Adhesion Research Articles

Enhanced Electrostatic Dust Removal from Solar Panels Using Transparent Conductive Nano-Textured Surfaces.

Dust accumulation on solar panels is a mjor operational challenge faced by the photovoltaic industry. Removing dust using water-based cleaning is expensive and unsustainable. Dust repulsion via charge induction is an efficient way to clean solar panels and recover power output without consuming any water. However, it is still challenging to remove particles of ≈30µm and smaller because Van der Waals force of adhesion dominates electrostatic force of repulsion. Here, the study proposes nano-textured, transparent, electrically conductive glass surfaces to significantly enhance electrostatic dust removal for particles smaller than ≈30µm. We perform atomic force microscopy pull-off force experiments and demonstrates that nano-textured surfaces reduce the force of adhesion of silica micro-particles by up to 2 orders of magnitude compared to un-textured surfaces from 460 to 8.6 nN. We show that reduced adhesion on nano-textured surfaces results in significantly better dust removal of small particles compared to non-textured or micro-textured surfaces, reducing the surface coverage from 35% to 10%. We fabricate transparent, electrically conductive, nano-textured glass that can be retrofitted on solar panel surfaces using copper nano-mask based scalable nano-fabrication technique and shows that 90% of lost power output for particles smaller than ≈10µm can be recovered.

Experimental and numerical analysis of mixed mode bending of adhesive-bonded and hybrid honeycomb core sandwich structures

This study investigates the potential of a hybrid joining method, called friction stir spot welding with disc and adhesive bonding (FSSW_D_AB), for bonding honeycomb core sandwich structures, offering an alternative to traditional adhesive bonding (AB) sandwich structures. The research focuses on the manufacturing of these hybrid joints and evaluating their performance compared to conventional adhesive bonding (AB) methods. Mixed Mode Bending (MMB) tests were performed to assess the mechanical behaviour of the joints under different loading conditions. Additionally, numerical analysis using cohesive zone modeling (CZM) was performed using both a honeycomb core with a cohesive layer and the homogenized core with an equivalent cohesive layer. The study reveals that the hybrid joining method significantly enhances the performance of honeycomb sandwich structures. The good agreement between the numerical predictions and the experimental results for all types of joints showed the usefulness of the proposed numerical model. However, the FEM-based stress and damage analyses of the joints provided crucial results on normal and shear stress distributions and delamination.

Biomolecule-functionalized exfoliated-graphene and graphene oxide as heteronucleants of nanocrystalline apatites to make hybrid nanocomposites with tailored mechanical, luminescent, and biological properties

Nanocrystalline apatite (Ap), known for its exceptional biological properties, faces limitations in hard tissue engineering due to its poor mechanical properties. To overcome this limitation, we investigated the preparation of nanocomposites through heterogeneous nucleation of calcium phosphate on exfoliated graphene (G) and graphene oxide (GO) flakes, selected for their outstanding mechanical properties. The flakes were treated (functionalized) with amino acids of varying isoelectric points—namely L-Arginine (Arg), L-Alanine (Aln) and L-Aspartic acid (Asp)— as well as citrate (Cit) molecules. Furthermore, Tb3+ was incorporated into the formulations to introduce luminescence and further enrich the functionality of the composite. The synthesis was conducted using the sitting drop vapor diffusion method. Functionalized GO/Ap nanocomposites significantly improved roughness, adhesion forces and elastic modulus compared to Ap and G-based particles. GO-Asp-Ap-Tb nanocomposites exhibited the highest roughness (163.8 ± 116.2 nm), while G-Cit-Ap had the lowest (6.8 ± 5.6 nm). In terms of adhesion force, GO-Cit-Ap-Tb reached the highest value (31.06 ± 13.3 nN), while G-Arg-Ap had the lowest (3.7 ± 1.8 nN) compared to Ap (13.6 ± 3.2 nN). For the elastic modulus, GO-Aln-Ap-Tb demonstrated the greatest stiffness (3489 ± 101.01 MPa) compared to Ap (30.2 ± 6.5 MPa), while G-Aln-Ap-Tb showed the lowest (17.2 ± 8.4 MPa). Concerning their luminescence, regardless of G/Ap and GO/Ap, the relative luminescence intensities depended on the biomolecule used and decreased in the order Arg > Aln >Asp and Cit. Furthermore, G/Ap and GO/Ap nanocomposites demonstrated good biocompatibility on murine mesenchymal stem cells at low concentrations, showing cell viabilities exceeding 80% at 0.1 μg/mL. This research offers a novel approach to enhancing the mechanical properties of apatites while preserving their good biocompatibility properties and introducing new functionalities (i.e. luminescence) in the composites, thereby expanding their range of applications in hard tissue engineering.

