Materials Advances最新文献

The incidence of bacterial infections associated with chronic wounds (CWs) has increased in recent years. Thus, a triaxial wet-spun fibrous system (containing three layers) was produced for CW healing. The triaxial fibers were loaded with cinnamon leaf oil (CLO), endowed with high antibacterial, antioxidant and anti-inflammatory features, and an antimicrobial peptide –alanine–alanine–proline–valine (AAPV) – capable of regulating the activity of human neutrophil elastase (HNE; highly expressed during inflammatory processes). To overcome the characteristic high volatility of essential oils (EOs), CLO was loaded at the system's core and blended with polycaprolactone (PCL) which has excellent elasticity and tensile strength. The intermediate layer was composed of sodium alginate (SA) which has high hydration capacity and AAPV. Finally, the shell was made of cellulose acetate (CA), ensuring the system's structural integrity and providing a porous network for the controlled release of AAPV and CLO. This research was divided into two parts, with the present addressing the biological characterization of the system, namely the controlled release of bioactive agents, their antibacterial, antioxidant and cytocompatibility profiles and the peptide-loaded fiber ability to inhibit HNE activity. AAPV-loaded wet-spun fibers attained a sustained release of up to 55% during 24 h of incubation in physiological-like media, also presenting effective HNE inhibition (≈65%). Additionally, CLO-loaded fibers demonstrated a controlled release of up to ≈52% during 24 h of incubation in PBS, reaching higher antibacterial and antioxidant profiles in comparison with the unloaded fibers. Data confirmed the biological potential, safety and suitability of the proposed system for future applications in CW care.

The increasing demand for sustainable and clean energy, driven by the finite supply of fossil fuels, has motivated researchers to explore alternative energy sources. Triboelectric nanogenerators (TENGs) are innovative devices that convert mechanical energy into electrical energy without the use of an external power source. The efficiency of TENG devices relies heavily on the materials employed. Polymeric materials with porous structures have proved particularly effective for TENG applications. Among these, polyurethanes (PUs) stand out as a versatile class of materials with significant potential across various applications, owing to their unique structure–property relationships. Flexible polyurethanes (FPUs) exhibit high elasticity, a three-dimensional pore network, and diverse densities that make them a promising material for energy harvesting applications. This review explores the materials, chemistry, recycling, and limitations of FPUs with a focus on their application in TENG devices. Furthermore, it compares the efficiency of FPUs in TENG devices with compact and other porous materials. The review concludes that FPU is a promising material for TENG devices across a wide range of applications, outperforming compact materials. This is mainly due to several advantages, such as high porosity, high elasticity, lightweight nature, versatility, durability, and cost-effectiveness. In addition, this review presents the future scope for the use of FPU in TENG applications.

A hydrothermally synthesized mesoporous CoFe₂O₄ (CF)/reduced graphene oxide (rGO) nanohybrid (nh) provides the electroactive surfaces and facilitates fast electron transfer between the nanofabricated bioelectrode–electrolyte interfaces, responsible for the high electrocatalytic activity in sensing adrenaline (AD). A promising biosensor for detecting adrenaline and bovine serum albumin (BSA) used as a real sample for diagnosing neurodegenerative diseases is described here. This study focuses on the electrochemical impedance biosensing of AD because of its unique ability to identify various kinds of health issues, including blood pressure, fight-or-flight response, memory loss, multiple sclerosis, Parkinson's disease, and cardiac asthma. A La/CF/rGO/ITO bioelectrode (La: Laccase) is the biosensor component. It is created by electrophoretic deposition (EPD) of a CF/rGO nh and drop-casting immobilization of the La-enzyme. The low charge-transfer resistance (R_ct) of the CF/rGO electrode was sensed by electrochemical impedance spectroscopy (EIS), confirming the synergistic impact of CF/rGO on the La/CF/rGO/ITO fabricated bioelectrode in AD detection. This gives the high heterogeneous rate constant (K_s: 2.83 × 10⁻⁴) and increases the surface adsorption and diffusion coefficient (D: 5.25 × 10⁻² cm² s⁻¹). The proposed biosensor exhibited high sensitivity (0.214 Ω μM⁻¹ cm⁻²), long linear range (1 to 500 μM), lower detection limit (LoD: 40.3 μM), high selectivity (RSD 5.8%), and stability with good recovery %, emphasizing its potential implementation in biosensing techniques for monitoring neurotransmitter disorders in real world applications.

