Spectroscopy Analysis Research Articles

Kinetic study of adsorption and photocatalytic degradation of methylene blue dye using TiO2 nanoparticles with activated carbon

Activated carbon (AC) exhibits limited adsorption capacity for pollutants. Conversely, titanium dioxide (TiO2) demonstrates excellent photocatalytic performance, making it a popular choice for pollutant removal. This study investigates the removal of methylene blue (MB) dye from wastewater using AC, TiO2@AC-2, and TiO2@AC-10 samples via adsorption and photocatalysis. The Energy Dispersive analysis of x-rays (EDAX) has confirmed the presence of Ti, C and O in the prepared samples without any impurities. All the diffraction peaks in x-ray diffractograms indicated the presence of pure anatase TiO2 (tetragonal phase) with no evidence of any other phase. Fourier transform infrared spectroscopy (FTIR) analysis identified a peak around 545 cm−1 in the TiO2@AC-2 sample, indicative of O-Ti-O stretching vibrations. This peak shifted to 602 cm−1 in the TiO2@AC-10 sample. Raman spectroscopy confirmed the presence of carbon (D and G bands) at 1310–1347 cm−1 and 1582–1597 cm−1. Additionally, characteristic Raman active bands for anatase TiO2 were observed at 154 cm−1 (Eg), 204 cm−1 (Eg), 398 cm−1 (B1g), 508 cm−1 (A1g), and 628 cm−1 (Eg). N2 adsorption–desorption isotherms revealed a mesoporous structure for all samples (AC, TiO2@AC-2, and TiO2@AC-10) with hysteresis loops, indicating pores ranging from 2 nm to 50 nm in diameter. Reflectance spectra of TiO2@AC-2 and TiO2@AC-10 displayed absorption edges at 368 nm and 385 nm, respectively, corresponding to a direct band gap of approximately 3.22 eV. Subsequently, these prepared samples were effectively employed for the removal of methylene blue (MB) dye from wastewater utilizing both adsorption and photocatalysis method. Under dark conditions, 20 mg L−1 doses of TiO2@AC-2 and TiO2@AC-10 resulted in 60% and 36% dye adsorption within 60 min respectively. In the presence of UV radiation, the degradation of dye was observed to be 74% and 95% by TiO2@AC-2 and TiO2@AC-10 respectively. This observation indicates that TiO2 nanoparticles along with AC leads to enhanced photocatalytic activity. The Langmuir–Hinshelwood model reveals lower rate constants for AC compared to the composite samples. This is likely because AC lacks inherent catalytic activity, requiring UV light to trigger adsorption. Conversely, TiO2@AC-10 exhibits the highest rate constants (K1 = 24.25 × 10−3 min−1 and K2 = 82.71 × 10−3 min−1), aligning with its higher TiO2 content confirmed by EDAX analysis. This suggests a significantly faster photocatalytic rate and superior degradation efficiency, even at a low sample concentration (20 mg L−1).

Green Light‐Responsive D‐π‐A‐π‐D Quinoxaline Emitters for Luminescent Solar Concentrators: Potential Integration in Agrivoltaic Systems

AbstractThe integration of photovoltaic technologies within agricultural settings, also known as agrivoltaics, is attracting increasing attention as a sustainable approach to ensure both clean energy and food supply. The success of this strategy relies on the development of innovative materials that can selectively convert specific wavelengths into energy while being transparent to photosynthetically relevant light. To this aim, here we report our endeavors in the synthesis of a new class of D‐π‐A‐π‐D quinoxaline fluorophores and their use in the preparation of wavelength‐selective luminescent solar concentrators. The dyes were expeditiously prepared following a direct arylation protocol and extensively characterized by spectroscopic analyses and computational studies. They present high light harvesting ability in the green region of the visible spectrum and good emission properties, which were fully retained in the solid state when embedded into a poly methyl methacrylate (PMMA) matrix. These materials were employed to construct LSC devices of promising efficiency, fostering further developments for the use of wavelength‐selective LSC in agrivoltaic systems.

