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A synthesis by plasma of polymers with structure of oxidized ethylene (PPEO) obtained from ethanol is presented in this work with the objective to obtain hydrophilic and potentially biodegradable PPEO films. The synthesis was carried with rf glow discharges in the 20–120 W interval obtaining films with a 0.38 μm/W growing rate thickness. Morphology, chemical structure, hydrophilicity and absorption of electromagnetic energy in the UV–visible interval were analyzed. The results indicated that PPEO has smooth surfaces with particles and/or folded areas with water contact angles between 72° and 97°, in the limit between hydrophilicity and hydrophobicity. The structural chemical analysis showed the presence of C–H and O–H bonds characteristic of the monomer, and C=O and ≈C≈ groups characteristics of plasma polymers with dehydrogenation and formation of multiple bonds. The absorption of electromagnetic energy of PPEO was more intense in the UV than in the visible wavelength interval. These characteristics indicate that PPEO can be biodegradable under the sunlight and/or under wet environments.

This research presents the obtaining of a biochar (CB) from the use of pomegranate peel (

There are many healthcare facilities in Spain that were built throughout the second half of the 20th century, and compose an interesting built heritage designed by outstanding architects of the architectural avant-garde. Some of them were included in the DOCOMOMO's list of buildings to be preserved and documented. As a consequence, every intervention on the hospitals' heritage requires a special attention and needs a deep knowledge of the building in advance of taking action. On the other hand, such a particular heritage is being continuously updated according to the new standards that derive from the current tendencies in hospital design, and also from advances in healing techniques. In this context, 3D Modelling and virtual reality should have a decisive impact on the way hospitals' complex spaces are designed, as they become useful tools for describing the previous stages of the buildings, as well as the impacts of new proposals. They can even change our experience of the built environment. As a step forward, we are developing a methodology to be applied to hospital design where these tools, together with BIM models -and in the near future, high-end immersive VR systems- play an important role., Ministerio de Economía y Competitividad

This work presents the formation of biochar with calcium nanoparticles (NPsCa) in function of pyrolysis time (C10, C30, C60, C120 and C180 min) using the Citrus tangerina peel and their evaluation in the remotion of Aflatoxin B1 (AFB1) in aqueous phase. Firstly, the Citrus tangerina was studied by Thermogravimetric analysis to determine the optimal temperature (TGA), obtaining a result of 600 °C. The biochar (NPsCa) were characterized by Scanning Electronic Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS), as well as surface properties including the identification of functional groups by Fourier Transform Infrared Spectrometry (FTIR), and energetic states through the X-Ray Photoelectron Spectroscopy (XPS). The adsorption studies were carried out on the different materials and later, the experimental data was adjusted to different mathematical models, obtaining the best fit of the kinetic data to the Ho-McKay model, whilst the adsorption isotherms were adjusted to the model of Langmuir, which indicates that the Aflatoxin B1 adsorption process is carried out through a monolayer chemisorption process with maximum sorption capacities (qm) ranging between 15.72 and 63.22 μg g-1 with the 180th minute being the adequate time to obtain the carbon with the best surface properties and the best adsorption capacity. Additionally, it was observed that each material can be reused up to five times in accordance with the results from the reuse cycles.

Several kinds of paper (Bond, Amate, Rice, Press, and Whatman#1) were studied in their original condition and were then exposed to gamma radiation between 3 and 15 kGy (0.9 kGy/h) with intervals of 3 kGy. The length and width of fibers (SEM) as well as pH were measured, and the chemical composition was determined by EDS. Pyrolysis characteristics (TGA and DTC), transmittance spectra by IR and X-ray diffraction patterns were studied as well. Whatman#1 contains only cellulose; whereas Bond, Press and Rice papers also contain calcite and Amate whewellite. All X-ray diffraction patterns showed Type I semicrystalline cellulose, but a slight presence of Type II was noted in the artisan papers (Amate and Rice). These results were confirmed by IR spectra and thermogravimetric analyses. Due to gamma irradiation no acidification nor change of fiber sizes or alteration of other studied parameters were observed. Therefore, these conditions may be recommended for the treatment of some deteriorated documents.

