Stainless steel components are widely used in engineering applications but remain vulnerable to corrosion and surface degradation in chloride-containing and pH-fluctuating environments. Conventional hydrophobic coatings often exhibit limited durability and insufficient interfacial stability. In this work, a modifier-free Cu-based hydrophobic coating was fabricated on laser-textured stainless steel microarrays using stepwise current-density electrodeposition. Unlike conventional hydrophobic metallic surfaces relying on low-surface-energy modification, this study regulates Cu growth by redistributing current-density history under the same nominal total charge input. The optimized coating formed a compact deposited Cu layer with balanced microarray geometry, showing an apparent Cu-cap thickness of 30.5 ± 1.5 μm and a pillar-top diameter of 100.8 ± 2.2 μm. It exhibited a water contact angle of 146.5° ± 0.9°, roll-off angle of 18.2° ± 1.1°, and apparent Vickers hardness of 91.8 ± 1.5 HV. Electrochemical tests in 3.5 wt% NaCl showed a corrosion current density of 1.07 ± 0.09 μA cm−2 and charge-transfer resistance of 18.3 ± 1.4 kΩ cm2. Short-term immersion in acidic, alkaline, and neutral chloride media, combined with EDS and Cu ion analysis, confirmed reduced surface degradation and Cu dissolution. After 60 days in NaCl, the coating retained measurable impedance response and partial hydrophobicity despite gradual Cu release and wetting degradation. The stepwise strategy provides a route for balancing wettability, mechanical integrity, and improved corrosion-related response under tested conditions.

Steel materials in marine environments are prone to coupled corrosion and wear during long-term service, which limits their durability. In this study, Cu/Ni layered micro-reentrant coatings were fabricated on laser-textured stainless steel by electrodeposition, and the effect of Ni deposition current density on microstructure and performance was investigated. The coating prepared at 0.03 A/cm2 exhibited a uniform and compact hierarchical micro/nano-structure, with an apparent Ni-related axial thickness increment of 11.0 mu m at the pillar tops. This coating showed a Vickers hardness of 187.8 HV, a water contact angle of 158 degrees f 1 degrees, and a roll-off angle of 4.5 degrees f 1.1 degrees. After reciprocating abrasion against 3000# abrasive paper under a 2 g load for 20 cycles, the coating retained 99.6% of its pillar height, with a height loss of 1.2 mu m, indicating better structural retention than coatings prepared at 0.015, 0.05, and 0.07 A/cm2. Electrochemical measurements of the as-prepared samples showed that the 0.03 A/cm2 coating exhibited a nobler corrosion potential, lower corrosion current density, and higher impedance response than the other Cu/Ni layered coatings. After immersion in acidic, alkaline, and neutral saline solutions, this coating retained relatively stable morphology and protective performance. After 60 days of immersion in 3.5 wt% NaCl, it maintained structural integrity and superhydrophobicity, with a contact angle of 152 degrees f 2 degrees and a roll-off angle of 9.2 degrees f 1.6 degrees. This work demonstrates that current-density-regulated Ni deposition enables the synergistic optimization of surface structure, mechanical stability, corrosion resistance, and long-term superhydrophobic durability.

Uncontrollable localized corrosion restricts the application of biodegradable magnesium alloys in biodegradable implants. This work designs a magnesium alloy with homogeneous degradation rate via potential gradient fabrication. A continuous potential gradient is built from the outer Zn-Zr layer to the inner pure Mg layer with a potential difference of 0.108 V, and it is enlarged to 0.26 V after solution treatment. The alloy exhibits significantly improved corrosion resistance with typical gradient corrosion morphology and a distinct interfacial buffering effect. The synergistic composition-potential gradient enables controllable unidirectional corrosion, offering a new strategy for producing biodegradable magnesium devices with durable functionality.

Magnesium-zinc (Mg-Zn) alloys have attracted considerable attention as implant materials due to their inherent biodegradability. Herein, we evaluate their performance in the acidic urinary environment characteristic of renal tubular acidosis (RTA). To this end, the corrosion response, degradation performance, and mechanical properties of Mg-xZn alloys with different zinc contents were examined in artificial urine (pH 5.7) designed to mimic RTA conditions. Relative to pure Mg, the Mg-6Zn alloy demonstrated a 2.35 times higher hardness and a 2.58 times higher ultimate tensile strength (UTS), reflecting substantial mechanical reinforcement. Initial immersion tests indicated that corrosion severity first decreased and then increased with higher Zn content. After 30 days, although the overall degradation of Mg-Zn alloys was greater than that of pure Mg, a reduced susceptibility to pitting corrosion was observed. Furthermore, the alloys maintained a UTS above 148.9 MPa and an elongation of 3.17 %, confirming preservation of essential mechanical integrity during degradation. These results highlight the potential of Mg-Zn alloys as functional biodegradable materials and provide insights for the design of next-generation magnesium-based bioresorbable implants.