Enhanced electroactive β‐phase and dielectric properties in P(VDF‐HFP) composite flexible films through doping with three calcium chloride salts: CaCl2, CaCl2·2H2O, and CaCl2·6H2O

AbstractFlexible dielectric films with a high dielectric constant, utilizing P(VDF‐HFP)/salt composites, were manufactured through the solution casting method. In this work, we studied the impacts of three calcium chloride salts—CaCl2, CaCl2·2H2O, and CaCl2·6H2O—on the surface morphology, crystalline phase transformation, mechanical properties, and dielectric responses of the P(VDF‐HFP) copolymer. The detailed structure and properties of all samples were assessed via scanning electron microscope (SEM), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), tensile testing, and LCR meter analysis. The experimental results demonstrated that the addition of calcium salts to the P(VDF‐HFP) composites induced a visibly microporous morphology, with the porosity and surface roughness of the composites gradually increasing with salt content. In comparison to the pure P(VDF‐HFP) film, the composite films exhibited decreased stiffness and heightened flexibility. Furthermore, a higher β‐phase fraction and notable enhancements in the dielectric constant resulting from the inclusion of calcium salts were observed. Consequently, the P(VDF‐HFP) composite filled with 3 wt% of CaCl2·6H2O demonstrated the highest capability for promoting the β‐phase fraction and dielectric constant, achieving values of 98.33% and 21.49% (at 10 Hz), respectively.

Uncovering Atomic-scale Dynamics in Solid Catalysts via X-ray-based Methods.

Deciphering the structural intricacies of catalysts is essential to advance their atomic-scale engineering. Solid catalysts are complex, with structural features spanning multiple length scales and involving dynamics, which possess challenges in understanding structure-performance relationships. However, advanced operando X-ray characterization techniques, including X-ray absorption spectroscopy (XAS), diffraction (XRD), and pair distribution function analysis (PDF) allow elucidation of structural features under working conditions, discovering transitions from supported nanocrystals to dispersed sites, from solid solutions to supported nanoparticles, or structural changes at the local level. In this mini-review, we discuss case studies exploring the structure of catalysts over different lengths and time scales under different applications, such as CO2 hydrogenation to methanol or the dry reforming of methane, using a combination of operando XAS, XRD and PDF.

Dual state emissive pyrene-fused benzopyrazaacenes and their solvatochromic behaviour

This study investigates how molecular orientation and microstructure influence the photophysical and electronic properties of pyrene-fused azaacenes. Four substituted pyrene-fused benzopyrazaacene compounds were synthesized via a single step cyclo condensation of K-conjugated pyrene quinone building blocks with 3,4-diaminobenzophenone. The synthesized molecules were characterized using IR, NMR spectroscopy and HRMS analysis. Photophysical and electrochemical properties were studied to explore the impact of molecular orientation and microstructure on the properties of pyrene-fused azaacenes. Substitutions at the 2, 7-positions of the pyrene core significantly affected the photophysical properties while demonstrating moderate solubility. Notably, the compounds exhibited pronounced solvatochromic effect across various solvents. Furthermore, the additional incorporation of a carbonyl moiety adjacent to the core expanded pyrene at the K-region resulted in dual state emission, influencing solid state emission accompanied by robust thermal stability. Theoretical calculations were performed to gain insights into the energy levels of the compound and its molecular orientation using time dependent density functional theory (TD-DFT).

Exploring trends and developments in cholesteatoma research: a bibliometric analysis.

Examination of the scientific literature on cholesteatoma from past to present using bibliometric methods. A total of 2353 articles on cholesteatoma between 1980 and 2023 were obtained from the Web of Science database and statistically analysed using bibliometric techniques. The journals with the highest number of contributions to the literature were Otology & Neurotology (n = 192), Acta Oto-Laryngologica (156) and Laryngoscope (149). The most impactful journals based on h-index and total citation (TC) counts were Laryngoscope (h:36, TC: 4241), Otology & Neurotology (29, 3141), and American Journal of Otology (26, 2071) respectively. The most prolific author was Kojima H. (n = 49). According to the findings of the Reference Publication Year Spectroscopy (RPYS) analysis, there has been a significant increase in academic interest in Cholesteatoma since its first description in 1959, particularly following the expansion of its definition in 1977. Subsequently, the trend of increased interest has risen rapidly in later years, with notable peaks in research intensity observed in 1989, 2006, and 2011. The highest academic trend occurred in 2006. In recent years, trending topics have included innovative approaches such as diagnostic and imaging methods particularly alongside technological developments, endoscopic surgery, recurrence and complications, prognosis and quality of life, artificial intelligence, and obliteration. In conclusion, the evolution of cholesteatoma and its research priorities reveal temporal shifts and emerging areas of interest over time. Primarily, diagnosis, treatment, and surgical approaches remain central. Additionally, research has expanded to encompass developments in surgical techniques, imaging modalities, cellular biology, pathology, and molecular mechanisms.