A novel method has been developed for the conversion of multi-walled carbon nanotubes (MWCNTs) into unzipped MWCNTs (UzMWCNT) using a modified Hummer's method followed by reduction. This technique allows for the controlled modification of MWCNTs in both transverse and longitudinal directions. The UzMWCNT exhibits unique structural characteristics that combine the properties of 1D nanotubes and graphene-like features. The UzMWCNT/PPy composite exhibited an impressive specific capacitance of 944 F g⁻¹ along with excellent cycling stability, retaining 92% of its capacitance after 5000 cycles. For the UzMWCNT/PPy//AC composite, the gravimetric capacitance decreased with increasing current density, from 400 F g⁻¹ at 1.0 A g⁻¹ to 162 F g⁻¹ at 2.5 A g⁻¹. Furthermore, the UzMWCNT/PPy//AC composite demonstrated outstanding long-term durability, retaining approximately 95% of its capacitance after 5000 cycles at a current density of 5 A g⁻¹, underscoring its excellent cycling stability. This research paves the way for the development of high-performance supercapacitor electrodes using hybrid materials derived from MWCNTs.

Recent studies have highlighted the promise of MXene-derived titanate nanoribbons (KTNR) as electrode materials for electrochemical sensing applications. This work investigates the electrochemical activity of potassium titanate nanoribbons synthesized from MXene for the development of a voltammetric sensor for ciprofloxacin detection. The sensor offers a sustainable approach for ciprofloxacin quantification, addressing critical needs in food safety, environmental monitoring, and healthcare diagnostics, ultimately contributing to the United Nations’ Sustainable Development Goals by mitigating antimicrobial resistance and supporting the One Health initiative. To initiate the experiments, the structural, stability/energetics, and electronic features of two dimer complexes, KTNR/ciprofloxacin and MXene/ciprofloxacin, had been computationally inspected using two in silico tools, and some important electronic parameters such as binding energy, HOMO–LUMO gap and dipole moment showed that the former one (KTNRs) was significantly more sensitive than the MXene with ciprofloxacin. 2D Ti₃C₂ MXene served as the precursor for the synthesis of potassium titanate nanoribbons. X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), elemental mapping, and energy-dispersive X-ray spectroscopy (EDX) techniques were employed to confirm the crystallinity, surface morphology, and layered structure of the synthesized nanoribbons. Atomic force microscopy (AFM), contact angle measurement and surface profilometry were used to characterize the fabricated electrode surface. The electrochemical and sensing properties of the materials were further evaluated using cyclic voltammetry (CV), differential pulse voltammetry (DPV), and electrochemical impedance spectroscopy (EIS). Subsequently, the nanoribbons were deposited onto a glassy carbon electrode (GCE) surface. The electro-oxidation behaviour of ciprofloxacin was then investigated using CV, DPV, and square wave voltammetry (SWV) in an optimized 0.1 M phosphate buffer solution (pH 8). The developed sensor exhibited a remarkable linear detection range of 0.6 μM (≈0.03 μg mL⁻¹) to 147.2 μM (≈7.18 μg mL⁻¹) for ciprofloxacin. Additionally, the limit of detection (LOD) achieved was 0.07, 0.0608, and 0.0264 μM for CV, DPV, and SWV, respectively. Notably, the electrodes demonstrated excellent selectivity towards ciprofloxacin detection in complex matrices, including marine water, river water, agricultural soil, organic fertilizer, milk, honey, poultry eggs, and simulated body fluids.

