Adhesion Of Films Research Articles

Tilted columnar metal film as transducer of transverse coherent acoustic phonons in picosecond acoustics

Picosecond acoustics has been widely used to study thin film elasticity, hypersound attenuation, and adhesion of thin films to substrates. A major limitation of the technique is its restriction to only longitudinal waves. Although work has been reported on the ultrafast generation and detection of transverse waves, a general method compatible with thin films deposited on silicon is still missing. In this work, we show that by depositing a tilted columnar metal film and using an optical detection sensitive to light polarization, it is possible to excite and detect optically both types of bulk acoustic waves in thin films. The protocol is first established on metalized glass substrates, then applied to a range of transparent films deposited on silicon (silica, AlN, AlScN, and SiC). In each case, Brillouin oscillations are detected at two frequencies, one being the longitudinal mode, the other the transverse. The film thickness and two sound velocities are measured in each thin film. Transverse coherent phonons as high as 116 GHz are observed in the SiC thin film.

X-Ray Photoelectron Spectroscopy of TixAl and TixAl/A-Si:H Interlayer with Different Thicknesses on Stainless Steel to Enhancing Adhesion of DLC Films

In this research, two intermediate layers were deposited on 316L stainless steel to improve the adhesion of diamond-like carbon (DLC) films, one composed of TixAl and produced using the RF sputtering technique with three thicknesses, 100 nm, 200 nm, and 300 nm; the other, interlayer composed of amorphous hydrogenated silicon (a-Si:H). The DLC films were deposited using the pulsed-DC PECVD method with an active screen to achieve the AISI 316L/TixAl //DLC and AISI 316L/TiₓAl/a-Si/DLC configurations. The binding energy between the substrate/TixAl and TixAl/a-Si:H was investigated via X-ray photoelectron spectroscopy with high-resolution spectra. The chemical composition and microstructure of the titanium–aluminum interlayers were investigated using energy-dispersive X-ray spectroscopy and X-ray diffraction, and the microstructure of the DLC coatings was studied using Raman spectroscopy. The coatings’ adherence was measured using scratch and indentation tests, and the hardness of the DLC coatings was determined with the nanoindentation test. The X-ray diffractograms did not allow the determination of any crystalline structure in the TixAl interlayers. The XPS results showed that between the AISI 316L substrate and the TixAl intermediate layer, Ti-O-Fe and FeAl2O4 were formed. On the other hand, at the TixAl/a-Si:H interface, TiSi2 and Al2SiO5 compounds were identified. The DLC coatings grew as hydrogenated amorphous carbon with a hydrogen content of around 30 at.% and a hardness of 24 GPa. The deposition methods used and the TixAl/a-Si:H interlayers allowed the obtainment of adherent DLC coatings on AISI 316L stainless steel substrates. High critical load values of about 30 N were obtained. The novelty of this work is underscored by the absence of previous studies that thoroughly examine the bonds present in interlayers used as gradients to enhance the adhesion of DLC.

Preparation and characterization of a low viscosity spray dust suppressant based on xanthan gum grafted sodium α-olefin sulfonate copolymer with proactive coal-adhesive and surface-active properties

To address the problem of the high viscosity of current composite dust suppressants, which results in spray droplet sizes that are not optimal for capturing respirable dust, a low viscosity, proactive coal-adhesive, long-lasting spray dust suppressant, XG-AOS/Tre, has been developed. The suppressant utilizes xanthan gum (XG) from microbial fermentation, with α-olefin sulfonate grafted onto its hydroxyl groups to form a copolymer (XG-AOS), reducing its viscosity while maintaining the surface activity of the hydrocarbon chain and its affinity for coal dust. It has a weighted average molecular weight of 398341, a surface tension of 26.1 mN/m, a viscosity of 1.59 mPa·s, and a contact angle of 48° with coal cake. The suppressant achieves a total dust suppression rate of 85.7 % and a respirable dust suppression rate of 85.9 %. Because of its surface activity and high molecular weight, it efficiently wets and settles coal dust. It retains 47.3 % of the water in its solution 24 h after being sprayed and forms an adhesive film upon complete evaporation, providing the coal dust with resistance to wind erosion. The dust suppressant improves the dust suppression rate for dust control in coal mining. Its properties contribute to the sustainable development and environmental protection of the coal industry.

