Crystalline Characteristics Research Articles

Synthesis of biopolymer blends nanocomposites embedded with mono-(Ag, Fe) and bi-(Ag-Fe) metallic nanoparticles using an eco-friendly approach for antimicrobial activities.

Plant-mediated solution casting is used to develop eco-friendly polymer blend nanocomposites from polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP) doped with Silver (Ag), Ferrous (Fe) monometallic and Silver-Ferrous (Ag-Fe) bimetallic nanoparticles (NPs). These nanocomposites were studied to understand their electromagnetic interface (EMI) shielding efficiency and antimicrobial activities, besides evaluating their physical and chemical properties. The Fourier transform infrared (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and energy dispersive X-ray (EDX) characterization techniques were used to examine the interactions between the polymers, the presence of silver and ferrous particles in the composites, the crystallinity shift, the surface morphology, the shape and size of the nanoparticles and the distribution of the nanoparticles in the composites. The FTIR spectra showed the interactions among the components of the composites. According to XRD spectra, the incorporation of nanoparticles into the PVA polymer significantly reduced the crystalline character of the polymer from 0.38 to 0.24 for the composition consisting of silver and iron nanoparticles in equal proportion. The results from SEM, EDX and XRD corroborate the presence of nanoparticle forms. The thermogravimetric analysis (TGA) tests reveal that the thermal stability of bimetallic composites is greater than that of monometallic composites. The tensile properties showed that the addition of nanoparticles to the PVA/PVP polymer matrix increased its mechanical strength from 59.3MPa to 85.5MPa. We examined its efficacy against Escherichia coli, Staphylococcus aureus and Candida albicans as microorganisms. Good antibacterial and antifungal activity was observed. The bimetallic composites demonstrated greater activity than monometallic composites against these bacterial and fungal species. All bimetallic nanocomposites have shown enhanced, loss due to reflection, loss due to absorption, and the total EMI shielding efficiency at 8GHz (X-band) and 16GHz (Ku-band) frequency. All these results ratify, that these newly developed bio nanocomposites are most suitable in many applications, in EMI shielding, nanotechnology, and medical fields.

Enhanced photocatalytic activities of LaCoO3 perovskite nanostructures for degrading cationic and anionic dyes

Sustainable and cost-effective technologies are crucial for addressing environmental pollution issues. Perovskite photocatalysts have gained increased attention as a potential solution which could be accounted to their tuneable structural characteristics, flexible bandgap, and superior catalytic properties. In this study, we synthesized Lanthanum Cobaltite (LaCoO3) perovskite nanostructures via co-precipitation for photocatalytic purposes. Morphological analysis revealed LaCoO3 nanoparticles with an average size of ∼33 nm whose crystalline characteristics were investigated as a function of annealing temperatures. We found that the pure and crystalline LaCoO3 phase formed after the post-annealing process at 600°C. Photocatalytic studies showed that the degradation potential of LaCoO3 was significantly improved when hydrogen peroxide (H2O2) was added as co-catalyst system. We achieved degradation efficiencies of up to 91% and 85% for MB and methyl orange (MO), respectively. LaCoO3/H2O2 exhibited excellent photocatalytic potential for degrading both anionic and cationic organic dyes for environmental remediation applications.

Enhanced Photocatalytic and Electrochemical Performance of MOF-Derived NiO-ZnO Oxide Composites for Wastewater Treatment and Sustainable Energy Storage

