SEM EDS Research Articles

Evaluation of Kunkur Fines for Utilization in the Production of Ternary Blended Cements

Ternary blended cements, such as limestone calcined clay cement (LC3), represent a type of strategic binder for the mitigation of environmental impacts associated with cement production. These are estimated to reduce CO2 emissions by about 40% compared to ordinary Portland cement (OPC). In this paper, we explore the possibility of producing such ternary blends by utilizing secondary raw materials that may be locally available. Specifically, the primary limestone that is commonly used in LC3 is herein substituted with quarry dust obtained by sourcing “kunkur”, a carbonate-rich sedimentary rock (also known as caliche) that can be locally utilized for the production of ordinary OPC clinker. To optimize the blending proportions of ternary cement consisting of OPC, calcined clay, and kunkur fines, a “design of experiment” (DoE) approach was implemented with the goal of exploring the possibility of reducing the amount of the OPC fraction to values lower than 50%. The properties of the formulated blends were assessed by a combination of techniques that comprise mechanical strength testing, XRD time-dependent quantitative phase analysis, and SEM–EDS microstructural and microchemical analyses. The results suggest that ternary blended cement based on kunkur fines forms hydration products, such as hemicarboaluminates, which are also observed in LC3. This shows that such waste materials can potentially be used in sustainable cement blends; however, the presence of kaolinite in the kunkur fines seems to affect their strength development when compared to both OPC and conventional LC3.

Koryŏ inlay celadon from Taicang Port of the Yuan Dynasty, China

Inlay celadon was a type of high-end ceramics of the Koryŏ dynasty (918–1392 AD) produced in the Korean Peninsula. It was conveyed to China during the Yuan dynasty (1279–1368 AD) as tribute or trade goods. In this study, the authors analyzed six samples of inlay celadon recently discovered at the prosperous Taicang Port of the Yuan and Ming dynasties in the lower Yangtze River, China. With scanning electron microscopy coupled with energy dispersive spectroscopy (SEM–EDS) and X-ray diffraction (XRD), the authors investigated the production technique, and compositional characteristics of these samples for the purpose of tracking their provenances. While the bodies are made of porcelain stone, the glazes are of porcelain stone and calcium-rich flux. The white inlay material in these samples is kaolinite-dominant, and the black one is made of quartz with high Fe content or a compound of quartz and raw materials with high Fe content. The results link the samples uncovered at the Taicang Port to the Samhǔngni Kiln in Kangjin-gun and the Uch'ǒlli and Chinsǒri Kilns in Buan-gun in Southern Korea. The products from these kilns were shipped to China in several shipments.

A highlightedly improved method for isolating and characterizing calcium oxalate crystals from tubercles of Mammillaria schumannii

BackgroundCalcium oxalate (CaOx) is the most prevalent and widespread biomineral in plants and is involved in protective and/or defensive functions against abiotic stress factors. It is, however, expected that this function has an extremely significant contribution to growth processes in plants bearing large amounts of CaOx, such as cacti growing in desert environment.ResultsIn our research, small-sized CaOx crystals (≤ 20 µm) with tetrahedral or spherical shapes were observed to dominate in each epidermal and cortical cell from the tubercles of Mammillaria schumannii, a species from the Cereoideae subfamily, having tubercles (main photosynthetic organs) united with adjacent ones almost into ridges on its stem. Because they have potential significant functions, differential centrifugations after mechanical blending were used to obtain these small-sized CaOx crystals, which extremely tend to adhere to tissue or suspend in solution. And then the combined Scanning Electron Microscope Energy Dispersive System (SEM–EDS) and Raman spectroscopy were further performed to demonstrate that the extracted crystals were mainly CaC2O4·2H2O. Interestingly, spherical druses had 2 obvious abnormal Raman spectroscopy peaks of -CH and -OH at 2947 and 3290 cm−1, respectively, which may be attributed to the occluded organic matrix. The organic matrix was further extracted from spherical crystals, which could be polysaccharide, flavone, or lipid compounds on the basis of Raman spectroscopy bands at 2650, 2720, 2770, and 2958 cm−1.ConclusionsHere we used a highlightedly improved method to effectively isolate small-sized CaOx crystals dominating in the epidermal and cortical cells from tubercles of Mammillaria schumannii, which extremely tended to adhere plant tissues or suspend in isolation solution. And then we further clarified the organic matrix getting involved in the formation of CaOx crystals. This improved method for isolating and characterizing biomineral crystals can be helpful to understand how CaOx crystals in cacti function against harsh environments such as strong light, high and cold temperature, and aridity.