Highly conductive and uniform PEDOT on poly(acrylic acid-vinylbenzyl chloride) functionalized surfaces

This study demonstrates increasing the uniformity and conductivity of poly(3,4-ethylene dioxythiophene) (PEDOT) thin films synthesized by vapor phase polymerization (VPP) through the utilization of a thin interfacial prime layer on the substrate surface. The prime layer, which is a copolymer of acrylic acid (AA) and vinylbenzyl chloride (VBC), was coated on the substrate surface using initiated chemical vapor deposition (iCVD) method. FTIR and XPS were used to analyze the structure of as-deposited films. The use of P(AA-VBC) copolymer as a prime layer allowed uniform and complete coverage of the oxidant solution on the substrate surface due to the hydrophilic nature of the AA constituent. During the VPP, the existence of the chlorine ions originating from the VBC constituent allowed in-situ doping of the as-deposited polymer, which contributes to the increased uniformity and the conductivity. The experimental studies were carried out to show the increase in uniformity, conductivity and adherence of the as-deposited PEDOT film in the presence of the prime layer. There was nearly a 4-fold increase in the conductivity of as-deposited PEDOT in the presence of the prime layer, with measured conductivity uniformity as high as 96% over a 5×5 cm2 glass surface.

A Review on the Effect of Wood Surface Modification on Paint Film Adhesion Properties

Wood surface treatment aims to improve or reduce the surface activity of wood by physical treatment, chemical treatment, biological activation treatment or other methods to achieve the purpose of surface modification. After wood surface modification, the paint film adhesion performance, gluing performance, surface wettability, surface free energy and surface visual properties would be affected. This article aims to explore the effects of different modification methods on the adhesion of wood coating films. Modification of the wood surface significantly improves the adhesion properties of the paint film, thereby extending the service life of the coating. Research showed that physical external force modification improved the hydrophilicity and wettability of wood by changing its surface structure and texture, thus enhancing the adhesion of the coating. Additionally, high-temperature heat treatment modification reduced the risk of coating cracking and peeling by eliminating stress and moisture within the wood. Chemical impregnation modification utilized the different properties of organic and inorganic substances to improve the stability and durability of wood. Organic impregnation effectively filled the wood cell wall and increased its density, while inorganic impregnation enhanced the adhesion of the coating by forming stable chemical bonds. Composite modification methods combined the advantages of the above technologies and significantly improved the comprehensive properties of wood through multiple modification treatments, showing superior adhesion and durability. Comprehensive analysis indicated that selecting the appropriate modification method was key for different wood types and application environments.

Dynamic response of hemispherical-shell sandwich structures subjected to underwater impulsive loading

In this study, experiments and numerical simulations are designed on aluminum sandwich structures with a hemispherical-shell core layer under underwater impact loading to investigate the dynamic response and energy absorption mechanisms. After the hemispherical-shell sandwich panels are designed and fabricated, they are loaded using an experimental apparatus incorporating fluid–structure interactions. The dynamic response of the sandwich panels is captured using the three-dimensional digital image correlation (3D-DIC) method of high-speed photography, and the energy-absorption mechanisms are analyzed via numerical simulation. This study primarily considers the effects of installation orientation, shock wave impulse and adhesive film on the sandwich panels. The results indicate that the deformation mode and impact resistance of the sandwich panels vary depending on the installation orientation. The displacement at the midpoint of the dry facesheet is linearly related to the shock wave impulse. At non-dimensional impulses exceeding 0.0085, the impact resistance of the forward installation target plate is higher. Additionally, the adhesive film significantly affects the deformation mode of the hemispherical-shell core layer. Its removal slightly increases the proportion of energy absorbed at the core. Quantitative and qualitative analyses of the structure-response-energy relationship are performed on the hemispherical-shell sandwich panels, thus providing guidance for investigations pertaining to the underwater impact resistance of future metal sandwich structures.

Sol-Gel Derived Alumina Particles for the Reinforcement of Copper Films on Brass Substrates.