Solar energy is a crucial and sustainable resource, necessitating material optimization for efficient use in solar-driven applications, particularly photocatalysis. Mixed-metallic nanocomposites, notably those derived from metal-organic frameworks (MOFs), have emerged as promising functional materials for environmental remediation and electrochemical energy storage. MOFs provide unique platforms for synthesizing diverse nanostructures, incorporating metals, oxides, sulfides, and nitrides within a porous carbon matrix. These resulting nanocomposites exhibit high crystallinity, retained morphologies, and tunable textural features. This study focuses on synthesizing a MOF-derived Ni/Zn nanocomposite (i.e., MD-Ni/Zn) from a bimetallic MOF to exploit its potential in photocatalytic pollutant degradation and electrochemical energy storage. Under UV irradiation, the MD-Ni/Zn nanocomposite efficiently degrades 98% of mixed (RhB+CV) dye within 60 minutes. This remarkable photocatalytic performance is attributed to the occurrence of mixed phases in the MD-Ni/Zn nanocomposite, minimizing the recombination efficiency of photoinduced e-/h+ through the p-n heterojunction mechanism. Electrochemical analysis reveals outstanding capacitance in the MD-Ni/Zn nanocomposite, reaching 1002 F/g at 5 A/g, emphasizing its suitability for enhanced electrochemical energy storage.

Dielectric Analysis of Amine Modified Nano-graphite: Effects of Thickness, Temperature and Frequency

Amine modified nano-graphite (NH2-NG) has been produced from nanographite (NG) powder via liquor ammonia (NH3) aqueous solution by microwave, ultrasonic methods. The surface modified NG have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) techniques which clearly demonstrate that synthesis of NH2-NG was successful. The crystalline characteristics of amine modified nanographite powder have been studied through XRD technique. The morphology structure of synthesized surface modified nanoparticles has been determined by SEM analysis. FTIR spectra confirmed the existence of amine groups on the surface of produced nano-graphite powder. NH2-NG pellet was prepared to analyse its dielectric properties as a function of thickness (1, 2, 3, 5 and 7 mm), frequency (range 10−2-105 Hz) and temperature (25, 50, 75 and 100 °C). As a function of frequency, the dielectric loss tangent and permittivity each exhibit a distinct relaxation peak that grows up to a thickness of 5 mm then decreasing. Because nanoparticles are capacitive, the capacitance values of NG and NH2-NG increase with thicknesses up to 5 mm and drop with frequency. The drop in dielectric permittivity of NG and NH2-NG pellets after 5 mm may be caused by an increase in resistivity. Positive temperature coefficient (PTC) of increased conductance is confirmed by the continuous increase in electrical conductivity of NG and NH2-NG with temperature. The degree of temperature has a significant impact on the dielectric loss tangent, dielectric permittivity, and electrical conductivity of NG, and NH2-NG.

Incorporation of Nano Selenium in Fish Diet and Assessment of Growth Performance and Biochemical Criteria of Labeo rohita

Selenium (Se) is an essential microelement utilized in aqua-feeds for aquatic animals’ normal growth, well-being and health. This work was intended to assess the growth performance of Labeo rohita (Rohu) resulting from the nano Se-merged diet. Nano Se was synthesized and its physico-chemical characteristics were characterized using UV-VIS, SEM, EDAX, XRD and FTIR for varying quantities of nano Se; Diets - I-0, II- 0.5, III-1, IV-1.5, V-2 and VI- 2.5 mg/ kg were prepared, making use of fish meal (FM), groundnut oil cake (GNOC), wheat flour (WF) and tapioca flour (TF). Feed-utilizing parameters and the biochemical composition of Rohu were evaluated subsequently after 28 days. The UV-Vis Spectroscopy revealed that nano Se was assessed in wavelengths of 200 to 500 nm and exhibited strong absorption at 322 nm. SEM image showed spherical morphology with an average particle diameter of 12.22 mm. EDAX spectrum recorded two signals at 1.5 keV and 11 keV. XRD patterns showed crystalline characteristics of nano Se at 2θ correlators of 23.5o, 29.7o, 41.4o, 43.6o, 45.4o, 51.7o, 55.9o and 61.5o. FTIR spectrum was examined in the range of 4000 – 500 cm-1. Rohu's growth performance and biochemical analysis revealed that the protein, carbohydrate and lipids of gill, liver and muscle of Rohu were highly increased in the case of diet IV containing 1.5 mg/kg nano Se.

