SEM-EDX Analysis Research Articles

“Hearts of gold” (Cuori d'oro): The case study of the leather corami of Palazzo Chigi in Ariccia

In this work we present the results obtained by different technical analysis in order to perform the characterization of the chromatic richness, the employed materials and the iconographic elements of different fragments of decorated and gilded leather corami coming from the archive of Palazzo Chigi of Ariccia (Rome) and employed, during the 17th century, as wallcoverings. Different microscopic and spectroscopic analyses have been performed by means of Ion Beam Analysis (IBA) and Macro Area X-Ray Fluorescence (MA-XRF) techniques available at the INFN LABEC ion beam laboratory in Florence and the Scanning Electron Microscopy-Energy Dispersive X-ray Analysis (SEM-EDX) of the Superconductivity Laboratory of the ENEA Frascati Research Center. The results aim to provide the scholar information about the manufacturing process and the materials employed for the production of these peculiar artefacts, also in order to plan the best and most appropriate conservation protocol. In particular, thanks to the SEM-EDX analysis it has been possible to characterize the layered structure of the samples and, specifically, the interface between the leather of the substrate, the metal foil of the so called meccatura and between these and the overlying pictorial layer. The IBA and MA-XRF techniques has helped in characterizing the painting palette employed while IBA has allowed to determine the conservation condition of the silver layer with the hypothesis of the incorporation of the silver leaf into the organic compound of the mecca as its main deterioration phenomena. These complementary techniques provide, therefore, a comprehensive understanding of the materials and iconographic elements of these leather-based artefacts, which is essential for their preservation and restoration as well as they contribute to a better understanding of the deterioration processes they incur.

Impact of Solder Voids on IGBT Thermal Behavior: A Multi-Methodological Approach

This study investigates the thermal behavior of Insulated Gate Bipolar Transistors (IGBTs) with a focus on the influence of solder voids within the device. Utilizing a combination of Finite Element Method (FEM) simulations, X-ray imaging, and SEM-EDX analysis, we accurately modeled the internal structure of IGBTs to assess the impact of void characteristics on thermal resistance. The findings reveal that the presence and characteristics of solder voids—particularly their size, number, and distribution—significantly affect the thermal resistance of IGBT devices. Experimental measurements validate the FEM model’s accuracy, confirming that voids disrupt the heat flow path, which can lead to increased thermal resistance and potential device failure. Five regression models, including Gaussian process regression (GPR) and neural networks, were employed to predict the thermal resistance based on void characteristics, with the GPR models demonstrating superior performance. The optimal GPR RQ model consistently provided accurate predictions with an RMSE of 0.0050 and R2 of 0.9728. Using the void percentage as the only input parameter for the regression models significantly impacted the prediction accuracy, showing the importance of the void extraction method. This study shows the necessity of minimizing solder voids and offers a robust methodological framework for a better prediction of the reliability of IGBTs.

Synthesis Routes of Sulfur-doped Porous Carbon from Mask Wastes for the Application of Supercapacitor Electrodes

Abstract Increasing demand of energy storage devices stimulates growing research in supercapacitors technologies. Waste-based supercapacitor electrodes has become one of areas to be explored as they offer an environmentally friendly approach. Here we synthesis porous carbon from wastes of medical masks which have been generated a lot since the pandemic. Medical masks are composed of polypropylene which have high porosity; hence they have a potential to be used as a porous carbon source for supercapacitor applications. The synthesis routes include a solvothermal process inside a Teflon autoclave in a microwave and a washing process using dilute acid solution and distilled water. The routes successfully transform polypropylene to porous carbon, confirmed by XRD, FTIR, SEM-EDX and Raman spectrum analyses. The present of C-S bond are indicated from FTIR spectrum, implying a successful doping of sulphur into porous carbon. The electrochemical analysis of the prepared electrode using cyclic voltammetry shows an EDLC-like feature with high specific capacitance of ∼375 Fg−1 at the scan rate of 5 mV/s.

Preparation of UiO-66 MOF-Bonded Porous-Layer Open-Tubular Columns Using an In Situ Growth Approach for Gas Chromatography.

