Excellent Adhesion Research Articles

In-situ Zn-Al layered double hydroxide conversion coatings prepared on galvanized steels by a two-step electrochemical method

Zn-Al layered double hydroxide (LDH) pretreatment layer was prepared by a novel two-step electrochemical method on galvanized steel surface from a precursor solution containing Al3+-only. In the first step, anodic currents are applied to Zn deposit to produce Zn2+ in solution near the substrate surface. Cathodic currents are then applied to ensure the cathodic deposition of LDH film. The obtained LDH coatings not only provide excellent adhesion to the metal surface, but also enhance the adhesion between metal substrate and the top epoxy coatings. The “LDH/epoxy” painting system can protect galvanized steel from rusting for at least 150 days.

Highly efficient anti-reflection coating on transparent material surface by a deposition-oxidation two-step process using very high-frequency plasma under atmospheric pressure

Using atmospheric-pressure (AP) helium (He)-based plasma excited by a 150 MHz very high-frequency (VHF) power, the formation of low-refractive-index silicon oxide (SiOx) layers for single-layer quarter-wave anti-reflection (AR) coatings of transparent substrate materials is studied. To effectively lower the refractive index of SiOx layers, a deposition-oxidation two-step process is adopted. Specifically, carbon and hydrogen-containing silicon oxide (SiOCH) films are coated in hexamethyldisiloxane and hydrogen-fed plasma on the substrates with fine polystyrene spheres arranged, and subsequently oxidized in oxygen-fed plasma. During the post-oxidation process, the SiOCH film is transformed into silica (SiO2)-like one and the polystyrene spheres underlying the film is simultaneously oxidized to be removed. As a result, a SiO2-like film with a very low refractive index of 1.23 and with excellent adhesion to the substrate is obtained. It is also demonstrated that the low-refractive-index coating functions well as a quarter-wave AR coating of a glass substrate.

Multifunctional Self-Healing Carbon Dot-Gelatin Bioadhesive: Improved Tissue Adhesion with Simultaneous Drug Delivery, Optical Tracking, and Photoactivated Sterilization.

Bioadhesives with all-inclusive properties for simultaneous strong and robust adhesion, cohesion, tracking, drug delivery, self-sterilization, and nontoxicity are still farfetched. Herein, a carbon dot (CD) is made to infuse each of the above-desired aspects with gelatin, an inexpensive edible protein. The CD derived through controlled hydrothermal pyrolysis of dopamine and terephthaldehyde retained -NH2, -OH, -COOH, and, most importantly, -CHO functionality on the CD surface for efficient skin adhesion and cross-linking. Facile fabrication of CD-gelatin bioadhesive through covalent conjugation of -CHO of the CD with -NH2 of gelatin through Schiff base formation was accomplished. This imparts remarkable self-healing attributes as well as excellent adhesion and cohesion evident from physicomechanical analysis in a porcine skin model. Improved porosity of the bioadhesive allows loading hemin as a model drug whose disembarkment is tracked with intrinsic CD photoluminescence. In a significant achievement, antibiotic-free self-sterilization of bioadhesive is demonstrated through visible light (white LED, 23 W)-irradiated photosensitization of the CD to produce reactive oxygen species for annihilation of both Gram-positive and Gram-negative bacteria with exceptional efficacy (99.9%). Thus, a comprehensive CD-gelatin bioadhesive for superficial and localized wound management is reported as a promising step for the transformation of the bioadhesive domain through controlled nanotization for futuristic clinical translations.

Dialdehyde cellulose (DAC) and polyethyleneimine (PEI) coated polyvinylidene fluoride (PVDF) membrane for simultaneously removing emulsified oils and anionic dyes

Developing high-efficiency membrane for oil and dye removal is very urgent, because wastewater containing them can cause great damage to human and environment. In this study, a coated membrane was fabricated by applying DAC and PEI onto the commercial PVDF microfiltration membrane for supplying the demand. The coated membrane presents superhydrophlic and superoleophobic properties with a water contact angle of 0o and underwater oil contact angle exceed 150°, as well as excellent low underwater oil adhesion performance. The coated membrane shows high separation efficiency exceeded 99.0% and flux 350.0 L·m−2·h−1 when used for separating for six kinds of oil including pump oil, sunflower oil, n-hexadecane, soybean oil, diesel and kerosene in water emulsions. Additionally, the coated membrane can effectively remove anionic dyes, achieving rejection rates of 94.7%, 93.4%, 92.3%, 90.7% for the CR, MB, RB5, AR66, respectively. More importantly, the membrane was able to simultaneously remove emulsified oil and soluble anionic dyes in wastewater containing both of them. Therefore, this novel coated membrane can be a promising candidate for treating complex wastewater.

