Surface Adhesion Force Research Articles

Surface-engineered caterpillar-like silica nanocomposites for enhanced interparticle friction and interlock in shear thickening suspension

This study presents a novel method for fabricating surface-engineered caterpillar-like silica nanocomposites by combining rod-like nanorods with spherical nanoparticles to control aspect ratios and surface functionalization. This unique design facilitates functional assembly at the nanoscale. Additionally, we developed an innovative composite by encapsulating polyurethane elastomers within shear thickening fluid (STF)-impregnated Kevlar, significantly enhancing the flexibility and durability of the resulting STF/Kevlar/PU composite. Microstructural and chemical modifications were characterized, and detailed rheological analysis revealed a 165 % increase in viscosity and a substantial rise in storage modulus from 91.56 to 18,640 Pa, indicating improved surface morphology and roughness. These enhancements promoted stronger interparticle friction and rotational motion during flow. Impact resistance tests further demonstrated a 314 % increase in peak impact force, driven by frictional interactions between the dispersed caterpillar-like particles. The results confirmed that surface roughness and adhesive forces play a critical role in activating stress-dependent frictional contacts, a key mechanism behind the improved performance. These findings highlight the potential of these composites for mitigating penetration injuries and offer precise control over the shear-thickening transition in engineering applications, making them promising candidates for lightweight protective materials.

Factors Affecting the Adhesion of Flour Particles to Stainless-steel Surfaces and Vacuum Dry-cleaning

Recent outbreaks and recalls linked to flour-based products have highlighted the need for improved cleaning methods in low-moisture environments. The factors affecting adhesion forces of flour particles, and the vacuum cleaning methodologies to overcome these forces, need to be better understood. The objectives of this study were to: (1) Measure electrostatic charge build-up in flour under different environmental conditions (20, 40, 60% relative humidity at room temperature), (2) quantify how powder size (US standard No. 60–80 or 80–100 mesh), electrostatic charge (charged and uncharged), and relative humidity impact the force required to remove the powder from an electropolished 304 stainless steel coupon (8 × 8 × 0.2 cm), and (3) determine the most effective vacuum nozzle angle (0, 45, 90° relative to the surface) for cleaning. Chargeability (nC) of flour samples was assessed using Faraday cup electrometry, while the surface adhesion force of the flour particles was measured using a custom-built impact tester. The surface cleanliness after vacuum treatments was assessed using ATP (adenosine triphosphate) swabs and a luminometer. Charged flour samples at 20% relative humidity (RH) exhibited a significantly higher charge compared to those at 40 and 60% RH. Within the 60–80 mesh range, charged flour showed higher adhesion rates than uncharged samples at both 20 and 40% RH. However, in the 80–100 mesh range, charged flour did not show a significant difference in adhesion when compared to uncharged samples at any RH level. Additionally, at 60% RH, surface residues measured by ATP were significantly lower for a vacuum angle of 90° than for 0° across both 60–80 mesh and 80–100 mesh size ranges of wheat flour. The vacuum cleaning treatment proved capable of overcoming the increase in adhesion from triboelectric forces; however, trace flour residues were still detected on stainless steel surfaces postvacuuming, indicating that vacuuming alone may be insufficient.

Multiscale revelation of asphalt morphology and adhesion performance evolution during stress relaxation process

The objective of this study is to investigate the evolution of asphalt morphology and adhesion properties during stress relaxation using atomic force microscopy (AFM) and molecular dynamics (MD) simulations. Changes in surface roughness, Derjaguin-Muller-Toporov (DMT) modulus, adhesion force, and force-distance curves were analyzed. Morphological and adhesion property evolution was assessed using correlation length and Lyapunov exponent. MD simulations provided insights into the internal stress-time relationship and free volume fraction of asphalt during relaxation. Results indicate that under constant tensile strain, the “bee structure” on the asphalt surface elongates, dark pits transform into light protrusions, microcracks heal, and surface roughness stabilizes after 10 h. Under compressive strain, similar changes occur but are more pronounced during tensile relaxation. The combined use of AFM and MD simulations offers a comprehensive understanding of the microscopic evolution mechanisms of asphalt under stress relaxation, providing valuable insights for optimizing asphalt pavement design and maintenance.