Unlocking high-performance HCl adsorption at elevated temperatures: the synthesis and characterization of robust Ca–Mg–Al mixed oxides

The presence of HCl and SO2 gas imposes limitations on syngas utilization obtained from household waste in a wide range of applications. The hydrotalcite-like compounds (HTLs) have been proved that could remove HCl efficiency. However, the research on impact of synthesis conditions of HTLs and SO2 on HCl removal was limited. In this study, a range of Ca–Mg–Al mixed oxide sorbents was synthesized by calcining HTLs, with variations in crystallization temperature, solution pH, and the Ca/Mg molar ratio. These sorbents were examined for their effectiveness in removing HCl at medium–high temperatures under diverse conditions. The adsorption performance of selected sorbents for the removal of HCl, SO2, and HCl-SO2 mixed gas at temperature of 350 °C, 450 °C, and 550 °C, respectively, was evaluated using thermogravimetric analysis (TGA). It was observed that the HTL synthesis parameters significantly influenced the HCl adsorption capacity of Ca–Mg–Al mixed oxides. Notably, HTLs synthesized at 60 °C, a solution pH of 10–11, and a Ca/Mg ratio of 4 exhibited superior crystallinity and optimal adsorption characteristics. For individual HCl and SO2 removal, temperature had a minor effect on HCl adsorption but significantly impacted SO2 adsorption rates. At temperatures above 550 °C, SO2 removal efficiency substantially decreased. When exposed to a mixed gas, the Ca–Mg–Al mixed oxides could efficiently remove both HCl and SO2 at temperatures below 550 °C, with HCl dominating the adsorption process at higher temperatures. This dual-action capability is attributed to several mechanisms through which HTL sorbents interacted with HCl, including pore filling, ion exchange, and cation exchange. Initially, HCl absorbed onto specific sites created by water and CO2 removal due to the surface’s polarity. Subsequently, HCl reacted with CaCO3 and CaO formed during HTL decomposition.Graphical abstract

Solution-processed CsPbBr3 perovskite films via CsBr intercalated PbBr2 intermediate for high-performance photodetectors towards underwater wireless optical communication

All inorganic CsPbBr3 perovskite is regarded as a promising candidate of halide perovskites and has attracted great attention due to its superior optoelectronic properties and stability. However, the low and unbalanced solubility of precursors and uncontrollable crystallization result in poor coverage and impurity phases in CsPbBr3 polycrystalline films, hindering the application in optoelectronic devices. In this work, a facile CsBr intercalated nanostructured intermediate based two-step method is reported for simultaneously achieving good morphology and pure phase of CsPbBr3 films. With the CsBr intercalation, the intermediate films deposited in the first step exhibit porous nanostructure and CsxPb2Br4+x crystal phase. This unique porous morphology and crystal structure favor CsBr solution penetration and Cs+ ion diffusion. First-principles calculations are conducted to investigate the phase diagram of intermediates and the diffusion kinetics of Cs+ ions in the various polymorphs. The key role of CsBr intercalation is confirmed for achieving high-quality CsPbBr3 perovskite films with features of pinhole free, pure phase, large grains, and high crystallinity. Photodetectors based on optimized CsPbBr3 films exhibit excellent performance with a peak EQE of 83%, responsivity of 0.35 A/W, and specific detectivity of 1.25×1013 Jones. Fast response speed is also achieved with rise/fall time of 1.41 μs and 2.06 μs and −3 dB bandwidth up to 800 kHz. Moreover, CsPbBr3 PD shows great potential in the application of underwater wireless optical communication due to its low background noise current under ambient light illumination. Overall, this work paves the way for further research on optoelectronic devices and their applications based on CsPbBr3 films.

Insights into Factors Affecting Ethylene-Vinyl Acetate Copolymer Crystallinity in Islatravir Implant.