Valorization of Eichhornia crassipes for the production of cellulose nanocrystals further investigation of plethoric biobased resource

Chemical processing is among the significant keys to tackle agro-residues utilization field, aiming to obtain value-added materials. Extraction of cellulose nanocrystals (CNCs) is an emerging route to valorize lignocellulosic wastes into high value particles. In this investigation, effect of acidic hydrolysis duration was monitored on size and morphology of obtained crystals; namely: CNCs from Nile roses fibers (NRFs) (Eichhornia crassipes). Different acidic hydrolysis duration range or different characterization techniques set this article apart from relevant literature, including our group research articles. The grinded NRFs were firstly subjected to alkaline and bleaching pretreatments, then acid hydrolysis process was carried out with varied durations ranging from 5 to 30 min. Microcrystalline cellulose (MCC) was used as reference for comparison with NRFs based samples. The extracted CNCs samples were investigated using various techniques such as scanning electron microscopy (SEM), Atomic force microscopy (AFM), Raman spectroscopy, and thermogravimetric (TGA) analysis. The figures gotten from SEM and AFM depicted that NRFs based CNCs appeared as fibril-like shapes, with reduced average size when the NRFs underwent pulping and bleaching processes. This was indicated that the elimination of hemicellulose and lignin components got achieved successfully. This outcome was proven by chemical composition measurements and TGA/DTG curves. On the other hand, AFM-3D images indicated that CNCs topology and surface roughness were mostly affected by increasing hydrolysis durations, besides smooth and homogeneous surfaces were noticed. Moreover, Raman spectra demonstrated that the particle size and crystallinity degree of NRFs based CNCs can be affected by acidic hydrolysis durations and optimum extraction time was found to be 10 min. Thermal stability of extracted CNCs-NRFs and CNCs-MCC was measured by TGA/DTG and the kinetic models were suggested to identify the kinetic parameters of the thermal decomposition of CNCs for each acid hydrolysis duration. Increasing hydrolysis duration promoted thermal stability, particularly for NRFs based CNCs. Results showcased in this article add new perspective to Nile rose nanocellulose and pave down the way to fabricate NRFs based humidity nano-sensors.

Comprehensive characterization of hemicelluloses obtained from Gleditsia sinensis Lam. pods and the application of moderately degraded hemicelluloses in galactomannan film

The Gleditsia sinensis Lam. pods (GSP) are consistently discarded as waste after saponin extraction due to a lack of industrial or high-value utilization. Herein, the hemicelluloses were extracted from two varieties of GSP and subjected to comprehensive characterization. The molar mass of DMSO-soluble hemicelluloses (53.3–66.0 kDa) was higher compared to that of alkali-soluble ones (24.9–32.6 kDa). The presence of minimal acetyl substitution (3.85–4.49 %) on xylan was unequivocally confirmed. NMR spectroscopic analysis indicated that the hemicelluloses in GSP predominantly consist of a 1,4-β-ᴅ-Xyl backbone with arabinose substituents at O-3 and 4-O-methyl-α-ᴅ-GlcA substituents at O-2 of the xylose residues. p-Coumaric acid substitution also occurred on the 1,4-β-ᴅ-Xyl backbone. Hydrothermal treatment significantly reduced the hemicelluloses' relative molar mass and produced 7–10 % xylo-oligosaccharides. Furthermore, the moderately degraded hemicelluloses exhibited significantly enhanced biological activity. Finally, the incorporation of the moderately degraded hemicelluloses imparted the galactomannan film with exceptional antioxidant properties (81.1 % DPPH scavenging activity), while negligibly affecting its transparency. Our study's findings will contribute to a comprehensive understanding of the structural and biochemical properties of hemicellulose in waste G. sinensis pods, thereby facilitating their enhanced utilization in industrial applications.