The anti-inflammatory effects of plant polysaccharides are well known. However, the stimulatory effects of polysaccharides under immunosuppressive conditions and their link with the polysaccharide structure is underexplored. In this work, the immune modulatory effects of a garlic polysaccharide (GP) are investigated via in vitro and vivo methods. It is observed that GP enhance the immune response of macrophages (RAW264.7) as indicated by the elevated levels of nitric oxide, TNF-α and IL-6. The observation that GP are able to stimulate the immune response in vitro was then explored with the use of an immunosuppressed mouse model. Surprisingly, GP exhibited dose-dependent up-regulatory impacts on the cyclophosphamide (CTX) suppressed levels of cytokines such as IFN-γ and IL-6 and immunoglobulins (e.g. IgA and IgG). The GP intervention reversed histopathological damage to the small intestine and spleen and increased fecal short-chain fatty acid levels. Moreover, GP modulates the gut microbiota dysbiosis by increasing the abundance of immunogenic bacteria such as g__norank_f__Erysipelotrichaceae, while inhibiting the over-abundance of g_Bacteroides. Functional predictions indicated that gut biomarkers of GP possessed the functions of glycoside hydrolase family 32 (GH32) and β-fructofuranosidase. It is concluded that GP is a promising immunostimulant for immune-compromised individuals.

Correctly torquing bone screws is important to achieve good patient outcomes. An automated system has been previously proposed that may allow more objective torquing of bone screws. Here the system is tested vs. a static torque limit in pig bone. 5 screws were first inserted until stripping to calibrate the dynamic and static limits. Then 6 were inserted limited to 80% of the mean stripping torque. Then 7 were inserted using 80% of the dynamic model-predicted stripping torque. The pull-out strength of the dynamic and static insertions were compared and no statistically significant difference was found. Future work should consider at using larger screws and different bone samples, with more repetitions to try and obtain a statistically significant result.

Metallic biomedical implants based on magnesium, zinc and iron alloys have emerged as bioresorbable alternatives to permanent orthopaedic implants over the last two decades. The corrosion rate of biodegradable metals plays a critical role in controlling the compatibility and functionality of the device in vivo. The broader adoption of biodegradable metals in orthopaedic applications depends on developing in vitro methods that accurately predict the biodegradation behaviour in vivo. However, the physiological environment is a highly complex corrosion environment to replicate in the laboratory, making the in vitro-to-in vivo translation of results very challenging. Accordingly, the results from in vitro corrosion tests fail to provide a complete schema of the biodegradation behaviour of the metal in vivo. In silico approach based on computer simulations aim to bridge the observed differences between experiments performed in vitro and vivo. A critical review of the state-of-the-art of computational modelling techniques for predicting the corrosion behaviour of magnesium alloy as a biodegradable metal is presented.

The effects of fibre orientation and laminate stacking sequence on the mechanical anisotropy of paper-based all cellulose composites produced via a partial dissolution route is examined. As part of this work, the fibre architecture and microstructure of the paper precursor is controlled and characterised in order to follow the anisotropy of the materials through from precursor to final composite material. The fibre orientation of the precursor was found to strongly influence the mechanical anisotropy of the final composite material. The ultimate tensile strength and Young's modulus of the paper-based all-cellulose composite laminates was 191 MPa and 17.5 GPa in the fibre direction, respectively, compared with 104 MPa and 10.4 GPa in the transverse direction, respectively. The ACC crystal structure was assessed with powder and transmission mode Wide-angle Xray diffraction (WAXD) to measure the changes in crystallinity and crystal orientation due to the dissolution process. The mechanical response of multi-axial all-cellulose composite laminates was also determined experimentally and compared with analytical predictions by Classical Lamination Theory, demonstrating the utility of CLT for the prediction of the elastic properties of ACC laminates.