Ti3C2-MXene/NiO Nanocomposites-Decorated CsPbI3 Perovskite Active Materials under UV-Light Irradiation for the Enhancement of Crystal-Violet Dye Photodegradation

Ti3C2-MXene material, known for its strong electronic conductivity and optical properties, has emerged as a promising alternative to noble metals as a cocatalyst for the development of efficient photocatalysts used in environmental cleanup. In this study, we investigated the photodegradation of crystal-violet (CV) dye when exposed to UV light using a newly developed photocatalyst known as Ti3C2-MXene/NiO nanocomposite-decorated CsPbI3 perovskite, which was synthesized through a hydrothermal method. Our research investigation into the structural, morphological, and optical characteristics of the Ti3C2-MXene/NiO/CsPbI3 composite using techniques such as FTIR, XRD, TEM, SEM–EDS mapping, XPS, UV–Vis, and PL spectroscopy. The photocatalytic efficacy of the Ti3C2-MXene/NiO/CsPbI3 composite was assessed by evaluating its ability to degrade CV dye in an aqueous solution under UV-light irradiation. Remarkably, the Ti3C2-MXene/NiO/CsPbI3 composite displayed a significant improvement in both the degradation rate and stability of CV dye when compared to the Ti3C2-MXene/NiO nanocomposite and CsPbI3 perovskite materials. Furthermore, the UV–visible absorption spectrum of the Ti3C2-MXene/NiO/CsPbI3 composite demonstrated a reduced band gap of 2.41 eV, which is lower than that of Ti3C2-MXene/NiO (3.10 eV) and Ti3C2-MXene (1.60 eV). In practical terms, the Ti3C2-MXene/NiO/CsPbI3 composite achieved an impressive 92.8% degradation of CV dye within 90 min of UV light exposure. We also confirmed the significant role of photogenerated holes and radicals in the CV dye removal process through radical scavenger trapping experiments. Based on our findings, we proposed a plausible photocatalytic mechanism for the Ti3C2-MXene/NiO/CsPbI3 composite. This research may open up new avenues for the development of cost-effective and high-performance MXene-based perovskite photocatalysts, utilizing abundant and sustainable materials for environmental remediation.

Welan gum as a new depressant for the flotation separation of chalcopyrite from talc

Taking chalcopyrite and talc as examples, this article explores an anionic polysaccharide polymer, Welan gum (WLG), as an environmental depressant of talc. It depresses talc in the flotation system, thereby improving the flotation index of chalcopyrite. The flotation test results showed that under the action of an 80 mg/L depressant, a chalcopyrite concentrate with Cu grade of 28.87 % and Cu recovery rate of 86.72 % was obtained, indicating efficient separation ability of chalcopyrite-talc. The zeta potential and adsorption results indicate that the adsorption capacity of WLG on the surface of chalcopyrite is significantly lower than that on the surface of talc. The contact angle tests found a significant change in the wettability of talc after the action of depressants. Fourier-transform infrared spectrum (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscope energy spectrum spectroscopy (SEM–EDS) studies have found that WLG is mainly adsorbed on talc through physical interactions. According to density functional theory (DFT) calculation analysis, the –COOH- and –OH in the WLG structure can interact with Mg, Si, and O atoms in talc.

