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In this study, the Zn-ZnO(Nw)@CuMnO2 heterostructure was successfully achieved by deposition of a bidimensional CuMnO2 film on the ZnO nanowires (NWs) layer, by the spin coating method. The novelty of this research is related to the growth of ZnO NWs by thermal oxidation at low temperatures, below the melting point of the Zn foil in a controlled atmosphere consisting of a mixed flow gas, Ar and O2. The structural and morphological properties of the heterostructures were assessed by XRD, UV-Vis, and SEM techniques. The as-obtained gas sensors based on Zn-ZnO(Nw)@CuMnO2 heterostructures were tested to detect 400 ppm. CO2 concentration at variable testing temperatures inside the testing chamber. The maximum sensibility value of 85.5% was obtained at the lowest operating temperature of 150 °C for the ZnONw5@CMO sensor, and when the temperature was increasing to 200 °C the sensibility response of 95.4% was recorded for the ZnONw7@CMO sensor. Current-voltage and current-time measurements were performed under different conditions to assess the heterojunction behavior and sensibility of the gas sensor.

In this paper, we report the synthesis of different silica materials via the acid-catalyzed sol–gel process at room temperature (25°C), using silane precursors with various alkyl chains (dimethyl, octyl and/or hexadecyl), in order to obtain thin films with anti-reflective and hydrophobic properties. Chemical, optical and structural properties of obtained silica materials were thoroughly characterized with various techniques such as FTIR and UV–Vis spectroscopy, AFM analysis, ellipsometric measurements, ESEM and TEM microscopy. Wettability of thin films was evaluated by water contact angle measurements. FTIR spectra of silica materials revealed that the intensity of the Si–O–Si characteristic bands varies depending on the precursor type. From AFM results, we found that the obtained films present a different microstructure as a function of the silica sol formulations. The hydrophobic character of the thin films increases with increasing the length of the hydrophobic chains following the order: dimethyl

In this research, fluorinated silica materials were prepared through sol–gel processing with tetraethylorthosilicate (TEOS), triethoxymethylsilane (MTES), and trimethoxyhexadecylsilane (HDTMES), using a fluorinated solution (FS) under acidic medium. The fluorinated solution (FS) was obtained by diluting the perfluorooctanoic acid (PFOA) in 2-propanol. These fluorinated sol–gel silica materials were placed on the glass surfaces in order to achieve the antireflective and hydrophobic fluorinated hybrid films. The structure and surface properties of the final samples were investigated by Fourier transform infrared spectroscopy (FTIR), ultraviolet/visible spectroscopy, thermogravimetric analysis (TGA), atomic force microscopy (AFM), and contact angle (CA) determinations. FTIR spectra demonstrated the presence of a silica network modified with alkyl and fluoroalkyl groups. Thermal analysis showed that the fluorinated sol–gel silica materials prepared with HDTMES have a good thermostability in comparison with other samples. Ultraviolet/visible spectra indicated that the fluorinated hybrid films present a reflectance of ~9.5%, measured at 550 nm. The water contact angle analysis found that the wettability of fluorinated hybrid films was changed from hydrophilic (64°) to hydrophobic (~104°). These hybrid films based on fluorinated sol–gel silica materials can be useful in various electronics and optics fields.

The main goal of the present paper was to synthesize the polyvinyl alcohol-SiO2 nanoparticles polymeric membrane by wet-phase inversion method. The efficiency of prepared membranes (without and with SiO2) was investigated using a versatile laboratory electrodialysis system filled with simulated wastewaters that contain zinc ions. All experiments were performed at following conditions: the applied voltage at electrodes of 5, 10 and 15 V, a concentration of zinc ions solution of 2 g L−1, time for each test of 1 h and at room temperature. The demineralization rate, extraction percentage of zinc ions, current efficiency and energy consumption were determined. The polymeric membranes were characterized by Fourier Transforms Infrared Spectroscopy-Attenuated Total Reflection (FTIR-ATR), Scanning Electron Microscopy (SEM) and Electrochemical Impedance Spectroscopy (EIS). The higher value of percentage removal of zinc ions (over 65%) was obtained for the polymeric membrane with SiO2 nanoparticles, at 15 V. The FTIR-ATR spectra show a characteristic peak located at ~1078 cm−1 assigned to the Si-O-Si asymmetrical stretching. SEM images of the polymeric membrane with SiO2 nanoparticles show that the nanoparticles and polymer matrix were well compatible. The impedance results indicated that the SiO2 nanoparticles induced the higher proton conductivity. The final polymeric membranes can be used for the removal of various metallic ions, dyes, organic or inorganic colloids, bacteria or other microorganisms from different natural waters and wastewaters.