This research presents a study of environmental monitoring at different sampling sites from the Metropolitan Area of the Valley of Toluca (MAVT) Mexico by means of moss samples. The selected sampling sites included urban, transitional and natural protected areas. The mosses were obtained in two campaigns within two periods of the year: rainy-season and dry-cold-season. During the sampling, seven species of moss were identified, among them: Leskea angustata (Tayl.) and Fabronia ciliaris (Brid.) were the most abundant. One sample of each species was analyzed by SEM in order to determine their morphology. After that, the samples were analyzed by instrumental neutron activation analysis (INAA) and total X-ray fluorescence spectrometry (TXRFS) in order to determine the metals concentration. The results indicate that the Urban Region was significantly impacted by pollution compared to the natural protected Areas. The cluster statistical analysis results indicated that the sampling sites with the highest concentration of metals are located in the urban areas. Enrichment factors show that As, Cr, Cu, Zn, Pb, Se, Cs, and Sb are highly enriched mainly by anthropogenic sources.

Effective Fe-TiOx magnetic nanoparticles were synthesized on pineapple-peel (CPa-Fe/TiOx) to evaluate their As(V) uptake capacity. The nanocomposite was characterized by means of BET surface analysis, SEM, TEM, XRD, FTIR and XPS. The results indicated the obtention of spherical nanoparticles with 5.7 nm of diameter distributed on the surface of pineapple peel with a Ti:Fe molar ratio of 2:1, while DRX indicate that the material is amorphous. IR spectra of the obtained CPa-Fe/TiOx present a number of bands at 3316, 2924, 2852, 1729, 1632, 1371, 1241, 1035, 590 and 545, indicating the existence of hydroxyl and carboxyl groups on the composite material. The nanocomposite was evaluated as an adsorbent of As(V) and experimental parameters as time, pH, concentration and temperature were evaluated. CPa-Fe/TiOx were effective at pH = 5.5, sorption isotherms showed that sorption capacities of the Fe-TiOx, were dependent on the site density, surface area and temperature change. The equilibrium data was modelled with the help of Langmuir and Freundlich equations, based on the values of correlation coefficients (R2) the Langmuir isotherm equation was excellently fitted to the experimental data of the arsenic adsorption with a maximum adsorption uptake of 40 mg/g under the studied conditions. The thermodynamic results showed that the sorption of As(V) onto CPa-Fe/TiOx was feasible, spontaneous and exothermic, through mechanism ligand effect-surface, with the interaction between oxy-hydroxides of Fe and Ti with oxy-anions of arsenic present in solution.

The objective of this work was to synthesize particles of titanium oxide and cerium oxide supported on carbon, which was obtained through the pyrolysis of orange peel. The materials were characterized using scanning electron microscopy, X-ray diffraction, infrared spectroscopy, and the specific surface area from Brunauer-Emmett-Teller method. The photocatalytic properties of the synthesized materials were determined by the degradation of phenol in 30 mg/L aqueous solutions. TiO 2 -CeO 2 particles were obtained with an average spherical size of 57 nm and were supported on the carbon surface; this material presented a specific surface area of 296 m 2 /g and degrades ∼40% of phenol after 240 min of UV irradiation.

The degradation of methyl orange (MO) in presence of a natural zeolite from San Luis Potosi, Mexico, previously homo-ionized with Na cations (HNaZ) and impregnated with iron boride nanoparticles (HNaZ-Fe) is presented. Iron boride nanoparticles (FeB-NPs) synthesized by chemical reduction, as well as HNaZ and HNaZ-Fe materials were characterized by using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray (EDX), Mossbauer and UV–vis spectroscopies. SEM and TEM measurements showed characteristic spherical shapes associated with FeB-NPs with mean diameter of 120 nm and located on the zeolite’s surface. Whereas the homo-ionized zeolitic material, HNaZ, did not present any type of interactions with MO, the HNaZ-Fe material, with a mass ratio 1:0.06 of HNaZ:Fe, respectively, mostly degraded this dye. The kinetic study showed that the degradation process of MO followed the second order kinetic reaction with a degradation rate constant of 0.0012 g/(mg h) and an 80% dye degradation was always obtained for all used concentrations of MO, which ranged from 50 up to 500 mg/L. The degradation of MO was confirmed by the presence of sulfanilic acid, as detected by UV–vis spectroscopy through the band at 248 nm.