Remediation of persistent organic pollutants through statistical treatment using the CoFe2O4@Fe3O4-based magnetic nanocomposite

In the present study, the CoFe2O4@Fe3O4-based magnetic nanocomposite was synthesized and applied as an adsorbent material in the polycyclic aromatic hydrocarbons (PAHs) remediation, which include phenanthrene (Phe), benzo[b]fluoranthene (B[b]F), benzo[k]fluoranthene (B[k]F), and benzo[a]pyrene (B[a]P). The experimental conditions were investigated using a factorial experimental design (24) with the aim of carrying out a systematic evaluation of the solution pH, equilibrium time, concentration of pollutants, and magnetic nanocomposite mass. The characterization of the CoFe2O4@Fe3O4 adsorbent by the FTIR and XRD analyses showed success in the formation of magnetic nanoparticles. In addition, the SEM–EDS analysis exhibited images of nanometric spheres, uniform morphology, and the presence of Fe, Co and O as main components, as well as a type IV isotherms with H1 hysteresis as a typical formation of a mesoporous nanocomposite with high surface area (244.28 m2 g−1) and large pore volume (0.19 cm3 g−1). The statistical treatment revealed that the pH and the adsorption time are variables that little or nothing influenced the adsorptive properties of the CoFe2O4@Fe3O4 to remove the PAHs mixture, contrary to the PAHs concentration and the CoFe2O4@Fe3O4 mass, which are important variables. Finally, the best experimental conditions were obtained for the adsorption tests between 13 (pH 3, time = 5 min, concentration = 1000 µg L−1, and mass = 50 mg) and 16 (pH 10, time = 200 min, concentration = 1000 µg L−1, and mass = 50 mg), whose overall desirability (OD) values were 1.00 and removal efficiency varied between 92.40 and 96.60 %; 95.00–97.00 %; 90.80–96.30 %; and 93.50–96.80 %, respectively, for Phe, B[b]F, B[k]F, and B[a]P.

Morphology and molecular phylogeny of two new species of Psammophaga (Rhizaria, Foraminifera) from the west coast of India

Benthic foraminifera are unicellular eukaryotic protists that construct an organic, agglutinated, or calcareous test wall. Although single-chambered (monothalamous) foraminifera are ubiquitous in marine habitats worldwide, they are poorly known compared to their multi-chambered relatives, notably from the tropical marine environments of India. In this study, we describe two new species of marine monothalamid genus Psammophaga Arnold, 1982, from the Rajapuri Creek, coastal Maharashtra, India (Arabian Sea). Psammophaga holzmannae sp. nov. is ovoid to spherical shaped, 103–246 µm in length, single aperture, translucent to orange color cytoplasm, outer surface is composed of agglutinated fine clay particles, and ingested mineral grains are concentrated near its aperture. Psammophaga sinhai sp. nov. is oblong, elliptical, or droplet-shaped, 279–448 µm in length, single aperture, yellow olive color cytoplasm, the exterior surface formed of agglutinated fine clay particles, and the ingested mineral grains are dispersed throughout the body. Phylogenetic analyses based on partial small subunit rRNA gene sequences position new species within the Clade E of monothalamids and are genetically distinct from other Psammophaga. Elemental (SEM–EDS) analysis of engulfed mineral grains revealed preferential selection and uptake of heavy opaque titaniferous minerals from the ambient environment in the cytoplasm.

Multi-method analysis of a historic wooden trough from Kentucky, USA: a case study in corroborating artifact oral histories with heritage science

Oral history indicates that a large wooden trough held in storage at the University of Kentucky’s William S. Webb Museum of Anthropology was a component of the saltpeter mining operation in Mammoth Cave in the late 18th and early 19th centuries, worked largely by enslaved persons. We used multiple heritage science methods, including radiocarbon wiggle-match dating, tree-ring dating, scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM–EDS), and optical scanning, combined with historical research, to examine the trough. Our analysis supports the oral history of the trough as an artifact of the mining system in Mammoth Cave. This case study illustrates how heritage science methods can provide corroboration for the origins and biographies of poorly documented historical artifacts.