Development of Novel Women's Friendly Antifungal Microemulsion Loaded Gel for Vulvovaginal Infections

Aim: The research was carried out to develop the microemulsion-loaded gel of curcu-min, alkylpolyglucoside, and tea tree oil to treat vulvovaginal candidiasis infection. Methods: Screening of oils, surfactants, and co-surfactants was done based on solubility studies and the construction of pseudo-ternary phase diagrams with curcumin. The microemulsion was characterized for globule size, zeta potential, viscosity, and thermodynamic stability. Ex-vivo studies were carried out using Franz diffusion cells. The antifungal activity of microemulsion-loaded hydrogel was evaluated using the cup plate method using Candida albicans ATCC 10231 in glucose yeast agar medium. Results: The selected micro-emulsion consisted of curcumin 35μg/mL, IPM+TTO (1:1) 0.1 mL, Milcoside 100 + Acconon MC 8-2 EP NF 0.6-0.3 mL, phosphate buffer pH 4 160 mL showed maximum thermodynamic stability and exhibited lowest particle size and highest intensity. The viscosity of microemulsion-loaded gel was 11.2 pa.s. The surface tension of the microemulsion was measured by tensiometer and was found to be 26.07 mN/m. Antimicrobial susceptibility test-ing assay was done according to NCCLs assay protocol, and the EC50 value of our formulation was found to be 0.4465 μg/mL. In-vitro drug release and ex-vivo permeation studies showed 67.9% release in 420 minutes and 83.02% release in 360 minutes, respectively. An in-vitro irrita-tion study concluded that there was no redness or irritation on goat mucosa. Conclusion: The texture analysis test showed adhesiveness at -172.46 g s at - 4.60 adhesive force, and the peak load was 13.40 g. The microemulsion-loaded gel formulation can be a promis-ing alternative to the marketed formulations available for vaginal yeast infections.

Recent progress of soiling impact on solar panels and its mitigation strategies: A review

Global warming has become a serious concern due to the increased consumption of fossil fuels. Therefore, green energies have received extensive attention. Among all renewable energies, solar energy is one of the most accessible sources of energy that can be used in the electrical sector. However, it is a well-known fact that solar panels, the main transformers of solar energy into electricity, experience a decrease in performance due to soiling. Various methodologies are available for mitigating soiling losses on solar panels, including traditional approaches like water-based cleansing and robotic arms. However, these conventional methods are increasingly avoided due to drawbacks and the lack of water resources. Alternative strategies involve using advanced thin films with transparent conductive and anti-soiling properties. While transparent conductive films are active and augment electrical fields to repel dust particles through electrostatic forces, anti-soiling films are passive and reduce adhesion forces between dust particles and solar cell surfaces. The present study aims to fill the gap in the existing literature by providing a comprehensive review of passive methods for reducing dust on solar panels, which has been lacking until now. The methodologies and the test methods used in these approaches such as self-cleaning, dust repulsion, and mechanical abrasion tests are illustrated, offering researchers a thorough overview of previous studies. Finally, additional research topics and future perspectives for enhancing the key properties of these surfaces such as transparency, durability, thermal shock resistance, ease of coating process, affordability, and nontoxicity are discussed.