TiO2 – based materials were synthesized via acid-catalyzed sol-gel method using tetraethoxysilane (TEOS) and/or methyltriethoxysilane (MTES) - as silane coupling agents. The physical and chemical properties of the obtained TiO2 – based materials were characterized through FT-IR and UV–Vis spectroscopy, TGA, AFM analysis and contact angle measurements. FT-IR spectra demonstrated that the silane coupling agents react via a cross-link and covalently bond on the TiO2 surface. TGA analysis of samples was used to investigate the effect of addition of silane precursor into the TiO2 matrix. Diffuse reflectance spectra revealed that the addition of silane agents improved the antireflective properties of obtained thin films. Water contact angle of TiO2 - based materials showed that the wettability of the thin films was influenced by the addition of TEOS and/or MTES during the modification process. AFM images showed smooth surfaces (RMS roughness up to 3 nm) but with morphological peculiarities depending on the chemical modification, with TEOS, MTES or both, of the TiO2 parental matrix. Transparent and hydrophobic coatings were obtained with MTES addition in the modification process of TiO2 nanoparticles via acid-catalyzed sol-gel method.

This work is devoted to examine the effectiveness of the different commercial liquid additives for fish (sweet corn and molasses) on corrosion of mild steel in natural water by different methods (gravimetric and potentiostatic polarization) at room temperature. The corrosion tests were employed to evaluate corrosion rate (CR) and inhibition efficiency (IE %). The maximum inhibition efficiency was obtained for the inhibitor type molasses of 90.00% by gravimetric method for a period of 3 hours and over 31 % by potentiostatic polarization method. It was found that the commercial liquid additives acted as a good inhibitors for the tested environment. Furthermore, the corroded metal was observed by metallographic microscope.

Environmental contamination, extensive exploitation of fuel sources and accessibility of natural renewable resources represent the premises for the development of composite biomaterials. These materials have controlled properties, being obtained through processes operated in mild conditions with low costs, and contributing to the valorization of byproducts from agriculture and industry fields. A novel board composite including lignocelullosic substrate as wheat straws, fungal mycelium and polypropylene embedded with bacterial spores was developed and investigated in the present study. The bacterial spores embedded in polymer were found to be viable even after heat exposure, helping to increase the compatibility of polymer with hydrophilic microorganisms. Fungal based biopolymer composite was obtained after cultivation of Ganoderma lucidum macromycetes on a mixture including wheat straws and polypropylene embedded with spores from Bacillus amyloliquefaciens. Scanning electron microscopy (SEM) and light microscopy images showed the fungal mycelium covering the substrates with a dense network of filaments. The resulted biomaterial is safe, inert, renewable, natural, biodegradable and it can be molded in the desired shape. The fungal biocomposite presented similar compressive strength and improved thermal insulation capacity compared to polystyrene with high potential to be used as thermal insulation material for applications in construction sector.

In this research work, silica nanoparticles and silica-gentamicin nanostructured solution were synthesized by using the microwave-assisted synthesis, in basic medium, using two silane precursors (tetraethylorthosilicate and octyltriethoxysilane) and the antibiotic (gentamicin sulfate). The prepared materials were characterized through Fourier transform infrared (FTIR) spectroscopy, TGA analysis, transmission electron microscopy (TEM), and atomic force microscopy (AFM) to investigate the morphology and structure. Antimicrobial studies of the silica-gentamicin nanostructured solution versus silica nanoparticles were performed against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli. FTIR spectra showed that the gentamicin has been loaded to the silica nanoparticles. AFM analysis showed that the morphology of the silica-gentamicin nanostructured solution has changed, and agglomerations of particles are present at the surface. Antimicrobial testing, performed using the diffusion method through spot inoculation, indicates that the silica-gentamicin nanostructured solution exhibited activity against the resistant strain. The obtained silica-gentamicin solution can be used as biochemical agent for the prevention and treatment of microorganisms which are deposited on different surfaces (e.g., glass, plastic, ceramic).

