UV Region Research Articles

الاستخلاص الانتقائي للكليميبيرايد في المستحضرات الصيدلانية وفي مصل الانسان عن طريق تقنية MIP-SPE المركبة

This paper demonstrates that the synthesizing and storage of molecular-imprinted polymers (MIP) at room temperature using bulk polymerisation of Glimepiride (Glim.) is characterized by high sensitivity, reduced costs, increased stability, and extended life. The research used 1:15:20 mmol ratios of template, monomer and cross-linking agents for the polymerisation in order to ensure an appropriate adsorption capacity. Benzoyl peroxide BPO was employed as the initiator for the functional monomer Allyl chloride C3H5Cl , cross-linked with Ethylene glycol dimethacrylate EGDMA C10H14O4, thereby creating MIP for Glimepiride (Glim-MIP) that could be characterised with UV-Visible Spectrophotometry at 274.5nm, for pharmaceutical drugs. Fourier-transform infrared spectroscopy (FTIR) and Scanning electron microscopy (SEM) was used for the human serum. The elution process that was applied to the template (Glim.) from the Glim-MIP created cavities that were caused by the porogenic mixture solvents that were created from (acetic acid, methanol) 1:9 respectively, successfully removed by repeated washing for 20 hours, the polymer was dried at room temperature. The maximum adsorption capacity was 11.7797 µmol/g using (0.1) g weight of Glim-MIP. which adhered to the Langmuir isotherm model. A solid-phase extraction (SPE) syringe packed with molecular imprinted polymers (MIPs) was employed to selectively separate and pre-concentrate the Glimepiride in multiple pharmaceutical drugs from several sources. The human serum was based on the use of deionized water to dilute the serum, followed by heating of the serum with methanol. Subsequently, few drops of 1N hydrochloric acid were applied to detect Glimepiride at UV region 274.5 nm by applying the standard addition method.

Novel nanobuds from the combination of B12N12 nanocage and carbon nanotube: Design and DFT study

In this research, carbon nanotubes and B12N12 nanocage were combined together and, in different configurations, a covalent bond between them was created to design new nanobuds. After optimizing the designed structures, their vibration frequency was calculated to ensure the absence of imaginary frequencies. Also, the relative energy of the structures was calculated and used to analyze the relative population of different configurations and showed that about 99 % of the molecules belong to a specific configuration (configuration B) and about 1 % belong to another configuration (configuration C). Consequently, the population of other configurations can be ignored. To further investigate the stability of structures, it was shown that configuration B has the highest cohesive energy and the most stability. It was clearly shown that the designed nanobuds have electrical properties similar to nanotubes and higher electrical conductivity than B12N12, and the electric charge transfer from B12N12 to nanotubes been taken place. Polarizability and superpolarizability, which indicate linear and nonlinear optical properties, were calculated. it was shown that the hybridization of B12N12 and carbon nanotubes and the creation of nanobuds improve the linear and nonlinear optical properties to a great extent. Finally, it was shown that similar to the parent nanotube, the nanobuds absorb light in the visible region, while B12N12 absorbs light in the UV region. The resulting nanobuds have more absorption lines than nanotubes and thus, their optical activity is even improved compared to nanotubes.

A facile route to synthesis NixFe1−xFe2O4 ferrofluids with optimal rheological and magneto‐optical properties

AbstractThis study presents an easy method for synthesizing ultrafine NixFe1–xFe2O4 nanoparticles with adjustable composition (x = 0–.8), followed by their stabilization into ferrofluids. Structural identification of the crystalline structure, lattice points, and grain boundaries from the broadened diffraction peaks reveal an average crystalline size of the nanoparticles as 10–16.5 nm. Transmission electron microscopy images reveal spherical magnetite nanoparticles with a particle size ranging from 6 to 13 nm, consistent with diffraction studies. In ferrofluids, the NixFe1–xFe2O4 nanoparticles are stabilized in kerosene with oleic acid, a surfactant. Absorbance data of the ferrofluids is seen in the 200–400 nm wavelength region of UV–vis spectra. The magnetic properties of the samples are probed using a Superconducting Quantum Interference Device. The synthesized samples exhibit superparamagnetic behavior at room temperature (300 K). The saturation magnetization of the samples decreases with an increase in Ni composition (x = 0–.8), ranging from 54 to 28 emu/g. This study explores the magnetic and magneto‐optical properties of NixFe1–xFe2O4 ferrofluids. Magneto‐viscosity of ferrofluids is also studied, and the final application of such ferrofluids in data storage, catalysis, and biomedical applications is discussed.