The degradation of methyl orange (MO) dye, in the presence of pure iron nanoparticles (Fe-NPs) and supporting them in natural zeolite-type clinoptilolite (Fe-Z), were studied. The degradation tests consisted of analyzing the dependence of pH, initial concentration of MO, contact time between systems Fe-NPs ↔ MO and Fe-Z ↔ MO, and temperature, respectively. The highest degradation percentages of MO ranging from 80 to 100% occurred at pH values between 3 and 10; below 3 and above 10, relatively low degradation percentages were measured. Whereas nearly 100% of MO degradation was obtained with pure Fe-NPs for all studied MO concentrations and from 30 °C to 50 °C, for the composite Fe-Z, the degradation of MO was both MO concentration and temperature dependent with the highest degradation percentages at 50 °C. Besides, while using pure Fe-NPs the degradation of 100% of MO was reached at a contact time of 6 h at temperatures between 20 °C and 50 °C. However, when using the composite Fe-Z, the degradation percentages of MO were from 80% to 90% which was reached in 17 h, for temperatures between 15 °C and 50 °C. The resulting kinetic degradation data of MO from pure and supported Fe-NPs was analyzed by considering several empirical models, from which the temperature dependent rate constants were obtained, with best values of ~0.2 h−1at 15 °C and ~1.86 h−1at 50 °C and establishing endothermic-degradation processes. By using these rate constants and the Arrhenius relation, an activation energy (Ea) for the degradation process was determined, being for the Fe-NPs ↔ MO system slightly higher than for the Fe-Z↔ MO system.

The nanoparticles technology has received considerable attention for its potential applications in groundwater treatment for the removal of various pollutants as Cadmium. In this work, iron boride nanoparticles were synthesized in pure form and in presence of homo-ionized zeolite clinoptilolite, as support material. These materials were used for removing Cd (II) from aqueous solutions containing 10, 50, 100, 150, 200, 250, 300 and 400 mg/L. The characterization of these materials was made by using X-ray Diffraction, Scanning Electron Microscopy and Mossbauer Spectroscopy. Pure iron boride particles show a broad X-ray diffraction peak centered at 45∘ (2𝜃), inferring the presence of nanocrystals of Fe2B as identified from Mossbauer Spectroscopy. The size of these Fe2B particles was within the range of 50 and 120 nm. The maximum sorption capacities for Cd (II) of iron boride particles and supported iron boride particles in homo-ionized zeolitic material were nearly 100 %. For homo-ionized zeolite and homo-ionized zeolite plus sodium borohydride was ≥ 95 %.

This work presents a study about the effect of gamma irradiation in plasma polymers derived from pyrrole. Gamma rays modify the whole energetic equilibrium between the nucleus and the electron clouds which results in rearrangements of atoms, molecules and in modifications in the properties of irradiated materials. Two types of interactions were analyzed, in polypyrroles synthesized from irradiated monomers, and in polypyrroles irradiated after the synthesis. The doses studied were 18 and 40 kGy. The polymers were synthesized by plasma at 13.56 MHz and 100 W. The results indicated that the exposure to gammas promoted dehydrogenation and creation of groups with double and triple bonds. The multiple bonding was reflected in the electrical conductivity which increased up to 9 orders of magnitude, from 10−11 in non irradiated polymers to 10−2 S/m in the polymers synthesized with monomers irradiated at 40 kGy. Another effect of gammas was the increase in the roughness of polymers which affects the hydrophilicity, this property was evaluated by measuring the contact angle of polymers with a Krebs-Ringer solution. The angles reached up to 72° in surfaces with the greatest pores.