Transparent and antireflective coatings were prepared by deposition of modified silica materials onto polyvinyl chloride (PVC) substrates. These materials were obtained by the sol-gel route in acidic medium, at room temperature (25 &deg, C), using different alkoxysilanes with various functional groups (methyl, vinyl, octyl or hexadecyl). Physicochemical and microstructural properties of resulted silica materials and of thin coatings were investigated through Fourier Transforms Infrared Spectroscopy (FTIR), UV-Vis spectroscopy, Thermal Gravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Atomic Force Microscopy (AFM) and ellipsometric measurements. Wetting behaviors of the silica coatings were evaluated by measurement of static contact angle against water. FTIR spectra of materials confirmed the high degree of cross-linking that result from the formation of the inorganic backbone through the hydrolysis and polycondensation reactions together with the formation of the organic network. These sol-gel silica coatings showed a reduction in the reflectance (10%) compared with uncoated PVC substrate. AFM reveals that the films are uniform, and adherent to the substrate, but their morphology is strongly influenced by the chemical composition of the coating matrices. These silica coatings can be useful for potential electronic and optical devices.

Due to their range of applications, from anti-icing to self-cleaning, low-adhesion, antibacterial. [...]

The aim of this work was to investigate the corrosion inhibition effect of natural seaweeds in seawater on carbon steel. The corrosion efficiency of carbon steel in the absence and the presence of natural seaweeds in seawater was evaluated by the gravimetric method at room temperature and calculating the corrosion rate and protection degree. The experimental results showed that the corrosion rate on carbon steel decreased when the seaweeds were used. In addition, the value of protection degree (P) was greater than 60% when seaweeds were used. Natural seaweeds reduce the corrosion rate and can be considered an ecofriendly corrosion inhibitor for carbon steel.

Magnesium&ndash, aluminum (Mg-Al) and magnesium&ndash, aluminum&ndash, nickel (Mg-Al-Ni) layered double hydroxides (LDHs) were synthesized by the co-precipitation method. The adsorption process of Mn2+ from synthetic wastewater was investigated. Formation of the layered double hydroxides and adsorption of Mn2+ on both Mg-Al and Mg-Ni-Al LDHs were observed by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive Spectrometry (EDX) analysis. XRD patterns for prepared LDHs presented sharp and symmetrical peaks. SEM studies revealed that Mg-Al LDH and Mg-Al-Ni LDH exhibit a non-porous structure. EDX analysis showed that the prepared LDHs present uniformly spread elements. The adsorption equilibrium on these LDHs was investigated at different experimental conditions such as: Shaking time, initial Mn2+ concentration, and temperatures (10 and 20 &deg, C). The parameters were controlled and optimized to remove the Mn2+ from synthetic wastewater. Adsorption isotherms of Mn2+ were fitted by Langmuir and Freundlich models. The obtained results indicated that the isotherm data fitted better into the Freundlich model than the Langmuir model. Adsorption capacity of Mn2+ gradually increased with temperature. The Langmuir constant (KL) value of Mg-Al LDH (0.9529 &plusmn, 0.007 L/mg) was higher than Mg-Al-Ni LDH (0.1819 &plusmn, 0.004 L/mg), at 20 &deg, C. The final adsorption capacity was higher for Mg-Al LDH (91.85 &plusmn, 0.087%) in comparison with Mg-Al-Ni LDH (35.97 &plusmn, 0.093%), at 20 &deg, C. It was found that the adsorption kinetics is best described by the pseudo-second-order model. The results indicated that LDHs can be considered as a potential material for adsorption of other metallic ions from wastewater.

Smart polymeric micelles (PMs) are of practical interest as nanocarriers for the encapsulation and controlled release of hydrophobic drugs. Two hydrophobic drugs, naturally-based curcumin (Cur) and synthetic 5-fluorouracil (5-FU), were loaded into the PMs formed by a well-defined pH-sensitive poly(2-vinyl pyridine)-b-poly(ethylene oxide) (P2VP90-b-PEO398) block copolymer. The influence of the drug loading on the micellar sizes was investigated by dynamic light scattering (DLS) and it appears that the size of the PMs increases from around 60 to 100 nm when Cur is loaded. On the contrary, the loading of the 5-FU has a smaller effect on the micellar sizes. This difference can be attributed to higher molar mass of Cur with respect to 5-FU but also to higher loading efficiency of Cur, 6.4%, compared to that of 5-FU, 5.8%. In vitro drug release was studied at pH 2, 6.8, and 7.4, and it was observed that the pH controls the release of both drugs. At pH 2, where the P2VP sequences from the &ldquo, frozen-in&rdquo, micellar core are protonated, the drug release efficiencies exceed 90%. Moreover, it was demonstrated, by in vitro assays, that these PMs are hemocompatible and biocompatible. Furthermore, the PMs protect the Cur against the photo-degradation, whereas the non-ionic PEO corona limits the adsorption of bovine serum albumin (BSA) protein on the surface. This study demonstrates that these pH-sensitive PMs are suitable for practical utilization as human-safe and smart, injectable drug delivery systems.