Islatravir, a highly potent nucleoside reverse transcriptase translocation inhibitor (NRTTI) for the treatment of HIV, has great potential to be formulated as ethylene-vinyl acetate (EVA) copolymer-based implants via hot melt extrusion. The crystallinity of EVA determines its physical and rheological properties and may impact the drug-eluting implant performance. Herein, we describe the systematic analysis of factors affecting the EVA crystallinity in islatravir implants. Differential scanning calorimetry (DSC) on EVA and solid-state NMR revealed drug loading promoted EVA crystallization, whereas BaSO4 loading had negligible impact on EVA crystallinity. The sterilization through γ-irradiation appeared to significantly impact the EVA crystallinity and surface characteristics of the implants. Furthermore, DSC analysis of thin implant slices prepared with an ultramicrotome indicated that the surface layer of the implant was more crystalline than the core. These findings provide critical insights into factors affecting the crystallinity, mechanical properties, and physicochemical properties of the EVA polymer matrix of extruded islatravir implants.

Ge1−xSnx layers with x∼0.25 on InP(001) substrate grown by low-temperature molecular beam epitaxy reaching 70 °C and in-situ Sb doping

Ge1−xSnx with x∼25%, group-IV alloy semiconductor, is highly attracted to mid-infrared (MIR) photodetector applications because of its narrow bandgap with ∼0.25 eV, the compatibility to the Si integrated circuit platform, and lattice matching of Ge0.75Sn0.25 to InP substrate. Although the heteroepitaxial growth of Ge0.75Sn0.25 on InP has been reported, the basic physical properties of Ge0.75Sn0.25 have not yet been clarified. In this study, we discuss three topics: (1) understanding the crystalline growth features of Ge0.75Sn0.25 on InP, (2) revealing the thermal stability of Ge0.75Sn0.25, and (3) developing a carrier-control technique. First, we found that a low-temperature molecular beam epitaxy could achieve a Ge0.75Sn0.25 layer with superior crystallinity without dislocations. However, low Sn-content Ge1−xSnx regions are locally formed during the Ge0.75Sn0.25 heteroepitaxy; the origins of the low Sn-content Ge1−xSnx regions were discussed by transmission electron microscopy analysis. In addition, we found that lowering the growth temperature from 100 °C to 70 °C also effectively reduces the area of the low Sn-content Ge1−xSnx regions. Next, we found that Ge0.75Sn0.25 layers grown at 70 °C sustain thermal stability up to 200 °C without causing crystalline degradations. Finally, we demonstrated the in-situ Sb doping to Ge0.75Sn0.25. We found that the undoped and in-situ Sb-doped Ge0.75Sn0.25 layers exhibited p-type and n-type conduction, respectively, with carrier concentrations of order 1019 cm−3 by Hall effect measurement. This study suggests the MIR photodetector application is practically possible using low-temperature processes with process temperatures lower than 200 °C.

Imaging a solvent‐swollen polymer gel network by open liquid transmission electron microscopy

AbstractVisualizing the network of a solvent‐swollen polymer gel remains problematic. To address this challenge, open transmission electron microscopy (TEM) was applied to thin gel films permeated by a nonvolatile ionic liquid. The targeted physical gels were prepared by cooling concentrated solutions of poly(ethylene glycol) in 1‐ethyl‐3‐methyl imidazolium ethyl sulfate [EMIM][EtSO4]. During the cooling, gelation occurred by a frustrated crystallization of the dissolved polymer, leading to a percolated, solvent‐permeated semicrystalline network in which nanoscale polymer crystals acted as crosslinks. Crystalline features ranging from ~5 to ~200 nm were observed, with the visible network strands dominantly consisting of long curvilinear crystallites of ~15–20 nm diameter. Nascent spherulites irregularly decorated the network, creating a complex structural hierarchy that complicated analyses. Lacking diffraction contrast, TEM did not visualize the many disordered, fully solvated PEG chains present in the voids between crystals. Recognizing that a network's three dimensionality is ambiguous when assessed through two‐dimensional microscopy projections, a small gel region was studied by TEM tomography, revealing a nearly isotropic three‐dimensional arrangement of the curvilinear crystallites, which displayed remarkably uniform cylindrical cross sections.

Effect of PVP Molecular Weights on the Synthesis of Ultrasmall Cus Nanoflakes: Synthesis, Properties, and Potential Application for Phototheranostics.

