Chemical Surface Modification Research Articles

Quantitative design criterion for mechanical interface functionalization regarding adhesion strength in chemically pre-treated polymer-metal hybrids using fractal dimension

ABSTRACT Polymer-metal hybrids (PMH) are common lightweight materials, whereas adhesion between metal and polymer is largely determined by the metallic surface design. Approaches in interface functionalization comprise both, mechanical and chemical surface modification. Therefore, surface modification on aluminum EN AW-6082 has been conducted prior to thermal joining to glass-fiber reinforced polyamide 6. Laser beam machining with a variation of structure density was carried out to produce defined groove structures. In addition, chemical surface modification by Boehmite hot water treatment as well as organo-silane couple agents were realized. Subsequently, the joint strength was assessed in lap shear tests. In order to quantitatively correlate the features of surface structure to the joint strength, regression analysis considering different chemical states were conducted. Hereby, the surface structure was represented on the one hand by the structure density and on the other hand by the calculated fractal dimension on cross-sectional images. The results revealed that using both, mechanical and chemical surface modification by laser machining as well as silanization, not only added together but moreover acted beneficial to each other. In addition, the fractal dimension proved to be a promising design criterion for linear correlation of joint strength independent of the chemical state.

Enhancing electrochemical performance of graphene oxide/polyaniline composite through plasma-assisted chemical cross-linking and surface modification

The composite of graphene oxide (GO) and polyaniline (PANI) is a promising electrode material for supercapacitors. A high loading of PANI can provide large specific capacitance, but it is a pervasive challenge to reconcile long-term cycling stability and high-rate discharge. Herein, we focus on a GO/PANI composite with low PANI content (∼25 wt%), developing a stable network of GO with an even distribution of PANI. Moreover, significantly enhanced electrochemical performance is achieved by utilizing plasma technology. The specific capacitance increases by 99 % to 433 F g−1 at 1.5 A g−1 after Argon (Ar) plasma treatment. Even at 15 A g−1, a capacitance retention rate of 91 % is obtained. After 15,000 cycles, the capacitance retention rate is 93 %, surpassing most previously reported GO/PANI composite electrodes. The further assembled all-solid-state supercapacitors can deliver a high energy density of 13.6 Wh kg−1 and exceptional cycling stability. According to results of characterization, it is demonstrated that Ar plasma imparts GO/PANI better surface morphology and achieves etching, reduction of GO, and cross-linking of GO and PANI, thereby activating the electrochemical activities of GO and PANI while ensuring stability. In this regard, the synergistic effects of cross-linking, reduction, and etching, and the mechanism are theoretically illustrated by dynamic differential equations. This work presents plasma processing unique charm for designing graphene-based materials via a customized strategy, exploiting an effectual approach to drive the applications of graphene-based materials in energy storage.

A parametric study on chemical activator selection and soaking procedure development for barium incorporation in concurrent activated and surface modified palm kernel shell derived activated carbon

The concurrent activation and surface modification (CAM) process is an integrated process used to synthesise palm kernel shell derived activated carbon (PKSdAC) in this study. CAM involves chemical activation and surface modification via metal impregnation in one process. This study investigated the usage of different acids as chemical activators and different soaking procedures for impregnating barium (Ba) in CAM-PKSdAC. It shows that chemical impregnation of PKS using 10% sulphuric acid (H2SO4) mass loading via two soaking steps can impregnate a high Ba amount of 0.86–2.98 wt. % in CAM-PKSdAC, compared to one soaking step. The two soaking steps procedure reduced the overage formation of BaSO4 from sealing the pores of PKS. Comparing HCl and H2SO4, at 30% acid mass loading, the impregnation of PKS with H2SO4 produced a higher impregnated Ba amount in CAM-PKSdAC. BaSO4 generated from the reaction between H2SO4 on the PKS surface with BaCl2 solution causes a reduction reaction at high temperatures. BaSO4 reacted with a carbon-reducing agent and is reduced to barium sulphide (BaS), impregnating Ba on CAM-PKSdAC. In conclusion, H2SO4 was found to be the suitable chemical activator with two soaking steps for the CAM process.