Highly radiation-stable DLC coatings for a new class of detectors: Structural and morphological features

Within the framework of the FTM-NEXT INFN (Fast Time Micropattern gaseous detectors - next of Nuclear Physics National Institute) experiment, we produced hydrogen-free diamond-like carbon films through pulsed-laser deposition to serve as resistive layers in modern resistive micro-pattern gaseous detectors that must work in extreme radiation environments at future colliders. To obtain homogeneous diamond-like carbon coatings, over medium-to-large size (3 cm × 3 cm), with excellent adhesion to the substrate and with typical surface resistivity values in the range of 1–100 MOhm/sq, growth conditions had to be optimized. In this paper we report on the stability of resistive diamond-like carbon layers subjected to increasing doses of irradiation with proton beams accelerated to an energy of 2 MeV. The morphological, structural, and electrical properties, also at the nanoscale level, of diamond-like carbon coatings following ion irradiation were studied by electron microscopy, electron diffraction, electrical transport characterization and scanning tunneling spectroscopy.

A biomimetic mineralized collagen hydrogel containing uniformly distributed and highly abundant dopamine‐modified hydroxyapatite particles for bone tissue engineering

AbstractIn this study, hydroxyapatite (HAp)/mineralized collagen hydrogel composites were prepared by incorporating different amounts of dopamine‐modified HAp particles during the process of collagen self‐assembly and simultaneous mineralization. Zeta potential results showed that the surface charge of modified HAp particles was altered, and scanning electron microscopy patterns indicated that HAp particles were uniformly distributed in the hydrogels. The occurrence of collagen biomineralization was indirectly reflected by the results of Ca and P content in the hydrogel supernatant, and the results of ash content indicated that the mineral content of the hydrogels could be up to 60% or more, which was close to the inorganic content in natural bone. The results of CCK‐8 and ALP activity assays showed that mineralized collagen hydrogels were favorable for cell proliferation and differentiation, and the hydrogels containing dopamine‐modified HAp particles obtained a higher expression of osteogenic differentiation related transcription factor. The results showed that the excellent adhesion properties of dopamine contributed to enhance the bone repair potential of the composites, suggesting that mineralized collagen hydrogel composites containing dopamine‐modified HAp particles, which could mimic the structure and composition of bone, have a promising potential as bone tissue engineering scaffolds.

A TLR4-Targeting Bioactive Peptide Hydrogel to Regulate Immune-Microenvironment for Diabetic Wound Repair.

Persistent inflammation and disrupted immunoregulation are critical factors in impeding diabetic wound healing. While immunoregulatory hydrogel dressings hold significant promise for clinical applications in diabetic wound healing, the current application often demands intricate interventions and high-cost treatments involving cytokines and cell therapies. The development of single component immunoregulatory hydrogels remains a complex challenge. To address this issue, an active peptide hydrogel with immunoregulatory properties targeting the TLR4/NF-kB pathway, aiming to promote rapid diabetic wound healing, is engineered. The hydrogel sequence comprises naphthalene derivative, phenylalanine, and glycine to modulate hydrophilic/hydrophobic characteristics. The amino group on arginine contributes to tissue adhesion and regulation of intermolecular forces, ultimately yielding stable gels. The results underscore the formation of the peptide hydrogel (NFA) via the physical crosslinking of self-assembled nanofibers in water, thereby affording both excellent injectability and tissue adhesion. Notably, NFA demonstrates significant potential in promoting wound healing in a mouse model with full-thickness wounds by regulating macrophage responses in the inflammatory microenvironment through the TLR4/NF-kB pathway.

Effect of Tannic Acid Concentrations on Temperature-Sensitive Sol-Gel Transition and Stability of Tannic Acid/Pluronic F127 Composite Hydrogels.