Copper sulfide nanoparticles (CuS) hold tremendous potential for applications in photothermal therapy (PTT) and photoacoustic imaging (PAI). However, the conventional chemical coprecipitation method often leads to particle agglomeration issues. To overcome this challenge, we utilized polyvinylpyrrolidone (PVP) as a stabilizing agent, resulting in the synthesis of small PVP-CuS nanoparticles named PC10, PCK30, and PC40. Our study aimed to investigate how different molecular weights of PVP influence the nanoparticles' crystalline characteristics and essential properties, especially their photoacoustic and photothermal responses. While prior research on PVP-assisted CuS nanoparticles has been conducted, our study delves deeper into this area, providing insights into optical properties. Remarkably, all synthesized nanoparticles exhibited a crystalline structure, were smaller than 10 nm, and featured an absorbance peak at 1020 nm, indicating their robust photoacoustic and photothermal capabilities. Among these nanoparticles, PC10 emerged as the standout performer, displaying superior photoacoustic properties. Our photothermal experiments demonstrated significant temperature increases in all cases, with PC10 achieving an impressive efficiency of 51%. Moreover, cytotoxicity assays revealed the nanoparticles' compatibility with cells, coupled with an enhanced incidence of apoptosis compared to necrosis. These findings underscore the promising potential of PVP-stabilized CuS nanoparticles for advanced cancer theranostics.

Comparative Study on the Impact of Different Extraction Technologies on Structural Characteristics, Physicochemical Properties, and Biological Activities of Polysaccharides from Seedless Chestnut Rose (Rosa sterilis) Fruit.

Seedless chestnut rose (Rosa sterilis S. D. Shi, RS) is a fresh type of R. roxburghii Tratt with copious functional components in its fruit. Polysaccharides are recognized as one of the vital bioactive compounds in RS fruits, but their antioxidant and hypoglycemic properties have not been extensively explored. Hence, in this study, accelerated solvent extraction (RSP-W), citric acid (RSP-C), 5% sodium hydroxide/0.05% sodium borohydride (RSP-A), and 0.9% sodium chloride (RSP-S) solution extraction were individually utilized to obtain RS fruit polysaccharides. The physicochemical properties, structural characteristics, and biological activities were then compared. Results indicated that extraction methods had significant influences on the extraction yield, uronic acid content, monosaccharide composition, molecular weight, particle size, thermal stability, triple-helical structure, and surface morphology of RSPs apart from the major linkage bands and crystalline characteristics. The bioactivity tests showed that the RSP-S, which had the greatest amount of uronic acid and a comparatively lower molecular weight, exhibited more potent antioxidant and α-glucosidase inhibitory property. Furthermore, all RSPs inhibited α-glucosidase through a mixed-type manner and quenched their fluorescence predominantly via a static quenching mechanism, with RSP-S showing the highest binding efficiency. Our findings provide a theoretical basis for utilizing RSPs as functional ingredients in food industries.

Investigation of optical and dispersion parameters poly vinyl alcohol doped Safranin O dye (PVA/SO) thin film

Optical characteristics of polyvinyl alcohol/Safranin O dye (PVA/SO) thin films prepared by casting technique have been examined. Compositions and crystalline features of PVA/SO thin films are investigated with X-Ray Diffraction analyses. Ultraviolet–Visible spectroscopy has been utilized to measure the absorption and transmission optical properties of the thin films through the wavelength range 300-900 nm. Two regions can be recognized in absorption coefficient related to the direct band gaps, which are about 3.93 eV of the fundamental energy gap and 2.11eV of the onset gap. The theoretical WempleDiDomenico model has been performed to quantify the static refractive index n and the dispersion energy in addition to the oscillation energy (Eo). The results reveal that the data of the refractive index dispersion in this model obeyed the single oscillator, which is used to deduce the dispersion and the high frequency dielectric constant. In the examined wavelength range, it has been investigated the complex dielectric constant of PVA/SO dye thin films. The ratio of the carrier concentration to the effective mass has been estimated. Oscillation energy values have been examined in this study by describing the expression Eo ≈ Eg and checking the Wemple-DiDomenico model. PVA/SO thin films have interesting physical properties for solar cell applications.