CO adsorption mechanisms on transition metal surfaces and factors influencing the adsorption

CO adsorption on transition metal (TM) surfaces has been extensively studied. Compared to the "vertical adsorption" (CO⊥M) in which the C–O bond is normal to the surface with the C bonded to the surface, few studies are devoted to the "parallel mode" (CO||M) where the C–O bond is (near) parallel to the surface with both C and O atoms interacting with the surface. Here we report density functional calculations of CO adsorption on the stable surfaces of 27 TMs. The results show that CO adsorbs only in CO⊥M mode on IB, IIB, VIIB and VIII TMs while both CO⊥M and CO||M modes exist on IIIB to VIB TMs, with CO||M being more stable. Overlap population analysis reveals that the interactions between metal d AOs and O 2p AOs dominate the CO||M mode where the CO π bond is greatly weakened, resulting in significantly activated CO. The adsorption mode and adsorption energy can be tuned by ensemble effect, lattice strain and crystal structure, while the ligand effect is weak and is not able to change the adsorption mode of CO. The present work demonstrates that ensemble effect, lattice strain and crystal structure can be utilized to modify surface chemistry and promote catalytic performance effectively.

An Integrated Photonic Biosensing Platform for Pathogen Detection in Aquaculture.

Aquaculture is expected to play a vital role in solving the challenge of sustainably providing the growing world population with healthy and nutritious food. Pathogen outbreaks are a major risk for the sector, so early detection and a timely response are crucial. This can be enabled by monitoring the pathogen levels in aquaculture facilities. This paper describes a photonic biosensing platform based on silicon nitride waveguide technology with integrated active components, which could be used for such applications. Compared to the state of the art, the current system presents improvements in terms of miniaturization of the Photonic Integrated Circuit (PIC) and the development of wafer-level processes for hybrid integration of active components and for material-selective chemical and biological surface modification. Furthermore, scalable processes for integrating the PIC in a microfluidic cartridge were developed, as well as a prototype desktop readout instrument. Three bacterial aquaculture pathogens (Aeromonas salmonicida, Vagococcus salmoninarum, and Yersinia ruckeri) were selected for assay development. DNA biomarkers were identified, corresponding primer-probe sets designed, and qPCR assays developed. The biomarker for Aeromonas was also detected using the hybrid PIC platform. This is the first successful demonstration of biosensing on the hybrid PIC platform.

Transitioning Low-Temperature GDC Socs: Lab to Commercialization Scale

Solid oxide fuel cells (SOFCs) electrochemically convert hydrogen and oxygen into electricity, heat, and water with high efficiency (~55%) [1], while in reverse operation, water and electricity are converted to hydrogen and oxygen in solid oxide electrolysis cells (SOECs). Appropriately designed solid oxide cells (SOCs) can operate in both SOFC and SOEC mode.Conventional SOCs typically demand elevated operating temperatures (800-1000°C), resulting in higher cost and accelerated degradation issues. Lowering operating temperatures below 600°C reduces thermal stresses, shortens start-up times, and broadens applications [2].Ce1-xGdxO2-δ (GDC), due to its superior oxygen ion conductivity at reduced temperatures, has lower ohmic losses than competing electrolyte materials. Thus, our 1.2 cm diameter circular anode supported GDC cell with 0.31 cm2 active area exhibits exceptional power densities, reaching approximately 3 watt per square centimeter at 650°C. Through optimal design, these cells exhibit exceptional performances in fuel cell mode, significantly enhancing efficiency and effectiveness when operating as an electrolyzer for fuel generation. This advance in performance is a result of mitigating the leakage current issues typical of ceria-based electrolytes through precise engineering of the cathodic microstructure and surface chemistry modification [3].The transition from lab-scale to large-scale commercialization (with active areas of 16 cm² &; 81 cm²) presents significant challenges such as tailoring material properties for large-cell versus button-cell synthesis while maintaining high performance levels.In this work we explore the challenges encountered during the scaling-up process. We report on fabrication strategies employed to achieve cell flatness, maintain high efficiency, ensure cost-effectiveness, and achieve long-term stability. Specifically, we have fabricated graded anode-supported cells [4] by developing an innovative lamination strategy involving tapes oriented perpendicular to each other. This approach notably contributed to achieving superior electrolyte densification and resulted in significantly flatter (low curvature values) with respect to both horizontal and vertical axes in cartesian coordinate space. When compared to the flatness values of 10x10 cm2 commercially available cells, our cells demonstrated remarkably flatter curvatures as shown in figure 1. This characteristic has proven highly beneficial for stack assembly, minimizing issues such as cell cracking and reducing sealing-related problems. By optimizing the cathode scaffold and infiltration process on larger area cells through a spray-coating machine, scaling up challenges are effectively mitigated compared to the button cell approach, where scaffold preparation and infiltration were performed using blade coating and a hand pipette, respectively. This approach effectively tackles electronic conduction issues in ceria-based electrolytes, leading to higher Open Circuit Voltages (OCVs) in fuel cell mode and increased efficiencies in reversible mode.

