Uncoated Material Research Articles

Inhibition of interfacial reaction and enhancement of mechanical properties of CF/Al composite

The properties of carbon fiber-reinforced aluminum matrix (CF/Al) composite for aerospace applications are often limited by interfacial reactions. In this study, chemical vapor deposition (CVD) was applied to prepare pyrolytic carbon (PyC) coatings with different thicknesses on CF surfaces to reduce the C/Al interfacial reaction and improve the mechanical properties. Liquid-solid infiltration extrusion (LSIE) was used to prepare CF@PyC/Al composite, and the effects of coating thickness on the interfacial microstructure, tensile properties and fracture behavior were investigated. The experimental results showed that the PyC coating enhanced the oxidation resistance of CF, but the toughness and tensile strength of the CF decreased. The coating effectively suppressed the generation of Al4C3 and provided a better quality interface for the composite. Compared with the uncoated CF/Al composite, the tensile strength of the CF@PyC/Al composite was enhanced by 35% at a coating thickness of about 0.23 μm. In addition, the strength and modulus of the coated material behaved more stably at different layup angles, whereas the uncoated material was more sensitive to angle changes. These performance enhancements are mainly attributed to the effective hindrance of Al4C3 production by the coating, which enhances the crack deflection frequency and enhances the energy absorption capacity.

Bioresorbable Polyester Coatings with Antifouling and Antimicrobial Properties for Prevention of Biofilm Formation in Early Stage Infections on Ti6Al4V Hard-Tissue Implants.

Implants made from titanium are used as prostheses because of their biocompatibility and their mechanical properties close to those of human bone. However, the risk of bacterial infection is always a major concern during surgery, and the development of biofilm can make these infections difficult to treat. A promising strategy to mitigate against bacterial infections is the use of antifouling and antimicrobial coatings, where bioresorbable polymers can play an important role due to their controlled degradability and sustained drug release, as well as excellent biocompatibility. In the present study, poly(d,l-lactide) (PDLLA) and poly[d,l-lactide-co-methyl ether poly(ethylene glycol)] (PDLLA-PEG) were studied, varying the PEG content (20-40% w/w) to analyze the effectiveness of PEG as an antifouling molecule. In addition, silver sulfadiazine (AgSD) was used as an additional antimicrobial agent with a concentration ≤5% w/w and incorporated into the PEGylated polymers to create a polymer with both antifouling and antimicrobial properties. Polymers synthesized were applied using spin coating to obtain homogeneous coatings to protect samples made from titanium/aluminum/vanadium (Ti6Al4V). The polymer coatings had a smoothing effect in comparison to that of the uncoated material, decreasing the contact area available for bacterial colonization. It was also noted that PEG addition into the polymeric chain developed amphiphilic materials with a decrease in contact angle from the most hydrophobic (Ti6Al4V) to the most hydrophilic PDLLA-PEG (60/40), highlighting the increase in water uptake contributing to the hydration layer formation, which confers the antifouling effect on the coating. This study demonstrated that the addition of PEG above 20% w/w and AgSD above 1% w/v into the formulation was able to decrease bacterial adherence against clinically relevant biofilm former strains Staphylococcus aureus and Pseudomonas aeruginosa.

Multifunctional surface modification to enhance the electrochemical performance of lithium-rich manganese-based cathode materials

The preparation of high-performance lithium-rich manganese-based cathode materials (LLOs) require attention to the redox of anions and the migration of transition metals (TM) during the cycling process. In this study, Ce ion-doped Li-rich cathode coated with La0.2Ce0.8O2, which has abundant oxygen vacancies on its surface, was prepared. The presence of the oxygen storage material La0.2Ce0.8O2 can effectively absorb the irreversible oxygen generated during cycling, preventing it from reacting with the electrolyte to form thick cathode electrolyte interface (CEI) coatings. These coatings hinder the relative activity of lattice oxygen in the bulk phase, reducing the specific capacity of the material. Additionally, the 5d metal ion Ce carries a large nuclear charge, causing a 'pinning effect' when it integrates into the LLOs structure. This effect reduces thermal oscillation in the lattice, impedes TM migration during battery charging and discharging, and effectively prevents voltage decay. Results indicate that after 100 cycles at 1C and 25 °C, the surface-coated materials maintain a discharge-specific capacity of 194 mAh/g, compared to 158 mAh/g for uncoated material. Voltage decay decreased from 4.4 mV/cycle to 1.8 mV/cycle, with an ICE of 91.5 % versus the original material's 82.8 %. The modified material also exhibits improved rate performance, retaining a specific capacity of 162 mAh/g at 3C, in contrast to the original material's 123 mAh/g.

