RSC Advances最新文献

The attachment and colonization of proteins and bacteria on the surface of implantable medical materials can lead to biofilm formation, which in turn promotes inflammation and increases the treatment burden. This study developed a hydrophilic coating with excellent adhesion and antifouling lubrication properties, by exploiting the adhesive capability of tannic acid (TA) and the antifouling zwitterionic polymer. TA–Fe³⁺ complex via coordination interactions formed a thin layer on the surface of polyethylene terephthalate (PET) and then poly(ethylenimine)-g-sulfobetaine methacrylate (PEI-g-SBMA) underwent a Schiff-base reaction with the TA layer, allowing the zwitterionic copolymer to be anchored onto the PET surface. Elemental and morphological surface analyses successfully confirmed the deposition of TA–Fe³⁺ complex and PEI-g-SBMA onto the surfaces. Water contact angle and friction coefficient tests indicated an improvement in the hydrophilic and lubricating properties of the surface after modification. Importantly, the modified surfaces exhibited a significant reduction in the adsorption of bovine serum albumin (BSA), demonstrating the excellent antifouling ability. Hemolysis tests were also conducted to assess the hemocompatibility of the coatings. The results indicated that lubricative and antifouling coatings can be easily prepared on medical material surfaces using the approach, which showed significant potential for applications in biomedical fields.

The rapid advancement of antibacterial nanostructured surfaces indicates that they will soon be integrated into real-world applications. However, despite notable progress, a comprehensive understanding of the antibacterial properties of nanostructures remains elusive, posing a critical barrier to the translation of this in vitro technology into practical applications. Among the numerous antibacterial nanostructures developed, nanowire structures play an important role due to their enhanced efficacy against bacteria and viruses and their ease of fabrication. Antibacterial nanowire structures exhibit the dual capability of lysing bacteria upon surface adhesion and mitigating bacterial colonization. The interplay of surface energy significantly influences bacterial adhesion, and macro surface roughness appears to be a pivotal determining factor. Macro-scale surface roughness not only modulates surface energy but also results in micro-scale topographical features that impact the bactericidal efficacy of nanowire structures. The integration of nanofabrication techniques on surfaces with macro-scale roughness yields multi-hierarchical micro- and nanoscale features, thereby possibly amplifying the bactericidal effect. Pseudomonas aeruginosa is an opportunistic pathogen that can cause serious infections. Moreover, this species has a higher risk of developing antibiotic resistance, which makes treatments for infections extremely difficult. Nanowire structures have demonstrated higher efficacy against P. aeruginosa species, making it a good alternative for fighting P. aeruginosa infections. This study demonstrates that heightened surface roughness amplifies the bactericidal potency of nanowire structures against P. aeruginosa bacterial species. The bactericidal effect reaches its maximum when the average surface roughness value is close to the bacterial cell size. This is contrary to the conventional assumption that the substrate surface must be smooth for the nanostructures to work, as the nanowire structures exhibit robust bactericidal efficacy, even when fabricated on rough surfaces. Therefore, the applicability of bactericidal nanostructures is expanded beyond smooth substrates. Consequently, these nanostructures can be effectively deployed on rugged industrial surfaces, broadening their potential impact across a diverse array of sectors. The widespread adoption of this nanotechnology promises transformative benefits not only to the medical sector but also to various industries. Moreover, by curbing bacterial infections, nanostructured surfaces hold the potential to reduce mortality rates and yield more direct economic dividends through waste reduction and enhanced safety. Ultimately, the widespread implementation of antibacterial nanowire technology stands poised to improve societal well-being and quality of life.

This work systematically investigated the relationship between the microstructure, and mechanical and magnetic properties of FeCoNiAl_0.75Nb_0.25 high-entropy alloy. Our results indicated that the microstructure of the alloy comprised a BCC solid solution phase along with a eutectic mixture of FCC and intermetallic phases. The application of heat treatment resulted in a significant evolution of the microstructure. The precipitation of the needle-like intermetallic phase occurred rapidly with increasing annealing temperature, reaching a maximum proportion at 825 °C, and decreased quickly upon further increase to 1000 °C. Correspondingly, the hardness and compressive yield strength of the alloy increased rapidly, attaining maximum values of approximately 600 HV and 2000 MPa, respectively. However, the precipitation adversely affected magnetic properties. The best values in the as-cast state for saturation magnetization, and coercive force are 0.67 T and 716 A m⁻¹, respectively, while the hardness remains 493 HV. Therefore, it is very suitable for magnetic parts requiring superior mechanical properties.