The recent development of the “eco-friendly” current has brought to the attention of researchers natural dyes that are biodegradable, do not cause allergies and generally have anti-UV protection, and antioxidant and antibacterial properties. In this study, we aimed to obtain hybrid materials of the dye–host matrix type, by using the sol–gel process. The silica network was generated by tetraethylorthosilicates and modified with organic siloxane derivatives: phenyltriethoxysilane, 3-glycidoxypropyltriethoxysilane, dimethoxydimethylsilane and dimethoxydiphenylsilane. The nanocomposites obtained by embedding curcumin in siloxane matrices were deposited on polyester fabric and evaluated for their properties, relative to the type of organic network modifier used. Fabrics covered with curcuminoid hybrid systems provide a hydrophobic surface, have fluorescent properties and a UPF +50, and, therefore, they can be used in various fields where it is necessary for textiles to provide signaling, self-cleaning or protection properties against ultraviolet radiation. The coated textile materials have very good resistance properties after several repeated washing cycles, and maintain the original UV protection factor at high values even after washing or during rubbing tests.

The main goal of this study was to present a facile and inexpensive approach for the preparation of hybrid coatings by the deposition under ambient air conditions of silver-based silica materials on glass substrates, which can be used to improve solar cells’ performance. The silica materials containing silver nanoparticles (AgNPs) were synthesized by the hydrolytic condensation of tetraethylorthosilicate (TEOS), triethoxymethylsilane (MTES), and trimethoxyhexadecylsilane (HDTMES), under acidic conditions, at room temperature (25 ± 2 °C). The silver nitrate solution (AgNO3, 0.1 wt. %) was used as a source of Ag+ ions. The final samples were investigated through Fourier Transform Infrared Spectroscopy–Attenuated Total Reflectance (FTIR–ATR), Transmission Electron Microscopy equipped with energy dispersive X–ray (TEM–EDX), UV–Vis spectroscopy, Atomic Force Microscopy (AFM), and Raman Spectroscopy (RS). The TEM images confirmed the formation of AgNPs and were found to be around 3 nm. It was observed that AgNPs were embedded in the silica matrix. EDX also confirmed the presence of the resulting AgNPs within the silica material. AFM images demonstrated that the morphology of the hybrid films’ surfaces can be changed as a function of sol–gel composition. RS analysis indicated that silanol groups were significantly present on the silver-based silica film surface. The UV–Vis spectra revealed that the hybrid coatings presented a reflectance of ~8%, at 550 nm. This study will enhance the value of nanocoating technology in optoelectronics, particularly in the development of nanostructures that improve the performance in thin-film solar cells.

Achieving a compound thin film with uniform thickness and high purity has always been a challenge in the applications concerning micro electro mechanical systems (MEMS). Controlling the adhesion force in micro/nanoscale is also critical. In the present study, a novel method for making a sputtering compound target is proposed for coating Ag–Au thin films with thicknesses of 120 and 500 nm on silicon substrates. The surface topography and adhesion forces of the samples were obtained using atomic force microscope (AFM). Rabinovich and Rumpf models were utilized to measure the adhesion force and compare the results with the obtained experimental values. It was found that the layer with a thickness of 500 nm has a lower adhesion force than the one with 120 nm thickness. The results further indicated that due to surface asperity radius, the adhesion achieved from the Rabinovich model was closer to the experimental values. This novel method for making a compound sputtering target has led to a lower adhesion force which can be useful for coating microgripper surfaces.