Orthotic Thermoplastic Demonstrates a Similar Contamination Potential with Bacillus Bacteria Recovered from Thermoplastic Radiation Therapy Patient Masks

Thermoplastics used to construct a variety of patient medical devices can become contaminated by harmful bacteria. We investigated whether two different Bacillus species recovered from patient radiation therapy thermoplastic masks could similarly contaminate thermoplastic material used to construct patient orthoses (splints). Bacillus bacteria form dormant spores, which have been shown to enhance its attachment to thermoplastics. Bacterial attachment and recovery were examined using an orthotic thermoplastic with an anti-stick coating being compared to uncoated material used in radiation therapy applications. Triplicate sample squares were seeded with a saline suspension of either B. cereus (MAB03F) or B. megaterium (DAB01F) containing a similar number of spores. Squares were subsequently sampled at 1 h, 1 week, 2 weeks, 4 weeks, and 8 weeks. The number of recovered bacteria was counted. Differences in material hydrophobicity were determined by water contact angle analysis. Both Bacillus species attached to each material within 1 h, and their spores were recovered at 8 weeks. However, a decreasing trend in adhesion, over time, was noted to the coated material with an opposite increasing trend in the uncoated material. Decreased Bacillus species spore adhesion to coated material with a lower hydrophobicity suggests a greater potential for spore transfer to patients wearing contaminated orthoses.

Comparative study on the synthesis and characterization of Gd2Zr2O7 nanoparticles by mechanical milling and Co-precipitation techniques

Gadolinium Zirconate nanoparticles were synthesized by Co-precipitation and Ball milling techniques. In this study, the effect of the synthesis technique and calcination temperature on the structural, morphological and thermal properties were investigated. The thermal properties examined showed that the GZ nanoparticles obtained from CP technique suffered two-fold weight loss as compared to BM technique. The SEM results revealed the formation of agglomerated particles. However, TEM results confirms the formation of nanoparticles of 10.5 nm and 8 nm by BM and CP techniques respectively. GZ particles obtained through CP technique showed better uniformity of particle size over BM technique. The functional groups of the nanoparticle were studied using FT-IR spectroscopy analysis. The XRD results confirm the formation of defect-fluorite structure and pyrochlore structure for the samples calcined at 1100 °C and 1400 °C (BM) respectively. The formation of the corresponding structures was further confirmed by Raman Spectroscopy. The thermal conductivity of the nanoparticle produced by ball milling and co-precipitation technique is almost same. As compared to NiCrAlY and uncoated substrate materials, the micro hardness of the GZ coatings has the maximum hardness of 594.6 HV, indicating the improved hardness behavior of TBC system.

Enhancing antibacterial properties of titanium implants through a novel Ag-TiO2-OTS nanocomposite coating: a comprehensive study on resist-killing-disintegrate approach