Enhanced adhesion strength of copper deposited epoxy composite films for chip substrates by tuning copper oxide and internal stress

Copper oxides and internal stress have an obvious influence on adhesion strength of copper deposited polymer composites. However, the effect of the evolution behavior of copper oxides and internal stress on adhesion force of chip substrates is no clear and rare far. Herein, the copper deposited epoxy-phenolic/silica composite film with different desmear time was fabricated by using wet chemistry and electrochemistry methods. The chemical structure, surface roughness, morphology, surface chemical state, crystal structure and adhesion strength of copper and epoxy resin substrate were characterized by scanning electron microscope (SEM), interference microscope, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The adhesion strength of samples is increased from 3 N/cm to 4.7 N/cm. The effect of the evolution behavior of copper oxides and internal stress on adhesion strength of copper deposited epoxy resin composite films at the interfaces was systematically investigated, the mechanisms and reason of increasing adhesion strength and interfacial adhesion failure for copper deposited epoxy resin composite substrates were revealed. This work will provide a guidance in theory and experiment to enhance interfacial adhesion force of epoxy resin composite films for advanced substrate in the future.

Enhanced adhesive hydrogel for emergency hemostasis by balancing adhesion and cohesion

Hydrogel adhesives have broad application prospects in biomedical fields such as tissue engineering and emergency rescue. However, due to the high water content and defective network structure, their inherent mechanical strength is low, which seriously hinders their application. In the present work, enhanced adhesive hydrogels could be synthesized by balancing cohesion and adhesion forces. The adhesive hydrogel composed of acryloyl aspartic acid and glycine shows a more dense mesh structure through intermolecular hydrogen bond interactions. As a result, the adhesive hydrogel exhibits enhanced tissue adhesion strength, which benefit from the balance between cohesion and adhesion.

Analyzing Binding Specificity in a Microparticle-Based DNA Displacement Assay Using Multiharmonic QCM-D.

Employing particles as a label is a common approach for signal amplification in various surface-based biosensors. However, the size dependency of adhesive forces can increase the likelihood of nonspecific interactions between the particles and surface. Hence, using microscale particles in surface-based sensors requires both developing surface chemistries with enhanced antifouling properties and precise methods for evaluating these properties. Here we employ a quartz crystal microbalance with dissipation monitoring (QCM-D) to investigate the binding specificity of microparticles anchored multivalently to DNA-functionalized surfaces. We design a competitive particle displacement assay by implementing toehold-mediated strand displacement as an actuator in the microparticle-substrate interface, in which specifically anchored particles dissociate from the surface upon DNA displacement. We evaluate the efficiency of particle displacement in various modified surfaces by measuring the dissipation change (ΔD) following the addition of invader single-strand DNA. We further show that, prior to the particle displacement step, the specificity of particle binding can be inferred from comparing QCM-D harmonics in the particle binding step. Our results suggest that the frequency of zero crossing in the coupled-resonator model, fZC, can be used to characterize the specificity of particle binding. In combination, fZC in the particle binding step and ΔD in the particle displacement step can be considered synergic measures for evaluating the specificity of particle binding on DNA-coated surfaces.

Revolutionizing copper pipe durability: Shielding against corrosion with graphene oxide through electrophoretic application

This research endeavors to utilize electrophoretic deposition (EPD) to coat copper (Cu) pipes with graphene oxide (GO) nanosheets, aiming to bolster their resistance against corrosion. To achieve this, a stable aqueous colloidal suspension of GO was meticulously prepared via liquid exfoliation in deionized water. This suspension served as an electrolytic solution for EPD. The EPD process involved the meticulous application of varied operational parameters such as deposition time, applied voltage, and GO nanosheet concentration to facilitate anodic deposition on the copper pipe’s surface. To gauge the efficacy of the GO coating, evaluations were conducted to assess adhesive force and stabilization using specialized coating adhesion scratch testing equipment. Further analysis of the resulting film on the Cu pipe was executed employing X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, and Fourier transform infrared spectroscopy (FT-IR). These methods provided detailed insights into the characteristics and properties of the GO material post-deposition. The study yielded noteworthy outcomes, revealing the achievement of a uniform, unbroken, and consistent coating film on the Cu pipe. This was accomplished by employing specific parameters as 60 s of deposition time, a GO concentration of 0.5 mg/mL, and a voltage of 20 V. Impressively, when subjected to a corrosive solution containing 3.5% sodium chloride, the corrosion protection exhibited a remarkable twofold enhancement compared to untreated copper tubing, boasting an efficiency (η) of 90.48%. These findings suggest that the Cu pipe, coated with GO using the EPD technique, holds significant promise for utilization in demanding industrial settings susceptible to corrosion challenges.