The aim of this study is to provide tailored alumina particles suitable for reinforcing the metal matrix film. The sol-gel method was chosen to prepare particles of submicron size and to control crystal structure by calcination. In this study, copper-based metal matrix composite (MMC) films are developed on brass substrates with different electrodeposition times and alumina concentrations. Scanning electron microscopy (FE-SEM) with energy-dispersive spectroscopy (EDS), TEM, and X-ray diffraction (XRD) were used to characterize the reinforcing phase. The MMC Cu-Al2O3 films were synthesized electrochemically using the co-electrodeposition method. Microstructural and topographical analyses of pure (alumina-free) Cu films and the Cu films with incorporated Al2O3 particles were performed using FE-SEM/EDS and AFM, respectively. Hardness and adhesion resistance were investigated using the Vickers microindentation test and evaluated by applying the Chen-Gao (C-G) mathematical model. The sessile drop method was used for measuring contact angles for water. The microhardness and adhesion of the MMC Cu-Al2O3 films are improved when Al2O3 is added. The concentration of alumina particles in the electrolyte correlates with an increase in absolute film hardness in the way that 1.0 wt.% of alumina in electrolytes results in a 9.96% increase compared to the pure copper film, and the improvement is maximal in the film obtained from electrolytes containing 3.0 wt.% alumina giving the film 2.128 GPa, a 134% hardness value of that of the pure copper film. The surface roughness of the MMC film increased from 2.8 to 6.9 times compared to the Cu film without particles. The decrease in the water contact angle of Cu films with incorporated alumina particles relative to the pure Cu films was from 84.94° to 58.78°.

An intelligent CFRP bolt with embedded carbon nanotube eddy current sensors for damage self‐diagnosis of bolted composite joints

AbstractRecognizing the critical demand for composite bolts and the damage‐mode complexity of composite bolt joints, this study introduces the concept of an intelligent carbon fiber reinforced polymer (CFRP) bolt, which achieves self‐monitoring of damage in small and complex CFRP bolted joints. The proposed eddy current sensor (ECS) is mainly composed of a coil made of carbon nanotube film and encapsulated with epoxy resin film. This achieves homogeneous embedding of the sensor by using the same material for both sensor and bolt. The CFRP bolt is fabricated by molding process, with the proposed ECS embedded in bolt shank. The numerical simulation results indicate that hole‐edge damages impact the distribution of induced current density and eddy current flow in CFRP plates. Additionally, the impedance amplitude of the ECS effectively monitors bearing damage propagation. Shear tests confirm that the integration method of the proposed ECS within the CFRP bolt introduces negligible intrusion to the host bolt's integrity. Experimental results demonstrate that the intelligent CFRP bolt can effectively monitor the damage propagation at the hole edge, with an accuracy for bearing damage exceeding 0.5 mm. At a working frequency of 10 MHz, the sensor's sensitivity in detecting a 0.5 mm bearing damage reaches 4.20%.Highlights An intelligent CFRP bolt was fabricated using the molding method. The embedding of the ECS did not cause adverse effects on the bolt. The proposed EC sensor is composed of carbon nanotube and epoxy resin adhesive films. The eddy current distribution at the hole edge of the CFRP bolted joints is analyzed. The ability of intelligent bolts to monitor hole edge damage is verified by experiments.

Programmable adhesion through triangular and hierarchical cuts in metamaterial adhesives.

Metamaterial design approaches, which integrate structural elements into material systems, enable the control of uncommon behaviours by decoupling local and global properties. Leveraging this conceptual framework, metamaterial adhesives incorporate nonlinear cut architectures into adhesive films to achieve unique combinations of adhesion capacity, release, and spatial tunability by controlling how cracks propagate forward and in reverse directions during separation. Here, metamaterial adhesive designs are explored with triangular cut features while integrating hierarchical and secondary cut patterns among primary nonlinear cuts. Both cut geometry and secondary cut features tune adhesive force capacity and energy of separation. Importantly, the size and spacing of cut features must be designed around a critical length scale. When secondary cut features are greater than a critical length, cracks can be steered in multiple directions, going both forward and backwards within a primary attachment element. This control over crack dynamics enhances the work of separation by a factor of 1.5, while maintaining the peel force relative to a primary cut. If hierarchical cut features are too small or too compliant, they interact and do not distinctly modify crack behaviour. This work highlights the importance of adhesive length scales and stiffness for crack control and attachment characteristics in adhesive films.This article is part of the theme issue 'Origami/Kirigami-inspired structures: from fundamentals to applications'.