Titanium (Ti) implants are widely used in orthopedic and dental applications due to their excellent biocompatibility and mechanical properties. However, bacterial adhesion and subsequent biofilm formation on implant surfaces pose a significant risk of postoperative infections and complications. Conventional surface modifications often lack long-lasting antibacterial efficacy, necessitating the development of novel coatings with enhanced antimicrobial properties. This study aims to develop a novel Ag-TiO2-OTS (Silver-Titanium dioxide-Octadecyltrichlorosilane, ATO) nanocomposite coating, through a chemical plating method. By employing a ‘resist-killing-disintegrate’ approach, the coating is designed to inhibit bacterial adhesion effectively, and facilitate pollutant removal with lasting effects. Characterization of the coatings was performed using spectroscopy, electron microscopy, and contact angle analysis. Antibacterial efficacy, quantitatively evaluated against E. coli and S. aureus over 168 h, showed a significant reduction in bacterial adhesion by 76.6% and 66.5% respectively, and bacterial removal rates were up to 83.8% and 73.3% in comparison to uncoated Ti-base material. Additionally, antibacterial assays indicated that the ratio of the Lifshitz-van der Waals apolar component to electron donor surface energy components significantly influences bacterial adhesion and removal, underscoring a tunable parameter for optimizing antibacterial surfaces. Biocompatibility assessments with the L929 cell line revealed that the ATO coatings exhibited excellent biocompatibility, with minimal cytotoxicity and no significant impact on cell proliferation or apoptosis. The ATO coatings provided a multi-functionality surface that not only resists bacterial colonization but also possesses self-cleaning capabilities, thereby marking a substantial advancement in the development of antibacterial coatings for medical implants.

Downsizing and coating effects on the electrochemical performance of Mn-doped iron fluorophosphate as cathode material for sodium-ion batteries

Sodium Mn-doped iron fluorophosphate Na2Fe0·5Mn0·5PO4F is a potential positive electrode material for lithium-ion and sodium-ion batteries. This study outlines the synthesis of Na2Fe0·5Mn0·5PO4F powder through a simplified and more accessible production method. The X-rays diffraction (XRD) technique showed a pure phase with monoclinic symmetry (S.G. P21/n). The resulting uncoated material (labeled as NFeMPF) was ball-milled with dopamine hydrochloride (mentioned as dopamine hereafter) as a carbon source to enhance the specific surface and improve its electronic conductivity. Raman spectra confirmed the presence of residual carbon after the pyrolysis process. Thermogravimetric analysis (TGA) demonstrated the stability of Mn-doped iron fluorophosphate up to 1000 °C. Additionally, Mössbauer spectroscopy disclosed structural improvements in the material, indicating the reduction of all Fe(III) when coated with dopamine. The uncoated material discharge capacity when cycled against sodium exhibits reversible capacities of only 80, 67, and 38 mAh/g during the first cycle at C/20, C/16, and C/5, respectively. The coated NFeMPF@D delivered improved capacities of 272 and 202 mAh/g at C/20 and C/16, respectively. This highlights the considerable promise of the investigated phosphate-based electrode material as a cathode composite for the next generation of sodium-ion batteries.

Improving the electrochemical performance of LiNi0.5Mn1.5O4 by ZnO nanocrystals coating

The cathodic material LiNi0.5Mn1.5O4 was produced by the Solution Combustion Synthesis method (SCS). The as-made crystalline nanoparticles were annealed at 900 °C, obtaining micron-sized particles, and then coated with ZnO nanocrystals at a weight relation between 0.5 and 2.5 wt%, also using the SCS method. The nanocrystalline porous coating was confirmed by XRD, SEM and TEM. Electrochemical measurements verified that all materials coated with ZnO nanoparticles improved their electrochemical properties concerning the uncoated material, preventing degradation over the cycles, and stability along cyclic voltammetry cycles. It was observed that a 1 wt% ZnO coating presents the best improvement in discharge capacity and rate capability, and that the charge transfer resistance of the coated material is reduced to 1/3 of the uncoated one after 100 electrochemical cycles. In this work, the simple, time and energy saving SCS method was verified to obtain nanoshell-coated LNMO microparticles with improved electrochemical performance.

Assessment of Mechanical Properties and Antimicrobial Effects of Hyaluronic Acid Coating on Absorbable Suture Material: An In-vitro Study