The thermally stable zirconium-based MOF, UiO-66, was employed for the preparation of bonded porous-layer open-tubular (PLOT) GC columns. The synthesis included the in situ growth of the UiO-66 film on the inner wall of the capillary through a one-step solvothermal procedure. SEM-EDX analysis revealed the formation of a thin, continuous, uniform, and compact layer of UiO-66 polycrystals on the functionalized inner wall of the column. The average polarity (ΔIav = 700) and the McReynolds constants reflected the polar nature of the UiO-66 stationary phase. Several mixtures of small organic compounds and real samples were used to evaluate the separation performance of the fabricated columns. Linear alkanes from n-pentane to n-decane were baseline separated within 1.35 min. Also, a series of six n-alkylbenzenes (C3-C8) were separated within 3 min with a minimum resolution of 3.09, whereas monohalobenzene mixtures were separated at 220 °C within 14s. UiO-66 PLOT columns are ideally suited for the isothermal separation of chlorobenzene structural isomers at 210 °C within 45 s with Rs ≥ 1.37. The prepared column featured outstanding thermal stability (up to 450 °C) without any observed bleeding or significant impact on its performance. This feature enabled the analysis of various petroleum-based samples.

Biosynthesis of Pt doped Zn bimetallic nanoparticles by using Polygonum glabrum extract for colorimetric, fluorimetric (Ni2+, Hg2+ and Fe2+) ions sensing and photocatalytic degradation of organic dye with electrochemical techniques

In the present study we aimed to explore the biosynthesis and characterization of monometallic platinum nanoparticles (PtNPs), zinc oxide nanoparticles (ZnONPs) are compared to the Pt doped ZnONPs (Pt-ZnONPs) and its sensing, electrochemical, photocatalytic properties. The bimetallic Pt-ZnONPs was synthesized by using Polygonum glabrum leaves extract; it acts as reducing agent and stabilizing agent. The analysis of colorimetric and fluorimertic sensing methods to determine the highly detection of Ni2+, Hg2+ and Fe2+ ions. The optical properties were characterized by UV-visible, FT-IR, XRD, XPS, SEM-EDX and TEM-SAED analysis. The synthesized monometallic PtNPs and ZnONPs are well dispersed spherical and hexagonal particles with sizes ranging from 8 nm to 25 nm. Electrochemical analysis were carried out the synthesized monometallic and bimetallic Pt-ZnONPs oxidation with reduction potentials by using cyclic voltammetry with UV-visible absorption spectroscopy based on band gap energy to calculation of LUMO and HOMO energy levels. The photocatalytic activities with band gap energy 96% for MeB indicated that only Pt doped ZnONPs for bimetallic Pt-ZnONPs nanocatalyst as compared to monometallic PtNPs and ZnONPs for single metal nanocatalyst actions. The highly sensitivity of Ni2+, Hg2+ and Fe2+ ions are combined with synthesized NPs extended to the oxidation-reduction potential for Pt2+ by Zn2+ ions may find sensitivity for trace different metal ions of pollution level with environmental sensing and photocatalytic applications.

Exploring the structural characteristics and dye removal capabilities of powder-, granule- and film- shaped magnetic activated carbon derived from Oleaster seed.

Dye pollution in water caused by excessive discharge of industrial effluent has become a major environmental problem in recent decades because of its irreversible effects on human health. In this study, low-cost carbon-based adsorbents synthesized from Oleaster seed (OS) were prepared in three forms of powder (PAC), film (FAC), and granule (GAC) and used for the removal of methylene blue dye. The properties of the synthesized adsorbents were characterized by SEM-EDX, BET, XPS and FTIR analyses. The maximum adsorption capacity (qmax) of PAC, FAC, and GAC adsorbents were obtained as 68.49, 32.25, and 15.10 mg/g, respectively at the optimum experimental conditions of pH = 10, adsorbent dosages of 0.5, 1, and 2 g/l, contact times of 60, 90, and 120 min, dye concentration of 10 mg/L, and temperature of 25°C. The Langmuir isotherm well described the equilibrium data for all three adsorbents. The pseudo-second-order kinetic model provided the best fit with the adsorption data obtained from all three adsorbents. Adsorption occurred spontaneously through a combination of chemical and physical mechanisms, with a thermodynamically exothermic process. The desorption experiments demonstrated that all the adsorbents have substantial potential for recovery. The novel activated carbon/alginate composite films are proposed as more promising biosorbents to remove MB dye from the aquatic environment compared to GAC adsorbents.

