FTIR Spectra Research Articles

Effect of partial substitution of K2O by MgO on the structure, and thermal, physical, optical properties and crystallization behaviour of K2O–MgO–B2O3–P2O5 glasses

In this work, a series of K2O–MgO–B2O3–P2O5 (KMBP) glasses were prepared by the melt-quenching method and the glass-ceramics were prepared by the one-step heat treatment. The thermal, structural, physical and optical properties, as well as the crystallization behaviour of the KMBP system, were investigated in detail using characterization techniques such as DSC, XRD, SEM, FTIR, transmittance spectroscopy and microhardness. As indicated by DSC, the thermostability and glass-forming ability were gradually enhanced through the partial substitution of K2O by MgO. XRD showed that the main crystalline phases of the glass-ceramics (GC) were gradually converted from the P–Mg–K–O based crystalline phases to the P–Mg–O based and the P–Al–O based crystalline phases. The SEM results indicated that tiny grain-like crystals were successfully precipitated from the parent glasses after heat treatment. The deconvoluted FTIR spectra results showed a gradual conversion of the [BO3] and [PO3] units towards the [BO4] and [PO4] units with the increase of the MgO contents. The increase in the degree of glass network polymerization was the essential reason for the increment in the microhardness of the parent glasses. The microhardness of GC featured a trend concordant with the crystallinity of the crystalline phases. The values of metallization criteria (MC) between 0.34 and 0.45, as well as the higher values of third-order nonlinear polarizability (χ(3)) and nonlinear refractive index (nnl) are indicative of the good suitability of the KMBP glasses for the nonlinear optical applications.

High Photocatalytic degradation of Methylene Blue and enhancing the Magnetization, AC conductivity of Dy3+ and Ce3+ doped CdCoFe2O4 nano ferrites

Photocatalysts that combine with dielectric and magnetic properties are vital because of a wide variety of applications for these combinations, and nanostructured magnetic semiconductive materials have attracted significant interest due to their potential applications. A series of Cd0.4Co0.6DyXCeXFe2-2XO4 spinel nano ferrites (nFs) were synthesized by using a highly efficient low-temperature method of citrate sol-gel auto-combustion for Methylene Blue (MB) dye degradation photocatalysts under visible light irradiation that combines with dielectric and magnetic properties are vital because of a wide variety of applications for these combinations, and nanostructured magnetic semiconductive materials have attracted significant interest due to their potential applications. The recycled MB is one of the hazardous textile dyes that is used extensively but causes risks for both humans and the environment. The prepared Dy3+ and Ce3+ doped Cd-Co nFs were polycrystalline with cubic structure, and crystalline size was increased from 15.78 to 21.02 nm with higher crystallinity, and the surface morphology changes from a spherical shape to a hexagonal shape with higher doping concentrations. The direct optical band gap values are increased. FTIR spectra reveal the stretching vibrations along the [M↔O] bond tetrahedral (A) and octahedral (B) sites. HRTEM results revealed that the prepared Cd-Co nFs have higher crystalline nature and high porosity. VSM indicates the sample's soft magnetic action and M-H hysteresis loops showed the highest saturation magnetization (Ms) is 12.243 emu/g, and retentivity increases around 6.038 emu/g, decreasing the dielectric tangent loss, dielectric constant and dielectric loss. The AC conductivity raised with applied frequency. The PL gives a blue emission, and photocatalytic has the highest degradation activity 40.93 % of MB would be successful after 120 min irradiation of X= 0.07 Dy3+ and Ce3+ doped Cd-Co nFs.

Investigation of structural, physical and optical properties of sodium boro-tellurite glasses doped with iron oxide