Introduction: The use of absorbable suture materials in surgical procedures is a critical aspect of wound closure and tissue repair. In recent years, there has been growing interest in exploring the potential benefits of incorporating Hyaluronic Acid (HA), a naturally occurring biopolymer, into these sutures. By shedding light on the interactions between HA and absorbable sutures, the present study seeks to provide valuable insights that could enhance the quality of surgical wound management. Aim: To assess the mechanical properties and antimicrobial effects of HA-coated and uncoated absorbable suture material. Materials and Methods: The in-vitro study was conducted at Saveetha Dental College, Saveetha Institute of Medical and Technical Sciences, Chennai, Tamil Nadu, India in a year 2022. A total of 70 samples of HA-coated and uncoated Vicryl 4-0 suture material were tested for tensile strength using an Instron machine. An anti-bacterial effect against Pseudomonas aeruginosa and Streptococcus mutans was assessed using a Mueller Hinton agar (MHA) plate, and the zone of inhibition was measured. Additionally, both the uncoated and HA-coated Vicryl 4-0 suture materials were analysed under the Scanning Electron Microscope (SEM) to determine the surface characteristics. An independent t-test was used to compare the tensile strength of coated and uncoated suture materials. Results: The mean tensile strength of uncoated and HAcoated suture material was 6.47±0.23 MPa and 3.78±1.02 MPa, respectively. The difference between both groups was statistically significant (p<0.05). For Pseudomonas aeruginosa and Streptococcus mutans, the zone of inhibition was 8.0±0.5 mm in diameter and 9±0.5 mm in diameter, respectively, around coated Vicryl 4-0 suture material, whereas no zone of inhibition was observed for both Pseudomonas aeruginosa and Streptococcus mutans around uncoated suture material. SEM analysis showed superior surface characteristics of HA-coated suture thread when compared to uncoated suture thread. Conclusion: HA-coated suture material does not exhibit superior tensile strength when compared to the uncoated suture material. However, HA-coated suture material has potent antibacterial effects against Pseudomonas aeruginosa and Streptococcus mutans. Additionally, SEM analysis showed improved surface characteristics in favour of the coated suture material.

Beam-Impact Validation of HL-LHC Collimator Materials: The “MultiMat-2” Experiment

In 2017, a proton-impact test on HL-LHC collimator materials was carried out in the HiRadMat facility at CERN. The experiment, called “MultiMat”, enabled the testing of uncoated and coated material composites and alloys, in most of the cases developed at CERN, for different beam collimation functionalities. Manufacturing of these materials was then passed to industry, leading to a series production for use in the collimators installed in the LHC during Long Shutdown 2 (LS2). The industrial versions of bulk and coating materials were tested in HiRadMat in 2021 in the “MultiMat-2” experiment, that efficiently re-used the same experimental test bench as for “MultiMat”. This new experiment demonstrated the reliability of the absorbers installed in LS2, and confirmed the possible use of alternative materials and coatings for the next LS3 collimator production. This paper describes the preparation and beam parameters of “MultiMat-2”, the experimental setup and the main results of the experiment.

Analysis of Nickel and Chrome Plating Temperature on Corrosion Rate of Steel in Seawater Environment

This study investigates the effect of Nickel and Chrome plating on ST 40 steel on corrosion resistance in a seawater environment. Several temperature variations were carried out during the chrome plating process, precisely at room temperature and 40℃, with a processing time of 5 seconds each and a voltage of 5 Volts. The Nickel plating was conducted with predetermined variables obtained from the initial research to achieve the most optimal results, especially the thickness of the plating formed. This process involves a temperature setting of 40℃, a processing time of 10 and 30 minutes, and a voltage of 5 Volts. To evaluate the results of this study, the corrosion testing was carried out using seawater corrosion media from 2 different beaches with 2.98% and 3.18% NaCl concentrations. In addition, microstructure testing is also conducted to determine changes in the structure of the base material after undergoing plating, and an optical microscope can be used to determine the thickness of the Nickel and Chrome layers. With Chrome plating at 40℃, the corrosion rate decreases compared to uncoated material in various seawater environments. The results emphasize that the plating process with the correct treatment can improve the corrosion resistance of steel, especially in seawater environments.