Effect of pin‐to‐plate atmospheric cold plasma on technological and nutritional functionality of horse gram (Macrotyloma uniflorum) flour

AbstractAtmospheric cold plasma (CP), an acclaimed nonthermal technology, has gained popularity for its effective microbial inactivation in food materials, concurrently improving functional and nutritional aspects. Despite the nutraceutical benefits, horse gram (Macrotyloma uniflorum) is underutilized in baking and confectionery due to presence of major antinutrients. Our aim is to leverage CP to enhance horse gram's properties, promoting its viability in these sectors. The present study investigates the effect of CP treatment with varying output voltage (10–30 kV) and exposure time (5–25 min) on horse gram flour's nutritional, functional, and antinutritional properties. Moreover, the molecular interactions, crystallinity, thermal stability, and morphological characteristics were analyzed. CP treatment doubled the nutritional properties of horse gram flour and amplified the functional attributes by 1.5 times as compared to untreated flour, but excessively higher voltage (30 kV) and time (15 and 25 min) declined them. Whereas the antinutritional components—tannin, saponin, and phytic acid—were reduced to 1.43 ± 0.01 μg TAE/g, 0.72 ± 0.01 mg diosgenin/g, and 5.26 ± 0.03 mg phytate/g, respectively, after CP treatment, enhancing digestibility of the flour up to 75%. Principal component analysis illuminated the intricate relationship between CP treatment and flour attributes. Both low voltage (10 kV) with moderate exposure (15 and 25 min) and high voltage (30 kV) with shorter duration (5 min) exhibited favorable correlations with physiochemical, bioactive, and functional properties. Conversely, high voltage with prolonged exposure displayed a notable negative correlation with antinutritional properties, structural, and thermal characteristics, revealing the nuanced impact of treatment conditions on the quality of flour. Overall, CP can be recognized as a potential novel technique for the techno‐functional reformation of underutilized food materials.Practical applicationsThe horse gram is one of the underutilized crops rather than being a huge source of health and nutritional benefits. On the other hand, cold plasma is a novel technique in food processing which can be used for improvement of structural and functional properties of food products. That is why the purpose of the study not only was to enlighten the nutritional composition of the horse gram flour but also to improvise its techno functional qualities using cold plasma. However, the presence of the antinutrients in the horse gram flour acts as constraints for digestibility. The application of cold plasma on horse gram flour reduced the antinutrients present in it as well as improved the physiochemical and nutritional characteristics significantly. Moreover, the structural characteristics of the flour were affected by cold plasma which increased its stability for longer shelf life. Furthermore, the functionality of the flour was enhanced which showed an opportunity the better dough characteristic, emulsifying properties. These findings would help the usage of the horse gram flour as food ingredients in various bakery and confectionary food applications.

An Intrinsically Transparent Polyamide Film with Superior Toughness and Great Optical Performance.

Polyamide 66 was extensively utilized in various applications contributed by its excellent mechanical performance and outstanding durability. However, its high crystallinity renders it to have low transparency, which seriously limits its application in optical devices. Herein, a highly transparent polyamide (PA) 66-based copolymer was reported using 4,4'-diaminodicyclohexylmethane (PACM), adipic acid, and polyamide 66 salt as the reaction monomers. Wide-angle X-ray diffraction (WAXD) analysis revealed that the crystal phase of the synthesized PA66/PACM6 displayed a clear transition from α to γ as the PACM6 increased accompanied by a decreased intensity in the diffraction peak of the copolymer, whose transmittance was successfully adjusted reaching as high as 92.5% (at 550 nm) when the PACM6 was 40 wt%. Moreover, the copolymer with a higher content of PACM6 exhibited larger toughness. On the other hand, the biaxially oriented films of PA66/PACM6 (20 wt%) were also prepared, and it was found that the transparency of the PA66/PACM6 copolymer could be further enhanced via adjusting the stretching ratio of the film. Furthermore, the mechanical strength of the biaxially oriented PA66/PACM6 was also improved with the increase in the orientation degree in the stretching process, indicating that the physical properties of the transparent PA66 were significantly influenced by its alicyclic structure, and the introduction of PACM into PA66 was capable of effectively improving the optical and crystalline characteristics of PA66, revealing that the synthetic strategy has great potential for guiding the design and development of transparent polyamide materials.