In this work, we demonstrate systematic studies on the influence of Fe2O3 on the structural and optical properties of transparent B2O3–TeO2–Na2O glasses containing the different concentrations of Fe2O3. The glasses were prepared via the standard melt quenching method, and the prepared glasses were characterized using, XRD, electron paramagnetic resonance (EPR), FTIR, and UV–visible spectroscopic techniques. Furthermore, we evaluated several physical properties of the glasses, including densities, molar volume, boron-boron separation, and oxygen packing density, with respect to the concentration of Fe2O3 in the host glass matrix. It is observed that the density of the glasses and the average boron-boron distance found increase with Fe2O3 concentration due to the modification in the glass network induced by the dopant ions. EPR spectra reveals the presence resonance signals at g ∼2.04 and g ∼4.26, hence it proves the existence of Fe3+ in distorted octahedral coordination and supported by UV–Vis absorption bands. The FTIR spectra revealed an increase in spectral intensity with the concentration of Fe2O3. This was attributed to the formation of non-bridging oxygens through converting BO4 units into BO3 units, which Fe2O3 mediated. The UV–visible spectral analysis showed a decreased energy band gap from 2.26 to 1.51 eV with increased Fe2O3 concentration. Additionally, we determined the Urbach energy, refractive index, optical basicity, and electronegativity, which are presented in detail.

SDS-Assisted Hydrothermal Growth and Photocatalytic Activity of Like-Caviar MoFe<sub>2</sub>O<sub>4</sub> Nanoparticle Decorated with Al<sub>2</sub>O<sub>3</sub>

Like-caviar molybdenum ferrite nanoparticles (MoFe2O4 NPs) have been successfully synthesized via a hydrothermal route in the presence of the negative surfactant (sodium dodecyl sulfate (SDS)). SDS acts as a template, stabilizer, and stops the aggregating process through storage. The mean crystal size of MoFe2O4 NPs rises with decorating it with Al2O3. Based on SEM analysis, the shapes of MoFe2O4, Al2O3, and their composite demonstrated like-caviar, like-brain cells, and like-grains, respectively. Al2O3 has been chosen to incorporate with spinel MoFe2O4 to make it color more light, this crucial step is necessary to enhance their optical characteristics. FTIR spectra observed the MoFe2O4 NPs are inverse spinel. The photo-decolorization test employs indigo carmine (IC) as a model pollutant. The quantum yields (Φ) of IC dye decolorization with studied photocatalysts are low, which may be created by quencher materials, dimerization of dye molecules, and photophysical deactivation processes (ISC process). Moreover, the photocatalytic activity of using MoFe2O4 raised after being decorated with alumina, which revealed an increase in the surface acidity, hydroxyl group adsorption, size, band gap, pHpzc of MoFe2O4 from 2.9–3.6 to 4.2–5.9 after decorated alumina. This pH is suitable for decolorizing IC dye, which has a pH of solution equal to 5.3.

The structural and optical properties of PVA/CMC copolymer cured by UV irradiation for different times

Poly(vinyl alcohol) (PVA)/carboxymethylcellulose (CMC) blend films with equal amounts (0.25 g) of both polymers were prepared through a simple and low-cost comparative casting method. Then, the PVA/CMC blend films were exposed to ultraviolet (UV) radiation for varied time intervals (1, 12, 26, 32, 40 and 48 h). The UV-irradiation effect on the physical properties of as-prepared films, including the structure, morphology, composite and optical properties (transmittance, absorbance and band gap (E g)), was examined. Field-emission scanning electron microscopy images showed that UV irradiation had a strong effect on the shape of PVA/CMC blend films. The X-ray diffraction patterns showed various crystalline qualities in the microstructure of as-synthesized samples. The Fourier transform infrared spectra showed that the UV-irradiation time and CMC film had a positive impact on the blend polymer structure since covalent connections were formed between CMC and PVA. Furthermore, the analysis results of optical inspections showed that the absorbance of the PVA/CMC films improved with an increment in irradiation time from 1 to 40 h. Important tuning of the E g values of blend films was realized. It showed a slight increase from 4.64 to 4.84 eV with increasing irradiation time from 1 to 40 h. The E g value (3.21 eV), however, displayed an inverted behavior due to an increased irradiation time of 48 h. This reduction could be ascribed to the creation of defects inside the blend band gap. Finally, the physical property modification of PVA/CMC blend film using UV irradiation made it an amazing contender in the optoelectronic field.

