Bulletin of Materials Science最新文献

(1−x)BiFeO₃–(x)Pb(Fe_2/3W_1/3)O₃ ceramics (x = 0.00–0.30) were synthesized by a solid-state reaction route. Structural characterization was done by X-ray diffraction and Raman spectroscopic studies. Existence of rhombohedral symmetry with the (R3c) space group up to x ≤ 0.20 and a transition to cubic symmetry with the (Pmoverline{3 }m) space group for x > 0.25, confirmed with Rietveld refinement. Raman studies also confirm the significant modification at the A-site due to the replacement of Bi³⁺ atom by Pb²⁺ indicating the structural modification in Pb(Fe_2/3W_1/3)O₃ (PFW) in BiFeO₃ (BFO). Morphology and microstructure were observed using SEM micrographs and the average grain size was decreased with the increase in PFW concentration (x). Enhanced magnetic and ferroelectric properties were observed up to x ≤ 0.20, which can be attributed to the suppression of spin-canted structure and reduced leakage currents. Hence, BFO–PFW solid ceramics, with a limited low composition region, can be useful for magneto-electric device applications.

Nowadays, an economically cheaper, NIR fluorescent probe is needed in order to identify the cancerous cells without skin cells damage. For this purpose, conventional conducting polymers are used. Under N₂ environment, the chemical polymerization of o-chloroaniline (OCA) was initiated by peroxydisulphate (PDS) with the help of rosebengal (RB) dye, both in the presence and absence of a 3% weight loading of Ag⁺ ion. The weight of the polymer was used to calculate the rate of polymerization (R_p) and yield percentage. Additionally, FTIR, UV–visible, fluorescence emission, thermogravimetric analysis, scanning electron microscopy and differential scanning calorimetry were used to analyse the poly(o-chloroaniline) (POCA) structure–property relationship. The FTIR spectrum confirmed the presence of benzenoid and quinonoid structures in POCA chains. The percentage yield and R_p both marginally increased in the presence of Ag⁺ ions. The T_g of RB end-capped POCA/Ag nanocomposite system was determined as 103°C. The energy of activation (E_a) value of 66.17 kJ mol⁻¹ was found for the structural degradation of RB in RB end-capped POCA. In comparison to the straightforward RB end-capped POCA system, the POCA/Ag^o nanocomposite system has higher thermodynamic parameter values. The experimental findings are thoroughly examined and contrasted with the values given in the literature.

We developed a facile synthetic method to construct a novel sandwiched coaxial core–shell heterojunction electrode by combining MnO₂ nanoflakes wrapped in Au nanoparticles decorated NiCo₂O₄ nanowires (NW) with carbon fiber cloth (NiCo₂O₄@Au@MnO₂). XRD, SEM and TEM techniques were used to characterize the structures of NiCo₂O₄@Au@MnO₂. Electrochemical measurements confirmed that such nanostructured composites possessed an electrochemical capacitance that was higher than that of each individual component due to synergistic effects. The NiCo₂O₄@Au@MnO₂ electrode has extremely high specific capacitance (1906.6 F g⁻¹ at 1 A g⁻¹) and excellent cycling stability (92.5% after 10,000 cycles) in a three-electrode system with 6M KOH electrolyte. Furthermore, the performance of an asymmetric supercapacitor of NiCo₂O₄@Au@MnO₂//AC was further evaluated, and the energy density was 98.3 Wh kg⁻¹ at a power density of 0.8 W kg⁻¹. The excellent electrochemical performance of such nanoscale architecture electrodes provides a new route for developing high-performance supercapacitors with 3D multicomponent heterojunction core-shell structures.

Through a simple grinding procedure, MIL-53Fe@PDI, a novel Z-scheme photocatalytic material, was synthesized. MIL-53Fe showed minimal photocatalytic activity under visible light for the degradation of doxycycline hydrochloride. Upon composite formation with PDI (perylene-3,4,9,10-tetracarboxylic diimide), the photocatalytic performance of MIL-53Fe significantly improved. The improvement was credited to the effective separation of carriers enabled by the Z-scheme heterojunction of MIL-53Fe@PDI, which hinders the recombination of electrons and holes generated by light. MIL-53Fe@PDI was utilized to enhance the breakdown effectiveness of doxycycline hydrochloride by triggering peroxymonosulphate in the presence of visible light. Thorough examinations were carried out to analyse how the amount of peroxymonosulphate, the concentration of doxycycline hydrochloride, various inorganic anions, and natural organic matter impact the activation of peroxymonosulphate for the degradation of doxycycline hydrochloride. Experiments involving radical quenching and analysis using electron paramagnetic resonance verified the activation mechanism of MIL-53Fe@PDI with peroxymonosulphate, indicating the significant involvement of sulphate and superoxide radicals in the degradation of doxycycline hydrochloride. Predictions of potential susceptible locations and routes of doxycycline hydrochloride were made using density functional theory calculations utilizing the Fukui function and UPLC-MS. Toxicity Estimation Software Tool indicated a gradual reduction in toxicity during the degradation of doxycycline hydrochloride. This study presents an effective and environmentally friendly approach for treating antibiotic wastewater.