Electric field modulated electronic, thermoelectric and transport properties of 2D tetragonal silicene and its nanoribbons

Using both first principles and analytical approaches, we investigate the role of a transverse electric field in tuning the electrical, thermoelectric, optical and transport properties of a buckled tetragonal silicene (TS) structure. The transverse electric field transforms the linear spectrum to parabolic at the Fermi level and opens a band gap. The gap is similar at the two Dirac points present in the irreducible Brillouin zone of the TS structure and increases in proportion to the applied field strength. However, a sufficiently strong electric field converts the system into a metallic one. A comparable band opening is also seen in the TS nanoribbons. Electric field-induced semiconducting nature improves its thermoelectric properties. Estimated Debye temperature reveals its superiority over graphene in terms of thermoelectric performance. The optical response of the structures is very asymmetric. Large values of imaginary and real components of the dielectric function are seen. The absorption frequency lies in the UV region. Plasma frequencies are identified and are red-shifted with the applied field. The current–voltage characteristics of the symmetric type nanoribbons show oscillation in current whereas the voltage-rectifying capability of anti-symmetric type nanoribbons under a transverse electric field is interesting.

Acridinedione-phthalimide conjugates: Intramolecular electron transfer and singlet oxygen generation studies for optical and photodynamic therapy applications

We reported herein the synthesis, characterization of hybrid conjugates composed of phthalimide (Phth) and acridine-1,8-diones (Acr) for optical and medical applications. For the synthetic procedure, a three-step synthetic strategy has been utilized. The optical properties of the examined 1,8-acridinedione–phthalimide connected molecules (AcrPhth 1–5) have been examined utilizing various spectroscopic techniques, e.g., steady-state absorption and fluorescence, and time-correlated single photon counting. The steady-state absorption studies showed that AcrPhth 1–5 absorbs the light in the UV and visible region. The fluorescence studies of AcrPhth 1–5 exhibited significant fluorescence quenching compared to the acridinedione control compounds (Acr 1–5) suggesting the occurrence of electron-transfer reactions from the electron donating acridinedione moiety (Acr) to the electron accepting phthalimide moiety (Phth). The rate and efficiency of the electron-transfer reactions were determined from the fluorescence lifetime measurements indicating the fast electron-transfer processes of the covalently connected AcrPhth 1–5 conjugates. Computational studies supported the intramolecular electron-transfer reaction of AcrPhth conjugates using ab initio B3LYP/6-311G methods. In the optimized structures, the HOMO was found to be entirely located on the Acr entity, while the LUMO was found to be entirely on the Phth entity. Further, the synthesized compounds were tested as photosensitizers for generating the singlet oxygen species, which is a key factor in the photodynamic therapy (PDT) applications. The nanosecond laser flash measurements enable us to detect the triplet-excited states of examined Acr and AcrPhth conjugates, determining the triplet quantum yields, and direct detecting the singlet oxygen in an accurate way. From this observation, the singlet quantum yields were found to be in the range of 0.12–0.27 (for Acr 1–5) and 0.07–0.19 (for AcrPhth 1–5 conjugates). The molecular docking studies revealed that compound AcrPhth 2 exhibited high binding affinity with for key genes (p53, TOP2B, p38, and EGFR) suggesting its potential as a targeted anticancer therapy.Graphical abstractEfficient intramolecular electron-transfer reaction for the light harvesting conjugates! In addition, the conjugates can be used as good photosensitizers for PDT

Aptamer and Thiol Co-Regulated Color-Shifting Fluorophores via Dynamic Through-Bond/Space Conjugation for Constructing Ratiometric RNA Sensor.