Structural, magnetic, low and high frequency dielectric properties of Al-substituted M-type SrCe hexaferrites synthesized in the presence of Tecomastans (yellow bell) leaves extract

This paper represents a study of the effect of Al-substitutions on structural, magnetic, and dielectric properties of Sr0.8Ce0.2Fe12-xAlxO19 (x = 0.00, 0.25, 0.50, 0.75 and 1.00) ferrites synthesized in presence of yellow bell leaves extract. All samples were synthesized using the sol-gel combustion technique with the influence of green synthesis by using leaves of Tecomastans (yellow bell) plant. These samples were preheated at 550 °C for 4 h and finally calcinated at 1150 °C for 6h. These samples were characterized using XRD, FTIR spectroscopy, SEM, VSM, LCR measurements, and VNA measurements. XRD patterns confirm the formation of a magnetoplumbite M-phase (hexagonal) with a minor impurity phase of CeO2 in all samples. Lattice parameters a and c are obtained from rietveld refinement, which are found in the range from 5.859 Å to 5.883 Å, and 22.96 Å to 23.05 Å respectively. FTIR spectra confirm the absence of organic compounds and the presence of an absorption band in the fingerprint region which are linked to the stretching of the metal-oxygen bond at the octahedral and tetrahedral site. The surface morphology of these samples is analyzed using SEM images. Grains with hexagonal plate shapes were observed in each sample. The average grain size varies in the range of 0.565μm to 1.455 μm. EDS data confirms the presence of desired elements in the respective sample. VSM analysis shows hard magnetic behavior in all samples. Magnetic parameters were found in the range, Ms: 36.281-43.397 emu/g, Mr: 12.297-19.841 emu/g, Hc: 2.0987 – 3.814 kOe. In low-frequency (20 Hz-2 MHz) dielectric measurements, the dielectric constant is high at low frequencies, which rapidly falls as frequency increases. Loss tangent curve shows a relaxation peak for each sample above 200 kHz. AC conductivity is very low in the order of 10-5 S/m in plateau region below 2 kHz, which increases as frequency increases. Cole-Cole plot suggests the effect of grain boundary contribution is higher in non-substituted sample compared to Al-substituted samples. In high-frequency (0.2 GHz- 20 GHz) measurements, the dielectric constant remains almost constant. These values are found in the range 5-7.5. Low loss tangent of 0-0.16 were observed in every sample in this frequency domain, with AC conductivity of the order of 10-2 S/m.

Reducing Free Fatty Acids in Crude Palm Oil Using Diethylene Glycol and Zinc(II) Chloride Based Deep Eutectic Solvent

Deep eutectic solvents (DES) were prepared by precise combinations of mol fractions of chemical compounds, resulting in a lowered melting point due to hydrogen bonding. This research aimed to elucidate the physicochemical attributes of DES and its effectiveness in mitigating free fatty acid (FFA) levels in crude palm oil (CPO). Zinc(II) chloride (ZnCl2) served as the hydrogen bond acceptor (HBA) while diethylene glycol (DEG) as the hydrogen bond donor (HBD). Characterization included freezing point, density, viscosity, conductivity, and pH determination. At a ZnCl2 mol fraction of 0.30, the resulting DES exhibited homogeneity with transparent liquid properties, featuring a freezing point below −10 °C, density of 1.42 g/mL, viscosity of 1933.40 cP, conductivity of 66.13 µS/cm, and pH 3.42. FTIR spectra confirmed hydrogen bond interactions between HBA and HBD. Applied to CPO at a 1:1 volumetric ratio (DES:CPO), with 2 h of stirring time at 50 °C, FFA content decreased from 4.11 to 0.86%. This research highlights DES as an environmentally sustainable purification agent, significantly reducing FFA levels in unrefined palm oil.

High plasma magnesium and phosphorus levels and their correlation with struvite urolithiasis in buffaloes