In this research, we report a simple and inexpensive way to prepare transparent and hydrophobic hybrid coatings through deposition of different silica materials on polyvinyl chloride (PVC) substrates. The silica materials were prepared using an acid-catalyzed sol–gel method at room temperature (25 ± 2 °C), using alkoxysilanes: tetraethoxysilane (TEOS), as the silica source, and ethoxydimethylvinylsilane (DMVES), triethoxyoctylsilane (OTES), and trimethoxyhexadecylsilane (HDTMES), as modifier agents. The obtained materials were characterized (either as powders or as thin films) by Fourier-transform infrared spectroscopy (FTIR), UV/Vis spectroscopy, transmission electron microscopy (TEM), thermogravimetric analysis (TGA), atomic force microscopy (AFM), spectroscopic ellipsometry (SE), and water contact-angle measurements. UV/Vis spectra showed that the PVC substrate coated with the silica material containing TEOS/DMVES/OTES had a transmittance of about 90% in the wavelength range of 650–780 nm. The water contact angles increased from 83° for uncoated PVC substrate to ~94° for PVC substrates coated with the sol–gel silica materials. These PVC films with hybrid silica coatings can be used as the materials for outdoor applications, such as energy-generating solar panel window blinds or PVC clear Windmaster outdoor blinds.

The goal of the present paper was to synthesize, characterize, and evaluate the performance of the modified composite based on magnetite (Fe3O4) and polyvinyl alcohol (PVA). The obtained composite was used to degrade Methyl Orange dye from synthetic wastewater by a laboratory photocatalytic reactor. Various parameters of the photodegradation process were tested: composite dosage, amount of hydrogen peroxide (H2O2), and pH. The composite was characterized by Fourier Transform Infrared (FTIR) Spectroscopy, X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). The degradation experiments indicated that the complete dye decolorization depended on the amount of H2O2. In addition, the H2O2 could accelerate Methyl Orange degradation to more highly oxidized intermediates in the presence of UV light (99.35%). The results suggested that the obtained modified composite could be used to treat wastewater containing various types of dyes.

This study presents a sol-gel method for preparation of bilayer coatings based on silica materials and iron (III) phthalocyanine - sensitized TiO2 nanoparticles (TiO2–Fe(III)Pc), deposited on glass surfaces. Silica materials were synthetized using organosilane precursors (dimethoxydimethylsilane (DMDMES), octyltriethoxysilane (OTES), and/or hexadecyltrimethoxysilane (HDTMES)), with a two-step acid reaction. The materials properties have been investigated using FT-IR and UV–vis spectroscopy, AFM analysis, and water contact angle. The photo-degradation experiments of thin films were developed using methylene blue as a standard contaminant. FT-IR spectra confirmed the successful grafting of silica materials onto the surface of TiO2–Fe(III)Pc nanoparticles. AFM analysis indicated that the thin films present a different nanostructure depending on the silica matrix and the existence of TiO2–Fe(III)Pc nanoparticles. Contact angle measurements showed that sol-gel coatings exhibit hydrophobic behavior (>99 ± 2°), before and after photo-degradation test. The presence of nanoparticles plays an important role in the development of coatings with photo-catalytic property.

Poly(butadiene)- b -poly(2-vinylpyridine)- b -poly(ethylene oxide) (PB P2VP PEO) triblock copolymers of various compositions and molecular weights were prepared by sequential anionic polymerization. Their micellization behavior was examined in heptane, which is a selective solvent for PB whereas P2VP and PEO are insoluble. Dynamic light scattering and viscometry were used to determine the basic micellar characteristics, such as aggregation number, micellar sizes, and polydispersity, which were correlated to the molecular characteristics of the copolymers. Such ABC triblock copolymers form structured micelle-like nanoparticles having a core–shell morphology with hydrodynamic diameters in the range of 45–75 nm.

Sol-gel derived organic-inorganic hybrid systems were obtained by applying alkaline-catalyzed co-hydrolysis and copolycondensation reactions of tetraethoxysilane (TEOS), methyltriethoxysilane (MTES), isobutyltriethoxysilane (IBTES), diethoxydimethylsilane (DMDES), and vinyltriethoxysilane (VTES), respectively, into a polymer latex functionalized with vinyltriethoxysilane (VTES). The properties of the latex hybrid materials were analyzed by FTIR, water contact angle, environmental scanning electron microscopy (ESEM), TEM and AFM analysis, respectively. FT-IR spectra confirmed that the chemical structures of the sol-gel derived organic-inorganic materials are changed as function of inorganic precursor and Si O Si networks are formed during the co-hydrolysis and copolycondensation reactions. The water contact angle on the sol-gel latex film containing TEOS + VTES increased to 135° ± 2 compared to 65° ± 5 for the blank latex, due VTES incorporation into latex material. TGA curves of hybrid sample modifies against neat polymer, the thermal stability being influenced by the presence of the inorganic partner. ESEM analysis showed that the latex hybrid films prepared with different inorganic precursors were formed and the Si-based polymers were distributed on the surface of the dried sol-gel hybrid films. TEM and AFM photos revealed that the latex emulsion morphology was modified due to the VTES incorporation into system.