Preparation of Tung Oil-Modified Raw Lacquer Films and Application for Mechanical Carving Technique

Raw lacquer, known for its superior performance as a natural liquid coating, boasts excellent physical and mechanical properties as well as durability, making it widely used in manufacturing. However, the high hardness of the lacquer film upon complete curing poses challenges for carving and mechanical engraving. Therefore, it is necessary to study the curing process of lacquer films to obtain films suitable for carving or mechanical engraving. This study involves the preparation of raw lacquer with varying amounts of tung oil added, followed by the measurement of film drying time, surface roughness, glossiness, hardness, and adhesion on substrates to determine the optimal drying conditions. Additionally, SEM analysis of the carved surfaces and FT-IR analysis were used to investigate the impact of tung oil addition on lacquer carving performance and its variation. The results indicate that tung oil, to a certain extent, contributes to a smoother lacquer film but adversely affects film hardness and adhesion to Prunus serotina. However, with an increase in the amount of refined tung oil to 15%, the film exhibits improved glossiness, smoother carving tool marks, and reduced debris, thereby validating the feasibility of mechanical carving of tung oil-modified raw lacquer to some extent.

Femtosecond laser-induced plasma-assisted backward deposition of robustly adherent porous carbon films on glass substrates

The simple and rapid production and transfer of high-quality carbon materials are crucial for the flexible and efficient fabrication of carbon-based electronic devices. Recently, a laser-assisted transfer method combining laser-induced carbonization and transfer printing was demonstrated for the one-step preparation and transfer of patterned laser-induced carbon films to transparent substrates. However, this method is limited by insufficient robustness and weak adhesion of the carbon film post-transfer. Herein, we developed a non-contact laser-induced plasma-assisted deposition method to deposit robustly adherent porous carbon films on glass substrates. By well-adjusting the laser parameters and inserting spacers with adjustable thickness, laser-induced plasma ablation replaced direct laser ablation during femtosecond laser scanning of the substrate-polyimide-carrier sandwich structure, resulting in micro-channels with a carbon-glass recast layer instead of easily peelable flakes on the glass substrate. This hierarchical structure significantly enhances the adhesion between the laser-induced carbon film and the glass substrate, ensuring outstanding stability of the deposited carbon film under various adhesion tests. Furthermore, compared to carbon films prepared by the laser-assisted transfer method, the obtained carbon films are hydrophilic, low-resistance, and porous, facilitating the fabrication of energy storage devices. To demonstrate its practical application, a planar carbon-based micro-supercapacitor was fabricated on glass, exhibiting excellent electrochemical and cycling performance.

Enhanced adhesion and wear resistance of DLC films on AZ31 alloy achieved with high bias voltage

Diamond-like carbon (DLC) films exhibiting high adhesion and exceptional wear resistance were successfully applied onto the AZ31 surface without a adhesive layer. The structural features of the film were examined utilizing Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), and Raman spectroscopy. Mechanical properties were evaluated through Nano-indentation testing, while adhesion was evaluated using a scratch tester. Residual stress was determined by Stoney's equation. The results indicate that utilizing a high substrate bias ranging from −500 to −800 V, results in the presence of multiple craters and dislocations, which contribute to the enhancement of high residual compressive stress and hardness in the DLC film. The heightened compressive stress effectively embeds carbon atoms into the surface of the soft AZ31, creating an interfacial layer that significantly improves adhesion and wear resistance of the film. In contrast, at moderate bias levels with a range from −300 to −500 V, an increase in substrate temperature leads to the expansion and discontinuation of adjacent layers that decreases the mechanical properties, adhesion, and wear resistance of the film. When at low bias levels between 0 and -300 V, the hardness, crack resistance, residual stress, and wear resistance all increase with increasing of bias. Additionally, in this work, the mechanisms of adhesion and wear for the biased film are analyzed.

Polyvinyl acetate wood adhesive stabilized with hydroxyethyl cellulose: synthesis and characterizations

Specifically, the conventional wood adhesive uses polyvinyl alcohol (PVA) as colloid to stabilise the polyvinyl acetate (PVAc) emulsion. Green materials are being used as a result of recent study on chemicals and alternative sources. This factor has made the substitution of sustainable biopolymers for petrochemicals considerably more important. An emulsifier, sodium lauryl sulphate (SLS), was used during the addition polymerization process to produce a hydroxyethyl cellulose-grafted-poly (vinyl acetate) (HEC-g-P(VAc)) emulsion from HEC and VAc. The purpose of the study was to increase the content of renewable materials in the emulsion. The adhesive films glass transition temperatures (Tg) have been identified via Differential Scanning Calorimetry (DSC). The performance of the PVAc emulsion-based adhesive in accordance with EN 204 and EN 205 standards was evaluated by measuring the tensile shear strength of wood joints under both dry and wet conditions. The viscosity of the adhesives significantly increased along with the addition of HEC. The application of HEC led to an increase in PVAc film hardness, which was confirmed by the film’s glass transition temperature. In an environment that was wet, after 24 h, the tensile strength of the sample containing HEC increased by 54% compared to a pristine sample, as per EN 204 and EN 205. Water resistance significantly increased in sample with HEC, as was found by measuring the water contact angle which is in line with wet strength. The overall study conclusion emphasises the superior water resistance and increased adhesion capabilities of PVAc emulsion-based wood adhesives stabilised by HEC.