BackgroundUrolithiasis is a common urinary tract disease in buffaloes, almost exclusively affects young males, and has significant economic and production impacts. We have investigated hemato-biochemical and urinary changes in an attempt to deduce their correlation with struvite urolithiasis in buffaloes. MethodsTen male buffalo calves with obstructive urolithiasis were used. Blood samples were used for hematology and elemental analysis. Urine samples were used for physico-chemical examination, microscopy, and elemental analysis. Uroliths were subjected to chemical functional group determination using the FTIR spectroscopy. ResultsThe mean neutrophil, leukocyte, and neutrophil-to-lymphocyte ratio was significantly (p < 0.05) higher in urolithic buffaloes than in healthy controls. The mean blood calcium and magnesium concentrations were significantly (p < 0.05) lower and higher in urolithic buffaloes than in healthy controls, respectively. Mean blood phosphorus concentration and calcium-phosphorus ratio were found to be non-significantly (p > 0.05) higher and lower in urolithic buffaloes than in healthy controls, respectively. The urine pH was highly alkaline. Multiple prismatic lid-shaped crystals, along with erythrocytes, leukocytes, and epithelial cells, were found in urine. The mean urinary magnesium and phosphorus concentrations were non-significantly (p < 0.05) higher in urolithic buffaloes than in healthy controls. A positive correlation of magnesium (r = 0.864, p = 0.001) and phosphorus (r = 0.849, p = 0.002) concentrations between the blood and urine was observed in urolithic buffaloes. The FTIR spectra of uroliths were similar to those of magnesium ammonium phosphate hexahydrate, MgNH4PO4·6H2O or struvite. ConclusionThe findings suggest that high plasma magnesium and phosphorus concentrations have a positive correlation with struvite urolithiasis in buffaloes.

Experimental investigation into coal wettability changes caused by reactions with scCO2-H2O

Geological CO2 sequestration (GCS) can help mitigate global warming and enhance methane recovery from coal beds. However, few studies have linked the effects of CO2 to surface chemistry changes controlling wetting behavior in deep coal beds. Contact angles (CAs) of CO2/N2-high volatile bituminous coal-water systems were measured under different temperatures and pressures. The surface chemistry and physical structure of coals were characterized to investigate changes in physicochemical properties and their relations with wettability after reactions. For N2 treatment, the time-dependence of static and dynamic CAs were insignificant, ranging within 4°. For gaseous CO2 treatment, the static CAs and the average advancing angles increased slightly. With supercritical (sc) CO2, both the static and dynamic CAs increased significantly, and θadv changed to intermediate-wet (92°). Reactions with minerals exposed to scCO2 resulted in greater surface roughness and heterogeneity, greater contact angle hysteresis and more surface sites occupied by scCO2 rather than H2O. Increases in hydrophobic functional groups and decreases in hydrophilicity were shown by FTIR spectra, reflecting the shedding of polar oxygen-containing functional groups, reduction of hydrogen bonds, and increasing percentage of hydrocarbons. XRD patterns obtained following scCO2-treatment showed that crystallite growth and molecular polymerization were higher toward graphite-like. The calculated structural parameters of functional groups and crystallites both showed elevated coal rank. Changes in crystallite structure, notably higher carbon content and decreased negative surface charge, are unfavorable for water-wetting. This study contributes to understanding surface chemistry changes responsible for decreased wettability during CO2-enhanced coal bed methane recovery and GCS in coal reservoirs.

Influence of Co(II) and Cd(II) metal ions on structural, electronic and nonlinear optical properties of 4-methoxypyridine-2-carboxylic acid complexes: An experimental and computational study

Molecular engineering of metal-organic frameworks has attracted increasing attention due to their potential technological applications in the fields of optics and photonics. Therefore, a number of organometallic complexes are investigated for nonlinear optical applications. The current research aimed to synthesize and investigate spectroscopic and nonlinear optical properties of two metal-organic coordination compounds, namely Co(MeOPic)2∙(H2O)2 and Cd(MeOPic)2∙(H2O)2. The FT-IR and UV-Vis spectra for the distorted octahedral Co(II) and Cd(II) complexes were recorded. In order to provide a deep understanding about the relation between structure and nonlinear optical properties, density functional theory studies were also applied to both of the complexes by using B3LYP/6–311++G(d,p)/LanL2DZ level. TG-DTA analysis demonstrated that Cd(II) complex is approximately stable up to 134 °C, and the same complex only loss the aqua ligands between 134 and 189 °C. Therefore, the main skeleton part continues to remain stable up to 208 °C. Static NLO studies also demonstrated that both complexes have weak responses due to centrosymmetric structures, while Co(II) complex is appropriate to third-order NLO applications (γ (0;0,0,0) = 148.70×10−36 esu and γ (-2w;w,w,0)=-1521.4×10−36 esu).