Chemical and mineral composition of bottom ash from agri-food biomass produced under low combustion conditions

The study aimed at conducting a detailed analysis of apple pomace (AP), walnut shells (WS), and sunflower husks (SH) ashes as potential raw materials for combustion at a temperature of 400 ± 15 °C (individual home furnace). Research methods such as ICP-OES/MS (atomic emission spectrometry with excitation in induced plasma and mass spectrometry), XRD (X-ray diffraction), and SEM–EDS (scanning electron microscopy with quantitative X-ray microanalysis) were utilized. Elemental CHNSO FlashSmart series analyser (Thermo Scientific) was employed for the analysis of oxygen (O). An automatic IR analyser was used to determine the carbon (C), total sulphur (S), and hydrogen (H) content. Total sulphur (S) and chlorine (Cl) were measured by the PN-EN ISO 16994:2016 standard. The nitrogen (N) content was determined by the catharometric method of chlorine by ion chromatography (IC). Higher concentrations of potentially toxic elements (PTE) such as As, Cr, Zn, Cd, Cu, Ni, Pb, Tl, U, and Th were detected in apple pomace ashes. The mineral composition of biomass ashes was found to be highly diverse, with sunflower husk ashes containing the highest amount of minerals, including quartz, dolomite, calcite, magnesite, sylvite, arcanite, fairchildite, and archerite. Quartz was identified in apple pomace ash, while in sunflower husk ash, it was determined to be present only as an amorphous substance. The estimated total dust emission to the atmosphere from biomass combustion was found to be at a similar value (1.23 to 1.35 kg/Mg).

Extraction of Rare Earth Elements from Brown Coals of the Sergeevskoe Deposit (Amur Region) According to Experimental Data

A series of experiments on the leaching of rare earth elements (REEs) from Miocene brown coals of the Sergeevskoe deposit with water and alkaline and acid solutions was carried out. Using a set of methods (ICP MS, XRD analysis, heavy concentrate analysis, SEM EDS, and IR spectrometry), it was revealed that acid leaching was the most effective: 72–99% of REEs was extracted with a 1 M solution of hydrochloric acid in 24–48 h. This fact indicates that most of the REEs in the brown coals of the Sergeevskoe deposit were associatedwith the organic matrix in the form of complexes with the carboxyl groups of humic and fulvic acids. The high percentage of REE extraction indicates the possibility of using coals from the Sergeevskoe deposit as an easily enriched source of REEs.

Optimization of resistance spot welding with surface roughness dissimilar mild steel with stainless steel

Resistance spot welding plays a critical role in the manufacture dissimilar material industry. However, there are differences in mechanical properties between mild steel and satinless steel so as to reduce the quality of welded joints. In order for differences in mechanical properties to be corrected, surface roughness was treated. The aim of this study was to optimize the welding parameters of DRSW with surface roughness by analysis using the Taguchi and Anova Methods. In this study discusses about investigates the Resistance spot welding parameters on weld geometry, mechanical properties, and SEM EDS on dissimilar materials of mild steel and stainless steel. The material thickness of the mild steel and stainless steel are 1 mm, respectively. The process parameters of the resistance spot welding joint used, example; surface roughness, current, welding time, and electrode force. Quality welding joint test results include weld geometry, mechanical properties, and SEM EDS. Weld geometry testing to determine the weld nugget profile. The mechanical properties test was shear tensile test, while the SEM EDS included macrostruture and microstructure observations. The results showed the highest nugget diameter 6.65 mm highest shear tensile strength 7.66 kN. The most influential parameter is current by 75.08 %, then surface roughness by 12.35 %. The highest tensile strength has fewer defects. Surface roughness treatment before welding is very good to make welding quality joints between mild steel and quality stainless steel increase. Surface roughness treatment was very good to be included when making welding procedures for welding engineers for welding processes resistance spot welding dissimilar mild steel with stainless steel.

Manufacturing technique for Jizhou painted porcelains in the Yuan dynasty and its influence on coloring

The Jizhou kiln was an important production center of the painted porcelains in Southern China during the Song and Yuan dynasties. The manufacturing technique of the painted porcelains in the Jizhou kiln potentially facilitated the emergence of the well-known blue-and-white porcelains in Jingdezhen. Herein, the chemical compositions and microstructures of the bodies, glazes and paintings of Jizhou painted porcelains from the Yuan dynasty were investigated through X-ray fluorescence (XRF), optical microscopy (OM), Raman spectroscopy and field emission scanning electron microscopy with energy dispersive spectroscopy (SEM‒EDS) to clarify the manufacturing characteristics of Jizhou painted porcelains and their impact on the coloring mechanism. The results showed that the bodies of Jizhou painted porcelains were made of local clay and those transparent glazes were made of local sericite-rich clay and botanic ashes. Black‒brown painted porcelains and red‒brown painted porcelains were methodically made by ancient potters by controlling pigment formulation, painting techniques and firing schedules. The colors of the black‒brown painting and the red‒brown painting were related to the α-Fe2O3 particles in the iron-rich minerals used in the pigment and the iron oxide crystals (α-Fe2O3 and ε-Fe2O3) precipitated on the glaze surface, respectively.