Meibomian gland lipid alterations and ocular surface sequela in Awat2 knockout murine model of meibomian gland dysfunction and evaporative dry eye disease

PurposeThere is an urgent need for animal models of meibomian gland dysfunction (MGD) and evaporative dry eye disease (EDED) to understand their pathophysiology and investigate novel therapeutics. This study sought to further define the acyl-CoA: wax alcohol acyltransferase 2 knockout (Awat2 KO) mouse as a model of EDED using a combination of novel clinical, biochemical, and biophysical endpoints. MethodsWildtype and Awat2 KO mice between 1 and 18 months of age were used. Ocular examinations and advanced imaging were performed. The lipidomic composition and in situ melting temperature of meibum were determined. qPCR was performed to define ocular surface gene and pro-inflammatory transcript expression. Dynamic contact angle goniometry was performed to assess the adherence capability of the ocular surface. ResultsAwat2 KO mice have mild, white, hyperreflective corneal opacities of the anterior stroma and significantly enlarged apical epithelial cells (P=0.0004). In Awat2 KO meibum, wax esters were 9-10 times lower than in wildtype meibum. Additionally, meibum melting temperature increased from 32° to 47°C (P<0.0001), leading to impaired meibum secretion and dilation of the central duct. Awat2 KO corneal epithelia had significantly decreased mucin expression (Muc1 and Muc4, P=0.0043) and increased interferon-γ production (P=0.0303). Awat2 KO globes have a significantly shortened time of droplet adherence to their ocular surface (P=0.0053), indicating a decreased tear film adherence capacity. Wildtype corneal epithelia does not express Awat2, indicating that the EDED phenotype is secondary to the loss of Awat2 from the meibomian glands. ConclusionsAwat2 KO mice recapitulate many of features of human MGD and EDED, representing a model to test novel therapeutics.

Crystalline Orientation Control Enhanced Adhesion of Perovskite to Large‐Area Readout Board for High‐Performance X‐Ray Imaging

AbstractHalide perovskites are reputed as highly promising photoelectronic materials for direct X‐ray detectors, but realizing large‐area flat‐panel imaging requires to address the compatibility issue of the electronic, surficial, and mechanical properties between the perovskite and the readout circuit board. Here, a low‐dimensional MA3Bi2I9 perovskite is chosen to achieve a good match in a balancing act between the two by exploiting an orientation control strategy for perovskite film growth. The most striking consequence of the orientation controlled growth is the excellent adhesion of the thick perovskite film to the electronic board in large area and effectively addresses the charge sharing effect, which has been notoriously difficult to achieve. The resulting detector, exhibits an X‐ray imaging area of 2.8 × 3.2 cm, with a spatial resolution of 4.0 lp mm⁻¹, the highest yet achieved for polycrystalline perovskite detectors based on TFT backplanes, and a sensitivity of 588 µCGyair−1 cm−2 while maintaining a dark current below 10 nA cm⁻2, this is also the highest value recorded to date for polycrystalline zero‐dimensional perovskite detectors. This device clearly revealing the intricate internal structures of both biological specimens and industrial products. This outcome demonstrates the potential of zero‐dimensional perovskites in X‐ray planar imaging and highlights the critical role of orientation control strategies.

Al Electroplating on Etched CFRP Surfaces in AlCl3-EmImCl Ionic Liquids

To improve the wear resistance of CFRP, Al electroplating on the surface was proposed. Etching of the resin on the CFRP surface in sulfuric acid solution was investigated to improve the adhesion of the Al plating film on CFRP. As a result of the etching treatment, more carbon fibers were found on the CFRP surface. Al film was electroplated to the etched CFRP in AlCl3-EmImCl ionic liquid; the adhesion strength of the Al plated film to the CFRP surface increased with etching time.

Development of Halloysite Nanohybrids-Based Films: Enhancing Mechanical and Hydrophilic Properties for Wound Healing.