Unexpected weakened formation of disinfection byproducts and enhanced production of halates by cupric oxide during chlorination of peptide-bound aspartic acid

Under the condition that the residual chlorine is guaranteed, the biofilm still thrives in drinking water distribution systems through secreting a large number of extracellular polymeric substances (EPS), in which protein components are the primary precursor of disinfection byproducts (DBPs), mostly in the form of combined amino acids. The aim of this study is to investigate the action of CuO on the formation of halates (XO3−, ClO3− and BrO3−) and DBPs (trihalomethanes, THMs; haloacetonitriles, HANs) with aspartic acid tetrapeptide (TAsp) as protein surrogate. The presence of CuO promoted the self-decay rather than TAsp-induced decay of oxidants, resulting in an increase in XO3− yield and a decrease in DBPs yield. It was CuO-induced weaker production of cyanoacetic acid and 3-oxopropanoic acid that induced the decreased yields of HANs and THMs, respectively. The FTIR and Raman spectra indicate a weak complexation between CuO and TAsp. Given this, the CuO-HOX/OX− complexes were inferred to be reactive to HOX/OX− but less reactive to TAsp. The study helps to better understand the formation of XO3− and DBPs during the chlorination of EPS, and propose precise control strategies when biofilm boosts in water pipes.

Comparative study of iodine-doped and undoped pyrrole grafting with plasma on poly (glycerol sebacate) scaffolds and its human dental pulp stem cells compatibility.

This study addresses the morphological and chemical characterization of PGS scaffolds after (6, 12, 18, 24, and 30 min) residence in undoped pyrrole plasma (PGS-PPy) and the evaluation of cell viability with human dental pulp stem cells (hDPSCs). The results were compared with a previous study that used iodine-doped pyrrole (PGS-PPy/I). Analyses through SEM and AFM revealed alterations in the topography and quantity of deposited PPy particles. FTIR spectra of PGS-PPy scaffolds confirmed the presence of characteristic absorption peaks of PPy, with higher intensities observed in the nitrile and -C≡C- groups compared to PGS-PPy/I scaffolds, while raman spectra indicated a lower presence of polaron N+ groups. On the other hand, PGS scaffolds modified with PPy exhibited lower cytotoxicity compared to PGS-PPy/I scaffolds, as evidenced by the Live/Dead assay. Furthermore, the PGS-PPy scaffolds at 6 and 12 min, and particularly the PGS-PPy/I scaffold at 6 min, showed the best results in terms of cell viability by the fifth day of culture. The findings of this study suggest that undoped pyrrole plasma modification for short durations could also be a viable option to enhance the interaction with hDPSCs, especially when the treatment times range between 6 min and 12 min.

Unveiling Anisomeles malabarica (L.) R.Br Ex Sims: Extracting Bioactive Compounds for Antibacterial And Antioxidant Activities

The allopathic herb Anisomeles malabarica (L.) R.Br ex Sims is a member of the Lamiaceae family of mints. This investigation aims to determine whether the acetone extract of Anisomeles malabarica (L.) R.Br ex Sims leaves exhibit in vitro antibacterial activity. The results of the phytochemical study showed that steroids, flavonoids, phenols, terpenoids, quinones, and saponin were present. TLC detected and separated potential chemical components present in the extract. The GCMS revealed the presence of volatile substances, and the LC-MS disclosed the existence of non-volatile substances based on the highest peak. The FT-IR spectrum data revealed the chemical compound's potential functional groups in the A.malabarica acetone extract. DPPH free radical scavenging showed that the acetone extract of conc. 40mg/ml, 60mg/ml, 80mg/ml and 100mg/ml possessed great antioxidant ability compared to standard. Escherichia coli, Bacillus subtilis, Bacillus cereus, and Klebsiella pneumonia were tested for antibacterial activity using the unpolished well diffusion technique. E. coli and B. subtilis were inhibited more effectively by the extract in conc.50μg/ml, 75μg/ml and 100μg/ml.