Tuning the adhesion of diamond/copper interfaces through surface chemical modifications and reconstruction

Diamond and diamond-like carbon (DLC) coatings are well-known for their exceptional combination of tribological and mechanical properties, such as low friction coefficients and wear rates, together with high hardness and elastic modulus. A significant limitation in their employment concerns their spallation from the substrate; it is thus interesting to explore how DLCs adhesion can be tuned through chemical modifications of its surfaces. We employ ab initio simulations to study the effect of surface reconstruction and chemical species intercalation (B, P, O, F, N, S, H) on the adhesion of non-reconstructed and Pandey-reconstructed C(111)/Cu(111) interfaces. We found that the increment of graphitization at the diamond surface decreases the adhesion. Moreover, when a high degree of surface graphitization is present the best way to increase adhesion is to select atoms able to act as chemical bridges (e.g., B and N), compensating for the lack of interaction between the surfaces. Conversely, adhesion reduction of ∼100% can be achieved, regardless of the degree of surface graphitization, by intercalating an atomic species that does not bond with the countersurface and prevents the interaction between the slabs, i.e. F and S.

Study on the regulation of droplet motion behavior on superhydrophobic surfaces

Wettability properties of the surface is essential for controlling the dynamic sliding of droplets, thereby facilitating surface self-cleaning and drag reduction. This study makes use of chemical etching and surface modification techniques to prepare superhydrophobic surfaces with micro-nano pore structures on copper. This research examines and evaluates the chemical composition, surface morphology, and hydrophobic characteristics of superhydrophobic surfaces, also investigates the exhibited excellent superhydrophobic properties, a positive correlation observed between the concentration of the modifier solution and the surface’s hydrophobic strength. Droplets move in an accelerated fashion on superhydrophobic surfaces, and the total resistance to droplet sliding decreases as the surface hydrophobicity increases and the wall tilt angle decreases. During the motion of droplets, the fluctuation range of the receding angle is considerably greater than that of the advancing angle, thereby rendering the receding angle as the primary determinant factor for droplet movement, and as the hydrophobicity of the surface improves, the fluctuation extent of the droplet’s receding angle experiences a significant diminution. Droplet motion on superhydrophobic surfaces comprises both slipping and rolling behaviors, the increased hydrophobicity of the surface and the larger tilt angle facilitate droplet movement in a slipping mode on the surface, within the experimental parameters, the proportion of rolling distance to slipping distance varies from 35 % to 15 %. This study has revealed innovative regulatory approaches for modulating the moving behavior of liquids on microstructured surfaces, potentially enabling the development of superior functional surfaces for fluid drag reduction or droplet manipulation in the future.

Unraveling cation intercalation mechanism in MXene for enhanced supercapacitor performance