Mg-Ca-TiO2 (MCT) composite scaffolds loaded with different concentrations of doxycycline (DC) with a network of interconnected pores with good compressive strength (5 ± 0.1 MPa) were fabricated via space holder method for the first time. The results showed that MCT-DC scaffolds possess a porosity and pore size in the range of 65–67% and 600–800 μm respectively. The bioactivity results exhibited the apatite formation on the MCT-DC scaffold surface, indicating that DC did not obstruct the bioactivity of MCT. The MCT-DC scaffolds drug release profiles show the initial burst and sustained drug release (55–75%) and the release rate could be adjusted via altering the DC concentration. The MCT loaded with 1 and 5% DC did not indicate cytotoxic behavior against MG63 cells while further DC loading resulted in some toxicity. Antimicrobial properties of MCT-DC scaffolds against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacteria were examined and the results reveal oblivious inhibition zone around each MCT-DC scaffold whereas no obvious inhibition is observed around the MCT scaffold. Therefore, MCT-DC composite scaffolds with low concentration of DC could be alternative candidates for infection prevention and bone tissue engineering.

Molecular Dynamics simulations were used to investigate the effects of absorbed water on interfacial adhesion in an epoxy glass composite. The composite comprised SiO2 fibres, gamma-Aminopropyltriethoxysilane (AMPTES) fibre sizing, and a diglycidyl ether bisphenol A (DGEBA)/isophorone diamine (IPD) epoxy matrix. An average solubility limit of 2.07 wt.% water was found in the simulated system, equivalent to 0.99 wt.% water in a full composite, while an experimental value of 1.15 wt.% was determined. The work of adhesion was calculated for simulated composites and compared to experimental tensile strength in unidirectional composites. Results for both dry and saturated conditions indicated SiO2-sizing as the critical interface for failure. Scanning electron microscopy of failed composites suggests more cohesive failures in the epoxy for the dry samples, while relatively clean fibre surfaces in the saturated samples indicate adhesive failure at the interface. This study shows how molecular simulation can be applied to sized fibre-reinforced composites.

It has been proposed that hydrogen bonding plays a role in promoting the electrospinnability of some materials. In this study, the role of non-covalent interactions in the electrospinnability of 2-hydroxypropyl-β-cyclodextrin (2HP-β-CD) was investigated by varying the physical-chemical properties the solvents. The rheological behaviour of a peroxide-aqueous/acetone-ethanol/NaHCO3 solution and an aqueous urea solution, as a function of aqueous 2HP-β-CD concentration, was compared. The rheological behaviour of 2HP-β-CD solutions was characterized by a frequency-independent stress relaxation plateau such as that observed in cross-linked polymer networks and reversible polymer gels with non-linear viscoelasticity. We conclude that the electrospinnability of 2HP-β-CD is, as evidenced by the changes in the morphology of the electrospun 2HP-β-CD materials, in agreement with other related studies on the electrospinning of Cyclodextrins. Also, the electrospinnability of 2HP-β-CD does appear to be related to the physical-chemical properties of the solvent systems (

In this work, the properties of cellulose (CE)/xyloglucan (XG) biopolymer blends are investigated, taking inspiration from the outstanding mechanical properties of plant cell walls. CE and XG were first co-solubilized in an ionic liquid, 1-ethyl-3-methylimidazolium acetate, in order to blend these biopolymers with a varying CE:XG ratio. The biopolymers were then regenerated together using water to produce solid blends in the form of films. Water-soluble XG persisted in the films following regeneration in water, indicating an attractive interaction between the CE and XG. The final CE:XG ratio of the blends was close to the initial value in solutions, further suggesting that intimate mixing takes place between CE and XG. The resulting CE/XG films were found to be free of ionic liquid, transparent and with no evidence of phase separation at the micron scale. The mechanical properties of the blend with a CE:XG ratio close to one revealed a synergistic effect for which a maximum in the elongation and stress at break was observed in combination with a high elastic modulus. Atomic force microscopy indicates a co-continuous nanostructure for this composition. It is proposed that the non-monotonous variation of the mechanical performance of the films with XG content is due to this observed nanostructuration.