GC-MS based identification of anti-microbial bioactive compounds, isolated from Bacillus halotolerans of marine sediment

Marine environments are known for their complex habitats due to the spread of industrial pollutants, and microorganisms that endure adverse conditions are evolving as extremophiles. The present study is designed to explore the antimicrobial activity of microbes present in marine ecosystems that secrete bioactive compounds. The bacterial strains VT-2, VT-4, and VT-5 isolated from the marine sediment exerted an inhibitory effect against the human pathogenic microorganisms Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa). Among the three strains, VT-5 exhibited efficient antibiotic potential. Based on biochemical characterisation, the VT-5 strain is gram-positive, rod-shaped, and demonstrates resilience to stress, salt, and drought. The 16 s r-RNA analysis confirmed Bacillus halotolerans, having a similarity of 99.75%. Bioactive compounds released by the VT-5 strain had efficient antibacterial activity, which was also observed in FESEM micrographs as deformation of cellular structure in pathogens. The chromatographic extraction of VT-5 was identified to have antibacterial bioactive compounds, and that was further determined by using FTIR and GC/MS. The peaks observed in the FTIR spectrum with different functional groups showed similarity to the structures of these isolated bioactive compounds. GC/MS analysis also revealed the presence of nine vital bioactive compounds, most of which have been reported to exhibit antimicrobial activity. Our study further strengthens that VT-5 (Bacillus halotolerans) is resistant to MDR (Pseudomonas aeruginosa) and MRSA (Staphylococcus aureus) pathogenic strains. Furthermore, this study explores marine-associated microbes as a promising avenue for new antimicrobial drugs, revealing possibilities for marine organism-derived compounds.

Sintesis Lapis Empat Fasa Aurivillius Ca1-xBaxBi3,5La0,5Ti4O15 Dengan Metode Lelehan Garam

The four-layer Aurivillius phase Ca1-xBaxBi3.5La0.5Ti4O15 (x = 0.2, 0.4, 0.6, 0.8, and 1) has been synthesized by molten salt method. The effect of varying x on the structure, morphology, and dielectric properties was studied. X-ray diffraction (XRD) and Le Bail refinement revealed that the compounds with the composition x = 0, 0.2, and 0.4 were single-phase product with orthorhombic A21am structure, whereas for higher x value (composition of Ba doped), a Ba2TiO4 impurity is found in products. Changes in unit cell volume were investigated, and the size increased with larger x. The substitution of larger Ba2+ ions resulted in a shorter Ti-O bond, shifting vibration mode to higher wave number that showed in FTIR spectra. SEM images show anisotropic plate-like grain with distributed particle sizes at 1.9 – 3.1μm. The dielectric constant values decrease with increasing x, otherwise the dielectric loss values increase for x = 0 and 0.2, however decrease for x = 0.4. The resulting Aurivillius compound has potential for applications in ferroelectric and piezoelectric devices.

Furan-oxadiazole hybrids as promising antioxidants: Synthesis, characterization, ADME and molecular docking studies on peroxiredoxin-2

The study involves the synthesis and characterization of a novel series of furan-based compounds 1–9 incorporating strategic modifications with isatin, pyrazole, and oxadiazole motifs. The synthesized compounds were characterized and assigned with different spectroscopic techniques such as FT-IR, 1H NMR, 13C NMR and mass spectra. Antioxidant screening assays using the DPPH radical scavenging method revealed that the oxadiazole derivative 9 exhibited exceptional antioxidant activity, with an EC50 value of 0.0038 mM, attributed to the oxadiazole ring's favourable electron delocalization and radical stabilization properties. Molecular docking simulations with the Peroxiredoxin-2 (Prdx-2) crystal structure (PDB: 5IJT) predicted favourable binding interactions for the synthesized compounds, with docking scores ranging from -6.1629 to -7.9878 kcal/mol. The sugar moieties facilitated hydrogen bonding interactions with key active site residues, while the furan and phenyl rings contributed to π-hydrogen interactions. Furthermore, in silico ADME prediction studies assessed the drug-likeness and pharmacokinetic properties of the compounds, identifying promising lead candidates for further optimization and development as potential antioxidant therapeutics targeting Prdx-2.

