion liberation was visualized by autometallographic tracing and showed liberation of gold ions. Biomechanical push-out tests and stereological histomorphometric analyses showed no statistically significant differences in the two groups. Although particulate gold was primarily observed surrounded by bone marrow tissue, no obvious clinically relevant short-term effects could be measured using gold as an anti-inflammatory mediator. These findings show that the released gold ions have only influenced cells adjacent to the particles without influencing the fixation and illustrates gold ions' limited field of effect. We suggest a new design for orthopedic implants by introducing gold dots on the prosthesis surface. This aims at suppressing the inflammatory foci along the implant-bone zone and reduces the risk of chronic inflammation before aseptic loosening without affecting bone remodeling. This implant model will be investigated in further studies.

Vehicle influence on calcium hydroxide pastes diffusion in human and bovine teeth

The purpose of this study was to compare the pH and calcium ion liberation after use of calcium hydroxide pastes with different paste vehicles in human or bovine teeth. Ninety-two single-rooted human and bovine roots were used. The roots were instrumented and an external cavity preparation was performed. The roots were divided in to human and bovine groups. Each group was subdivided into four subgroups (SB) according to the vehicle:SB1, detergent; SB2, saline; SB3, polyethylenoglycol + camphorated paramonochlorophenol (Calen PMCC) and SB4, polyethylenoglycol + furacyn paramonochlorophenol (FPMC). Specimens were immersed into saline solution at 37 degrees C and after 7 and 14 days pH and calcium ion measurements were made. The results were analyzed by anova and Tukey tests (P < 0.05). There was no statistical difference between bovine and human teeth in the pH analysis (P < 0.05), but bovine teeth provided larger calcium ion liberation than human teeth. Calen PMCC was statistically more effective for pH increase and calcium ion liberation in all analyses, followed by FPMC and saline. Detergent showed the lowest pH alterations and calcium ion liberation. The period of 14 days showed more calcium ionic liberation than the 7-day period.

Kinetic determination of morphine in illicit powders, using a fluoride selective electrode, based on reaction with 1-fluoro-2,4-dinitrobenzene

A simple, accurate and selective method is described for the determination of morphine in illicit powders, based on monitoring the initial rate of fluoride ion liberation from the reaction of morphine with 1-fluoro-2,4-dinitrobenzene at pH 9 and 35 °C, using a solid-state fluoride ion-selective electrode. Under optimized reaction conditions, as little as 15 μg/ml of morphine is determined with an average recovery of 99.5% and a mean relative standard deviation of 1.2%. Determination of morphine in real illicit powders containing 6–18% morphine gives results comparing favorably with those obtained from isocratic reverse-phase high-performance liquid chromatography. No interferences are caused by many structurally related and associated compounds such as codeine, acetylcodeine, ethylmorphine, acetylmorphine and diacetylmorphine (heroin).

Iron and manganese release in coal mine drainage wetland microcosms

The primary mechanisms responsible for the removal and retention of iron, manganese, and sulfate in constructed wetlands receiving acidic mine drainage (AMD) include the formation of metal oxides and sulfides within the sediments. This study was initiated to determine the kinetics of metal ion liberation, under reducing conditions, from synthetic and naturally occurring iron and manganese oxides typically found in AMD precipitates. Rates of metal ion liberation were determined during time series incubations of an organic substrate (spent mushroom compost) to which five metal oxides of varying crystallinity (amorphous and crystalline oxides of iron and manganese; natural AMD oxide) were added. All experiments were carried out in silicone-sealed polycarbonate centrifuge tubes incubated at 22°C for a period of 3, 7, 10, 14, 21 or 28 days. Tubes were sacrificed after each incubation period and were analyzed for redox potential, pH, sulfide, and metals. All tubes exhibited reducing potentials within 3 days coupled with rapidly increasing concentrations of iron and manganese. Liberation of iron and manganese decreased with increasing mineral crystallinity (amorphous &amp;gt; natural AMD ≫ crystalline). The results suggest that metal ion liberation from oxide minerals may be an important source of iron and manganese within constructed wetlands receiving AMD.

Iron and manganese release in coal mine drainage wetland microcosms

The primary mechanisms responsible for the removal and retention of iron, manganese, and sulfate in constructed wetlands receiving acidic mine drainage (AMD) include the formation of metal oxides and sulfides within the sediments. This study was initiated to determine the kinetics of metal ion liberation, under reducing conditions, from synthetic and naturally occurring iron and manganese oxides typically found in AMD precipitates. Rates of metal ion liberation were determined during time series incubations of an organic substrate (spent mushroom compost) to which five metal oxides of varying crystallinity (amorphous and crystalline oxides of iron and manganese; natural AMD oxide) were added. All experiments were carried out in silicone-sealed polycarbonate centrifuge tubes incubated at 22°C for a period of 3, 7, 10, 14, 21 or 28 days. Tubes were sacrificed after each incubation period and were analyzed for redox potential, pH, sulfide, and metals. All tubes exhibited reducing potentials within 3 days coupled with rapidly increasing concentrations of iron and manganese. Liberation of iron and manganese decreased with increasing mineral crystallinity (amorphous > natural AMD >> crystalline). The results suggest that metal ion liberation from oxide minerals may be an important source of iron and manganese within constructed wetlands receiving AMD.

Localized All-or-None Calcium Liberation by Inositol Trisphosphate

Laser confocal microscopy was used to monitor calcium ion (Ca2+) liberation from highly localized (micrometer) regions of intact Xenopus oocytes in response to photo-released inositol 1,4,5-trisphosphate (InsP3). Local Ca2+ release varied in an all-or-none manner with increasing amount of InsP3, in contrast to signals recorded from larger areas, which grew progressively as the concentration of InsP3 was raised above a threshold. Liberation of Ca2+ was restricted to within a few microns of the site of InsP3 release and, in response to agonist activation, localized regions of the oocyte showed asynchronous oscillations in cytoplasmic Ca2+ release. Results obtained with this technique provided direct evidence that InsP3-induced Ca2+ liberation was quantized and suggest that the InsP3-sensitive Ca2+ pool may be a collection of independent, localized compartments that release Ca2+ in an all-or-none manner.

Physical, chemical and biological studies on transition metal complexes of chelating tridentate ligand

The interaction of 1-benzoin-4-phenylthiosemicarbazone (H2 BPS) with some transition metal ions has been investigated. The ligand can function as a tridentate chelating agent, giving M(HBPS)2 and M(BPS). Potentiometric studies proved that the mechanism of chelation is based on hydrogen ion liberation. Spectral studies in solution show that the ligand could be used for the microdetermination of CuIIions. On the basis of magnetic and spectral data, an octahedral structure is proposed for the CoII and NiII complexes and a square-planar structure for the CuII complex. The corrosion inhibition of aluminium in Cl3CCO2H using H2BPS is studied. The electrical conductivity of H2BPS and of its complexes have been measured. The ligand shows an activation energy in the range of semiconducting materials. The antimicrobial activity of all compounds has also been demonstrated.