Optimization of the Alkali-Silane Treatment of Agave lechuguilla Fibers (Ixtle) for Potential Reinforcement in Polymeric Composites

Reinforced polymeric composites with natural fibers have garnered significant interest in recent years due to the need for biomass utilization and the requirements of various industries, such as automotive and construction. Among these natural fibers, Agave lechuguilla fiber, commonly known as ixtle (FIx) or Tampico fiber, exhibits important characteristics such as length, high strength, and durability. However, there is limited literature on its conditioning, functionalization, and utilization as a reinforcing material in polymeric composites (CP). This study presents the optimization of the alkali-silane treatment of FIx, identifying the most suitable reaction conditions to enhance their thermal stability, tensile strength, and silane coupling agent (ACSi) grafting on the fiber surface. The chemical treatment with ACSi proved highly effective, resulting in a significant grafting content, which was confirmed through FTIR and SEM–EDS analyses. The high level of functionalization did not compromise the mechanical performance of the fibers, suggesting that functionalized FIx holds great potential as a reinforcing material in CP. These findings open new paths for the sustainable use of Agave lechuguilla fibers, contributing to the development of environmentally friendly and high-performance polymeric composites in various industrial applications.

Long-time irradiation effect on corrosion behavior of aluminum alloy in pool water of low-power research reactor

This study conducted an evaluation of the corrosion behavior of an aluminum alloy utilized in the Isfahan Miniature Neutron Source Reactor (MNSR). The component analyzed, dry channel (DC), had been exposed to radiation for 12 years in a water environment within the reactor pool since its installation. To determine the effect of radiation on the corrosion of the LT-21 aluminum alloy used in the DC, different parts of the pipe were sampled and various tests were performed. These tests included mechanical strengths (impact, and micro-hardening), XRD, TEM, SEM–EDS, and potentiodynamic polarization (PDP). The parameters measured included corrosion potential, corrosion rate, changes in microscopic structure, and mechanical properties of the aluminum alloy along the entire length of the DC. The neutron and gamma dose distribution along the height of the DC, which was 540 cm, was calculated to determine the correlation between the dose distribution and observed corrosion. The study found that the corrosion mechanisms were complex and resulted from the simultaneous presence of the DC in the pool water and radiation from the reactor core. The observed results are presented and discussed in this study.

Interactions of Crucible Materials With an FeOx–SiO2–Al2O3 Melt and Their Influence on Viscosity Measurements

Viscosity is a critical parameter during metal extraction, influencing the settling of valuable droplets, slag handling, and mass transfer. The viscosity of oxide melts can be measured with high-temperature rheometers. During such measurements, interactions between the crucible and the oxide system can change the chemical composition, melt structure, and thus the viscosity. For increased reliability of viscosity measurements, the influence of crucible and spindle materials on viscosity must be studied. In this study, the viscosity of a synthetic FeOx–SiO2–Al2O3 melt was measured using the rotating spindle technique and three different crucible and spindle materials (Mo, Fe, and Ni) to determine the interactions with the melt and the influence on viscosity. The interaction was evaluated by comparing the post-experimental chemical analyses, the Fe/Fe2+/Fe3+ content, visual observations, and using scanning electron microscopy–energy dispersive spectroscopy (SEM–EDS). The results showed that all the crucibles partially dissolved into the melt, affecting the melt structure, composition, and, thus, the viscosities. The viscosity data obtained using the Mo setup interacted the least with the melt, was the most stable, and with the best reproducibility.Graphical

A multi analytical characterization of a small bronze figurine from Gran Carro site (Bolsena Lake, Italy)