Constructing liquid crystalline elastomer multi-fold gratings with side-on epoxy liquid crystalline monomers

ABSTRACT The fabrication of liquid crystalline elastomer (LCE) with reversible deformation is promising for development of intelligent materials and equipment. Preparing new liquid crystalline monomer (LCM) and developing novel LCE structures are crucial for the fabrication of advanced LCE. Herein, we design and synthesis a series of side-on nematic epoxy LCM, and then fabricate corresponding LCE with micropillar array via photoinitiated polymerisation of a magnetic induced oriented LCMs with soft lithography patterned structures. 1H NMR, 13C NMR, COSY, FTIR and MS spectra confirm the structures of the LCMs. DSC and POM results demonstrate that the LCMs are nematic liquid crystals. SEM, OM, and POM observations indicate the successful fabrication of LCE micropillars that exhibit reversible contraction and extension during heating and cooling cycles. In addition, the thermal induced reversible deformation of the LCE micropillars is closely related to the structure of the LCM. By using the same method, functional LCE with multi-fold gratings are prepared by using the multi-fold gratings master mask during the fabrication process, providing a material foundation for the construction of intelligent surfaces that can selectively diffract light under external thermal stimuli.

Structure and gamma attenuation behavior of copper ions in host glass from the system (P2O5–LiF–CaF2)

Copper-doped lithium calcium fluorophosphate glasses in the compositional system (60−x)P2O5·20LiF·20CaF2·xCuO (x = 0−3 mol%) were prepared using the conventional melt quenching technique. X-ray diffraction confirmed the amorphous, non-crystalline phase of the glasses. Optical absorption spectra indicated the presence of additional broad visible-NIR absorption bands upon CuO doping, attributed to distorted Cu2+ ions. Possible overlaps from Jahn-Teller distorted sites or clustering into nanodomains may contribute to band broadening. The direct optical bandgap was found to reduce from 3.89 eV to 1.17 eV with increasing CuO content. The study of physical parameters showed almost linear variation in density (2.62–2.95 g/cm3) and molar volume (40.45–35.29 cm3/mol) with incremental CuO substitution, explained by changes in structural packing efficiency and formation of Cu–O complexes. FTIR spectra revealed vibrations corresponding to phosphate structural groups. The simulation of radiation shielding parameters displayed steady improvements with higher CuO fractions, which were related to enhanced photon interactions via photoelectric absorption and Compton scattering.

Well-dispersed Ni-nanoparticles in the lamellas of the synthesized clinoptilolite for CH4 and CO2 reforming

The impregnation and ion exchange methods were employed to prepare the Ni-modified clinoptilolites (CPs). Their physicochemical properties and structural features were evaluated by various characterizations, such as XRD patterns, SEM and TEM images, Raman and FT-IR spectra, XPS and H2-TPR, N2 sorption isotherms, and TG analysis. The results demonstrated that the loaded Ni nanoparticles were highly dispersed on the lamellar surfaces of the synthesized CPs. Meanwhile, their CH4 and CO2 dry reforming reactions (DRM) at 500–900 °C were conducted utilizing Ni species as active sites. The results demonstrated that the Ni-loaded CPs exhibited greater catalytic activity than the Ni-exchanged CPs, besides that, the Ni-loaded CPs demonstrated the highest catalytic stability at 700 °C. However, the carbon deposition of the Ni-loaded CPs seemed more difficult to eliminate than that of the Ni-exchanged CPs in the DRM durations. These results elucidate the excellent performances of the developed Ni-modified CPs for designing more stable and efficient Ni-based DRM catalysts.

Synthesis of Green Carbon Dots from Nephelium Lappaceum L. Seeds

In this study, rambutan (Nephelium Lappaceum L.) seeds were used to fabricate green carbon dots (gCDs) by employing a hydrothermal process. The synthesized CDs were evaluated using Fourier transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) for the structural properties as well as UV-Vis and fluorescence spectrophotometry for the optical properties. UV-Vis examination revealed that the produced gCDs showed emission-dependent photoluminescence excitation, with two absorption peaks at 265 nm and 330 nm. The presence of functional groups and chemical composition such as C=C, C=O, -COOH, and -OH on the surface of gCDs was confirmed by the results of FTIR and XPS spectra. Consequently, gCDs present several opportunities for exploration in a range of applications.