All Dry in One Step (ADIOS to Water) Synthesis of W-Coated Li1+X(Ni0.7Mn0.3)1-XO2

Cathode powders for lithium-ion batteries are typically made from hydroxide precursors with the intended transition metal composition and calcined with a lithium source at high temperatures to make LiMO2, where M = Ni, Mn, Co. However, large amounts of process water and salts like NaOH are used in the co-precipitation process employed to make these hydroxide precursors1. Purifying and drying the precursors after co-precipitation requires additional energy input and produces waste streams that are difficult to treat, as illustrated in Fig. 1a. In this work, we introduce a simple, solvent-free method to produce tungsten (W) coated Li1+x(Ni0.7Mn0.3)1-xO2 (NM73) materials from a mixture of Ni, MnO2, LiOH·H2O and W precursors. NM73 was chosen as the primary focus of investigation so that cobalt is avoided due to its scarcity and high cost.The starting reagents are dry mixed and calcined, followed by jet-milling. An extra reheating step after jet-milling is advantageous for minimizing cation disorder and lithium surface impurities. Pure phase, R -3m single crystal NM73 materials can be made with this method and Rietveld refinement analysis showed that low Ni/Li mixing was achieved. W is believed to remain at the surface, forming a separate LixWyOz phase2. The addition of W was found to reduce the mean particle size and improve both the initial discharge capacity and first cycle efficiency. Small amounts of W increase the initial discharge capacity up to 197 mAh/g. Full coin cells were made from both coated and uncoated materials. Their cycling performance is shown in Fig. 1b, revealing improved capacity retention as another improvement afforded by the W coating.The proposed method simplifies the current production process of LiMO2 by eliminating the need for hydroxide precursors entirely. Cobalt-free single crystal materials with excellent electrochemical performance can be made all-dry in one step, potentially reducing the cost of cathode materials significantly and eliminating waste streams.

Advanced process characterization and machine learning-based correlations between interdiffusion layer and expulsion in spot welding

Over the past decades, substantial endeavors have been dedicated to unraveling the intricacies inherent to Resistance Spot Welding (RSW). However, a comprehensive and consensual understanding of the RSW process physics is still lacking, including the exact number of physical phases behind the RSW process. For example, a widely accepted model indicates that metal only starts melting after the peak of dynamic resistance, while the latest research on welding uncoated materials challenges this by suggesting that melting begins around the resistance peak. Furthermore, most of existing physical models only consider welding materials without coatings in a controlled lab setting, whereas coated sheet metal is the norm in real production. Addressing these challenges, this paper introduces an enhanced model for RSW that considers the melting phase of the coating's InterDiffusion Layer (IDL) in Press Hardening Steels (PHS). This phase is believed to influence both welding quality and the occurrence of expulsions. Additionally, the timing at which each phase starts has been determined by analyzing real-time, multi-variable sensing data from various welding scenarios, and a signal processing technique has been devised to automatically identify when these phases begin. Leveraging this refined process understanding and characterization, meaningful explainable features are extracted, and a data-driven multilayer perceptron model is constructed for 1) predicting IDL thickness and 2) detecting expulsions upon predicted IDL thickness. The experimental results validate that the proposed IDL-inclusive model advances existing physical models for RSW and the IDL prediction improves the RSW defect detection and process monitoring.

Design and fabrication of nickel-chromium reinforced 2-stage energy efficient pyrolysis reactor for waste plastics applications

ABSTRACTThis paper focuses on the design and fabrication of a two-stage energy-efficient plastic waste reactor, which is capable of melting the various types of waste plastics such as HDPE, LDPE, PS, PVC, PET, PVC, PP, and in the melting temperature in the range of 400 οC to 1000 οC. The methodology involved in this experimental process is a superalloy with a nickel-chromium alloy percentage composition of 15CR85S for the reactor and 20CR80S for the furnace part. The plasma arc welding process is applied in the temperature range 10000 οC with a coating thickness of 75 microns over the materials, followed by 15CR85S-75μm YSZ. 20CR80S-75μm YSZ and 15NI85S-75 μm YSZ. The salt spraying technique is employed in this analysis. The potential benefits of this experimental process is that a reactor made up of 15CR85S-75μm YSZ gives promising results of lesser thermal expansion in the range of 10 K−1 × 10−6 for 15CR85S-75μm YSZ for uncoated 13K−1×10−6, Which 15CR85S-75μm YSZ material is 23% superior to uncoated materials. The crack porosity of 20CR80S-75μm YSZ is excellent in the order of 400 × 10−6, and for uncoated material, it is located in the order of 600 × 10−6. 20CR80S-75μm YSZ material is 50 % superior to uncoated materials.