This work presents a study about the synthesis by plasma of organometallic compounds of titanium oxides (TiO) obtained from titanium tetraisopropoxide (TTIP) and water on polyethylene (PE) to form TiO-PE superficial composites. The objective is the synthesis of TiO nano and meso particles attached on PE supports. The synthesis was carried out by plasma in a vacuum tubular glass reactor at 13.56 MHz, 10−1 mbar and 100–150 W. The accelerated particles in the plasma have the function of separating the organic and inorganic segments of TTIP bonding the TiO particles with PE. The resulting TiO-PE superficial compounds have agglomerates of spherical and oval organometallic particles with diameter between 50 and 3000 nm as a function of the time of synthesis. The agglomerates contain Ti and C oxides with a tendency to change from film to particles as a function of the energy applied in the synthesis. The contact angles of the superficial composites varied from 40° to 76°.

This work presents a study about the chemical structure of titanium oxide (TiO) particles synthesized by plasmas using titanium tetrapropoxide, Ti(-O-CH2-CH2-CH3)4. In plasmas, practically all chemical bonds are susceptible to participate in the reactions producing different results than those obtained by the traditional chemical routes. The particles obtained this way are semispheres and fibers grouped in random and layered structures in the 120-500 nm interval and mean diameter of 86.4 nm (fibers) and 308.6 nm (semispheres). The analysis of the resulting TiO structure was performed by IR and XPS finding that the main chemical state of Ti in these conditions was O2-Ti-O2 (Ti surrounded by O) which is part of the precursor structure, however, in O, the main chemical state was Ti-O-Ti formed with the rupture of the pre- cursor Ti-O-C bonds. These last bonds reduce the conjugation between the structure of both elements, O2-Ti-O2 and Ti-O-Ti, to produce organometallic compounds. Other chemical states appeared showing consecutive dehydrogenation steps during the synthesis with the formation of multiple bonds as a consequence of the continuous collisions in the plasma. These results allow us to follow the chemical reactions promoted by this kind of plasmas to produce TiO nanoparticles which are essentially conformed of intensive dehydrogenation.

Organometallic compounds made of titanium oxide (TiOx) and pyrrole (Py) were synthesized by plasma to combine the photoelectronic activity of TiO and Py in hybrid materials with potential use in photostimulated processes as photoelectronic devices in pollutant degradation or in solar photocollectors. The Ti precursors were based on titanium tetrapropoxide combined with Py in 1:1 mass ratio in a vacuum tubular glass reactor under resistive electrical glow discharges of water vapor plasmas. The TiOx–Py hybrid compounds with x in the 2.75–3.55 interval absorbed electromagnetic radiation in two regions with different intensities. The first and most intense one was from approximately 190 to 350 nm and the other from roughly 350 to 900 nm, which indicates that in the first interval, the TiO fraction dominates the absorption and that the activity of the second region belonged to Py segments. The electrical conductivity was in the (10−6–10−10) S/m interval with activation energy in the (0.015–2.42) eV range, depending on the reaction time and synthesis conditions.

The energy transfer at room temperature between Tb 3+ and Eu 3+ ions sorbed onto SrTiO 3 powders is investigated, using Time-Resolved Laser-induced Fluorescence Spectroscopy (TRLFS). Several published works deal with the energy transfer between two lanthanide ions in co-doped matrices but it is the first time that transfer processes between two lanthanide ions sorbed on a solid surface is reported. The results show that the energy transfer between sorbed Tb 3+ and Eu 3+ ions on strontium titanate is a non-radiative process and follows a dipole–dipole type interaction. Moreover, the higher the acceptor ions Eu 3+ concentration, the more efficient the energy transfer. It is shown that no energy migration between the Tb 3+ donor ions occurs. A formalism based on the model of Inokuti–Hirayama is used and allows one to fit the non-exponential Tb 3+ fluorescence decay. It is thus possible to evaluate the critical radius ( R 0 ) of the influence sphere of the sorbed Tb 3+ ions. According to the previous works, two sorption sites are considered for the sorbed rare-earth. The calculated radii are similar to those obtained for other couples of donor–acceptor lanthanide ions reported in the literature.