Synthesis and characterization of yttrium iron oxide/PPy nanocomposites for supercapacitor application by chemical oxidative polymerization method

ABSTRACT Polypyrrole (PPy)/Yttrium Iron oxide (YIG) nanocomposite was synthesized by the chemical oxidation polymerization method. Yttrium iron oxide is also known as iron yttrium oxide or yttrium iron garnet denoted as YIG (Y3Fe5O12). YIG is a familiar material among the rare earth garnets and is also commonly used in electronic devices. Fourier transform infrared (FT-IR) spectroscopy analysis reveals the strong interaction between PPy and YIG nanoparticles. The crystal structure for the PPy and PPy nanocomposites is observed by X-ray Diffraction (XRD) and the average crystalline size calculated by Scherrer’s formula for PPy/n-YIG is 27.47 nm. Surface morphology of the samples identified by scanning electron microscopy. Optical properties were studied by UV–Vis spectroscopy. From the 2-probe method, AC electrical conductivity for n-YIGPPy is found to be 1.05 × 10−5 S/cm, higher than that of the polypyrrole. The electrochemical performance of PPy and YIG/PPy nanocomposites was observed by cyclic voltammetry (CV). The combination of optical, electrical properties of YIG/PPy nanocomposites suits supercapacitor applications.

Evaluation of Calcarenite Degradation by X-ray Photoelectron Spectroscopy Analysis inside the Rupestrian Church of San Pietro Barisano (Matera, Southern Italy)

Evaluation of Calcarenite Degradation by X-ray Photoelectron Spectroscopy Analysis inside the Rupestrian Church of San Pietro Barisano (Matera, Southern Italy)

Exploring Defect-Engineered Metal-Organic Frameworks with 1,2,4-Triazolyl Isophthalate and Benzoate Linkers.

Synthesis and characterization of DEMOFs (defect-engineered metal-organic frameworks) with coordinatively unsaturated sites (CUSs) for gas adsorption, catalysis, and separation are reported. We use the mixed-linker approach to introduce defects in Cu2-paddle wheel units of MOFs [Cu2(Me-trz-ia)2] by replacing up to 7% of the 3-methyl-triazolyl isophthalate linker (1L2-) with the "defective linker" 3-methyl-triazolyl m-benzoate (2L-), causing uncoordinated equatorial sites. PXRD of DEMOFs shows broadened reflections; IR and Raman analysis demonstrates only marginal changes as compared to the regular MOF (ReMOF, without a defective linker). The concentration of the integrated defective linker in DEMOFs is determined by 1H NMR and HPLC, while PXRD patterns reveal that DEMOFs maintain phase purity and crystallinity. Combined XPS (X-ray photoelectron spectroscopy) and cw EPR (continuous wave electron paramagnetic resonance) spectroscopy analyses provide insights into the local structure of defective sites and charge balance, suggesting the presence of two types of defects. Notably, an increase in CuI concentration is observed with incorporation of defective linkers, correlating with the elevated isosteric heat of adsorption (ΔHads). Overall, this approach offers valuable insights into the creation and evolution of CUSs within MOFs through the integration of defective linkers.

Adhesive-free bonding for hetero-integration of InP based coupons micro-transfer printed on SiO2 into Complementary Metal-Oxide-Semiconductor backend for Si photonics application on 8″ wafer platform