Endophytic fungi-assisted biomass synthesis of eco-friendly formulated silver nanoparticles for enhanced antibacterial, antioxidant, and antidiabetic activities

Fungi-mediated biosynthesis of silver nanoparticles is one of the promising nanomanufacturing processes. Using endophytic fungi isolated from potential medicinal plants has emerged as a novel approach for producing several metal oxide nanoparticles in a green and cost-effective manner. The present study validates the biomimetic synthesis of silver nanoparticles of endophytic fungus (Phyllosticta capitalensis Henn.) (Phyllo-AgNPs) isolated from the leaves of Annona muricata and the effect of process variables, i.e., reductant concentration, ratio of AgNO3 to reductant concentration, reaction time and reaction pH to achieve maximum efficiency using the factorial design approach. The nanoparticle formation was confirmed by absorption peaks between 400 nm and 500 nm, followed by their characterization by UV–visible spectroscopy, TEM, SEM-EDX, XRD, particle size, and zeta potential analysis. The in-vitro antioxidant, antidiabetic and antimicrobial potential (agar well dfiffusion and minimum inhibitory concentration) of Phyllo-AgNPs at various concentrations were assessed. The Phyllo-AgNPs scavenged the 2,2-diphenyl-1-picrylhydrazyl radical and inhibited the activity of α-amylase and α-glucosidase enzymes at an IC50 of 31.75 ± 0.70, 39.32 ± 1.12 and 28.56 ± 1.08 μg/mL, respectively. The antimicrobial potential was determined against Listeria monocytogenes, Staphylococcus aureus, Escherichia coli and, Salmonella typhimurium. The study revealed the therapeutic potential of Phyllo-AgNPs against pathogenic microorganisms. Additionally, the in-vitro antioxidant and antidiabetic activities showed improved results compared to the standard (ascorbic acid and acarbose). By taking note of this, Phyllo-AgNPs can be further studied for pre-clinical trials, which would be beneficial in developing novel medicines with no adverse effects for the benefit of mankind.

Albumin-derived perfluorodecalin-based hybrid systems with developed effective surfaces aimed at biomedical application

The study aims to approach a coating layer based on alginate functionalized with albumin nanocoated oxygenating factor, constituting a safe and even contact surface with epithelial cells in system components for medical devices to support maintaining the human lung cells’ function. The alginate coating layer with incorporated albumin-coated oxygenating element was designed (ALG_Alb-PFD). As an oxygenating factor, perfluorodecalin was applied at three saturation levels with oxygen: 0%, 21%, and 100%. The studies were performed on human adenocarcinoma A549 cell lines derived from human lung epithelial cells cultured in configuration with the designed coatings. Scanning electron microscopy, flow cytometry, and fluorescence microscopy were applied to evaluate cell function and the system morphology. AFM and SEM-EDX characterized the coating layer material. The designed coating ensured the viability of human lung cells cultured on the coating layer during 10 days of culture. An oxygenating factor presence was confirmed by SEM-EDX analysis of the ALG_Alb-PFD. However, no significant discrepancies were noted between the coatings with different saturation levels after 10 days of culture. Moreover, the AFM-analyzed profiles of the coating surface confirmed/indicated the formation of additional elements in the coating due to using an oxygenating element, which increases the effective contact area with cells. The platform based on alginate with the developed surface of contact of oxygenating factor incorporated within the coating layer ensures the sustained growth and morphology of the human lung cells, which can be considered a therapeutic element of system components of medical devices for maintaining human lung cells’ function.