Epoxy coating reinforced with graphene-PANI nanocomposites for enhancement of corrosion-resistance performance of mild steel in saline water

Protective coatings enriched with different types of chemical additives, functional fillers, and nanostructured materials are gaining immense interest to minimize corrosion. The present work demonstrates the synthesis of chemically functionalized reduced graphene oxide (rmGO) and emeraldine salt form of polyaniline (PANI-ES)-based rmGO-PANI-ES nanocomposites as protective functional fillers for epoxy coating to inhibit mild steel corrosion. The oxidative polymerization of aniline into PANI-ES is initiated on nitrogen-rich active sites of rmGO, and it propagates along the basal plane of rmGO, eventually enwrapped the graphene sheets by interfacially grown PANI-ES. The synthesis of rmGO-PANI-ES nanocomposites and their chemical, morphological, crystalline, and structural characteristics are examined by the FTIR, 13C NMR, XPS, XRD, Raman, SEM, and HRTEM analyses. The multiple interactions between the highly polar nitrogen-rich rmGO-PANI-ES nanocomposites and the epoxy matrix strengthened the coating and increased the hardness and elastic modulus. The corrosion inhibition performance of epoxy coating enriched with the rmGO-PANI-ES nanocomposites is probed by electrochemical impedance spectroscopic (EIS) and salt spray tests using an accelerated corrosive environment (3.5 wt% NaCl). The rmGO-PANI-ES-15 nanocomposite having 0.15 wt% rGO in epoxy coating showed superior corrosion inhibition performance. The total electrochemical impedance of epoxy coating (8.7 ×103 Ω.cm2) increased to 4.7 ×1015 Ω.cm2 after incorporating 1 wt% rmGO-PANI-ES-15 nanocomposite. The enhancement of electrochemical impedance by ∼12 orders of magnitude demonstrates the effectiveness of the rmGO-PANI-ES nanocomposites for corrosion mitigation in a harsh corrosive environment. The high surface area and remarkable structural barrier of the 2D chemically functionalized graphene furnished excellent protective coverage. The PANI-ES of rmGO-PANI-ES nanocomposites formed a passive layer of fully reduced leucoemeraldine base of PANI (PANI-LEB) on the coating-mild steel interface by accepting the electrons, generated during the anodic oxidation of iron. These events collectively increase the impedance by multifolds and inhibit steel corrosion. The present findings revealed that graphene-enriched conductive polymeric nanocomposites-based coatings can be promising solution to mitigate corrosion of metal-based installations in a marine environment.

Characterization and Visible Light-driven Photocatalytic Activity of SnS2/BiVO4 Nanocomposites Prepared by Sonochemical-based Process

Bismuth vanadate (BiVO4) is a good candidate photocatalyst material with good activity under visible light exposure. The photodecomposition performance of BiVO4 could be enhanced by combining it with compatible tin sulfide (SnS2). In this work, the synthesis of SnS2/BiVO4 nanocomposite was carried out by sonochemical process at room temperature with varying concentration ratios of SnS2:BiVO4 (0.05:1, 0.10:1, 0.15:1, 0.50:1 and 1:1). The crystallinity and morphological features of as-synthesized powders demonstrate the majority of BiVO4 monoclinic phase accompanying minority of SnS2 rhombohedral phase. FE-SEM micrograph shows the irregular shape with various particle sizes. The optical band gap of the composite inquired by Kubellka-Munk calculation is about 2.6 eV. The photocatalytic performance of as-synthesized nanocomposite was evaluated by means of decomposition of organic dye under visible light irradiation. The 0.05:1 ratio of the SnS2/BiVO4 sample exhibits superior photocatalytic activity with 60% decomposition of Rhodamine-B organic dye within 120 minutes. Keywords: Bismuth vanadate, Tin sulfide, Nanocomposite, Photocatalyst material

Monolithic Catalysts Supported by Emulsion-Templated Porous Polydivinylbenzene for Continuous Reduction of 4-Nitrophenol.