Transparent hydrophobic or super-hydrophobic thin films prepared on plastic substrates haveattracted attention in recent years because they can be suited to optical applications such as lenses [...]

The camouflage effect aims to reproduce natural or artificial surroundings in terms of color, [...]

The recent development of several methods for extracting curcumin from the root of the plant Curcuma longa has led to intensified research on the properties of curcumin and its fields of application. Following the studies and the accreditation of curcumin as a natural compound with antifungal, antiviral, and antibacterial properties, new fields of application have been developed in two main directions—food and medical, respectively. This review paper aims to synthesize the fields of application of curcumin as an additive for the prevention of spoilage, safety, and quality of food. Simultaneously, it aims to present curcumin as an additive in products for the prevention of bacterial infections and health care. In both cases, the types of curcumin formulations in the form of (nano)emulsions, (nano)particles, or (nano)composites are presented, depending on the field and conditions of exploitation or their properties to be used. The diversity of composite materials that can be designed, depending on the purpose of use, leaves open the field of research on the conditioning of curcumin. Various biomaterials active from the antibacterial and antibiofilm point of view can be intuited in which curcumin acts as an additive that potentiates the activities of other compounds or has a synergistic activity with them.

Nanosized zinc oxide (ZnO) particles modified with different silane coupling agents (octyltriethoxysilane (OTES), octadecyltriethoxysilane (ODTES) and (3-glycidyloxypropyl)trimethoxysilane (GPTMS)) were synthesized in basic catalysis using the sol-gel method. The structure and morphology were characterized by dynamic light scattering (DLS), environmental scanning electron microscopy (ESEM) and Fourier transform infrared spectroscopy (FTIR) for bonding characteristics. The final hybrid materials were deposited on three types of metallic substrates (aluminum (Al), copper (Cu) and zinc (Zn)) in order to obtain coatings with ultrahydrophobic and anti-corrosion properties. Water wettability was studied revealing a contact angle of 145° for the surface covered with ZnO material modified with ODTES. The water contact angle increased with the length of the alkyl chain supplied by the silica precursor. The anti-corrosive behavior of ZnO/silane coupling agents particles deposited on metallic substrates was studied by the linear polarization technique in neutral medium.

Fluorescent film-forming materials were obtained by embedding salicylaldazine (SAA) in silica hybrids generated by sol&ndash, gel processes from different silane precursors in acid catalysis. Tuned local environments for the fluorophore were generated in the hosting network by modifying silica sols with organic groups through the co-condensation of tetraethylortosilicate (TEOS) and different alkoxysilanes hydrolysis products. The photophysical properties of the luminescent hybrid films were studied in direct relationship with structural, textural, and surface properties and based on interactions between SAA species and the silica hosting network. Film-forming materials were studied in order to determine differences in absorption and fluorescence emission due to the environments around the fluorophore. The variations recorded in the fluorescence emission spectra of the hybrid films were related to interactions established between the fluorophore species and their sterically hindered surroundings of the host hybrid silica, where free molecular motions are restricted. The influence of the type and amount of network modifier and of the fluorophore loading on the transparency of the films and fluorescence intensity was also investigated. The study carried out led to the elucidation of the necessary conditions for obtaining luminescent film-forming materials with high luminescence intensity and transparency useful for the design of new light concentrators.

The realization of some composite materials that allow the best removal of H2S from syngas was the main objective of this work. Thus, the optimization of the technological parameters for obtaining composites based on Zn-Ti was achieved. The paper studies the influence of calcination temperature on the characteristics of the binary ZnO-TiO2 system used to synthesize a composite material with suitable properties to be used subsequently for syngas treatment. The mineralogical and structural analyzes showed that starting with the calcination temperature of 700 &deg, C the material synthetized is composed mainly of zinc orthotitanate which possess the corresponding characteristics to be finally used in the treatment of the syngas for its desulfurization. At this calcination temperature the material has a compact structure most likely due to sintering of the formed titanates. These composites have a texture that places them rather in the category of non-porous materials, the pore volume and their surface area obviously decreasing as the calcination temperature increases. A maximum sulfur removal degree of about 97% was obtained by using a composite synthetized at a temperature of 700 &deg, C (ZT-700).