In mechanoluminescence stress sensors, understanding the relationship between light emission performance and sensor structural stability is crucial to ensure the accuracy, sensitivity, and reliability of stress sensing during operation. Any minor structural damage or debonding at the particle–epoxy interface will reduce stress transfer capacity and hamper the light emission from SAOED particles. Instead of replacing the sensors with reduced light emission performance, self-healing epoxy vitrimers can open up new opportunities for recovering mechanoluminescence, offering durable and environmentally friendly high-performance stress sensors. This study investigates two epoxy vitrimer systems for ML stress sensors compared to commercial epoxy. Siloxane bond exchange-based ML stress sensors are found to be promising in terms of light intensity, stress sensitivity, and ML recovery. Exposing sensors to a thermal treatment revealed an increase in light intensity, which is associated with a temperature effect on SAOED particles and self-healing bond exchange in dynamic epoxy networks.

Cellulose nanocrystals (CNC) are widely used due to their biodegradability, high strength, large surface area, and functional versatility. This study investigates the interaction between CNC and acrylate emulsions, which mainly focuses on their impact on emulsion characteristics, polymerization behaviour, and storage stability. CNC was incorporated into an acrylate miniemulsion system at varying concentrations, followed by the systematic study of its effects on particle size, interfacial tension, zeta potential, yield, and viscosity. The morphology of CNC-acrylate systems was analysed using infrared spectroscopy and scanning electron microscopy (SEM). The results demonstrated that CNC effectively co-stabilized acrylate miniemulsions and enhanced their stability before polymerization. Although CNC did not directly participate in polymerization or affect yield or reaction rates, it slowed the diffusion of free radicals. However, CNC concentrations higher than 1 wt% negatively impacted post-polymerization storage stability and caused aggregation of droplets. These findings reveal the dual role of CNC as both a stabilizing and aggregating agent, offering new insights into its potential for the design of advanced polymer systems.

Monotherapy in diabetes management is losing interest due to its ineffectiveness in achieving optimal glycaemic control in a significant proportion of diabetic patients. Therefore, combined therapy is increasingly preferred by clinicians, which offers enhanced effectiveness and a better safety profile for managing the condition. The present work deals with the designing of a dual drug nanocarrier based on MCM-48 and 12-tungtophosphoric acid (TPA) for the co-delivery of Glipizide (GLP) and Metformin Hydrochloride (MTF) as well as its characterization using various techniques. An in vitro release study was carried out at two different pHs (pH 1.2 and pH 7.4) at 37 °C under stirring conditions which was further supported by an in vitro dissolution study carried out using a USP Type II dissolution apparatus. The obtained results were compared with that of the marketed available formulation, Glirum-MF, and the designed nanocarrier showed a better controlled release of both the drugs in comparison with the conventional drug. Additionally, considering the anticancer properties of both the drugs, MTT assay indicated that the carrier is non-toxic while the drug loaded nanocarrier shows apoptosis against HepG2 cells.

Nitrogen-rich metal organic frameworks (MOFs) structures have a great potential for the chemical fixation of CO₂. In this direction, we have utilized the highly efficient nitrogen-rich dual linker MOF of nickel(II) as a heterogeneous catalyst in solvent-free chemical fixation of CO₂ into cyclic carbonates at ambient pressure. In this present work, nitrogen-rich nickel-MOF, Ni-ImzAdn, was synthesized from imidazole and adenine as efficient nitrogen-rich linkers under hydrothermal conditions (Imz = Imidazole and Adn = Adenine). The Ni-ImzAdn was characterized thoroughly via various physicochemical analyses such as FT-IR, SEM, EDX, EDX-mapping, XRD, ICP-OES, BET, BJH, TG-DTA, CO₂-TPD, and NH₃-TPD. Ni-ImzAdn with adequate free nitrogen sites exhibit high catalytic activity in the cycloaddition of CO₂ with styrene oxide (93% yield) at solvent-free and ambient pressure. The high activity of Ni–ImzAdn was attributed to the synergistic effect of strong Lewis acid and strong Lewis base sites on the catalyst, which were acquired by CO₂ and NH₃-TPD respectively. In addition, the MOF catalyst was presented as highly recyclable without significant loss of activity after six reaction cycles and low metal ion leaching (analyzed by (ICP-OES)). Thermogravimetry-differential thermal analysis (TG-DTA) showed the MOF catalyst had high thermal stability up to 318 °C.