Fluorophores with color-shifting characteristics have attracted enormous research interest in the quantitative application of RNA sensors. It reports here a simple synthesis, luminescent properties, and co-transcription ability of de-conjugated triphenylmethane leucomalachite green (LMG). This novel clusteroluminescence fluorophore is rapidly synthesized from malachite green (MG) in reductive transcription system containing dithiothreitol, emitting fluorescence in the UV region through space conjugation. The co-transcribed MG RNA aptamer (MGA) bound to the ligand, resulting in red fluorescence from the through-bond conjugation. Given the equilibrated color-shifting fluorophores, they are rationally employed in a 3WJ-based rolling circle transcription switch, with the target-aptamer acting as an activator to achieve steric allosterism. This one-pot system allows the target to compete continuously for allosteric sites, and the activated transcription switches continue to amplify MGA forward, achieving accurate Aflatoxin 1 quantification at the picomolar level in 1h. Due to the programmability of this RNA sensor, the design method of target-competitive aptamers is standardized, making it universally applicable.

Ultra Broad‐Band Excitable Organic–Inorganic Copper(I) Halides: Large‐Scale Synthesis, Outstanding Stability, and Highly Efficient White Light‐Emitting Diodes Application

AbstractOrganic–inorganic copper(I) halides (OICHs) have recently attracted great attentions for their unique optoelectronic properties. However, most of them have poor stability and narrow excitation in UV region, which seriously hinder their applications in efficient white light‐emitting diodes (WLEDs). Herein, 0D (C19H18P)2Cu4I6 with super broad‐band excitation (300–500 nm) and yellow emission with the absolute photoluminescence quantum yield of 87.4% is synthesized in a quantity of gram scale. Specifically, (C19H18P)2Cu4I6 possesses exceptional thermal‐, photo‐, air‐stability, and can maintain efficient emission even if soaked in water, ethyl acetate, and isopropanol over 30 days. WLEDs with remarkable color stability under various driven currents are fabricated using 450, 400, 365, and 310 nm LED chips. The ideal WLEDs based on single (C19H18P)2Cu4I6 by 450 nm LED chip presents high color rendering index of 86.7, and outstanding luminous efficiency of 90 lm W−1. To the best of the knowledge, this is the highest value that is achieved based on single‐component OICHs using blue light chip. This work not only promotes the prospect of OICHs in WLEDs but also significantly broadens their application in special lighting fields, such as underwater illumination.

Atomic-like UV emission generated in hexagonal boron nitride single crystals by thermal annealing

A series of atomic-like photoluminescence (PL) emission peaks in UV region near 4.0 eV were created by thermal annealing hexagonal boron nitride (h-BN) single crystals in air. The pristine h-BN did not have these peaks, emitting strong phonon-assisted band edge PL with peaks at 5.78 and 5.89 eV. After annealing the h-BN crystals in ambient air, a new atomic-like sharp emission in UV region at 4.09 eV with a line width of 0.2 nm appeared along with its phonon replicas at 3.89 and 3.69 eV in the low temperature (8 K) PL measurement. Further testing demonstrated that annealing the h-BN samples in the temperature window of 700–950 °C for 60 min generated the atomic-like emission. The peak position of the emission line is stable with the temperature and PL excitation power. Our study also suggests that the defect responsible for the atomic-like emission resides in the surface region.

Structure-Property Correlations in CZTSe Domains within Semiconductor Nanocrystals as Photovoltaic Absorbers.

Semiconductor nanocrystals (NCs) are promising materials for various applications. Two of four recently identified CuαZnβSnγSeδ (CZTSe) domains demonstrate metallic character, while the other two exhibit semiconductor character. The presence of both metallic and semiconductor domains in one NC can hugely benefit future applications. In contrast to traditional band gap studies in the NC community, this study emphasizes that NC domain interfaces also affect the electronic properties. Specifically, the measured band gap of a tetrapod-shaped CZTSe NC is demonstrated to originate from two specific domains (tetragonal I and monoclinic P1c1 Cu2ZnSnSe4). The heterojunction between these two semiconductor domains exhibits a staggered type-II band alignment, facilitating the separation of photogenerated electron-hole pairs. Interestingly, tetrapod NCs have the potential to be efficient absorber materials with higher capacitance in photovoltaic applications due to the presence of both semiconductor/semiconductor interfaces and metal/semiconductor "Schottky"-junctions. For the two photo-absorbing domains, the calculated absorption spectra yield maximum photon-absorption coefficients of about 105 cm-1 in the visible and UV regions and a theoretical solar power conversion efficiency up to 20.8%. These insights into the structure-property relationships in CZTSe NCs will guide the design of more efficient advanced optical CZTSe materials for various applications.