Recently, interest in polyphenol-containing composite adhesives for various biomedical applications has been growing. Tannic acid (TA) is a polyphenolic compound with advantageous properties, including antioxidant and antimicrobial properties. Additionally, TA contains multiple hydroxyl groups that exhibit biological activity by forming hydrogen bonds with proteins and biomacromolecules. Furthermore, TA-containing polymer composites exhibit excellent tissue adhesion properties. In this study, the gelation behavior and adhesion forces of TA/Pluronic F127 (TA/PluF) composite hydrogels were investigated by varying the TA and PluF concentrations. PluF (above 16 wt%) alone showed temperature-responsive gelation behavior because of the closely packed micelle aggregates. After the addition of a small amount of TA, the TA/PluF hydrogels showed thermosensitive behavior similar to that of PluF hydrogels. However, the TA/PluF hydrogels containing more than 10 wt% TA completely suppressed the thermo-responsive gelation kinetics of PluF, which may have been due to the hydrogen bonds between TA and PluF. In addition, TA/PluF hydrogels with 40 wt% TA showed excellent tissue adhesion properties and bursting pressure in porcine intestinal tissues. These results are expected to aid in understanding the use of mixtures of TA and thermosensitive block copolymers to fabricate adhesive hydrogels for versatile biomedical applications.

Combined application of surfactants and iron-based metal–organic framework nanoparticles for targeted delivery of insecticides

With the development of smart delivery systems for pesticides, many studies revealed that nanodelivery methods have great potential for use in efficient and sustainable agriculture; however, field application of the nanopesticides is still a challenge. In this study, the application of a chlorfenapyr (CF)-loaded iron-based metal–organic framework (CF@MIL-101-SL) to maize and its control efficacy for Spodoptera frugiperda were investigated in detail. The results showed that, compared with a suspension concentrate of CF (CF-SC), a solution of CF@MIL-101-SL with the surfactant aerosol OT exhibited excellent wetting, deposition and adhesion with maize leaves. The CF@MIL-101-SL NPs exhibited bidirectional translocation in maize, which significantly enhanced the transport of CF to the target tissues. Field trials revealed that CF@MIL-101-SL maintained > 75 % control efficiency after 21 d of spraying, indicating significantly greater insecticidal activity and persistence than CF-SC. Spray application of CF@MIL-101-SL gave high initial deposition rates, long half-lives on tender and old leaves and significantly reduced pesticide drift into the environment. Based on a biosafety assessment, spraying with CF@MIL-101-SL reduced the negative effects of CF on plants during the growth period. In addition, CF@MIL-101-SL increased the survival rate of Harmonia axyridis larvae and reduced the impacts of CF on the growth and intestinal damage of Harmonia axyridis. In summary, these results highlight the advantages of metal–organic framework delivery systems for multidimensional enhancement of pesticide efficacy, persistence, and safety and provide data on field application and the environmental risks of nanodelivery systems.

Water‐Soluble Multifunctional Binder with Extraordinary Bonding Strength for High‐Voltage Sodium‐Ion Batteries

AbstractWith the ever‐increasing demand for low‐cost energy storage systems, sodium‐ion (Na‐ion) batteries have received great attention. However, the large volume change, sluggish reaction kinetics, and unstable electrode/electrolyte interphase during cycling inevitably deteriorate the performance of Na‐ion batteries. Herein, a high‐voltage water‐soluble multifunctional binder with an extraordinary bonding strength is investigated. Such water‐soluble binder not only exhibits an excellent adhesion strength to maintain the mechanical integrity and enhance the Na‐ion diffusion across the interfac but also constructs a robust protective layer to prevent side reactions and improve the cycle durability at high voltages. As a result, a specific capacity of 91.3 mAh g−1 at 10.0C and high capacity retention of 92.3% for 1000 cycles are achieved. A good cycle stability and rate performance between 2.5 and 4.4 V can be observed after pairing with a high‐voltage electrode, and the practical application of the high‐voltage water‐soluble multifunctional binder is further confirmed by a 0.95 Ah Na‐ion pouch cell.

Hydroxypropyl chitosan/ε-poly-l-lysine based injectable and self-healing hydrogels with antimicrobial and hemostatic activity for wound repair

The biggest obstacle to treating wound healing continues to be the production of simple, inexpensive wound dressings that satisfy the demands associated with full process of repair at the same time. Herein, a series of injectable composite hydrogels were successfully prepared by a one-pot method by utilizing the Schiff base reaction as well as hydrogen bonding forces between hydroxypropyl chitosan (HCS), ε-poly-l-lysine (EPL), and 2,3,4-trihydroxybenzaldehyde (TBA), and multiple cross-links formed by the reversible coordination between iron (III) and pyrogallol moieties. Notably, hydrogel exhibits excellent physicochemical properties, including injectability, self-healing, water retention, and adhesion, which enable to fill irregular wounds for a long period, providing a suitable moist environment for wound healing. Interestingly, the excellent hemostatic properties of the hydrogel can quickly stop bleeding and avoid the serious sequelae of massive blood loss in acute trauma. Moreover, the powerful antimicrobial and antioxidant properties also protect against bacterial infections and reduce inflammation at the wound site, thus promoting healing at all stages of the wound. The study of biohydrogel with multifunctional integration of wound treatment and smart medical treatment is clarified by this line of research.