Biomass waste from grapefruit peel extract was used for the preparation of MgO–SiO₂ composites in situ in order to develop effective electrocatalytic composites based on NiO/MgO–SiO₂. The MgO–SiO₂ composites were subsequently deposited with NiO using a modified hydrothermal method. The synthesized materials were analyzed to investigate their morphology, crystal structure, chemical composition, functional group, and optical band gap. The structural analysis allowed us to determine the orientation of the nanoparticles, the cubic phase of NiO and MgO, the significant loss of optical band gap, and the enriched functional groups on the surface of NiO/MgO–SiO₂ composites. The electrochemical properties were investigated in the presence of an alkaline solution of KOH. To study the oxygen evolution reaction (OER) in 1 M KOH aqueous solution, different NiO/MgO–SiO₂ composites were investigated. It was found that the NiO/MgO–SiO₂ composite that contained the highest amount of MgO–SiO₂ (sample 3) had a lower overpotential than the NiO/MgO–SiO₂ composite with the lowest amount of MgO–SiO₂. Sample 3 exhibited an overpotential of 230 mV at 10 mA cm⁻² over a period of 40 hours with excellent stability. The superior electrochemical activity of the NiO/MgO–SiO₂ composite (sample 3) was demonstrated in an energy storage device using 3 M KOH aqueous solution, and asymmetric supercapacitor devices were fabricated in 3 M KOH solution. According to the ASC's specifications, a specific capacitance of 344.12 F g⁻¹ and an energy density of 7.31 W h kg⁻¹ were found for the device at a fixed current density of 1.5 A g⁻¹. After over 40 000 galvanic charge–discharge repeatable cycles at 1.5 A g⁻¹, sample 3 of the NiO/MgO–SiO₂ composite exhibited excellent cycling stability with 88.9% percent capacitance retention. During the performance evaluation of the NiO/MgO–SiO₂ composites, grapefruit peel extract was confirmed as a potential biomass waste for the fabrication of high-performance energy conversion and storage devices.

The field of magnetobiology is garnering increasing interest due to its significant contributions across various disciplines, including biotechnology, medicine, and agriculture. Despite experimental evidence indicating the impact of magnetic fields on living organisms, the precise molecular-level effects of these fields remain unclear. Experimental studies of these phenomena at the molecular scale present significant challenges. In this regard, contributions from physics and theoretical chemistry are particularly relevant. However, the computational methodologies developed thus far are unable to incorporate magnetic fields into complex systems such as membrane proteins or biomolecules. In this context, the present work integrates the homogeneous magnetic flux density (B) term into the Verlet velocity algorithm implemented in the GROMACS package. This modification enables molecular dynamics simulations for such systems under the influence of a magnetic field. The implementation has been validated using two model systems: a free ion exposed to B ranging from 80 kT to 1500 kT, and a water box exposed to B between 0 T and 10 T. Furthermore, the stability of a protein was tested under the influence of B ranging from 0 T to 10 kT. The results demonstrated that the systems behaved in accordance with both theoretical and experimental expectations, thereby validating the modification of the algorithm and paving the way for future applications.

Traditional cement-based road materials face problems of high energy consumption and carbon emissions, and the use of activated solid waste as a substitute for cementitious materials has been applied in road engineering. Sludge gasification slag (SGS), a product obtained from the pyrolysis and gasification of sludge, is a typical silicon–aluminum-rich solid waste that exhibits good compatibility with alkaline activation systems due to its potential activity. This study focuses on the component reconstruction mechanism of SGS in alkali-activated materials, employing cement (P) and carbide slag (CS) for synergistic modification, exploring the mechanism for enhancing the cementitious properties of sludge gasification slag under multi-component mixing conditions, and verifying its feasibility for use in cement-stabilized macadam. The results show that GSGS and GCS have a synergistic activation effect in the cement hydration system, promoting the formation of C–(A)–S–H gel and AFt. When both are incorporated in a mass ratio of 6 : 4 and account for 70% of the composite system, the compressive strength is increased by 53.19% compared to alone. When the composite material is used in cement-stabilized macadam with a 40% replacement ratio of cement, there is no significant decrease in strength, verifying the feasibility of using cement-composite sludge gasification slag in cement-stabilized macadam.