The investigation of optoelectronic properties of doped and co-doped Tm3+ and Tb3+ Bi4Ge3O12 scintillation crystal: New insights from the first principle study

In this article, the structural, electronic, and optical characteristics of Germanium Bismuthate Ge3Bi4O12 doped and co-doped Tm and Tb have been studied through ab initio calculations based on density functional theory (DFT). The pure Ge3Bi4O12 was studied by plane DFT using the modified Becke-Johnson approximation (mBJ). To gain a better understanding of the electronic structure and optical properties of Tm and Tb doped Germanium Bismuthate, Ge3Bi4O12, compounds, the GGA + U approximation to density functional theory, in which a generalized gradient approximation (GGA) functional is coupled with a localization correction to tackle on-site correlation as inspired by the Hubbard model, is offered as an alternate technique. The optical parameters like real/imaginary dielectric function, absorption, energy loss function, extension coefficient, and the density of states were calculated and discussed. The electronic structure of Germanium Bismuthate, Ge3Bi4O12, reveals an indirect band gap in both its pure and Tm, Tb-doped forms, with the valence and conduction bands positioned at different points in the Brillouin zone. The electronic structure analysis confirms that an intermediate band is present in Germanium Bismuthate, Ge3Bi4O12, doped with Thulium (Tm); however, this feature is absent in the Terbium (Tb)-doped variant. The valence band near the Fermi level is predominantly derived from the electronic states associated with the O-p orbitals and the Ge-p orbitals. The presence of intermediate bands in the electronic structure of the doped compounds plays a critical role in influencing the optical parameters in the visible region. The doped compounds exhibit optical behaviors in the UV region that are consistent with those of the host materials, demonstrating pronounced peak intensities that are largely independent of their density. This study provides a comprehensive analysis of the electronic and optical properties of the doped compounds, which are essential for understanding their potential technological applications. These findings can guide the design of novel materials by highlighting how specific dopants influence these properties.

Scrutinizing the influence of vanadium (V5+) in Gd:MgO nanoparticles in their physicochemical properties and photocatalytic properties

Using a simple precipitation technique the preparation of V doped Gd:MgO nanoparticles are successfully achieved. Using various conventional characterization methodologies the microscopic structure, morphological and physicochemical characteristics of the synthesized particles were analyzed. Observed optical bandgap of the material lays in UV region hence photocatalytic experiments were carried out using UV light illumination. Toxic textile dye namely methyl orange (MO) and methylene blue (MB) was used as model pollutant. Among the synthesized nanoparticles 5 wt% V doped Gd:MgO performed well in photocatalytic degradation of MO and MB dye. Surface charge of the prepared photocatalyst (point of zero charge PZC) was analyzed by salt titration method. pH influence in the degradation process was scrutinized by maintaining different pH values.

Sol–Gel Synthesis and Characterizations of Spinel Nickel Chromite (NiCr2O4) Nanoparticles to Study their Photocatalytic, Antibacterial and Anticancer Activities