Novel Cr/Si-Slurry Diffusion Coatings for High Temperatures

Surface enrichment in Al, Si, and Cr can greatly improve high temperature oxidation resistance of many alloys. Al, Si, and Cr coatings are commonly applied via simple slurries or more complex pack cementation processes. Due to the high melting point of Cr, the deposition of Cr-based diffusion coatings by the slurry technique has proved challenging, and to date, Cr has mostly been applied by pack cementation. Here, a novel Cr-Si coating process via the slurry technique is described which has been developed and then demonstrated on two Ni-based superalloys, Rene 80 and Inconel 740H. The addition of Si to the slurry lowers the melting point via a Cr-Si eutectic and enables the formation of a liquid phase during heat treatment. Through this Cr-Si slurry coating process diffusion layers enriched by Cr and Si of about 150 µm were achieved. Oxidation behavior was studied through isothermal exposures at 900 °C for 1000 h in lab air. Uncoated Rene 80 and IN740H both showed formation of a Ti-containing Cr2O3 scale below a thin TiO2 top layer. Underneath the external scale a zone of internally oxidized Al grew over the exposure time and reduced the load-bearing cross-section progressively. In comparison, the Cr/Si-coated samples did not show internal Al oxidation, but a slow-growing Si-rich oxide film underneath the external Cr2O3 scale. This subscale represents an additional oxygen diffusion barrier. Thus, the weight gain during exposure for the coated samples was significantly lower than for the uncoated materials.

The Role of Surface Coating in P’2‐Na0.67Mn0.67Ni0.33O2: Enhancing Capacity and Stability of Layered Cathodes for Sodium‐ion Batteries

AbstractP’2‐Na0.67Mn0.67Ni0.33O2 (NMNO) is one of the most promising cathodic materials for new generation sodium‐ion batteries (SIBs). One drawback that is preventing its commercialization is however the high instability in the potential window 2.5–4.5 V vs. Na+/Na, caused by degradation reactions affecting the material's structure and composition. Herein we propose a strategy to overcome this weak spot introducing the surface coating of the material particles with inert magnesium oxide, that has been chosen as coating agent because of its low molecular weight. This protective layer is able to reduce the structural instability of the material without modifying the mixed conduction properties and thus globally stabilizing the electrochemical performances. In fact, the electrode of NMNO coated with 7 % of MgO, after an initial stabilization, was able to deliver over 90 mAh g−1 of reversible specific capacity at a current value of 50 mA g−1, with a capacity retention of 70 % after 250 cycles, to be compared with the 30 mAh g−1 of the uncoated material. The effect of the coating on the particles surface is here investigated with differential electrochemical mass spectrometry, to analyze the influence of the treatment on the electrode/electrolyte interphase.

Experimental and theoretical analysis of exhaust manifold by uncoated and coated ceramics (Al2O3, TiO2 and ZrO2)

This research work focuses on the experimental and theoretical analysis of the exhaust manifold with novel ceramic coatings (TiO2 Coatings; ZrO2 coatings; and Al2O3 coatings) and these coatings were applied on the manifold by the plasma arc technique with a temperature range of 14,000 οC and micron coatings ranging from 350 to 400μ. The implementation of these coatings over the exhaust manifold gives enormous benefits such as improvised endurance strength, higher heat dissipation, and flexible directional heat flux compared to uncoated materials. From the numerical analysis, it is found that the ceramic coatings give lower thermal residual stresses compared to the uncoated materials. Among the three coatings, Al2O3 coatings give optimal performance in terms of heat dissipation, heat flux, and directional heat flux and also lower thermal residual stresses. From the overall analysis; it is also clear that the implementation of ceramic coatings on the exhaust manifold gives enormous advantages in terms of corrosion resistance and lesser maintenance as compared to uncoated materials.