This paper presents the results of an archaeometric analysis carried out on an early Iron Age anthropomorphic figurine discovered in the area of the Gran Carro on Bolsena Lake (Latium, Italy) site, currently interpreted as a place of worship. This statuette is considered a unicum, both because of the context in which it was found and because of its stylistic characteristics similar to those of bronzes from the Nuragic civilization (Sardinia, Italy). Its discovery and the data obtained from this work provide further evidence in support of numerous previous studies suggesting the presence of trade and direct exchanges between Sardinia and southern Etruria. The research was performed through some non-destructive investigations such as Energy Dispersive X-Ray Fluorescence (EDXRF) combined with Monte Carlo Simulation (MC) and micro-invasive investigations such as Scanning Electron Microscopy coupled by Energy Dispersive Spectroscopy (SEM–EDS) and by Electron Probe Micro-Analysis (EPMA), metallography and lead isotope analyses (LIA), performed on a selected micro-fragment. The combination of non-destructive techniques (EDXRF-MCS) for the characterization of the artefact allowed us to obtain data similar to those obtained with micro-invasive surveys, further demonstrating the effectiveness of the method. The results indicate that the statuette is made of a bronze alloy and that the copper metal was extracted from Sardinian deposits.

Effect of a harsh circular environment on self-healing microbial-induced calcium carbonate materials for preventing Pb2+ migration

Microbially induced carbonate precipitation (MICP) is increasingly being explored for Pb-contaminated water bodies and soil remediation. However, the Pb-related precipitate resulting from the MICP process can possibly leach acid over time when subjected to harsh environments, causing serious threats to human health. In this study, for the first time, self-healing microbial-induced calcium carbonate (MICC) materials are proposed and applied to prevent Pb2+ migration where the Pb-related precipitate is acid leached after spore germination, spore-vegetative cell transformation, urease secretion, and urea hydrolysis, thereby producing spore-containing precipitation. This process was repeated five times to explore the effect of a harsh circular environment on self-healing MICC materials. Results indicated that Pb immobilization would have deteriorated if the inosine and trace elements had not been intervened during spore germination and spore-vegetative cell transformation, respectively. The spores and vegetative cells provided extra nucleation sites for Pb2+ and minerals to attach. The extracellular polymeric substances (EPSs) combined Pb2+ with functional groups and chemical bonds to prevent their migration to surrounding environments. The scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM–EDS) images also indicated that the cerussite mineral was precipitated prior to the calcite mineral because Pb2+ had more affinity to combine with CO32- and OH-. An immobilization efficiency of greater than 95% remained nearly the same after five cycles, while it reduced very quickly to less than 10% after three cycles when neglecting the self-healing MICC materials, thus highlighting their relative merits.

Formulation and characterization of environmentally benign chicken feather-based wood preservatives

This paper develops chicken feather protein-based wood preservatives (CFP-WP). The treatability, leachability and chemical structure of the CFP-WP were analyzed. The crystallinity, thermal properties, micromorphology and decay resistance against fungi of the treated wood samples were investigated to examine their efficacy. The production cost of CFP-WP was also assessed. The results showed that CFP-WP (Cu, B and small molecular amino acids) was able to penetrate into wood cell walls and the active ingredients of preservatives interacted with wood constituents were well fixed onto wood blocks, evidenced by SEM–EDS observation, NMR, FTIR, XRD and TGA/DTG analysis. The morphology analysis elucidated that CFP-WP effectively protected wood against decay fungi. Decay experiments verified that the new preservative prolonged the wood service life, reducing the mass loss up to 10.88% from 51.02% compared to the untreated wood. Further, the production cost of CFP-WP (approx. 130–140 €/tonne) is nearly 30% lower than the commercial price of conventional market preservatives, such as ACQ (approx. 210 €/tonne). The excellent functionalities of this CFP-WP eco-friendly formulation present a great potential to be used as an environmentally benign wood preservative.