MXenes are two-dimensional materials with high electrical conductivity, adjustable composition, and tunable surface terminations, holding promise for supercapacitors (SCs). However, the susceptibility to interlayer restacking and the attachment of inactive -F terminations reduce their capacitances and rate performance. To resolve these issues, electrochemistry-driven cation intercalation (ECI) followed by calcination is proposed to unclog the interlayers and modify surface chemistry simultaneously. It is found that Mn-modified Ti3C2Tz MXene exhibits exceptional volumetric capacitance (1655.5 F cm−3 at 1 mV s−1, 1.5 times higher than that of pristine Ti3C2Tz) and excellent rate performance (72.3 % retention from 1 A g−1 to 50 A g−1) due to the unblocked interlayers and the increased -O terminations. Density Functional Theory (DFT) results reveal that the intercalated Mn2+ displayed the largest formation energy difference, manifesting a great driving force to form active -O terminations, which is crucial for improving electrochemical performance. Kinetic analysis reveals that the intercalated Mn2+ increases the termination-related capacitances (pseudocapacitance and diffusion-controlled capacitance) significantly. Symmetric and asymmetric SCs demonstrate high energy densities at high powers, showing the advance of the Mn-intercalated Ti3C2Tz. The findings clarify how metal cation intercalation affects MXene performance, providing insights for designing MXene-based electrodes in energy storage applications.

Enhancing the mechanical properties of CF-reinforced epoxy composites through chemically surface modification of carbon fibers via novel two-step approach by addition of epichlorohydrin

The chemical surface modification was carried out in this study to improve the interface connection between carbon fiber (CF) and epoxy matrix to study the mechanical and fracture behavior of CF-reinforced epoxy composites. Finite element analysis was carried out by using ABAQUS software to simulate the variation of the tensile strength (TS), interfacial shear strength (IFSS), and interlaminar shear strength (ILSS). The chemical surface modification was carried out by the chemical oxidation by nitric acid and subsequently, addition of monomer resin of epichlorohydrin in a solution at 80 °C. The Raman spectroscopy, Fourier transform infrared spectroscopy, and scanning electron microscopy were carried out to ensure the successful surface modification of CFs. Subsequently, surface-modified CF-reinforced epoxy composites were prepared through the hand lay-up method with the volume fraction of 20 wt.%, and curing was carried out at 80 °C for 4 h. The TS, IFSS, and ILSS values equaled 462.82 MPa, 156 MPa, and 4.1 MPa for modified CF/epoxy composites were achieved, respectively, which are improved remarkably compared to unmodified ones (380, 81, and 2.9 MPa). These improvements are attributed to the successful surface modification of CFs by epichlorohydrin. The surface modification causes the increase in wettability of CFs and the formation of mechanical interlocking and interaction between CFs and epoxy matrix was achieved through uniform and homogenous distribution of epichlorohydrin on the surface of CFs. Fractography was carried out, which indicated the sound and uniform adhesion between CF and epoxy matrix. Achieved results are consistent with simulated results.

Mechanically stable superhydrophobic surfaces constructed by laser surface texturing and micro-arc oxidation of TC4 alloy prepared based on SLM

In this paper, a superhydrophobic surface was prepared on the surface of Ti–6Al–4V (TC4) alloy prepared by selective laser melting (SLM), and the water contact angle (WCA) was 156.8°. The laser surface texturing (LST) and chemical modification treatments were combined with a micro-arc oxidation (MAO) treatment to improve the mechanical durability of the superhydrophobic surface. The surface morphology, wettability, wear resistance, and abrasion resistance of the composite coatings were analyzed, and the mechanism of abrasion resistance on superhydrophobic surfaces was discussed. The superhydrophobic surface that was prepared withstood abrasion under 600 # sandpaper at a pressure of 2.9 kPa and a movement distance of 1020 cm. In addition, the prepared superhydrophobic surface showed better wear resistance and friction reduction in friction experiment, exhibiting more stable coefficient of friction (COF) curve, lower COF value, and narrower abrasion marks. The results show that the prepared composite coatings not only exhibit superhydrophobicity, but also good mechanical stability, which effectively improves the mechanical property of superhydrophobic sample and significantly prolongs its service life in harsh environments. This study provided a new idea and preparation method for the preparation of mechanically stabilized superhydrophobic surface.