Probing effect of counterions on electric field stimuli responsive behaviours of smart organoboron-based polyelectrolytes

This is the first study to be introduced to the electrorheology (ER) literature focusing on organoboron-based polyelectrolyte colloidal systems namely: polymeric lithium tartaric acid borate (Poly-LiTB) and polymeric sodium tartaric acid borate (Poly-NaTB). Syntheses of functional polyelectrolytes were monitored via 1H-NMR, ATR-FTIR and SEM-EDX analyses. Electrical conductivity measurements indicated that Poly-LiTB and Poly-NaTB were in semi-conductive region indicating potential smart ER behaviour. A higher polarizability was detected for 20 wt.% Poly-LiTB dispersions in silicone oil (SO) by dielectric measurements. As expected, improved ER performances were obtained for Poly-LiTB/SO colloidal dispersion (τy = 265 Pa, EReff = 87, G′ = 80 kPa at 10 Hz, τc = 98 Pa, recovery% = 68) compared to Poly-NaTB/SO colloidal dispersion (τy = 195 Pa, EReff = 38, G′ = 42 kPa at 10 Hz, τc = 42 Pa, recovery% = 67). To sum up, it was determined that the best ER activity was detected by the organoboron-based polyelectrolyte containing Li+ counterion with smaller ionic radius and higher ionic mobility when their physicochemical properties are taken into account.

Development of bentonite-based organo-geopolymer hybrid wood binder

The study addresses concerns associated with formaldehyde-based adhesives in wood panel board production by proposing geopolymer-based wood binders as promising, formaldehyde-free alternatives. Using bentonite, the research delves into the development and performance properties of this geopolymer wood binder. The BET method was employed for the surface characterization of precursor raw materials for binder preparation. Si and Al elements identified through XRF analysis were correlated with characteristic bands in the FTIR spectrum. Alkaline activation solutions, employing sodium silicate and sodium hydroxide with a molar ratio range of 0.5 to 2.5 (SiO2:Na2O), revealed that binders with a molar ratio of 2.5 exhibited lower pH and higher adhesion strength. Different geopolymer formulations at solution to powder ratios (s/p) of 1.33, 3, and 3.5 determined s/p 3.5 as optimal for bentonite-based organo-geopolymer binders. Viscosity, gel time, pH, and solids content were examined, showing the effectiveness of substituting 10% silica fume to enhance the geopolymerization process and improve adhesion. Modifications using citric acid, sucrose, paraffin, pMDI, triacetin, and resorcinol demonstrated wet bonding strength comparable to urea formaldehyde adhesive. Analytical techniques, including FTIR spectroscopy, XRD analysis, and SEM EDX analysis, provided insights into functional groups, crystallographic properties, and microstructural characteristics. The concentration of Si and Al compounds on the bonding line, coupled with Na element diffusion, was observed through these analyses. Light microscopy of lap shear samples revealed a thinner bonding line, affirming effective binder penetration into wood cell lumens in bentonite-based organo-geopolymer binder formulations.

Process Intensification for Enhanced Fluoride Removal and Recovery as Calcium Fluoride Using a Fluidized Bed Reactor.

This study explored the feasibility of fluoride removal from simulated semiconductor industry wastewater and its recovery as calcium fluoride using fluidized bed crystallization. The continuous reactor showed the best performance (>90% fluoride removal and >95% crystallization efficiency) at a calcium-to-fluoride ratio of 0.6 within the first 40 days of continuous operation. The resulting particle size increased by more than double during this time, along with a 36% increase in the seed bed height, indicating the deposition of CaF2 onto the silica seed. The SEM-EDX analysis showed the size and shape of the crystals formed, along with the presence of a high amount of Ca-F ions. The purity of the CaF2 crystals was determined to be 91.1% though ICP-OES analysis. Following the continuous experiment, different process improvement strategies were explored. The addition of an excess amount of calcium resulted in the removal of an additional 6% of the fluoride; however, compared to this single-stage process, a two-stage approach was found to be a better strategy to achieve a low effluent concentration of fluoride. The fluoride removal reached 94% with this two-stage approach under the optimum conditions of 4 + 1 h HRT combinations and a [Ca2+]/[F-] ratio of 0.55 and 0.7 for the two reactors, respectively. CFD simulation showed the impact of the inlet diameter, bottom-angle shape, and width-to-height ratio of the reactor on the mixing inside the reactor and the possibility of further improvement in the reactor performance by optimizing the FBR configuration.