Effects of particle size on the magnetic cleaning system for manned lunar explorations

A magnetic cleaning system comprising a permanent magnetic roll with a non-magnetic sleeve and a particle collection component is a unique dust mitigation technology in lunar explorations. Enhanced cleaning performance can be achieved by optimal balancing of the forces applied to the particles. The effects of particle size on the capture and release performances were investigated through experiments using size-sorted particles of a lunar regolith simulant and a simple analysis of the force balance varying with the particle size. Experimental and calculated results clarified that the capture of the particles was predominantly facilitated by the magnetic force, while their release was primarily due to the centrifugal force. Although the release of captured particles smaller than 25 μm is one of the challenges in this system due to the adhesion force, this force also contributed to the capture of the small particles with lower magnetic permeability. This magnetic cleaning system, demonstrating its utility in removing particles not only from spacesuits but also from other equipment, achieved the capture and release rates exceeding 70 % and 90 %, respectively, when the simulant particles were dispersed on a flat surface. Moreover, the capture rate of simulant particles with higher magnetic permeability improved, reaching approximately 85 %.

The flotation deashing separation performance of high-ash fine coal-slime using humic acid depressant and insights to its depressant mechanism

Effective inhibition of clay minerals remains a challenge in the flotation separation of fine coal with high ash content. The quest for efficient, environmentally friendly, and cost-effective depressants to improve the flotation efficiency of fine coal-slime has become a focus of current research. Humic acid (HA), a macromolecular organic compound widely present in nature, is known for its non-toxic, low-cost, and biodegradable properties. In this study, the potential selective depressant HA was utilized to enhance the recovery of low-ash clean coal in the coal-kaolinite system. Adsorption and inhibition mechanisms were explored through contact angle measurements, X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM) methods. Flotation tests demonstrated that HA, at varying dosages, significantly increased combustible matter recovery while reducing ash recovery compared to conventional flotation. Optimal conditions, with an HA dosage of 750 g/t, resulted in a combustible matter recovery of 40.56 % and an ash content of 17.77 % in the clean coal. Contact angle measurements confirmed that high-dosage HA significantly reduces the coal surface hydrophobicity, resulting in a rapid decline in the recovery of combustible matter. It did not significantly alter the contact angle of kaolinite, however, across the entire range of HA dosages. Furthermore, XPS studies revealed that the reduction in hydrophobicity on the coal surface after HA adsorption is mainly attributed to the coverage of surface carbon–carbon/carbon-hydrogen groups (C–C/C–H) and the increased presence of carbonyl groups (C = O). Additionally, the study found that HA predominantly adsorbs on the Si-OH groups of kaolinite. Finally, AFM results showed that the primary mechanism underlying the altered heterocoagulation behavior between coal and kaolinite is HA’s effect on their interaction forces. The optimal flotation results achieved at the HA dosage of 750 g/t are primarily attributed to the consistent presence of repulsive forces during the approach process and weak adhesion forces during the retraction process between coal and kaolinite, thus reducing kaolinite coating on the coal surface. These findings provide a promising direction for utilizing HA to enhance flotation deashing of high-ash coal-slime.