Preparation and sustained-release study of Litsea cubeba essential oil inclusion complex with γ-cyclodextrin-metal–organic frameworks

BackgroundLitsea cubeba essential oil (LCEO) is a food additive that requires encapsulation to delay its release due to its irritating nature. To identify an appropriate inclusion material, gamma (γ)-cyclodextrin (CD)-metal organic frameworks (MOF) were prepared, and the sustained release of the inclusion complex (IC) was studied.ResultsThe γ-CD-MOF was formed using γ-CD, potassium hydroxide (KOH), cetyltrimethylammonium bromide (CTAB), and silane coupling agents through the vapor diffusion method. The highest encapsulated rate achieved was 26.02%, with a temperature of 50 °C, a stirring time of 2.5 h, and an LCEO to γ-CD dosage ratio of 1:8. During the adsorption test, the amount of LCEO gradually increased within the first 180 min. However, after this time, there was no significant change in the adsorption amount of LCEO, indicating that the γ-CD-MOF had reached adsorption equilibrium. The average release rate of the IC reached 9.76% at 11 h. By comparison, the average release rate of the IC with γ-CD was 9.30% at 10 min, resulting in a diffusion index of 0.349. Under ultraviolet (UV) scanning, the sustained-release solution of the IC exhibited a strong characteristic citral absorption peak at 238 nm. Moreover, under infrared spectroscopy scanning, the absorption peak intensity of the IC was 1.19 times higher than that of blank γ-CD-MOF at 1676 cm−1. The IC, as observed through a scanning electron microscope, exhibited round pellets with a diameter of 40–60 μm. Energy dispersive spectroscopy images showed uniform distribution of potassium and sulfur elements. In X-Ray diffraction, the diffraction peaks of the IC were found at 5.27°, 7.45°, 10.54°, 12.08°, 14.20°, 14.92°, 15.84°, 16.68°, 19.24°, 21.80°, and 23.69°, with no significant change in the adsorption amount of LCEO. The Brunauer–Emmett–Teller (BET) testing revealed that the surface area of γ-CD-MOF was 5.089 m2/g, and the pore diameter was 3.409 nm by the Barrett–Joyner–Halenda (BJH) method.ConclusionThese data demonstrated that the sustained effect of the γ-CD-MOF was superior to that of γ-CD. The adsorption kinetics curve followed the Quasi-primary kinetics model, while the release curve adhered to the Ritger–Peppas model. Furthermore, the release behavior was primarily governed by the Fick diffusion mechanism, which was advantageous for achieving the sustained release of LCEO. The UV spectrum, infrared spectroscopy (IR), scanning electron microscopy–energy dispersive spectroscopy (SEM–EDS), X-ray diffraction (XRD), and BET techniques confirmed the successful formation of the IC of LCEO with γ-CD-MOF. This study offers a promising technical solution for delaying the release and improving the sustained-release product of LCEO.Graphical

The Influence of Alumina Airborne-Particle Abrasion on the Properties of Zirconia-Based Dental Ceramics (3Y-TZP)

The objective of this study was to assess the effect of airborne-particle abrasion with alumina particles of various sizes (50 μm, 110 μm, 250 μm) on the surface properties of 3Y-TZP (3 mol% yttria-stabilized tetragonal zirconia polycrystals). The analysis comprised the Vickers hardness test (HV1kp), a surface roughness evaluation (Ra, Rq, Rz, Rsk, Rsm, Rt, Vo, profile displays), and SEM–EDS microanalysis (scanning electron microscopy–energy-dispersive X-ray spectroscopy). Any statistical relationships were assessed using the Kruskal–Wallis one-way analysis-of-variance-by-rank test (p = 0.05). While airborne-particle abrasion with 50 µm alumina significantly increases the Vickers hardness of 3Y-TZP (1678.8 HV1kp), 110 μm and 250 μm alumina particles do not appear to have any such effect. The surface roughness of 3Y-TZP increases with the size of the alumina particles (Ra, Rq, Rz, Rt, Vo: vertical plane and retention volume assessment); a higher Rsm (horizontal plane assessment) was noted for specimens air-abraded with 250 µm alumina particles; air abrasion with 50 μm alumina particles yielded a symmetrical surface roughness profile (Rsk). The major topographic pattern of the surface of 3Y-TZP is altered by alumina airborne-particle abrasion, with larger alumina particles causing more severe changes. Aluminum traces on the 3Y-TZP surface are observed. The shape of the alumina particles is irregular, with rough edges; the size of the alumina particles plays a significant role in the air abrasion of zirconia-based dental ceramics, affecting their morphology and properties.