This work describes the synthesis of organometallic titanium oxides using low-pressure plasmas of water on titanium tetrapropoxide (TTP) in solid phase with glow discharges in the 0.3 - 0.9 mbar, 100 - 150 W and 60 - 240 min intervals. The accelerated particles in the plasma promoted chemical reactions which produced the partial separation of organic and inorganic parts of TTP with the consequent formation of TiO in organometallic films and particles with photosensitivity. These compounds could hardly be obtained by conventional chemical synthesis. The size of particles was calculated in the 50 - 414 nm interval. The elemental analysis of the titanium oxides indicates that the C/Ti and O/Ti atomic ratios are in the 0.63 - 0.54 and 1.89 - 1.96 intervals respectively, depending on the conditions of synthesis, which suggests that the organic residues are approximately half of the inorganic content. This proportion affects the X-ray diffraction of the organometallic compounds making them essentially amorphous; however, they may have overlapped arrangements resembling some faces of anatase, at 25.3o and 32.5o, and rutile, at 43o, phases. The electrical conductivity of TiO between 20℃ and 100℃ was from 10–10 to 10–12 S/m with activation energy in the 0 - 2.12 eV interval with 3 tendencies associated with temperature.

This study deals with the characterization of a marine sediments profile from the Gulf of Tehuantepec, Mexico. Ten sediment samples obtained from a core of 18.3 m of length were analysed. Although there have been numerous marine sediments studies carried out in Mexico, more are needed to better understand the sea floor formation. Crystallographic, morphologic, physical, chemical and gamma ray activity analysis were carried out on the samples. The analysis results showed a decrease in organic matter content as a function of sea depth; this value is related to the specific surface area. Some hazardous materials as Cr, Mn, Ni, Sr and Hg were also identified by PIXE in some samples, probably due to anthropogenic activity. The presence of uranium a naturally occurring element was found in all the samples, suggesting a migration through all materials of strata, radioactive elements such as 226Ra, 235U, 212Pb, 214Pb, 228Ac, 208Ti, 214Bi, 228Ac and 40K were detected.

Seawater contains trace elements in solution, such as lanthanides and uranium, which can act as natural tracers when they flocculate to form the sediments of the seabed. Uranium is a special case because it is a radioactive element with isotopic ratio close to 1.14 (234U/238U) in sea water. Uranium is also present in all fractions of sediments, although the isotopic ratio in each fraction takes a specific value depending on its origin and surrounding environment. This work has been conducted in order to analyze lanthanides and uranium in a core of sea sediments. It is focused on separating the fractions forming the layers along the depth profile of the core sample so as to determine the 234U/238U activity ratios in fractions of organic matter, aquatic life skeletons and dissolved minerals. The Neutron Activation Analysis showed the presence of U, Lu, Hf, Eu, Ce and Yb ranging up to 50 ppm while alpha spectrometry gave a series of 234U/238U activity ratios which are discussed on the basis of statistical analysis.