Adhesive interactions within microbial consortia can be differentiated at the single-cell level through expansion microscopy

Investigating microbe-microbe interactions at the single-cell level is critical to unraveling the ecology and dynamics of microbial communities. In many situations, microbes assemble themselves into densely packed multispecies biofilms. The density and complexity pose acute difficulties for visualizing individual cells and analyzing their interactions. Here, we address this problem through an unconventional application of expansion microscopy, which allows for the "decrowding" of individual bacterial cells within a multispecies community. Expansion microscopy generally has been carried out under isotropic expansion conditions and used as a resolution-enhancing method. In our variation of expansion microscopy, we carry out expansion under heterotropic conditions; that is, we expand the space between bacterial cells but not the space within individual cells. The separation of individual bacterial cells from each other reflects the competition between the expansion force pulling them apart and the adhesion force holding them together. We employed heterotropic expansion microscopy to study the relative strength of adhesion in model biofilm communities. These included mono- and dual-species Streptococcus biofilms and a three-species synthetic community (Fusobacterium nucleatum, Streptococcus mutans, and Streptococcus sanguinis) under conditions that facilitated interspecies coaggregation. Using adhesion mutants, we investigated the interplay between F. nucleatum outer membrane protein RadD and different Streptococcus species. We also examined the Schaalia-TM7 epibiont association. Quantitative proximity analysis was used to evaluate the separation of individual microbial members. Our study demonstrates that heterotropic expansion microscopy can "decrowd" dense biofilm communities, improve visualization of individual bacterial members, and enable analysis of microbe-microbe adhesive interactions at the single-cell level.

Spontaneous Lifting and Self-Cleaning of Gas Hydrate Crystals.

Crystal fouling, which refers to the accumulation of precipitates on surfaces and the associated damage, is a common problem in many industrial processes. In deepwater oil and gas transportation, hydrate blockage poses as a considerable barrier. Consequently, modifying hydrophobicity of surfaces has become an increasingly focused strategy to mitigate hydrate. However, the design of surfaces that effectively control the hydrate remains challenging. Herein, we report a superior smooth anti-hydrate material based on silanized modification. The low-adhesion silanized silicon wafer (SSW) realizes a win-win strategy of hard formation and easy removal. Through a comprehensive study combining experimental validation with theoretical analysis, the unique characteristics of SSW in the field of anti-hydrate surfaces were deeply discussed. Various hydrate crystals exhibited a completely different hydrate growth mode at the SSW surface, in which hydrate crystals spontaneously elevated and lifted themselves off from the surface. The presence of the fluorine element on the SSW surface allowed self-lifting growth of hydrate crystals after they covered the water droplet. And the loose and porous crystal structure in this self-lifting growth could reduce the contact area between the hydrate crystals and the substrate, allowing the crystals with minimal adhesion force and removal disturbance. Furthermore, the gas enrichment on the SSW surface also reduced the contact with the substrate, thereby decreasing the adhesion and allowing self-cleaning behavior. These results indicate that the silanized surface is a promising candidate for developing anti-hydrate materials for hydrocarbon production and transportation industry.

In-situ thermally induced formation of an ultra-glossy hydrophilic surface for oil fouling prevention in TiO2@MXene membranes

Oil droplets are inevitably deposited on the surface of membranes, resulting in membrane contamination during oily sewage separation. To effectively prevent oil fouling, a TiO2@MXene membrane with an ultra-glossy hydrophilic surface was designed via in-situ thermal induction to regulate the membrane surface structure and properties. Through high temperature-induced evolving the Ti valence and the functional groups of Ti3C2Tx, uniform TiO2 nanoparticles were generated in-situ on the Ti3C2Tx surface while altering the surface structure and properties, which considerably improved the hydrophilicity, underwater oleophobic properties, and surface finish of the membrane. Specifically, the TiO2@MXene membrane (MT600) exhibited a low water contact angle of 7.5° and a high underwater oil contact angle of 133.3°. Notably, the oil adhesion force of the membrane was as low as 0.0013 μN, outperforming most oil water separation membranes. Thus, the unique structure and surface properties endowed MT600 membrane with excellent oil retention (TOC removal efficiency of > 95 %) and antipollution ability (permeance decay rates of < 10 %) for oil-in-water emulsion separation. This is because the ultra-glossy hydrophilic and oleophobic surface prompted the formation of a continuous and stable hydration layer on the membrane surface and prevented oil droplets from falling into the membrane grooves. Benefiting from the robust, ultra-glossy surface, the MT600 membrane exhibited excellent long-term durability and reusability (emulsion permeance recovery of > 90 %) in high-salt, highly acidic, and highly alkaline environments. This study opens pathways to realize ultra-glossy membrane surface for the efficient demulsification of small size emulsions and long-lasting, stable oil water separation.