Rapid Fabrication of Antilunar Dust Aluminum Surface by Nanosecond Laser Etching.

Although a dust-repellent surface is desirable for lunar exploration missions, its fabrication process is complicated and time-consuming. Herein, we report a simple and fast method to fabricate a lunar dust-repellent surface by texturing on an Al substrate via nanosecond laser etching. The laser-induced photothermal effect can rapidly create hierarchical papillary structures on 25 × 25 mm Al substrates (within 30 s). Both atomic force microscopy (AFM) and in situ scanning electron microscopy (SEM) reveal that such structures enable a reduced contact area between the Al substrate and lunar dust and thus reduced adhesion. The reduced dust adhesion force of Al substrates facilitates improving their antidust performance. By optimizing processing parameters, the Al substrate etched with a laser scanning spacing of 80 μm exhibits a lower dust adhesion force (9.58 nN) due to the smallest contact area with dust. Accordingly, its static antilunar dust performance (dust coverage of 1.95%) is significantly improved compared to the pristine Al substrate (dust coverage of 12.98%). Besides, the accumulated dust on the laser-etched Al substrates with low surface adhesion force is easily cleaned up by flipping and gravity (the dust residual rates are less than 17%). The Al substrate with excellent antidust ability presents good potential for lunar exploration missions.

Lorentz Force-Actuated Bidirectional Nanoelectromechanical Switch with an Ultralow Operation Voltage.

The high operating voltage of conventional nanoelectromechanical switches, typically tens of volts, is much higher than the driving voltage of the complementary metal oxide semiconductor integrated circuit (∼1 V). Though the operating voltage can be reduced by adopting a narrow air gap, down to several nanometers, this leads to formidable manufacturing challenges and occasionally irreversible switch failures due to the surface adhesive force. Here, we demonstrate a new nanowire-morphed nanoelectromechanical (NW-NEM) switch structure with ultralow operation voltages. In contrast to conventional nanoelectromechanical switches actuated by unidirectional electrostatic attraction, the NW-NEM switch is bidirectionally driven by Lorentz force to allow the use of a large air gap for excellent electrical isolation, while achieving a record-low driving voltage of <0.2 V. Furthermore, the introduction of the Lorentz force allows the NW-NEM switch to effectively overcome the adhesion force to recover to the turn-off state.

Effects of liquid lubricants on the surface characteristics of 3D-printed polylactic acid

In this study, 3D-printed Polylactic acid (PLA) specimens were manufactured and polished using various lubricants to assess their surface, friction, and wear characteristics. After polishing, the surface roughness decreased by approximately 80% compared with that before polishing, except when acetone was used as the lubricant. In particular, under deionized (DI) water and acetone lubrication conditions, the friction coefficient decreased by 63% and 70%, respectively, whereas the specific wear rate decreased by 88% and 83%, respectively, compared with the unpolished specimens. In the case of dry polishing, adhesion, friction, and wear increase owing to surface damage. Ethanol and IPA polishing resulted in hydrolysis and increased friction, but slightly decreased wear rates. The surface of the specimen polished with acetone dissolved and became very rough. Only the surface polished with DI water exhibited hydrophobic properties. When acetone and DI water were used as lubricants, the surface adhesion force, adhesion energy, friction coefficient, and wear rate were lowest. The finite element analysis results showed that the polished surface exhibited stable contact pressure and friction force, while the unpolished surface showed large fluctuations in contact pressure and friction force owing to the laminated pattern. These results suggest that the polishing process is crucial for improving the surface characteristics and mechanical performance of 3D-printed PLA parts.