A facile and cost-effective sol–gel technique has been used to synthesize nickel chromite (NiCr2O4) nanoparticles (NCNPs) at 700°C to investigate their photocatalytic together with antibacterial and anticancer activities. The synthesized nanopowder was characterized by Thermogravimetric thermal analysis (TG-DTA), X-ray Diffraction Spectroscopy (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), High-Resolution Transmission Electron Microscopy (HR-TEM), Fourier Transform-Infrared Spectroscopy (FT-IR), X-ray Photon Electroscopy (XPS) and UV–Visible Diffuse Reflectance Spectroscopy (UV-DRS) and Photoluminescence (PL). Beyond 700°C, the thermal durability of NCNPs was confirmed by TG-DTA analysis. The synthesized NPs were cubic structured corresponding to their spinel structure, a crystallite size of 38[Formula: see text]nm and an optical bandgap of 2.7[Formula: see text]eV. The PL spectra revealed emission bands in the visible and UV regions. The surface-phase-pure elemental and electronic arrangement of the NCNPs were verified by X-ray photon spectroscopy. Photocatalytic activity of NCNPs against Methylene Blue dye revealed 89% degradation in 1[Formula: see text]h. The in vitro antibacterial and anticancer activities of NCNPs were also examined. Among the tested microbes, Staphylococcus aureus exhibited the highest level of sensitivity (9[Formula: see text]mm), while Escherichia coli had the lowest (5[Formula: see text]mm) against NCNPs. The MTT test revealed the significant cytotoxicity of NCNPs against carcinogenic HeLa and MCF-7 cells. Thus, the synthesized NCNPs could be rated as potential photocatalytic, bactericidal and anticarcinogenic agents.

Wide absorption spectrum and rapid response time of PEC photodetectors based on MoS2–Se nanocomposites

Photoelectrochemical (PEC) photodetectors convert light into electrical signals via PEC processes, providing high sensitivity, positioning them as promising candidates for next-gen optoelectronic devices. Over the past few years, there has been a significant interest in the field of photodetection regarding 2D materials, owing to their advantageous properties. In this study, the PEC photodetection of hydrothermally synthesized MoS2–Se nanocomposites have been systematically tested. Structural analysis confirms the coexistence of MoS2 and Se phases in the synthesized nanocomposites with crystallite sizes in the nanoscale dimension. Optical studies indicate that MoS2–Se nanocomposites exhibit broadened absorption spectrum extending to UV region, unlike pure MoS2 which absorbs solely in the visible region. This enhances their sensitivity for wide-band photodetectors with a small bandgap (1.01–1.34 eV). Optoelectronic study revealed superior performance of MoS2–Se thin film PEC device with efficient photoresponse with a responsivity of 38.3 μA/W and fast response time of 0.12 s. The novelty of this research resides in the integration of these unique features in MoS2–Se nanocomposites for PEC photodetectors, explored for the first time. The innovative aspect of this study involves employing spin coating to deposit 2D MoS2–Se thin films, which enhances control over film thickness and uniformity, thereby resulting in improved responsivity and photocurrent.

Nonlinear optical properties of KnCl (n = 2–7) superalkali clusters

The lowest energy structures along with the low lying isomer, stabilities, electronic properties, optical properties and nonlinear optical responses of KnCl (n = 2–7) clusters were studied within the density functional theory. The second order energy difference, dissociation energy and GH-L (HOMO–LUMO gap) point out that KnCl (n = 3, 5, 7) clusters are more stable. The calculated adiabatic ionization energies (AIE) for the KnCl (n = 2–6) clusters are in agreement with the measured ionization energies. The optical properties, namely optical electronegativity and refractive index, depends on the GH-L energy values. The K atom capped planar rhombus geometry of the K4Cl causes the noticeable vibrational frequency shift compared to the rest of IR spectra of the clusters. The first static hyperpolarizability (β o) values are in the range of 2.33 × 103 –2.87 × 104 au and the second static hyperpolarizability varies between 5.74 × 106 au and 38.9 × 106 au for the cluster. The nonlinear optical response is due to the superalkali nature of KnCl (n = 2–7) clusters. From computed β vec values, the hyperpolarizability has projection on the dipole moment vector for the superalkalis except the K2Cl and K5Cl. The absorption spectra point out that KnCl (n = 6–7) clusters can be suitable as a NLO material since they have transparency in the deep UV region (λ< 300 nm).