Facile chemical surface modification of boron nitride platelets and improved thermal and mechanical properties of their polymer compounds for 2.5D/3D packaging applications

Thermally conductive yet electrically insulative epoxy composites are sought after as encapsulation materials to tackle the heat dissipation challenges in modern electronics. In this work, we developed a novel one-step and facile solvothermal reflux method using a high-boiling-point solvent to surface-modify hexagonal boron nitride (h-BN) with glycine. By refluxing glycine at high temperature, amino functional groups are grafted onto the BN surface, which can enhance the affinity of fillers for epoxy and reduce the interfacial thermal resistance of the filler/epoxy composites. We investigated the mechanism of glycine-grafted layer formation, optimizing reactant mass ratios for enhanced interfacial thermal transport. The resulting BN@G11/epoxy composites exhibit a remarkable thermal conductivity of 1.04 W/mK at 30 wt% modified-BN loading, representing a 477.8 % increase over neat epoxy and 57.5 % higher than h-BN/epoxy composites at equivalent BN filler loading. Additionally, these composites demonstrate improved thermomechanical properties, confirming the strengthened BN/epoxy interface bonding using modified BN fillers. Compared to other surface treatment methods, this solvothermal reflux approach stands out for its scalability and cost-effectiveness. This scalable and eco-friendly innovation presents a competitive strategy for designing polymer-based composites for thermal management, catering to the demands of future 2.5D/3D semiconductor packaging.

Recent advances to engineer tough basalt fiber reinforced composites: A review

AbstractBasalt fibers, known as “green materials without pollution in the 21st century”, have gained widespread attention due to its good mechanical properties. Basalt fiber‐based composites have applications in various fields such as construction, transportation, energy, and protection. However, as an inorganic fiber material, basalt fiber is hard and brittle and prone to catastrophic failure, reducing the safety of the material. Therefore, it is important to strengthen the toughness of basalt fiber‐based composites. This paper reviews the contributions made by researchers in recent years to enhance the toughness of basalt fiber reinforced composites. It mainly focuses on four aspects: physical and chemical modification of fibers surface, mixed application of multiple fibers, different textile and 3D printing technology, and design of biomimetic structures. Through these methods, the toughness of basalt fiber‐reinforced composite materials was increased by 10%–90%. In today's advocacy for green industrial development, the research and application of basalt fibers are very important for advancing the process of green development. These contributions can promote the application of basalt fiber in engineering fields.Highlights Basalt fiber is a green material without pollution. Basalt fiber reinforced composites is the key material for engineering field. Strengthening interfacial adhesion can significantly improve the toughness of composites. Basalt fibers can serve as an alternative to glass fibers in composite materials. The hybridization of basalt fibers with soft fibers can effectively enhance the toughness of composites.

Wettability tuning on stainless steel LIPSS by laser oxidation and its implication on cavitation bubble dynamics

The modification of surface wettability of stainless steel is essential for many biological applications and industrial implementations. Having a hydrophobic or hydrophilic surface is ideal depending on its application. In this study, the wettability tuning of stainless steel was carried out by producing LIPSS at different laser peak energies. Results showed non-significant changes in the periodicity of the ripples, however hydrophilicity increased with greater laser energies. Raman spectroscopy and SED analysis demonstrated the presence of iron oxide peaks and increased oxygen concentration, demonstrating a chemical surface modification governed by oxidation. Transitions from hydrophilic to hydrophobic surfaces were accomplished by ethanolic triethoxyoctylsilane coated LIPSS. Hydrophobicity enhancement was achieved by the adsorption of organic species promoted by the oxide layer at the ripples. The dynamics of cavitation bubbles close to the coated LIPPS were analyzed. A reduction of the main bubble lifetime with hydrophobicity, whereas a delay of collapse time and deformation of the rebound bubble were found. This led to an experiment for erosion testing producing multiple cavitation events. An increment of surface damage area with increased hydrophobicity was observed. This was attributed to longer collapse times of the rebound bubble which led to stronger shockwaves at the samples surface. This work demonstrates a simple method to tune the surface wettability of stainless steel by laser oxidation, which is a crucial factor for applications related to cavitation phenomena.