Dynamic Changes of Capsular-Intraocular Lens Adhesion in Plate-Haptic Hydrophilic and Loop-Haptic Hydrophobic Eyes.

The aim of this work is to investigate the dynamic changes of capsular-intraocular lens (IOL) adhesion in plate-haptic hydrophilic and loop-haptic hydrophobic eyes. Cataract eyes that met the inclusion criteria were randomly assigned to receive implantation of a plate-haptic hydrophilic or loop-haptic IOL. The anterior capsular adhesion, posterior capsular adhesion, and the configurations of the capsular bend were evaluated using swept-source optical coherence tomography at 1day, 1week, 1month, and 3months postoperatively. In total, 66 eyes of 66 patients were eligible for the analysis: 33 in the plate-haptic group and 33 in the loop-haptic group. The contact between the anterior capsule and IOL in the plate-haptic group was earlier than that in the loop-haptic group upon comparing the measurements taken at 1day and 1week (p = 0.001, p = 0.003, respectively). The complete attachment of the posterior capsule and IOL in the plate-haptic group was significantly greater at 1week, 1month, and 3months (p = 0.001, p = 0.000, p = 0.001, respectively). The capsular bend index of the plate-haptic group was significantly greater than that of the loop-haptic group at each time points except at 1day (p = 0.007, p = 0.049, p = 0.005, respectively). Furthermore, a new type of capsular bend, "cocked adhesion," was observed in the plate-haptic eyes. The plate-haptic IOL demonstrated excellent capsular adhesion compared to the loop-haptic IOL, which was probably attributed to haptic compressibility. A special cocked configuration of the capsular bend in plate-haptic IOL was observed for the first time. Further studies are warranted to confirm the effect of the new type of capsular bend.

Visible light-induced photocatalytic and antibacterial adhesion properties of superhydrophilic TiO2 nanoparticles

Bacterial infections triggered by patient or healthcare worker contact with surfaces are a major cause of medically acquired infections. By controlling the kinetics of tetrabutyl titanate hydrolysis and condensation during the sol–gel process, it is possible to regulate the content of Ti3+ and oxygen vacancies (OVs) in TiO2, and adjust the associated visible light-induced photocatalytic performance and anti-bacterial adhesion properties. The results have shown that the Ti3+ content in TiO2 was 9.87% at the calcination temperature of the reaction system was 300 °C and pH was 1.0, corresponding to optimal photocatalytic and hydrophilic properties. The formation of a hydrated layer on the superhydrophilic surface provided resistance to bacterial adhesion, preventing cross-contamination on high-touch surfaces. The excellent photocatalytic self-cleaning performance and anti-bacterial adhesion properties can be attributed to synergistic effects associated with the high specific surface area of TiO2 nanoparticles, the mesoporous structure, and the presence of Ti3+ and OVs. The formation of superhydrophilic self-cleaning surfaces under visible light can serve as the basis for the development of a new class of anti-bacterial adhesion materials.

Maize‐derived zein/acrylic hybrid emulsion for superior skin adhesion and water resistance in cosmetic adhesives

AbstractWaterborne acrylic emulsions are considered suitable materials for cosmetic skin adhesives because of their positive attributes, such as their safe water‐based polymerization process and low volatile‐organic‐compound emissions. The significant challenge of inadequate water resistance in emulsion adhesives, which is primarily caused by the excess surfactants retained at the interface of emulsion particles upon film formation, necessitates urgent resolution for their viable application as cosmetic adhesives. Zein, a corn‐derived protein, possesses hydrophobic amino acids that provide exceptional water‐repellent characteristics. Therefore, zein is expected to exhibit a remarkable skin‐adhesion attribute. This paper presents the introduction of a pioneering zein/acrylic hybrid emulsion exhibiting remarkable skin adhesion and water resistance, which was achieved through the use of zein, a corn‐derived protein. After formation, the zein/ sodium dodecyl sulfate (SDS) complex can unfold the zein chain, thereby enhancing skin adhesion, while concurrently inhibiting surfactant migration to enhance water resistance. The zein/SDS complex was introduced into the Pre‐emulsion (PE) manufacturing process during emulsion polymerization. As expected, the zein/acrylic hybrid emulsion demonstrated favorable skin adhesion and a notable improvement in water resistance. This approach presents a promising avenue for the practical application of emulsion nanoparticles as eco‐friendly cosmetic adhesives, offering excellent durability and skin adhesion through the utilization of naturally derived proteins.