Synthesis, characterization, and breakthrough modeling of low-cost graphene oxide-sand supported adsorbent filter for the separation of lead and chromium ions

The existence of lead and chromium ions in waterbodies severely affects the biological activities of aquatic creatures that directly affect human health. A graphene oxide-sand (GO-sand)-based composite filter has been successfully used as a Rapid Sand Filter (RSF) to remove Lead (II) and Chromium (III) ions in water. Boehm titration, FTIR, RAMAN, XRD, and SEM-EDX analyses confirmed GO-sand’s active sites, semicrystalline, and irregular morphology. Moreover, lead and chromium adsorption using a GO-sand composite was established by XPS and SEM-EDX analyses. The results of the batch study showed significant adsorption (289.68 mg g−1 and 258.87 mg g−1) along with significant removal (96.4 % and 95.6 %) of Pb (II) and Cr (III), respectively. Among Langmuir, Freundlich, and Liu isotherms, the adsorption isotherm showed an excellent fit with Liu isotherm. The response surface methodology (RSM) study suggested adequate quadratic models and exceptional covenant between the predicted and actual figures with a significant coefficient determination (R2 > 0.920). The kinetic study finding revealed the best fit for the Elovich kinetic model (R2 = 0.995 (Pb), R2 = 0.967 (Cr)), and the thermodynamics study confirmed endothermic adsorption. Pareto analysis confirmed that solution pH was the most significant parameter towards adsorption. Furthermore, the regenerated adsorbent demonstrated practical reusability up to four adsorption–desorption cycles, revealing the process’s sustainability.

Use of a high-entropy oxide as an oxygen carrier for chemical looping

One mixed oxide with 5 cations in equimolar proportions in the sublattice, to fulfil high-entropy oxide (HEO) criteria, has been developed and investigated as oxygen carrier for chemical looping combustion processes. As far as we know, nobody has explored this class of material for chemical looping combustion. Material is prepared by direct mixing of five metal oxides (CuO, Mn2O3, Fe2O3, TiO2, MgO), followed by calcination at 1000, 1100 and 1200 °C for 6 h in air. XRD characterization provides strong evidence that the synthesized oxygen carriers possess the hallmark properties of HEO, and SEM-EDX analysis shows an overall homogeneous metal distribution. Materials have one main cubic phase with the empirical formula MnCuMgFeTiO7, dominating under all conditions. One of the key objectives of this study is achieved, reduce chemical stress during redox cycles. Oxygen transfer capability is investigated by thermogravimetric analysis and batch fluidized bed reactor experiments for different fuels and atmospheres. Mass-based oxygen transport capacities for lattice oxygen and oxygen uncoupling are around 5.5 wt% and 1.1 wt%, respectively. This work opens up a new dimension for the future preparation of oxygen carriers for chemical looping processes, since the vast compositional space of HEO provides opportunities to tune both chemical and physical characteristics.

Optical, thermal, FTIR, SEM-EDX and 1H NMR analysis of Chenopodium album (Bathua) powder prepared using different drying techniques

Chenopodium album (L.) is an underutilized agricultural crop consumed as a leafy vegetable in Asian countries. Although perishable and cultivated in a specific season, it contains nutrients and phytochemicals in abundance. Preservation by employing drying techniques helps in their utilization in the off-season for better food security. In the present study, Chenopodium album leaves were dried using sun, tray, and freeze drying. The different powder samples were characterized on the basis of their physicochemical, optical, and thermal properties. The water activity of powder samples ranged between 0.29 and 0.56. The highest color retention (L* value 47.21) and lowest particle size (11.5 µm) was observed in freeze dried samples. Fourier-transform infrared spectroscopy and Nuclear magnetic resonance spectra confirmed the presence of several functional groups. Thermal analysis revealed the thermal degradation of powder due heat as depicted by change of state and loss of weight. Surface morphological study indicated that powder samples were flowable and element analysis showed presence of C, O, K, Ca, Mg, P, S element in powders.