Micro-Transfer printing (µTP) is a promising technique for hetero-integration of III-V materials into Si-based photonic platforms. To enhance the print yield by increasing the adhesion between the III-V material and Si or SiO2 surface, an adhesion promoter like Benzocyclobutene is typically used as interlayer. In this work, we demonstrate µTP of InP based coupons on SiO2 interlayer without any adhesive interlayer and investigate the mechanism of adhesive free bonding. Source coupons are InP-based coupon stacks on a sacrificial layer that is removed by a chemical wet etch with FeCl3. For the target we fabricated amorphous-Si waveguides on 8″ wafer encapsulated by a High Density Plasma SiO2 which was planarized by a chemical mechanical polishing procedure. We used O2 plasma to activate both source and target to increase adhesion between coupon and substrate. To get a better understanding of the bonding mechanism we applied several surface characterization methods. Root mean square roughness of InP and SiO2 was measured by atomic force microscopy before and after plasma activation. The step height of the micro-transfer printed source coupon on the target wafer is estimated by optical step profiler. We used Raman peak position mappings of InP to analyze possible strain and contact angle measurements on SiO2, before and after plasma activation to observe a change in the hydrophilicity of the surface. X-ray Photoelectron Spectroscopy analysis was used to characterize the surface energy states of P2p, In3d, O1s for InP source and Si2p, O1s for SiO2 target. Our results demonstrate direct bonding of InP coupons by means of µTP without the need of a strain-compensation layer. In this way, a promising route towards Complementary Metal-Oxide-Semiconductor compatible use of µTP for the hetero-integration of InP is provided.

Biodegradable chelator GLDA intercalated magnesium/aluminum layered double hydroxides for efficient phosphate capture and removal from wastewater

Phosphate removal and recovery from wastewater play a vital role in controlling water eutrophication and facilitating resource recycling. Adsorbents of layered double hydroxides (LDHs) exhibit promising potential in the removal of phosphate; however, the removal efficiency often suffers insufficient as easy aggregation and inevitable loss of LDHs. Herein, a novel N, N–bis (carboxymethyl)–L–glutamic acid intercalated magnesium–aluminum LDH (GLDA@MgAl–LDH) were successfully synthesized. Intercalating with GLDA spawned dual functionality, i.e., the layer spacing expansion elevated the loading of phosphate, while GLDA also acted as additional binding sites toward phosphate. A higher phosphate capture (＞90%) was obtained in pH 5.0–8.0. Phosphate uptake was predominantly observed within the first1h, reaching equilibrium in approximately 4 h. The maximum adsorption capacity of 44.17 mg g–1 was attained for GLDA@MgAl–LDH at pH 6.70, which are far higher than that of pristine MgAl–LDH. GLDA@MgAl–LDH also had the excellent stability and reusability in five adsorption/desorption experiments. The GLDA@MgAl–LDH demonstrated significant efficacy in treating actual phosphate-containing wastewater in the fixed–bed adsorption column. Spectroscopic analysis, in conjunction with density functional theory, elucidated that GLDA intercalation enhanced the adsorption efficiency of MgAl–LDH. The key mechanisms facilitating phosphate removal included electrostatic attraction, anion and ligand exchange, and surface complexation. The above results highlight that GLDA@MgAl–LDH could serve as a promising and environmentally friendly candidate for phosphate treatment from the real wastewater.

Regulating Surface Dipole Moments of TiO2 for the pH-Universal Cathodic Fenton-Like Process.

Although electro-Fenton (EF) processes can avoid the safety risks raised by concentrated hydrogen peroxide (H2O2), the Fe(III) reduction has always been either unstable or inefficient at high pH, resulting in catalyst deactivation and low selectivity of H2O2 activation for producing hydroxyl radicals (•OH). Herein, we provided a strategy to regulate the surface dipole moment of TiO2 by Fe anchoring (TiO2-Fe), which, in turn, substantially increased the H2O2 activation for •OH production. The TiO2-Fe catalyst could work at pH 4-10 and maintained considerable degradation efficiency for 10 cycles. Spectroscopic analysis and a theoretical study showed that the less polar Fe-O bond on TiO2-Fe could finely tune the polarity of H2O2 to alter its empty orbital distribution, contributing to better ciprofloxacin degradation activity within a broad pH range. We further verified the critical role of the weakened polarity of H2O2 on its homolysis into •OH by theoretically and experimentally investigating Cu-, Co-, Ni-, Mn-, and Mo-anchored TiO2. This concept offers an avenue for elaborate design of green, robust, and pH-universal cathodic Fenton-like catalysts and beyond.