Chronic wounds characterized by prolonged inflammation and persistent infection pose a significant burden to global healthcare systems. Currently, antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs) are administered to patients. Prolonged use of antibiotics is severely discouraged owing to the rapid rise in antimicrobial resistance, and the use of NSAIDs can also increase the risk of infection. Thus, the discovery of novel therapeutics for chronic wounds is crucial. Antimicrobial peptides (AMPs) are an emerging class of therapeutics, which are effective and has no known mechanism of inducing resistance. Anti-inflammatory peptides (AIPs) are another class of therapeutic peptides that can reduce inflammation by eliciting anti-inflammatory cytokine response. A single peptide possessing both AMP and AIP activities can be an ideal therapeutic for the treatment of chronic wounds. However, the discovery of peptides with multiple properties via experimental testing is a daunting task. In this work, we propose a classification framework using machine learning for the identification of wound healing peptides (WHPs) i.e., which possess both AMP and AIP activities. The proposed framework uses XGBoost algorithm with amino-acid composition, sequence analysis and physicochemical properties as feature representation methods (FRMs) to develop binary classifiers. The model developed by combining all the three FRMs, resulted in the highest accuracy of 93.3 and 76.2% for AMP and AIP classifications, respectively. An easy-to-use freely accessible web tool (WHP-Pred) has also been developed.

In recent decades, massive exudation of heavy metals into natural water bodies has become prevalent world wide, posing threat to the environment, individuals and their well-being. Owing to its prolonged half-life and non-biodegradability, potential accumulation of heavy metals can cause serious health problems. Several cutting-edge diagnostic methods are being utilized for the assay of heavy/toxic metals. Certainly, these methods hold some limitations, such as requirement for extortionate devices and strenuous operations that can only be carried out in laboratories. This led to the emergence of detection methods based on sensors. Among various breakthroughs, paper-based analytical devices as well as paper-based microfluidic devices have turned up as one of the economical, convenient, easily disposable and portable substitutes for on-site detection. This study discusses the current analytical methods and paper-based devices used for heavy metal detection in the first phase followed by the discussion on comparative analysis of various analytical methods. In addition, there are techniques for heavy metal detection, which use substrates like paper, polydimethylsiloxane, etc. using colorimetric, fluorescence or electrochemical sensing, have also been discussed. The development of programmable paper-based microfluidic devices has been emphasized in the second phase of the discussion. Finally, the future progressions and developments in this field have also been proposed.

Heat conduction plays a vital role in the performance and durability of any component. A wide range of applications are available that demand a good heat conduction ability. The property used to understand the heat conduction behaviour in a solid is called effective thermal conductivity (K_eff). It is recommended to reinforce an adequate amount of filler material in the matrix to increase the K_eff of the composite. The current study used carbon black (CB) particulates, a by-product of waste tyre pyrolysis, as the reinforcing agent in the epoxy resin. The composites are prepared by solution casting method with different volume % of filler. To study the thermal behaviour of samples, effective thermal conductivity, glass transition temperature (T_g) and co-efficient thermal expansion (CTE) are measured as a function of vol.% of filler. After plotting the experimental results, it is noticed that the K_eff and T_g are increased and CTE is decreased with an increase in vol.% of CB. The percolation threshold is also calculated from the K_eff vs. vol.% curve. Various mathematical models are incorporated to verify the experimental results of effective thermal conductivity. A finite element method (FEM) based numerical model is also developed to study the thermal conductivity behaviour of composites. ANSYS MECHANICIAL APDL is used for the FEM analysis. The FEM results showed a marginal variation from experimental data at 0.99 vol.% of CB. The reason behind this is the formation of voids during sample making, the effect of which is not taken in FEM.

Al–Si-based alloys are widely used in the automobile and aerospace industries, whereas high entropy alloys have emerged with many attractive properties. In this study, AlCoCrFeNi high entropy alloy (HEA) is employed to improve the properties of AlSi10Mg alloy through a metal matrix composite approach. Metal matrix composite powder mixture was sintered at 500°C using a hot press at a pressure of 50 MPa. HEA phase was found to be distributed uniformly. An increase of 20 and 40% in hardness and compressive strength were observed by reinforcing HEA in AlSi10Mg alloy.

The present work investigates electrochemical oxidation of chlorine using cobalt oxide (Co₃O₄) nanoparticles synthesized through a co-precipitation method, resulting in a cubic lattice structure with space group Fd-3m (227). This study demonstrates that Co₃O₄ nanoparticles exhibit superior performance compared to noble electrocatalysts in chlorine evolution reactions (CERs). Key electrocatalytic parameters were optimized, with Co₃O₄ achieving an overpotential of 120 mV at a current density of 10 mA cm⁻², a Tafel slope of 112 mV d⁻¹ and a charge transfer resistance of 9.6 Ω. Additionally, wettability results revealed that cobalt oxide possesses minimal hydrophobicity, which helps in faster chlorine evolution process. We believe, this study provides valuable addition in understanding the designing of effective electrocatalysts for CER.