Unlocking the potential of a chemically modified blue phosphorene as anode materials for high-performance sodium-ion batteries

Blue phosphorene (Blu-Pn) has recently been identified as a new two-dimensional (2D) form of black phosphorus via the epitaxial growth method and has shown the ability to host a substantial amount of Na while serving as an anode in sodium-ion batteries (NIBs). However, its structural instability is an issue that hinders its further exploitability in NIBs. In this paper, we propose to chemically modify the Blu-Pn network by substituting six phosphorus atoms with a carbon source in the form of a C6 ring, constructing a new and robust CP2 nanosheet. Based on the state-of-the-art non-local van der Waals corrected density functional theory and ab initio molecular dynamic (AIMD) simulations, we systematically explore the feasibility of the designed CP2 as a potential anode material for NIBs. Adding a C6 ring in the Blu-Pn lattice reduces its energy gap from 2 eV to 1.3 eV, which disappears after Na adsorption, indicating a conductive character. Attributed to the synergistic effect, the adsorption energy of Na on CP2 nanosheet (−2.22 eV) is greatly decreased in comparison to the pristine carbon source (e.g., graphene with −0.78 eV) and pristine Blu-Pn (−1.85 eV). The Na diffusivity on CP2 at 300 K is predicted to be 4.90 × 10−11 m2/s by AIMD. The specific capacity is up to 604.1 mAh/g, which exceeds that of the commercialized graphite anode (372 mA h/g). Ultimately, the designed electrode provides a small open circuit potential of 0.66 V that falls within a desirable voltage range. This work paves the way for exploring Blu-Pn 2D anode materials for NIBs technology and provides valuable insights into surface chemical modification towards the long-term stability of Blu-Pn.

Physical and Chemical Surface Modification of Recycled Polystyrene Films for Improved Triboelectric Properties

Polystyrene (PS) is a very common material in packaging. In this study, it is recycled by turning it into energy harvesting devices: triboelectric generators. Herein, heat‐pressed films of recycled PS are formed and their surfaces are modified physically and chemically. The triboelectric properties of the films are determined using a dynamic testing machine, and the performance of the triboelectric generators is evaluated with a high‐speed contact–separation system. The developed charge density of the triboelectric generator increases two orders of magnitude—from 0.03 to 1.52 nC cm−2—by combining these surface modification methods. Such high values of charge density enable the production of single material triboelectric generators.

Laser Machining at High ∼PW/cm2 Intensity and High Throughput

Laser machining by ultra-short (sub-ps) pulses at high intensity offers high precision, high throughput in terms of area or volume per unit time, and flexibility to adapt processing protocols to different materials on the same workpiece. Here, we consider the challenge of optimization for high throughput: how to use the maximum available laser power and larger focal spots for larger ablation volumes by implementing a fast scan. This implies the use of high-intensity pulses approaching ∼PW/cm2 at the threshold where tunneling ionization starts to contribute to overall ionization. A custom laser micromachining setup was developed and built to enable high speed, large-area processing, and easy system reconfiguration for different tasks. The main components include the laser, stages, scanners, control system, and software. Machining of metals such as Cu, Al, or stainless steel and fused silica surfaces at high fluence and high exposure doses at high scan speeds up to 3 m/s were tested for the fluence scaling of ablation volume, which was found to be linear. The largest material removal rate was 10 mm3/min for Cu and 20 mm3/min for Al at the maximum power 80 W (25 J/cm2 per pulse). Modified surfaces are color-classified for their appearance, which is dependent on surface roughness and chemical modification. Such color-coding can be used as a feedback parameter for industrial process control.

Enhancing optical biosensing: Comparing two physical treatments for GPTES chemical functionalization of Cyclo-Olefin Copolymer foil

Cyclo-olefin-copolymer (COC) transparent films are currently the best choice for micro-fluidic bio-sensors for point-of-care diagnostic applications using optical signal detection. However, while the optical and mechanical properties of this polymer are extremely good, the adhesion of the bio-probes on this surface is not optimal, due to its chemical structure, that presents only saturated carbon bonds. The deposition of organo-silane molecules on the COC surface is one of the most effective ways to overcome this problem. But, for the surface functionalization, a surface physical treatment is necessary before the chemical modification of the COC surface. In this paper a comparison of the effectiveness of two different physical treatments, oxygen plasma and UV-ozone, is reported. In particular, the exposure time of the UV-Ozone treatment has been selected to avoid the problem of auto-fluorescence of the modified COC surface, that was observed also for relatively short UV exposure (around 10 min). An investigation of the reactive radicals created on the surface after the physical treatments and the following chemical modification with the organo-silane molecule (GPTES) has been performed using X-ray photoemission spectroscopy. The surface energy and morphology of the films have been also measured by contact angle and optical profilometry. Finally, the bio-probes adhesion performances of the COC surfaces obtained with the two physical treatments and the chemical modification were tested in a fluorescence-based assay, using an organic light emission diode to excite the fluorescence. We observed that the UV-ozone treatment allows to obtain a siloxane network with some reactive epoxy radicals on the COC surface, however, their quantity and distribution are less important and homogeneous than in the oxygen plasma treated surfaces.