Stereochemical insights into enantioselective antiplasmodial lignanamides from the twigs and leaves of Solanum erianthum

Stereochemical investigations on the twigs and leaves of Solanum erianthum afforded five pairs of lignanamide enantiomers and a previously undescribed phenolic amide (3). Particularly, two pairs of previously undescribed lignanamide racemates (1a/1b–2a/2b) represent the first case of natural products that feature an unreported 5/5-fused N/O-biheterocyclic core. Their structures, including the absolute configurations, were determined unambiguously by using spectroscopic analyses and electronic circular dichroism calculations. A speculative biogenetic pathway for 1–3 was proposed. Interestingly, these lignanamides exhibited enantioselective antiplasmodial activities against drug-sensitive Plasmodium falciparum 3D7 strain and chloroquine-resistant Plasmodium falciparum Dd2 strain, pointing out that chirality plays an important role in drug development.

Multidimensional information fusion and analysis of ultraviolet absorption spectroscopy: Simultaneous detection method for copper and zinc ion concentrations in seawater

Heavy metal pollution poses a significant threat to marine ecological environments and serves as a crucial indicator for seawater quality assessment. The enrichment of heavy metals severely impacts marine ecosystem health and poses threats to human food safety, underscoring the critical importance of monitoring heavy metal levels in marine waters. In this paper, UV absorption spectroscopy was used to collect the spectra of seawater containing different concentrations of Cu and Zn ions, which overcomes the problems of traditional methods that require extensive pre-treatment and lossy samples. To address the characteristics of the data, the Savitzky-Golay (SG) filtering algorithm is used for preprocessing. The acquired spectra are then subjected to further data analysis using the proposed multidimensional information fusion method called SpectraNet Fusion Algorithm (SFA) for UV absorption spectroscopy. The local feature information extraction module and the whole domain information feature extraction module were respectively used to predict the regression of the data in parallel two-channel, and the output results were integrated to form a new feature map, which was further processed by the feature information fusion module, and finally output the prediction results corresponding to the spectra to realize the accurate detection of Cu and Zn heavy metal ions in seawater. The coefficient of determination (R2) of the model training set established by this method reaches 98.00 %, the root mean square error (RMSE) reaches 0.0389, and the mean absolute error (MAE) reaches 0.0243, combined with the experimental design, the detection range was 5 μg·L−1 to 90 μg·L−1,which realizes simultaneous and high-precision prediction of Cu and Zn heavy metal ions in seawater.

Phenylacetic acid, an anti-vaginitis metabolite produced by the vaginal symbiotic bacterium Chryseobacterium gleum

The human microbiome contains genetic information that regulates metabolic processes in response to host health and disease. While acidic vaginal pH is maintained in normal conditions, the pH level increases in infectious vaginitis. We propose that this change in the vaginal environment triggers the biosynthesis of anti-vaginitis metabolites. Gene expression levels of Chryseobacterium gleum, a vaginal symbiotic bacterium, were found to be affected by pH changes. The distinctive difference in the metabolic profiles between two C. gleum cultures incubated under acidic and neutral pH conditions was suggested to be an anti-vaginitis molecule, which was identified as phenylacetic acid (PAA) by spectroscopic data analysis. The antimicrobial activity of PAA was evaluated in vitro, showing greater toxicity toward Gardnerella vaginalis and Candida albicans, two major vaginal pathogens, relative to commensal Lactobacillus spp. The activation of myeloperoxidase, prostaglandin E2, and nuclear factor-κB, and the expression of cyclooxygenase-2 were reduced by an intravaginal administration of PAA in the vaginitis mouse model. In addition, PAA displayed the downregulation of mast cell activation. Therefore, PAA was suggested to be a messenger molecule that mediates interactions between the human microbiome and vaginal health.

In situ generation of azo dyes on silk fibroin through three-step chemical modification

To enhance the efficiency and reduce the environmental footprint of silk dyeing, this study introduces a novel method that synthesizes azo dyes directly on silk fibroin (SF) using a three-step chemical modification at room temperature. Initially, SF undergoes modification with isatoic anhydride to yield aromatic primary amino-modified silk fibroin (SF–NH2). Subsequently, SF-NH2 is treated with nitrous acid to produce diazotized silk fibroin (SF–N2+). In the final step, SF-N2+ is combined with coupling components to directly form azo chromophores on the SF, culminating in the creation of coloured silk fibroin (SF–NN-CC). The efficacy of the three-step dyeing method was validated using infrared spectroscopy and colour development analysis. The modification sites on SF-NH2 were identified as the hydroxyl and amino groups of amino acid residues, confirmed through simulated reactions. SF-N2+ demonstrated excellent storage and thermal stability under dry conditions; however, its stability decreased in wet environments. Various coupling components were then reacted with SF-N2+ to synthesize in situ yellow, red, crimson, and green azo dyes on SF. The formation of covalent bonds between the dyes and SF was verified using DMF stripping methods. The dyed SF-NN-CC fabrics underwent testing for fastness, revealing wet fastness rating above grade 4. These findings demonstrate that the three-step modification process represents an innovative, energy-efficient, and fast-reacting dyeing method for SF.