Spatial light assisted femtosecond laser direct writing of a bionic superhydrophobic Fresnel microlens arrays

High quality imaging and self-cleaning function are two significant factors for Fresnel Microlens Arrays (FMLAs) to operate properly in outdoor environment. Bionic superhydrophobic FMLAs are explored for outdoor uses due to their ability allowing free rolling down of water droplets taking away dust particles. Current photolithographic method of fabricating FMLAs involves multi-processing steps, which increase the complexity of the microlens array structure as well as reduces the optical imaging capability of the lenses. In this study, we report a method for creating bionic superhydrophobic FMLAs by integrating the Nepenthes Alata crescent structures with FMLAs fabricated by spatial light assisted femtosecond laser direct writing, i.e. Two-Photon Polymerization (TPP). The fabricated FMLAs were further modified with Perfluorooctyltrimethoxysilane (F13) to enhance hydrophobicity and surface uniformity. Results show that the optimized bionic FMLAs exhibit superhydrophobicity in different liquid media and excellent self-cleaning ability. The water contact angle (CA) reached 156.3°, a low rolling angle of 4.7°, and surface adhesion force of 25.5 μN. The FMLAs designed have excellent imaging characteristics and focusing ability. This research provides insights into the fabrication and performance optimization of bionic superhydrophobic FMLAs, offering potential applications for outdoor optical systems.

Magnetic porous microspheres altering interfacial thermodynamics of sewage sludge to drive metabolic cooperation for efficient methanogenesis

Controllable and recyclable magnetic porous microspheres (MPMs) have been proposed as a means for enhancing the anaerobic digestion (AD) of sludge, as they do not require continuous replenishment and can serve as carriers for anaerobes. However, the effects of MPMs on the interfacial thermodynamics of sludge and the biological responses triggered by abiotic effects in AD systems remain to be clarified. Herein, the underlying mechanisms by which MPMs alter the solid–liquid interface of sludge to drive methanogenesis were investigated. A significant increase in the contents of 13C and 2H (D) in methane molecules was observed in the presence of MPMs, suggesting that MPMs might enhance the CO2-reduction methanogenesis and participation of water in methane generation. Experimental results demonstrated that the addition of MPMs did not promote the anaerobic bioconversion of soluble organics for methanogenesis, suggesting that the enhanced methanogenesis and water participation were not achieved through promotion of the bioconversion of original liquid-state organics in sludge. Analyses of the capillary force, surface adhesion force, and interfacial proton-coupled electron transfer (PCET) of MPMs revealed that MPMs can enhance mass transfer, effective contact, and electron–proton transfer with sludge. These outcomes were confirmed by the statistical analyses of variations in the interfacial thermodynamics and PCET of sludge with and without MPMs during AD. It was thus proposed that the MPMs enhanced the PCET of sludge and PCET-driven release of protons from water by promoting the interfacial Lewis acid–base interactions of sludge, thereby resulting in the enrichment of free and attached methanogenic consortia and the high energy-conserving metabolic cooperation. This proposition was further confirmed by identifying the predominant syntrophic partners, suggesting that PCET-based efficient methanogenesis was attributable to the enrichment of genomes harbouring CO2-reducing pathway and genes encoding water-mediated proton transfer. These findings offer new insights into how substrate properties can be altered by exogenous materials to enable highly efficient methanogenesis.

Anti-ageing and rheological performance of bitumen modified with polyaniline nanofibres