A monolithic catalyst was fabricated through an emulsion-templating method, postpolymerization modification, and in situ loading of active constituents. To achieve a high specific surface area, divinylbenzene (DVB) was solely employed as the monomer, while the porous structure was adjusted with the porogen content and the types of initiators. Then, anchor points were introduced on the pore wall through nitration and amination of the polymeric scaffold. Using a controlled "silver mirror reaction", monolithic catalysts were obtained after loading of silver nanoparticles (Ag NPs), which was verified from morphological and crystallinity characteristics. The catalytic performance of the resultant monolithic catalyst was determined with the model reduction of 4-nitrophenol (4-NP). In static catalysis, the monolithic catalyst was proved to have a reactively high apparent rate constant and a good reusability. Furthermore, a flow reactor was fabricated with the monolithic catalyst, showing a high efficiency and long-term durability for the continuous reduction of 4-NP. This work broadened the adjustment of porous structures and the subsequent application for emulsion-templated monoliths.

Uncovering the Crystalline Packing Advantages of Asymmetric Y‐Series Acceptors for Efficient Additive‐Insensitive and Intrinsically Stable Organic Solar Cells

AbstractOrganic solar cells (OSCs) hold immense potential as renewable energy sources, but the performance‐stability conundrum remains a major obstacle on the road to OSC commercialization. To address this, in this study, molecular packing behaviors of representative state‐of‐the‐art Y‐series non‐fullerene acceptors (NFAs) are studied, focusing on their terminal group symmetries. Utilizing grazing‐incidence wide‐angle X‐ray scattering, the distinct crystalline packing structure of these NFAs is revealed. Remarkably, NFAs with asymmetric terminals exhibited excellent additive insensitivity and thermal stability for their crystalline structure, unlike their symmetric counterparts. Molecular dynamics simulations confirmed the stable and robust crystalline feature of asymmetric NFAs and attributed to their large molecular dipole moments. These findings showed the great potential of asymmetric NFAs in fabricating efficient and intrinsically stable additive‐free OSC devices for real applications.

A novel digitonin/graphene oxide/iron oxide nanocomposite: synthesis, physiochemical characterization and antioxidant activity.

In this work, iron oxide (Fe3O4) magnetic nanoparticles (MNPs) and graphene oxide (GO) nanosheets were prepared via the co-precipitation technique and the Modified Hummer method. Fe3O4 MNPs and GO nanosheets were combined to prepare Fe3O4/GO nanocomposite and subsequently conjugated with Digitonin (DIG) in order to obtain a dual-targeted delivery system based on DIG/Fe3O4/GO nanocomposite. SEM images reveal the presence of Fe3O4 MNPs at a scale of 100nm, exhibiting dispersion between the GO nanosheets. Aggregation of the DIG/Fe3O4/GO nanocomposite was observed at various size scales. The XRD structural analysis confirms the crystal structure of the prepared samples. The Fe3O4 MNPs demonstrated the main XRD-diffracted peaks. Also, GO nanosheets exhibit crystalline characteristics on the (001) and (002) planes. The predominant peaks observed in the DIG/GO/Fe3O4 nanocomposite are attributed to the crystal phases of Fe3O4 MNPs. The FT-IR vibrational modes observed in the GO/DIG/Fe3O4 nanocomposite indicate the presence of crosslinking between GO nanosheet layers and the Fe3O4 MNPs. The antioxidant activity of the prepared samples was measured and the DIG/GO/Fe3O4 nanocomposite demonstrated a significantly high antioxidant activity in both 2-diphenyl-1-picrylhydrazyl (DPPH·) and 2,2-azino-bis-3-ethylbenzthiazoline-6-sulfonic acid (ABTS·+) tests.