Electron Structure of α‐, β‐Te2MoO7 and Photocatalytic Decomposition of Antibiotics

AbstractTwo modifications of Te2MoO7 oxide have been prepared by different synthetic methods. The crystal structure and composition have been studied by X‐ray diffraction analysis and X‐ray microanalysis. The phase of α‐Te2MoO7 has been synthesized by solid‐state reaction from ammonium salts and characterized by monoclinic structure with P21/c. The β‐Te2MoO7 compound has been formed in hydrothermal conditions and has amorphous nature. The thermal behavior of β‐Te2MoO7 modification is characterized by the phase transition into α‐form, however after melting the amorphous state has restored. The electron structure has been investigated experimentally by X‐ray photoelectron spectroscopy and UV‐vis diffusion reflectance spectra and theoretically by approximation using atomic electronegativity. Despite the same composition, the band gap of β‐Te2MoO7 corresponds to visible light, whereas α‐Te2MoO7 adsorbs light in UV region. The both modifications are able to generate superoxide radicals in vacuum or air and hydroxyl radicals in water under irradiation. The HPLC‐MS analysis has shown the quite deep decomposition of dye and antibiotics by α‐Te2MoO7, whereas amorphous phase almost does not lead to any oxidation.

Fabrication of cobalt-doped ZnS thin films by successive ionic layer adsorption and reaction for UV–visible photodetectors on flexible substrate

Photodetectors are widely employed in research and innovation, necessitating swift response times, precision, and stability. However, their application in commercial and industrial settings is hindered by limited flexibility and a constrained capacity to respond across a broad spectrum. In this study, we adopted a facile, cost-effective, and room temperature Successive Ionic Layer Adsorption and Reaction (SILAR) technique to craft thin films of Cobalt-doped ZnS on a flexible paper substrate. The Cobalt doping, with varying wt.% (0, 0.5, 1, and 1.5) exhibiting excellent responsivity to both UV and visible spectra. Zinc Sulfide (ZnS), renowned for its wide bandgap, serves as a versatile semiconductor, making it an ideal candidate for photodetectors. The introduction of Cobalt broadened the responsivity of ZnS, covering a wide spectrum, including UV and visible regions. Structural confirmation of the material was achieved through XRD and Raman analyses. Scanning Electron Microscopy revealed the aggregated spherical nanostructure of ZnS on the cellulose substrate. Verification of Cobalt presence in the ZnS thin film and assessment of elemental oxidation states were conducted using XPS. Temporal response and I–V characteristics of the device were evaluated under varying light conditions, specifically at wavelengths of 325 nm and 700 nm at different intensities. Responsivity calculations yielded values of 22.5 mA/W for UV illumination (light intensity 0.6 mW/cm2) and 37.6 mA/W (light intensity 0.4 mW/cm2) for visible light, with corresponding response times recorded as 1.45 s and 2.13 s, respectively. In addition to performance assessments, bending cycle studies were conducted, demonstrating the excellent flexibility of the device up to 800 cycles. The Cobalt-doped ZnS device, as fabricated, emerges as a promising material for energy harvesting.

Electrochemical analysis of hydrothermally synthesized 2D/1D WS2/WO3 nanocomposites for solar cell application

The nanocomposites of transition metal dichalcogenides (TMDs) and metal oxides (MOs) show enhanced properties for photovoltaic applications. In view of this, we have reported the synthesis of a series of tungsten sulphide/tungsten oxide (WS2/WO3) nanocomposites, wherein tungsten to sulphur ratio has been gradually varied to achieve the optimized properties for photovoltaic applications. The samples were analysed for structural, optical, morphological, microstructural, electrokinetic and electrochemical properties by various characterization techniques. Integrating the properties of WS2 and WO3 provided enhanced properties in the form of wider absorbance range, optimized band gap, better colloidal stability and reduced charge transfer resistance. The as-synthesized nanocomposites showed the absorbance in UV & visible regions with the band gap varying from 1.54 eV to 1.68 eV. The zeta potential measurement showed high colloidal stability of some of the nanocomposites with values < −30 mV along with their uniform distribution. The electrochemical behaviour of the samples has been studied by cyclic voltammetry and potentio electrochemical impedance spectroscopy in which prominent redox peaks and diffusive behaviour have been observed. The impedimetric properties revealed the presence of Warburg diffusion which shows their suitability for photovoltaic applications. The sample with least sulphur to tungsten molar ratio was observed to have lowest charge transfer resistance and highest exchange current density of 198.8 μA. The samples with molar ratio nearly unity have high charge transfer resistance and low exchange current density. The present work reveals that the optical, electrokinetic and electrochemical properties of WS2/WO3 nanocomposites can be optimized for solar cell application by controlling the precursors’ concentration.