Hydrophobic Coating of Vegetable-Tanned Leather with Dodecylamine

Vegetable-tanned leather exhibits a hydrophilic character due to the abundance of hydroxyl groups (-OH). In this study, the surface of vegetable-tanned leather was modified to become hydrophobic. The leather was coated using dodecylamine (DDA) through the padding method in the finishing process. The concentration of DDA varied from 1%, 2%, 3%, and 4% to identify the optimum concentration. The coating process was assisted by an activator, either acid or base, to improve the adhesion of DDA to leather. Uncoated vegetable-tanned leather was used as a control. The success of coating was identified using FT-IR and SEM-EDX analysis. The hydrophobicity of leather was conducted through a water resistance test. The success of coating is shown by the increase in their weight and thickness. Absorption bands of alkyl and amino groups of DDA are observed in FT-IR spectra around 1450 cm-1 and 3400 cm-1, respectively. SEM micrographs show that coated leathers have flatter surfaces as a consequence of DDA attachment on the leather surface. The water resistance test proves that the use of DDA can improve the leather hydrophobicity and enhance the water absorption time by up to 4 times. The optimum water absorption time is obtained when using 2% DDA.

Sequestration of hazardous alizarin Red S dye from water using mesoporous sponge-PANI composite

In this paper, the performance of the combination of polyaniline, a conductive polymer, and a polyurethane-based dishwashing sponge (sponge/PANI) on the adsorptive removal of Alizarin Red S dye from aqueous solutions was investigated. Firstly, polyurethane-based dishwashing sponges were cut into pieces and then coated by PANI. The sponge/PANI composites were characterized by XRD, SEM-EDX, BET, and FTIR-ATR analysis. Optimum conditions (adsorbent dosage: 0.1 g/50 mL, pH: 6–8, contact time: 120 min, agitation rate: 120 rpm) for adsorption were determined. Adsorption data were applied to different isotherm and kinetic models. According to the isotherm models, Langmuir model was found to be more suitable and the maximum adsorption capacity was found to be 188.68 mg/g at 298 K. According to the adsorption kinetic data, the adsorption process was found to follow the pseudo-second order kinetic model. Meanwhile, from the study on the adsorption mechanism, electrostatic interactions, H-bonding and interlayer force were considered to be the main driving force for adsorption. From the adsorption thermodynamic data, it was found that the adsorption of ARS dye was exothermic ( Δ H o = − 24.00 kJ / mol ) and spontaneous ( Δ G o = − 30.26 kJ / mol at 298 K ). Furthermore, from the reusability studies carried out, it was determined that the prepared adsorbent can be effectively used repeatedly. When the adsorption results were evaluated, it was determined that PANI-coated sponge composites effectively adsorbed Alizarin Red S dye. Moreover, the adsorption efficiency is open to improvement through optimization of surface properties by different methods such as doping.

Utilization of Bengkalis Beach Sand Silica as Raw Material in the Synthesis of Zeolite 4A

Zeolite 4A is a porous material that is widely used as an adsorbent, catalyst, membrane, ion exchanger, molecular sieve, etc. As a source of silica in the synthesis of zeolite 4A, silica from natural materials, biomass waste or chemicals has been used. In this research, silica extracted from Bengkalis beach sand (BBS) was used as raw material. The silica content in its oxide form, silicon oxide (SiO2) in BBS reaches 90%. The synthesis of zeolite 4A was carried out using a hydrothermal process, by varying the mole ratio of Si/Al from the reactant sodium silicate to sodium aluminate, namely 1.2:1; 1.4:1; 1.6:1 at reaction temperatures of 100, 110 and 120°C. Based on characterization using X-ray diffraction and an infrared spectrometer, the best conditions were obtained at a mole ratio reactant of 1.6, a reaction temperature of 100°C with a crystallinity percentage reaching 80.97%. Based on SEM-EDX analysis, the zeolite has an agglomerated morphology with a Si/Al ratio of around 1.09. The surface area, pore volume, and pore diameter of the synthesized zeolite were analyzed using a Brunauer-Emmet-Teller (BET) technique, respectively 81.844 m2/g, 0.039 cm3/g, and 3.07 nm.