Influence of the use of an adhesive connection on the joint strength of modular hip endoprostheses.

Modular hip implants enables a more precise adaptation of the prosthesis to the patient's anatomy. However, they also carry the risk of increased revision rates due to micromotion at the taper junction. In order to minimize this risk, one potential solution is to establish an adhesive bond between the metal taper junctions. Load-stable bonding techniques, already successfully employed in dentistry for connecting materials such as metals and ceramics or different alloys, offer a promising approach. Nevertheless, the bond strength of tapered adhesive bonds in modular hip implants has not been investigated to date. Twenty-eight tapered junctions, consisting of a taper (female taper) and a trunnion (male taper) were turned using TiAl6V4 ELI (n = 16) and CoCr28Mo6 (n = 12). The process parameters cutting speed (vc = 50 m/min or 100 m/min) and feed (f = 0.1 mm, 0.05 mm or 0.2 mm) were varied for the trunnions. For each set of process parameters, one trunnion and one taper were additionally subjected to sandblasting. To investigate the effect of geometry, angular mismatch in the samples were measured. The taper pairs were bonded with a biocompatible adhesive, and push-out tests were subsequently performed. The push-out forces generated from the taper connections where both tapers were sandblasted showed a mean push-out force of 5.70 kN. For the samples with only the trunnion sandblasted, the mean force was 0.58 kN, while for the samples with only taper sandblasted the mean push-out force was 1.32 kN. When neither of the tapers was sandblasted the mean push-out force was 0.91 kN. No significant effect of the process parameters on the push-out force was observed. Only the reduced valley depth Svk showed a slight correlation for the CoCr28Mo6 samples (R2 = 0.54). The taper pairs with taper mismatch (between trunnion and taper) greater than |0.1°| did not show lower push-out forces than the specimens with lower taper mismatch. Sandblasted and adhesive-bonded tapered connections represent a viable suitable alternative for modular hip implant connections. Slight differences in taper geometry do not result in reduced push-out forces and are compensated by the adhesive. In mechanically joined tapers these differences can lead to higher wear rates. Further investigation under realistic test conditions is necessary to assess long-term suitability.

Suction-forced triboelectricity escalation by incorporating biomimetic 3-dimensional surface architectures

Triboelectric nanogenerators (TENGs), which operate on the principles of electrostatic induction and triboelectrification, have emerged as highly promising devices for energy harvesting, offering vast potential to address the challenges of energy depletion. In this study, we present a hierarchical bio-inspired architecture designed to enhance the triboelectric effect through a physically adhesive mechanism, achieved by creating a highly deformable 3D microstructure. This three-dimensional (3D) architecture, inspired by the male diving beetle, features properties that increase the contact area and compressibility of the interface by forming conformal contact with the electrode surface in both dry and wet environments. The architecture enhances van der Waals forces and generates multiple physical adhesion forces at the interface, leading to significant charge transfer. Compared to flat surfaces as well as various 3D bio-inspired architectures such as linear-shaped pillars and mushroom-like architectures, diving beetle inspired architecture demonstrated the highest triboelectric performance, generating voltage (∼42 V) and current (∼1008 nA) in dry conditions at 16 N of force. The results of this study offer a new perspective, demonstrating that triboelectricity can be efficiently generated through the strategic design of physically adhesive structures, as opposed to conventional TENGs that rely on structureless designs or chemical adhesives.

Substantive Dimethicone-Based Mucoadhesive Coatings.