Presented in this work is a synthetic approach for metastable Type I Chevrel phase sulfides, MMo₆S₈ (M = Ag, Sn), utilizing rapid microwave-assisted medium temperature intercalation. Using X-ray absorption spectroscopy the electronic structure and local coordination of sulfur and molybdenum bonding environments are probed as a function of a Type I metal intercalant. Intercalant promoter-induced electron donation effects were observed through analysis of the sulfur K-edge pre-edge feature and Mo L₃-edge in the X-ray absorption near edge regions. Calculated electron density maps reveal more covalent interactions between Ag and S atoms versus more ionic interactions between Sn and S. Changes in the Chevrel phase structure upon intercalation are investigated through Mo K-edge extended X-ray absorption fine structure analysis. Evaluation of Mo–Mo intracluster distances allows the cluster anisotropy of Type I CPs to be calculated as low as 1.84%. These findings help elucidate how electronic and local structures can be modulated through intercalation and the importance of cation identity to fine tune structures.

Sterilizing biomaterials before implantation is crucial, but this process can sometimes alter the physical, chemical, and morphological properties of collagen-based biomaterials, potentially leading to weaknesses. To address this issue, we propose a method that combines crosslinking and sterilization of collagen-based composite scaffolds through gamma-ray irradiation. In this study, poly(ε-caprolactone) (PCL)/collagen composite scaffolds were fabricated using an electrospinning technique and exposed to gamma rays at doses ranging from 15 to 45 kGy. The radiation dose was optimized to enhance mechanical properties, which indicated a higher degree of collagen crosslinking. Additionally, we demonstrated that both Gram-positive and Gram-negative bacteria were completely and effectively sterilized during the crosslinking process. In conclusion, gamma-ray irradiation shows great promise as a method for simultaneously inducing crosslinking and sterilization in collagen-based scaffolds, offering substantial potential for biomedical applications.

Herein, hybrid nanocomposite devices based on polyaniline (PANI) nanofibers decorated with gold nanoparticles (Au), as conductive fillers, and atactic polystyrene (aPS), as insulating matrix, were developed. To assess the effect of the PANI and Au synthesis procedure on the electrical behavior of the developed devices, PANI/Au nanosystems were synthesized via two different routes: (1) biphasic synthesis, wherein PANI nanofibers were grown through a biphasic synthesis procedure incorporating 1-dodecanthiol-capped Au (AuDT) nanoparticles, which were previously synthesized and dispersed in the reaction environment; (2) one-pot synthesis, wherein gold nanoparticles were directly reduced, starting with auric salt precursors on the PANI nanofiber surface, which were previously synthesized via a rapid mixing procedure. Thermal stability and the Au/PANI weight ratio were determined using thermogravimetric analysis (TGA). Furthermore, PANI/Au nanosystems were observed using transmission electron microscopy (TEM), revealing that the synthesis route significantly affected the morphology of nanosystems. Electrical characterization showed that aPS/PANI/Au hybrid nanocomposite devices exhibited a typical non-linear current–voltage curve with a closed hysteresis loop, which is a characteristic of memristive behavior. Moreover, devices made with fibers obtained via rapid mixing (PANI RM/Au) exhibited conductivities higher than those produced with fibers from biphasic synthesis (PANI BF/AuDT).

The energy crisis, driven by modern electronics and global warming from population growth, underscores the need for advanced textiles to regulate thermal environments. Researchers stress the need to improve high-performance polymer mats with enhanced thermal conductivity. This report delves into the morphological, mechanical, and thermal properties of exfoliated graphite (EG) when incorporated into polystyrene (PS) fiber mats and yarns through blend electrospinning. The incorporation of EG inside the fibers allowed us to obtain approximately twofold improvement in maximum stress and toughness compared to pristine PS mats. Thermal camera measurement showed significant improvement in heat transport for PS–EG fibers. The heating test showed a temperature increase of ∼2.5 °C for an EG-loaded PS mat, and in the case of a resistance wire coated with a PS fiber yarn, the increase reached 17 °C. The incorporation of EG into electrospun mats enables the recovery of more energy in the form of heat by enhancing the heating of the sample through infrared radiation. The temperature increased by 2 °C for PS and by 27 °C for PS–EG, respectively. The obtained results exhibit a great potential for the application of electrospun hybrid systems with EG in further advancement in the field of next-generation thermal management.