Tailoring the electronic and optical properties of ReS2 monolayer using strain engineering

In the present work, impact of various mechanical strains on the optoelectronic properties of monolayer ReS2 (m-ReS2) are investigated by using density functional theory. The bandgap of monolayer is determined to be 1.44 eV and 1.31 eV when computed using PBE and PBE + SOC methods. The monolayer displays outstanding electronic and optical tunability under biaxial compressive and shear strains. Under strain variations of 0 %–8 %, the bandgap for biaxial compression varies from 1.44 eV (1.31 eV) to 0.54 eV (0 eV), whereas for shear xx-yy strains, it varies from 1.44 eV (1.31 eV) to 0.34 eV (0.28 eV) when calculated using PBE (PBE + SOC) methods. A semiconductor-to-metal transition is observed for higher values of biaxial compressive strain. A pronounced impact of strain on the optical characteristics is likewise observed. We noticed that the absorption edge of monolayer ReS2 shifts from 1.32 eV to 0.50 eV with a 0 %–8 % increase in biaxial compression, leading to an 11 % red shift in wavelength per 1 % strain change. Moreover, high optical absorption (5 × 105 cm−1), lying from infrared to UV region is observed. The present study points out that strain engineering can be an efficient tool for modifying both the electronic and optical properties of m-ReS2 and may open new avenues for using this material in future optoelectronic applications.

Optical properties of nanocomposites based on polypropylene modified by nanoparticles of oxide compounds

The optical properties in UV, visible and near IR spectral regions for nanocomposites based on polypropylene modified by nanoparticles of oxide compounds ZrO2, Al2O3, SiO2, MgO, TiO2, ZnO were studied. A shift of the main optical absorption edge to the short-wave region upon modification by dielectric nanoparticles (MgO, ZrO2, and Al2O3) was established. The absorption edge shifts to the long-wave region upon the introduction of semiconductor nanoparticles (ZnO, TiO2) and amorphous SiO2 particles. In all spectra, the absorption bands at 1200, 1400, and 1720 nm characterized by overtone vibrations of CH, CH2, and CH3 molecular groups were recorded. OH groups make a certain contribution to the bands at 1400 and 1720 nm. The dependence of the intensity of these absorption bands on the type and concentration of nanoparticles used in the modification of polypropylene was analyzed. X-ray diffraction analysis of the studied nanocomposites was carried out, the formation of β-PP was registered upon modification by Al2O3 nanoparticles. Photoluminescence spectra of nanocomposites were studied. It was found that the introduction of nanoparticles (except SiO2) does not lead to the formation of new luminescence bands in PP.

A theoretical study on the solvent effects on adsorption behavior of naproxen with PLGA nanoparticles

The objective of this research is to study the influence of naproxen (NPX) adsorption on structural, electronic, and optical features of poly (lactic-co-glycolic acid) (PLGA) in the dichloromethane (CH2Cl2), chloroform (CHCl3), and water (H2O) phases through density functional dispersion correction (DFT-D) calculations. The analyses conducted in the chloroform phase, considering binding energy and chemical reactivity parameters, indicate that NPX forms stronger hydrogen bonds with PLGA in state B (−0.60 eV) compared to states A (−0.37 eV) and C (−0.47 eV), primarily through its carboxyl (–COOH) group by using B3LYP-D/6–311 + G** level of theory. The formation of hydrogen bonds between naproxen and PLGA in the chloroform phase is most stable compared to the dichloromethane and water phases. According to time-dependent density functional theory (TDDFT) calculations, the B3LYP method predicts the maximum optical absorption in the UV region for complex B, with an optical energy of 5.41 eV and an oscillator strength of 0.781, resulting in a maximum absorption peak at 229 nm. Based on the infrared (IR) spectra analysis, we find alterations in pristine PLGA and NPX due to their interaction. The interaction between NPX and PLGA results in more negative Gibbs free energy (ΔG) values, which in turn lead to an elevation in dipole moment, enhanced solubility, and a decrease in the energy gap (Eg). As a result of NPX adsorption, the decreased energy gaps enhance the electronic and optical sensitivity of PLGA to the NPX molecule.