It has been proposed that hydrogen bonding plays a role in promoting the electrospinnability of some materials. In this work, the significance of non-covalent interactions in the electrospinnability of aqueous sugar solutions (i.e. mono- and disaccharide) was investigated as a function of carbohydrate concentration. The electrospinnability of concentrated aqueous solutions of glucose, fructose, and sucrose was studied by physicochemical and rheological characterization methods, and by subsequently examining the resulting morphology via scanning electron microscopy. The results on the electrospinning of concentrated saccharide solutions indicated the significance of non-covalent interactions on the electrospinning of these systems. Electro-spinnability models based on critical concentration and visco-elasto capillary theories were compared with the experimental results. It is shown that visco-elasto capillary theory has the closest correlation with the experimental data. The electrospinnability of highly concentrated saccharide solutions appears to be directly related to the density and intermolecular bonding capacity of the solution.

In this work, a hybrid dual layer surface coating consisting of a silicon (Si) underlayer and poly(ε-caprolactone) (PCL) overlayer was investigated that was designed to reduce the corrosion rates of magnesium-based biomaterials. The Si underlayer was 1.2μm thick and composed of spherical nanoparticles. The overlayer of PCL was 75.2μm thick and comprised network of pores. Corrosion-induced reduction of the compressive strength of a Si/PCL-coated Mg–Ca–Bi alloy was lower than that of the uncoated or Si layer-coated alloys. However, the bonding strength of the Si coating (24.6MPa) was significantly higher than that of the Si/PCL-coated samples (6.8MPa). The Si/PCL coating dramatically enhances the charge transfer resistance of the Mg alloy (2.11kΩcm2) in simulated body fluid when compared with a Si-coated sample (2265.12kΩcm2). Si/PCL coatings are considered a promising route to control the corrosion rate and mechanical properties of Mg-based biomaterials.

A growing interest in biocomposites leads to the extension of commonly used three-dimensional braiding processes for composite preforming to cellulose-based fibres. A rayon fibre (Cordenka™) is processed on an Institut für Textiltechnik 3D rotary braiding machine, generally used for the processing of stronger and stiffer glass and carbon fibres. A rectangular profile was produced from 32 yarns and the braiding angle of the yarn was analysed. Analysis of the fibre tensile properties during the different processing steps revealed only a minor reduction in fibre strain. The fibre strength and Young’s modulus were unaffected by the braiding process showing that 3D rotary braiding can be extended to biobased fibres without any required changes.

This study presents molecular dynamics (MD) simulation methods for determining the solubility limit of water in a crosslinked epoxy network. Procedures are first presented for dynamically crosslinking an epoxy network consisting of diglycidyl ether bisphenol a (DGEBA) and isophorone diamine (IPD). Water molecules are then introduced into the crosslinked DGEBA-IPD structure. The excess chemical potential for the absorbed water was determined through combining thermodynamic integration and Widom's test particle insertion methods. The limiting moisture uptake of the epoxy structure was determined through comparing the reduced chemical potential of the water held within the epoxy to that of pure water. The DGEBA-IPD epoxy system was found to have a moisture solubility of 3.50-3.75 wt.% when immersed in water at 300 K.

Negative size effects are commonly reported for advanced composite materials where the strength of the material decreases with increasing volume of the test specimen. In this work, the effect of increasing specimen volume on the mechanical properties of all-cellulose composites is examined by varying the laminate thickness. A positive size effect is observed in all-cellulose composite laminates as demonstrated by a 32.8% increase in tensile strength as the laminate thickness is increased by 7 times. The damage evolution in all-cellulose composite laminates was examined as a function of the tensile strain. Enhanced damage tolerance concomitant with increasing specimen volume is associated with damage accumulation due to transverse cracking and strain delocalisation. A transition from low-strain failure to tough and high-strain failure is observed as the laminate thickness is increased. Simultaneously, scale effects lead to an increase in the void content and cellulose crystallinity at the core, with increasing laminate thickness.

All-cellulose composites are high performing green materials and solvent infusion processing makes their upscaled manufacturing possible. This study explored the use of aqueous 7wt.% NaOH/12wt.% urea solution as cost effective and environmentally friendly cellulose solvent for solvent infusion processing. A short dissolution time of 5min led to all-cellulose composite laminates with a tensile strength of 114±1.9MPa and a Young’s modulus of 7.8±0.5GPa. A decrease of tensile strength and Young’s modulus with increasing dissolution time from 5 to 60min was linked to changes in composite microstructure and fine structure of the reinforcing rayon fibres. It was shown that aqueous NaOH/urea solution is a promising alternative solvent, as it offers the advantages of shorter processing times and reduced solvent costs by 97%, while resulting in 25% stronger laminates, when compared to using ionic liquids.