467 Enhancing Cell Infiltration and Controlled Growth Factor Release for a Customized 3D-Printed Bone Graft Composite

OBJECTIVES/GOALS: Annually, 1.5 million global patients receive maxillofacial reconstruction. The gold standard, involving bone particulate, lacks reproducibility. To improve this, we have developed a custom 3D-printable, porous cover-core design. This study optimizes the hydrogel core properties and growth factor (GF) release for enhanced bone regeneration. METHODS/STUDY POPULATION: Different ratios of Methacrylated Gelatin (GelMa), Methacrylated Alginate (AlgMa) and tricalcium phosphate (α²-TCP) were combined to optimize cell viability, GF sequestration and mechanical stability. Material characterization was performed using a rheometer to determine the viscoelastic properties of the blends. Release from disks loaded with FGF-containing PLGA microparticles was quantified with an ELISA kit. Furthermore, scanning electron microscopy (SEM) was conducted to quantify hydrogel porosity. In vitro studies were performed using NIH 3T3 murine fibroblasts in Corning Transwells while immunofluorescent, metabolic and osteogenic studies were performed in 96 well plates to investigate cell infiltration, cell adhesion, viability and differentiation, respectively. RESULTS/ANTICIPATED RESULTS: By adjusting the AlgGelMa ratio, we manipulated matrix properties. GelMa possesses excellent durability and cell adhesion due to intrinsic RGD-binding motifs. AlgMa enhanced swelling by 30%, growth factor sequestration by 50% in 24hrs, and matrix storage modulus without increasing the loss modulus which could cause cell migration away from the hydrogel. Varying the AlgGelMa ratio lowered pH, promoted cell infiltration, and reduced fibronectin accumulation. The addition of β-TCP is anticipated to improve cell differentiation towards an osteogenic lineage due to improved elastic modulus, calcium and phosphate ion concentration improving mineral deposition. DISCUSSION/SIGNIFICANCE: These findings suggest through the use of this composite, early cell infiltration can be increased and promoted due to FGF release, leading to increased osteointegration. Our porous cover-core design ensures efficient clot integration and early cell infiltration, enhancing osteointegration through FGF release.

Biodegradable all-natural hydrogel–mesh composite for wet tissues adhesion and infected wound healing

The application of meshes in surgery is severely limited by complications associated with the non-absorbable nature, the lack of bioactivities, and the need of sutures and/or staples to fix meshes on tissues. In this contribution, a self-adhesive hydrogel-mesh composite (HMC) with biodegradability and multiple bioactivities was developed to address these issues and meet the clinical requirements. In this HMC system, GelMA hydrogel network was first macrotopological entangled with the fibers of a natural small intestinal submucosa (SIS) meshes, and then strengthened by soaking in a multi-functional H-bond provider (i.e., tannic acid, TA) solution to form the G/SIS-TA composite. The pyrogallol groups of the TA molecules endow G/SIS-TA with excellent wet adhesiveness (shear strength: ∼60 kPa), antioxidant, and antibacterial ability. The G/SIS-TA was also found to exhibit excellent biodegradability, biocompatibility, and immunoregulatory activity. The G/SIS-TA significantly decrease the bacterial burden in a mouse peritonitis infection model and promote the healing of infected full-thickness rat skin wounds in vivo. This work not only reports a novel SIS-based HMC which was efficient in treating infected wounds, but also offers an innovative strategy of the development of self-adhesive bio-patch for various biomedical applications.

Synergistic enhancement of photothermal energy storage capacity of polyethylene glycol by polydopamine and nano-copper particles

Phase change materials (PCMs) are a crucial focus of research in the field of photothermal energy storage. However, due to their inherently low photothermal conversion efficiency, traditional PCMs absorb solar energy scarcely. The photothermal conversion ability of PCMs are usually enhanced by incorporating photothermal conversion nanoparticles. Polydopamine (PDA) is widely used in various fields due to its excellent photothermal conversion and adhesion performance. We dispersed PDA into PEG containing CuNPs to test the effect of PDA on thermal properties of cPCMs. Our team has conducted experiments to test the thermal characteristics and photothermal conversion ability of cPCMs. Results demonstrated that the addition of PDA mitigated the enthalpy loss caused by integrating CuNPs. The enthalpy of melting of cPCMs with addition of polydopamine is greater than that without polydopamine for the composites with different mass fractions. The addition of PDA in cPCMs enhanced their photothermal conversion capacity, resulting in higher temperatures being achieved within the same exposure time compared to samples without PDA. Therefore, the cPCMs with dispersed polydopamine can store higher energy. Meanwhile, PDA also improved the overall thermal conductivity of the material. Our work provided a new method to utilize the photothermal properties of polydopamine. Meanwhile, it can reduce the cost of photothermal energy storage PCMs and further improve the potential of PCM energy storage.