Most of the therapeutic systems developed for managing chronic skin wounds lack adequate mechanical and hydration properties, primarily because they rely on a single component. This study addresses this issue by combining organic and inorganic materials to obtain hybrid films with enhanced mechanical behavior, adhesion, and fluid absorption properties. To that aim, chitosan/hydrolyzed collagen blends were mixed with halloysite/antimicrobial nanohybrids at 10% and 20% (w/w) using glycerin or glycerin/polyethylene glycol-1500 as plasticizers. The films were characterized through the use of Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), and electron microscopy. The mechanical properties were evaluated macroscopically using tensile tests, and at a nanoscale through atomic force microscopy (AFM) and nanoindentation. Thermodynamic studies were conducted to assess their hydrophilic or hydrophobic character. Additionally, in vitro cytocompatibility tests were performed on human keratinocytes. Results from FTIR, TGA, AFM and electron microscopy confirmed the hybrid nature of the films. Both tensile tests and nanomechanical measurements postulated that the nanohybrids improved the films' toughness and adhesion and optimized the nanoindentation properties. All nanohybrid-loaded films were hydrophilic and non-cytotoxic, showcasing their potential for skin wound applications given their enhanced performance at the macro- and nanoscale.

Effect of Ta on selective oxidation behavior and oxide film adhesion of alumina-forming austenitic alloys

The effects of Ta on the selective oxidation behavior and scale adhesion of Fe-45Ni-25Cr-4Al-1.5Nb-0.4C-xTa (x=0.6, 0.9, 1.2, 1.5 wt%) austenitic alloys at high temperature under low oxygen pressure were investigated. The FCC, MC-(Ta, Nb)C, M23C6 and B2-NiAl phases were found in the annealed alloy. Addition of Ta significantly promoted the formation of an external Al2O3 layer and inhibited growth of Cr2O3 and spinel at 850 °C under oxygen pressures of 10−18 atm and 10−24 atm. Similar oxidation behavior was observed in two-step oxidation process (650 °C for 8 hours and 1000 °C for 16 hours). Ta and Nb preferentially segregated at the interface between the oxide scale-matrix as well as grain boundary within the oxide scale during oxidation, and inhibited outward diffusion of Al and Cr. A large oxygen activity gradient was formed in the oxide film, resulting in the formation of columnar grains. Due to a significant decrease in oxygen activity at the front of the reaction, selective oxidation of alumina was promoted. Furthermore, the scratch test technique was used to quantify the adhesion of oxide scales. Peg-like structures formed by Ta and Nb positively influenced the adhesion properties of the oxide scale.

Natural Product-Based Pressure-Sensitive Adhesives via Carveol-Dithiothreitol Thiol-Ene Step-Growth Polymerization.

Pressure-sensitive adhesives occupy a large role in the commercial use of polymers; however, they are typically limited to nondegradable formulations using petroleum-based materials. As the plastic and environmental crises have intensified, the need for renewable starting materials and degradable designs has similarly deepened. With that goal, we endeavored to make adhesive films from renewable terpenes as a safer and more sustainable route to PSAs. Specifically, based on our previous report of the cross-linking ability of a carveol-based carbonate through thiol-ene chemistry, we report further exploration of the adhesive possibilities of this system. A carbonate monomer of dimerized carveol was linearly polymerized with dithiothreitol via UV-initiated thiol-ene chemistry and formed into adhesive coatings, with unmodified geraniol doped in as a tackifier. We obtained a range of adhesive properties based on the ratio of exo-methylene to thiol units and reported on the degradation of the adhesive coatings.

Injectable and photocurable precursors with their improved adhesive elastomeric films by nature-inspired marine mussels chemistry

Photocurable materials, capable of being delivered as liquids and rapidly cured in situ within seconds using UV light, are garnering increased interest in advanced minimally invasive procedures. Examining living organisms to extract novel principles and technologies, and subsequently applying them into synthetic materials to enhance their performances holds a central position in biomimetics (bioinspiration). In this exploration, we delve into the multifaceted world of marine mussel adhesion, emphasizing the pivotal role of 3,4-dihydroxy-L-phenylalanine (L-DOPA) in adhesive proteins. Simultaneously, we navigated the promising realm of elastomers derived from fatty acid dimers. 90° peeling test and fluorescence microscope indicate that the adhesiveness of the catechol-containing samples (5 % and 10 %) to the hydrophilic surface versus control samples were ∼ 4 and 8 times higher, respectively, as compared to within the tested group. Overall, our results suggest that the incorporation of methacrylated L-DOPA in the synthesis of photocured elastomeric networks leads to lower water contact angle and improved adhesiveness, creating new avenues for potential biomedical applications.