The purpose of this work is the study of the interaction mechanisms between U(VI) ions and SrTiO3 surfaces as a function of pH and temperature (25, 50, 75 and 90 °C) by coupling thermodynamic and spectroscopic approaches. First, the reactivity towards U(VI) for both surface sites of the strontium titanate (triple bond; length of mdashTisingle bondO and triple bond; length of mdashSrsingle bondO) has been investigated as a function of the temperature. The N2-BET specific area was measured: View the MathML source. The surface site density has been determined from potentiometric titrations (6 sites/nm2 for each site triple bond; length of mdashTisingle bondO and triple bond; length of mdashSrsingle bondO). The potentiometric titration data have been simulated, for each temperature, using the FITEQL 4.0 software and the constant capacitance model, taking into account both protonation of the triple bond; length of mdashSrsingle bondOH surface sites and deprotonation of the triple bond; length of mdashTisingle bondOH ones (one pK model). The intrinsic strontium protonation constant increases with an increasing temperature, while the titanate deprotonation one decreases. Moreover, both enthalpy and entropy changes corresponding to the surface acid–base reactions have been evaluated using the van't Hoff relation. The uranium(VI) ions are sorbed onto SrTiO3 surfaces in the 0.5–5.0 pH range with an initial cation concentration equal to 10−4 M. The U(VI) surface complexes were identified by using time-resolved laser-induced fluorescence spectroscopy (TRLFS). For all the studied samples, the fluorescence spectra and the corresponding lifetime values do not change with the pH and the temperature. Two U(VI) complexes sorbed onto SrTiO3 were detected and the corresponding lifetimes are 60±5 and 12±2 μs whatever the temperature (25, 50, 75 and 90 °C). The sorption edges were simulated with the FITEQL 4.0 code. The sorption equilibrium constants of the U(VI)/SrTiO3 system between 25 and 90 °C were obtained with the constant capacitance model (CCM), considering two reactive surface sites. According to the spectroscopic characterization, two types of surface complexes, namely [(triple bond; length of mdashSrOH)(triple bond; length of mdashTiOH)UO2]2+ and [(triple bond; length of mdashTiOH)(triple bond; length of mdashTiO)UO2]2+, were considered. Finally, enthalpy (ΔrH°) and entropy (ΔrS°) changes were calculated from the temperature-dependent sorption constants, by the application of the van't Hoff formalism. The formation of the [(triple bond; length of mdashSrOH)(triple bond; length of mdashTiOH)UO2]2+ surface complex was found to present an endothermic character associated to an increase in the disorder of the system. On the contrary, the formation of the [(triple bond; length of mdashTiOH)(triple bond; length of mdashTiO)UO2]2+ surface complex led to an exothermic process with only a slight increase in the disorder of the system.

The purpose of this research is the dating of some mammoth bones from the Valley of Mexico, with the uranium-series method, which can determine the activity of the isotopic relationships 234U/238U and 230 Th/234U. Since not all samples could be dated by this method, it was necessary to apply other techniques as well. First of all, the total concentration of uranium was determined in mammoth bones by U. V. spectrometry, then a study of the conservation state of mammoth bone was carried out by scanning electron microscopy and X-ray diffraction. In this way the limiting factors at the application of this method for dating mammoth bones can be determined.

Composite particles were synthesized using titanium oxide attached to polyethylene (TiO x –PE) films by plasma techniques and used for the removal of Cr(VI) from aqueous solutions in batch systems. The precursor to synthesize TiO was titanium tetrapropoxide (TTP) modified by collisions with accelerated particles in the plasma of water in order to separate the fractions of organic and inorganic TTPs that reorganize into small organometallic particles attached to the surface of PE. Before adsorption, the TiO x particles have spherical profiles agglomerated on the PE surface. The diameter was between 70 and 120 nm in agglomerates of around 500 nm; however, as the pH of the Cr solutions increased, the morphology of these particles changed to fibred patterns. The specific surface area was 163 m 2 /g, which is greater than that for commercial TiO 2 and the pore size was 2.86 nm with a pore density of 0.11 cm 3 g −1 . The study results showed that the maximum Cr adsorption capacity (5.32 mg g −1 ) was obtained at pH = 3. The retention rate of Cr in the first minute was approximately 23%, and after 40 minutes, the rate reached up to 75%. During the adsorption process, a strong pH-dependent adsorption as a function of pH was observed. The adsorption kinetics of the TiO x –PE composites was studied using a pseudo-second-order model. The Cr(VI) experimental isotherm data were described by the Langmuir model.

This manuscript presents the synthesis of carbon modified with iron nanoparticles (CFe) and iron carbide (CarFe) from the pyrolyzed crown leaves of pineapple ( Ananas comosus ) treated with iron salts. The materials that were obtained were used for the removal of As(V) from aqueous media. The carbonaceous materials were characterized by Scanning Electron Microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), X-Ray Photoelectron Spectroscopy (XPS) and Mossbauer Spectroscopy. The specific area (BET), number site density and point of zero charge (pH pzc ) were also determined. The kinetic parameters were obtained by fitting the experimental data to the pseudo-first-order and pseudo-second-order models. Different isotherm models were applied to describe the As(V) adsorption behavior. The kinetics of As(V) sorption by CFe and CarFe was well defined for the pseudo-second-order model ( R 2 = 0.9994 and 0.999, respectively). The maximum As(V) uptake was 1.8 mg g −1 for CFe and 1.4 mg g −1 for CarFe. The results obtained indicated that both materials are equally useful for As(V) sorption. The As(V) experimental isotherm data were described by the Freundlich model for CFe and CarFe.