Ground tire rubber and coffee silverskin as sustainable fillers in EPDM compounds for rubber‐to‐steel bonded systems in roofing applications

AbstractIn this paper two waste fillers, namely ground tire rubber (GTR) and coffee silverskin (CSS, a waste bio‐product from the coffee‐making process), have been used to produce sustainable ethylene‐propylene‐diene monomer (EPDM) rubber compounds vulcanized on steel sheets to fabricate rubber‐to‐steel bonded systems for industrial roofing applications. The compounds have shown good mechanical performances, with elastic moduli in the range of 13–16 MPa, tensile strength of 13–20 MPa and elongation at break >400%, and strong adhesion to the metal substrate. Moreover, the rubber‐to‐steel bonded systems present good sound insulation properties (mean sound transmission loss [STL] of 39 dB and noise level reduction in simulated hailstones impact tests of 62 dB with respect to bare steel 73 dB). Accelerated UV‐ and thermal‐aging tests have shown excellent adhesion of the compounds to the metal substrate with the CSS acting as an antioxidant agent preventing excessive polymer degradation. The selected waste‐derived materials result in promising fillers for more sustainable rubber compounds.Highlights Waste fillers were used to produce sustainable rubber compounds. Rubber‐to‐steel bonded systems for roofing applications were produced. Rubber‐to‐steel bonded systems have good sound insulation properties. Rubber‐to‐steel bonded systems have excellent adhesion. Coffee silverskin filler acts as an antioxidant agent.

Tyrosinase-Modified UHMW SELP Polymers as Wet and Underwater Adhesives to Achieve Multi-interface Adhesion.

The presence of a hydration layer in humid and underwater environments challenges adhesive-substrate interactions and prevents effective bonding, which has become a significant obstacle to the development of adhesives in the industrial and biomedical fields. In this study, ultrahigh-molecular-weight (UHMW) silk-elastin-like proteins (SELP) with 3,4-dihydroxyphenylalanine (DOPA) converted from tyrosine residues by tyrosinase exhibited excellent adhesive properties on different interfaces, such as glass, aluminum, wood, polypropylene sheets, and pigskin, under both dry and wet conditions. Additionally, by incorporating trace amounts of cross-linking agents like Fe3+, NaIO4, and tris(hydroxymethyl) phosphine (THP), the mussel-inspired adhesives maintained a stable and excellent adhesion, broadening the conditions of application. Notably, the UHMW SELP adhesive exhibited remarkable underwater adhesion properties with a shear strength of 0.83 ± 0.17 MPa on glass. It also demonstrated good adhesion to biological tissues including the kidney, liver, heart, and lungs. In vitro cytocompatibility testing using L929 cells showed minimal toxicity, highlighting its potential application in the biomedical field. The sustainable, cytocompatible, cost-effective, and highly efficient adhesive provides valuable insights for the design and development of a new protein-based underwater adhesive for medical application.

Self‐healing characteristics of superabsorbent polymers in epoxy coating for corrosion inhibition of carbon steels

AbstractThis study evaluated the self‐healing characteristics of superabsorbent polymers (SAP) in epoxy polyamide paint systems applied using brush application. The SAP underwent preliminary characterization to determine its primary properties and was then incorporated into the epoxy primer at different percentages. The epoxy‐SAP coating systems then underwent various tests to evaluate their self‐healing capability. Excellent adhesion is obtained with the coating system composed of initial epoxy primer, epoxy‐SAP layer, final epoxy primer, and an epoxy enamel topcoat. Electrochemical impedance spectroscopy (EIS) reveals that the addition of SAP increased the charge transfer resistance and pore resistance and decreased the double layer capacitance of the coating system in a span of 5 h, confirming the self‐healing of the coating. Maximum corrosion protection for 5 h is obtained between 15 to 20 wt% SAP. Lastly, it is determined through long‐term immersion tests that the addition of SAP in the coating significantly decreases the rust formation; however, the coating starts to peel off due to the swelling of SAP after 2–3 days.