Intrinsic MXene-Ti3C2Tx enhanced high sensitivity Mach-Zehnder interferometric microstructured optic fiber temperature sensor

A temperature sensing method with simple fabrication, real-time detection, and high sensitivity is proposed, and the feasibility of the method is experimentally verified. The sensing unit uses a single-no-multi-no-single (SNMNS) Mach-Zehnder Interferometric (MZI) structure to excite a stronger evanescent field and compares the effect of two different lengths of multimode fibers on the temperature sensing performance. To enhance the sensor sensitivity, a novel 2D material with superior photothermal, optoelectronic, and structural properties, MXene-Ti3C2Tx, was innovatively coated on the optical fiber surface. The intrinsic MXene-Ti3C2Tx material was prepared by the water bath method and characterized by scanning electron microscopy (SEM) and X-ray diffraction spectroscopy (XRD). The same temperature sensing experiments were carried out on uncoated and coated material fibers respectively, and the results showed that the temperature sensitivity improved from a minimum of 61.97 pm/℃ to 120.71 pm/℃ over the temperature range of 30℃∼80℃, an improvement of 94.7 % in sensitivity, with linearity all above 0.98. This paper combines for the first time the sensitive 2D material MXene-Ti3C2Tx with a microstructured fiber-optic temperature-sensing unit, providing a new way of thinking in the field of temperature detection and showing great promise in the field of fiber-optic sensing.

Detailing the influence of PEO-coated biodegradable Mg-based implants on the lacuno-canalicular network in sheep bone: A pilot study.

An increasing prevalence of bone-related injuries and aging geriatric populations continue to drive the orthopaedic implant market. A hierarchical analysis of bone remodelling after material implantation is necessary to better understand the relationship between implant and bone. Osteocytes, which are housed and communicate through the lacuno-canalicular network (LCN), are integral to bone health and remodelling processes. Therefore, it is essential to examine the framework of the LCN in response to implant materials or surface treatments. Biodegradable materials offer an alternative solution to permanent implants, which may require revision or removal surgeries. Magnesium alloys have resurfaced as promising materials due to their bone-like properties and safe degradation in vivo. To further tailor their degradation capabilities, surface treatments such as plasma electrolytic oxidation (PEO) have demonstrated to slow degradation. For the first time, the influence of a biodegradable material on the LCN is investigated by means of non-destructive 3D imaging. In this pilot study, we hypothesize noticeable variations in the LCN caused by altered chemical stimuli introduced by the PEO-coating. Utilising synchrotron-based transmission X-ray microscopy, we have characterised morphological LCN differences around uncoated and PEO-coated WE43 screws implanted into sheep bone. Bone specimens were explanted after 4, 8, and 12 weeks and regions near the implant surface were prepared for imaging. Findings from this investigation indicate that the slower degradation of PEO-coated WE43 induces healthier lacunar shapes within the LCN. However, the stimuli perceived by the uncoated material with higher degradation rates induces a greater connected LCN better prepared for bone disturbance.

Study on the Effect of Chitosan Modification Technology on Antibacterial Properties of Textiles.

The chitosan is fixed in an amide group of activated carboxyl groups and biological primary amino groups of nonwoven PET for antibacterial properties. Uncoated materials have fewer wetting properties and are less biocompatible. The objectives of the study were to evaluate surface chemical compositions and biocompatibility, antibacterial, and hydrophilic properties of polyester fabrics grafted with chitosan oligomers and after being activated by atmospheric pressure plasmas. A 2% 14.8mg/cm2 uncolored PET woven fabric was dissolved in chitosan solution. Atmospheric pressure plasmas were used to activate polyester fabrics grafted with chitosan oligomers on both sides. Cell proliferation assay was performed for the biocompatibility study. The American Association of Textile Chemists and Colorists method was used to measure the width of the antibacterial zone and the Japanese Industrial Standard was used to count the number of bacterial colonies. Chitosan-coated and -activated uncolored PET woven fabric showed fewer percentage free carbon (p < 0.0001), higher percentage free oxygen to free carbon ratio (p < 0.0001), higher percentage free nitrogen to free carbon ratio (p = 0.0453), and higher percentage free oxygen plus free nitrogen to free carbon ratio (p < 0.0001) than untreated PET woven fabric. The dynamic contact angle of a water droplet and the wicking time were shorter for chitosan-coated and -activated uncolored PET woven fabric than untreated PET weaved fabric (p < 0.0001 for all). Chitosan coating leads to PET woven fabric being higher biocompatible, wettable, and antibacterial than untreated PET woven fabric.