Enhanced anti-breast cancer activity of green synthesized selenium nanoparticles by PEGylation: induction of apoptosis and potential anticancer drug delivery system

Breast cancer is a disease associated with high morbidity and mortality rates worldwide. The potential use of biogenic nanoparticles as alternative anticancer agents has been immensely acknowledged in several studies, particularly selenium nanoparticles (SeNPs). Nanoparticles were synthesised using the aqueous extract of Moringa peregrine (MPM-SeNPs) and were PEGylated (PEG-MPM-SeNPs). MPM-SeNPs were characterised by chemical and physical techniques. The successful capping of MPM-SeNPs with PEG was confirmed by spectrophotometric measurements and via Fourier-transform infrared spectroscopy (FT-IR) analysis. Furthermore, the effect of PEGylation of MPM-SeNPs on enhancing their anti-breast cancer activity and as a drug delivery agent was evaluated. Therefore, the loading efficiency and release of DOX at different pH values were measured; the antiproliferative activity of PEG-MPM-SeNPs against the adenocarcinoma breast cancer cell line (MDA-MB-231) was evaluated and compared with that of biogenic MPM-SeNPs and DOX-conjugated PEG-MPM-SeNPs. PEG-MPM-SeNPs and DOX-PEG-MPM-SeNPs had reduced IC50 values compared to MPM-SeNPs; IC50 of 11.54 ± 1.74 and 31.27 ± 2.9 μg mL−1 compared to 71.4 ± 3.4 μg mL−1, respectively. MPM-SeNPs and PEG-MPM-SeNPs caused apoptosis to MDA-MB-231 cells with a significant decrease in the mitochondrial membrane potential (MMP), increase in the released cytochrome C (Cyt C), and activation of caspase-3/9 (P < 0.05). Linking DOX to PEG-MPM-SeNPs led to an increase in caspase-3/8 concentrations and an increase in the released Cyt C, but there were non-significant differences in MMP (P > 0.1) between treated and untreated control cancer cells. MPM-SeNPs and PEG-MPM-SeNPs caused apoptotic reactions via an intrinsic pathway, while linking DOX to PEG-MPM-SeNPs caused apoptosis in cancer cells through an extrinsic pathway.

Isosorbide-based Poly(arylene ether) biopolymer membranes for gas separation

Efforts to utilize biopolymer membranes to diminish the carbon footprint of separation processes are ongoing. Herein, we report the fabrication of isosorbide (ISB)-based poly(arylene ether) biopolymer membranes, including ISB-based poly(arylene ether sulfone) (I-PAES) and ISB-based poly(arylene ether ketone) (I-PAEK) for gas separation. The robust mechanical properties and amorphous nature of ISB-based biopolymers allow for their application to gas separations. Both positron annihilation lifetime spectroscopy (PALS) and free volume analysis using density measurements reveal that replacing bisphenol A (BPA) in polysulfone (PSF) with ISB results in a significant reduction in free volume owing to the absence of bulky dimethyl groups and the presence of polar aliphatic ether groups. Substituting the sulfone group for a ketone group further decreased free volume. Solid-state CP/MAS 13C NMR analysis discloses that substituting ISB and replacing sulfonyl moieties with carbonyl groups restricts the rotational motion of internal rings, resulting in inhibited gas diffusion. Consequently, the I-PAEK membrane exhibited H2/CO2 and H2/CH4 selectivities more than three times and five times higher, respectively, compared to the PSF counterpart. Our present study demonstrates the feasibility of ISB-based poly(arylene ether) biopolymer membranes for gas separation.