Multifunctional curcumin-based polymer coating: A promising platform against bacteria, inflammation and coagulation

The extensive use of polymers in the medical field has facilitated the development of various devices and implants, contributing to the restoration of organ function. However, despite their advantages such as biocompatibility and robustness, these materials often face challenges like bacterial contamination and subsequent inflammation, leading to implant-associated infections (IAI). Integrating implants effectively is crucial to prevent bacterial colonization and reduce inflammatory responses. To overcome these major issues, surface chemical modifications have been extensively explored. Indeed, click chemistry, and particularly, copper (I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction has emerged as a promising approach for surface functionalization without affecting material bulk properties. Curcumin, known for its diverse biological activities, suffers from low solubility and stability. To enhance its bioavailability, bioconjugation strategy has garnered attention in recent years. This study represents pioneering work in immobilizing curcumin derivative onto polyethylene terephthalate (PET) surfaces, aiming to combat bacterial adhesion, inflammation and coagulation. Before curcumin derivative bioconjugation, a fluorophore, dansyl derivative, was employed in order to monitor and determine the efficiency of the proposed methodology. Previous surface chemical modifications were required for the immobilization of both dansyl and curcumin derivatives. Ultraviolet-Visible (UV-Vis) demonstrated the amidation functionalization of PET surface. Other surface characterization techniques including X-ray Photoelectron Spectroscopy (XPS), Attenuated Total Reflectance Fourier Transformed Infrared (ATR-FTIR), Scanning Electron Microscopy (SEM) and contact angle, among others, confirmed also the conjugation of both dansyl and curcumin derivatives. On the other hand, different biological assays corroborated that curcumin derivative immobilized PET surfaces do not exhibit cytotoxicity effect. Additionally, corresponding inflammation test were performed, indicating that these polymeric surfaces do not produce inflammation and, when curcumin derivative is immobilized, they decrease the inflammation marker level (IL-6). Moreover, the bacterial growth of both Gram positive and Gram negative bacteria were measured, demonstrating that the immobilization of curcumin derivative on PET provided antibacterial properties to the material. Finally, hemolysis rate analysis and whole blood clotting assay demonstrated the antithrombogenic effect of PET-Cur surfaces as well as no hemolysis concern in the fabricated functional surfaces.

Tendon Decellularized Matrix Modified Fibrous Scaffolds with Porous and Crimped Microstructure for Tendon Regeneration.

Current engineered synthetic scaffolds fail to functionally repair and regenerate ruptured native tendon tissues, partly because they cannot satisfy both the unique biological and biomechanical properties of these tissues. Ideal scaffolds for tendon repair and regeneration need to provide porous topographic structures and biological cues necessary for the efficient infiltration and tenogenic differentiation of embedded stem cells. To obtain crimped and porous scaffolds, highly aligned poly(l-lactide) fibers were prepared by electrospinning followed by postprocessing. Through a mild and controlled hydrogen gas foaming technique, we successfully transformed the crimped fibrous mats into three-dimensional porous scaffolds without sacrificing the crimped microstructure. Porcine derived decellularized tendon matrix was then grafted onto this porous scaffold through fiber surface modification and carbodiimide chemistry. These biofunctionalized, crimped, and porous scaffolds supported the proliferation, migration, and tenogenic induction of tendon derived stem/progenitor cells, while enabling adhesion to native tendons. Together, our data suggest that these biofunctionalized scaffolds can be exploited as promising engineered scaffolds for the treatment of acute tendon rupture.