Optimization of Calcium Fluoride Crystallization Process for Treatment of High-Concentration Fluoride-Containing Semiconductor Industry Wastewater.

This study utilized a fluidized bed reactor (FBR) for fluoride removal from high-concentration fluoride-ion-containing simulated semiconductor industry wastewater and recovered high-purity CaF2 crystals. The effects of hydraulic retention time (HRT), pH, Ca2+ to F- ratio, upflow velocity, seed size and seed bed height were investigated by performing lab-scale batch experiments. Considering fluoride removal and CaF2 crystallization efficiency, 5 h HRT, pH 6, seed height of 50 cm and [Ca2+]/[F-] ratio of 0.55 (mol/mol) were found to be optimum. The effect of the interaction between the important process parameters on fluoride removal was further analyzed using response surface methodology (RSM) experimental design. The results showed that all the individual parameters have a significant impact (p = 0.0001) on fluoride removal. SEM-EDX and FTIR analysis showed the composition of the crystals formed inside FBR. HR-XRD analysis confirmed that the crystalline structure of samples was mainly CaF2. The results clearly demonstrated the feasibility of silica seed material containing FBR for efficient removal and recovery of fluoride as high-purity calcium fluoride crystals.

Demineralization effects of breast milk, formula milk and cow’s milk on the primary teeth. A study of SEM-EDX analysis

Purpose: It was aimed to investigate demineralization effects of breast milk, formula milk and cow's milk on deciduous teeth with SEM-EDX analysis. 
 Materials and methods: Demineralization effects of breast milk (Group-1), 3 different formula milks: Aptamil Pronutra-3 (Group-2), Hipp Organic-3 (Group-3), SmA Optipro-2 (Group-4) and cow's milk (Group-5) on newly extracted caries-free primary incisors were investigated on 5 teeth in each group. Each tooth was split in the sagittal direction from the midline and embedded in 2 separate acrylic blocks with their labial surfaces exposed. Half of the teeth was exposed to the milk material for 15 minutes, 4 times a day for 5 days, while the other half was kept in artificial saliva only. After the exposures, Scanning Electron Microscopy (SEM) images of the labial surfaces were taken and Energy Dispersive X-ray Spectroscopy (EDX) analyzes were performed. For the statistical analysis Independent-Samples T test, Man Whitney U and Kruskal-Wallis test were used. 
 Results: The most increased enamel porosity was seen in Group-2. A significant decrease was observed in the amount of Ca on tooth surfaces exposed to breast milk and formula milks, and a significant increase in the amount of both Ca and P after exposure to cow's milk (p=0.009). The decrease observed in the amount of Ca after exposure to breast milk was significantly higher than that of formula milks (p=0.001). 
 Conclusion: Formula milk and breast milk are not innocent in terms of causing demineralization, therefore awareness of parents and dentists on this issue should be increased.

Green Synthesis of Ag/Mg(OH)2 Nanocomposite from Potato Peel Extract (Solanum tuberosum) and Its Antioxidant Activity

Potato peel extract (PPE) is a rich source of polyphenols which could be used as reducing agents for the green synthesis of nanocomposites. The project aims to synthesize Ag/Mg(OH)2 nanocomposites (NCs) by using PPE and investigate its antioxidant activity. The phytochemicals in peel extract act as reducing, stabilizing, and capping agents in the reduction of precursor salts. SEM-EDX analyses of the bio-synthesized Ag/Mg(OH)2 NCs show the formation of Ag nanoparticles (NPs) on the surface of Mg(OH)2 carriers with various sizes in the nanoscale, while XRD patterns suggest the existence of Mg(OH)2 hexagonal crystalline structure. The antioxidant activity of Ag/Mg(OH)2 NCs was assessed through the DPPH free radical scavenging assay with IC50 values between 1.3 and 1.4 mg/mL. Compared to various plant-based Ag NPs, such values are remarkably closer to the IC50 of the standard ascorbic acid (0.6 mg/mL), promoting PPE-based Ag/Mg(OH)2 as an effective and ecofriendly antioxidant.