"Plasma polypyrrole was synthesized on stainless steel and Nitinol (Ni-Ti alloy) substrates in order to obtain polymermetal compounds with high adhesion. The work has the objective to cover metal surfaces with polymers to reduce the contact of metallic surfaces with biological tissues in human body implants. The metal samples were subjected to RF glow discharges with water vapor and argon to clean, oxidize and erode before the polymer coatings. After that, the synthesis of polymers was carried out by glow discharges during 10 min at 13.56 MHz, 10-1 mbar and 20 W. The results showed that the coating is carried out in consecutive thin layers with the morphology of the metal at the interface. The coated samples were immersed in phosphate solutions (PBS) pH = 7.4 to simulate the conditions of salt concentration in human arteries and veins. The PPy coated metal substrates have rough morphology with resistance to PBS solutions. However, Nitinol samples needed Ar besides water discharges to clean, oxidize and erode."

This work presents a study about the evolution of titanium oxide particles synthesized with glow discharges of water and Tetra Titanium Propoxide (TTP). The syntheses involved sequential changes of TTP from solid, liquid and vapor phases under resistive glow discharges at 13.56 MHz, 0.5-0.8 mbar and 100 W with reaction times between 60 and 240 min. The reaction of TTP and water between the electrodes originated titanium oxide powder composed of white particles with diameter between 106 and 695 nm and different geometries depending on the time of synthesis. These materials may have environmental applications in the sorption of toxic contaminants.

When a mineral surface is immersed in an aqueous solution, it develops an electric charge produced by the amphoteric dissociation of hydroxyl groups created by the hydration of the solid surface. This is one influential surface property. The complete hydration process takes a time which is specific for each mineral species. The knowledge of the aqueous solution contact time for complete surface hydration is mandatory for further surface phenomena studies. This study deals with the optimal hydration time of the raw zircon (ZrSiO4) surface comparing the classical potentiometric titrations with a fluorescence spectroscopy technique. The latter is easy and reliable as it demands only one sample batch to determine the optimal time to ensure a total hydration of the zircon surface. The analytical results of neutron activation analysis (NAA) showed the presence of trace quantities of Dy3+, Eu3+ and Er3 in the bulk of zircon. The Dy3+ is structured in the zircon crystalline lattice and undergoes the same chemical reactions as zircon. Furthermore, the Dy3+ has a good fluorescent response whose intensity is enhanced by hydration molecules. The results show that, according to the potentiometric analysis, the hydration process for each batch (at least 8 sample batches) takes around 2 h, while the spectrometric method indicates only 5 min from only one batch. Both methods showed that the zircon surface have a 16h optimal hydration time.

This study investigated the removal of Pb(II) from aqueous solutions by a maize (Zea mays) stalk sponge. Equilibrium and kinetic models for Pb(II) sorption were developed by considering the effect of the contact time and concentration at the optimum pH of 6 +/- 0.2. The Freundlich model was found to describe the sorption energetics of Pb(II) by Z. mays stalk sponge, and a maximum Pb(II) loading capacity of 80 mg g(-1) was determined. The kinetic parameters were obtained by fitting data from experiments measuring the effect of contact time on adsorption capacity into pseudo-first and second-order equations. The kinetics of Pb(II) sorption onto Z. mays biosorbent were well defined using linearity coefficients (R(2)) by the pseudo-second-order equation (0.9998). The results obtained showed that Zea may stalk sponge was a useful biomaterial for Pb(II) sorption and that pH has an important effect on metal biosorption capacity.