It is challenging to deliver therapeutics in the oral environment due to the wet surfaces, the nature of the mucosa and the potential for saliva washout. In this study, the development of a mucoadhesive dimethicone-based oral carrier system for adhesion to the hard tissue and mucosa in the mouth was examined. This study reports the viscosity and mucoadhesion of dimethicone based polymer blends. The viscosity of the materials was measured using a rheometer. The mucoadhesion of these materials was determined as the work of adhesion and peak tack force using the tensile test method with a texture analyzer. Materials were prepared with either calcium and phosphate salts or sodium fluoride as potential therapeutics for promoting remineralization and treating dentin hypersensitivity by mechanical occlusion. Scanning electron microscopy was used to look at mineral deposition on the surface of dental hard tissue after the application of the dimethicone-based formulations. The results of this study confirm the potential for using these dimethicone-based materials as mucoadhesive therapeutic delivery systems in the oral environment.

Three dimensional thermally frictional adhesive contact problem of quasicrystals materials

It is difficult to analytically solve the contact problem of one-dimensional hexagonal quasicrystal (1DHQ) coating considering the coupling effects of adhesion, friction force and frictional heat in the contact region, especially considering both the frictional heat and adhesion simultaneously. The thermally frictional adhesive contact problem of 1DHQ coating is investigated using a discrete convolution-fast Fourier transform-based (DC-FFT-based) semi-analytical method. The adhesive behavior is described based on the Maugis-Dugdale model, which was used to investigate the influence of adhesive force on the thermoelastic field. It is a continuum-mechanics model with all microscopic features subsumed in the elastic constants, covers only elastic behavior, omitting all other physical characteristics of quasicrystals. By developing an adhesion-driven conjugate gradient method (AD-CGM), the contact process is numerically implemented, and the DC-FFT method is applied to solve the contact displacement. The numerical results indicate that the contact area under the consideration of adhesive force is much larger than that without. For a given external force, the contact radius and adhesive radius increase with increasing parameters. And each physical quantity exhibits different changing trends with the variation of adhesive parameters, with 0.5 as the dividing line. The research results may provide theoretical guidance for the practical application of quasicrystals as thermal barrier coating materials, nanodevice materials, and intelligent robot coating materials.

Bacterial–host adhesion dominated by collagen subtypes remodelled by osmotic pressure

Environmental osmolarity plays a crucial role in regulating the functions and behaviors of both host cells and pathogens. However, it remains unclear whether and how environmental osmotic stimuli modulate bacterial‒host interfacial adhesion. Using single-cell force spectroscopy, we revealed that the interfacial adhesion force depended nonlinearly on the osmotic prestimulation of host cells but not bacteria. Quantitatively, the adhesion force increased dramatically from 25.98 nN under isotonic conditions to 112.45 or 93.10 nN after the host cells were treated with the hypotonic or hypertonic solution. There was a strong correlation between the adhesion force and the number of host cells harboring adherent/internalized bacteria. We further revealed that enhanced overexpression levels of collagen XV and II were responsible for the increases in interfacial adhesion under hypotonic and hypertonic conditions, respectively. This work provides new opportunities for developing host-directed antibacterial strategies related to interfacial adhesion from a mechanobiological perspective.

Strong and Environmental-Friendly Adhesive Glass Based on Chitin Nanoparticles

Chitin is a biopolymer that can be used as a candidate material for a strong and environmentally friendly glass adhesive. In the form of nanoparticles with needle-like morphology and attractive functional groups in the form of amide and hydroxyl, Chitin Nanoparticle (ChNP) shows a strong Van der Walls adhesive force against glass. In the study, ChNP was successfully isolated from crab shells from the sea of Lombok. The isolated ChNP has a characteristic size around 351 nm with -chitin conformation and needle-shaped morphology. Based on the results of shear strength testing, 0.42 mg of ChNP can withstand a load of 21 kg and the addition of Gum Arabic (GA) and Hen Egg White lysozyme (HEWL) in a ratio of 1: 1 to ChNP succeeded in increasing adhesion by 72%.