Asphalt pavements represent the great majority of roads worldwide. However, the bitumen physico-chemical properties change due to ageing processes during both the production and service life of the asphalt mixes. In recent years, a completely new trend has been observed in the road engineering industry oriented to extending the service life of roads, bringing direct economic, ecological and social benefits. This work presents the possibility of inhibiting ageing of road bitumen by using polyaniline nanofibers (PANI_NFs) as well as enhancing its rheological properties examined with Linear Amplitude Sweep (LAS) as well as Multiple Stress Creep and Recovery (MSCR) tests. These results show that the application of PANI_NFs maintains the primary penetration value of bitumen short-term and long-term aged road bitumen at 88 % and 52 %, respectively. Moreover, bitumen modification with PANI_NFs reduces the softening temperature increase by 33 % and 24 %, respectively, and the viscosity increase of road asphalt by 50 % and 25 %, respectively. PANI_NFs also stabilised the bitumen surface adhesion force, determined with AFM, consequently confirming the enhanced resistance to ageing processes. In addition, changes in the carbonyl index, sulphoxide index and aromaticity of bitumen demonstrated that PANI_NFs inhibit oxidation and aromatisation reactions of its components. The tests indicated a 4-fold decrease in the degree of bitumen component oxidation after short-term ageing and a 33 % decrease after long-term ageing. FTIR analysis also showed a reduction in the degree of bitumen component aromatisation process of 79 % and 76 % for short-term and long-term ageing, respectively. The LAS and MSCR test results also showed that PANI_NFs had a beneficial impact on the resistance of the bitumen to fatigue and rutting. Overall, the study results suggest that PANI_NFs consitute a promising modifier for bitumen in terms of ageing inhibition and performance characteristics.

Construction of functional epoxy resin coatings based on acid-doping polyaniline coated APP: Preparation, characterization and properties

Waterborne epoxy resin (WER) coatings have attracted more and more attention because of their excellent physical and chemical properties, however, WER's flammability and high insulation limit its application. In this paper, polyaniline (PANI) doped with four different acids (sulfuric acid, phosphoric acid, citric acid and amino trimethylene phosphonic acid) was used as the shell material to coat ammonium polyphosphate (APP), and a series of multifunctional WER fillers (PANIacids/APP) integrating flame retardant, smoke suppression and antistatic properties were prepared. Then, the PANIacids/APP was compounded with WER to prepare a functional WER coating. The structures and morphologies of the PANIacids/APP fillers were characterized by Fourier transform infrared spectrometer (FTIR), scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS), the results showed that acids doping could promote the formation of polyaniline coating on the surface of APP, and the PANIacids/APP filler doped by amino trimethylene phosphonic acid (ATMP) exhibits the best coating effect. Furthermore, the effects of PANIacids/APP fillers on the flame retardant property, smoke suppression property, electrical property and adhesion property of waterborne epoxy resins were explored. The results indicated that the carbon residue of WER coatings with PANIacids/APP fillers at 800 °C could reach 24.1 %-29.6 %, among which ATMP doping group has a residual carbon of 27.3 %. Also, the WER coating containing PANIATMP/APP filler possesses the best comprehensive performance, the coating has a limiting oxygen index of 31.7 % and passed V-0 level in the vertical burning test (UL-94). Compared with pure EP coating, the peak heat release rate of the PANIATMP/APP modified coating decreased by 78.1 % and the total heat release decreased by 37.8 %. Additionally, the surface resistance and adhesive force of the PANIATMP/APP modified coating reached 3.14×106 Ω and 11.8 MPa, respectively, which could meet the usage needs of anti-static application of the WER coatings.

Submicron-Thickness Ultraflexible Organic Light-Emitting Diodes via a Photoregulated Stripping Strategy.

With the rapid advances in imperceptible and epidermal electronics, the research on ultraflexible organic light-emitting diodes (OLEDs) has become increasingly significant, owing to their excellent flexibility and conformability to the human body. It is highly desirable to develop submicrometer-thick ultraflexible OLEDs to enable the devices to seamlessly conform to the surface of arbitrary-shaped objects and still function properly. However, it remains a huge challenge for currently reported OLEDs due to the lack of an appropriate stripping strategy. Here, for the first time, we develop a facile photoregulated stripping strategy for the fabrication of high-performance ultraflexible OLEDs with submicron thickness. Under ultraviolet (UV) irradiation, the surface adhesion force of the ultrathin photopolymer membrane can be adjusted from 16.9 to 5.1 N/m, thereby effectively controlling the laminating and detaching process. Based on this strategy, the resultant device thickness is as low as 0.821 μm, which is the lowest record among flexible OLEDs reported to date. More remarkably, excellent electrical properties with a maximum current efficiency (CE) of 62.5 cd/A, an external quantum efficiency (EQE) of 17.8%, and a low turn-on voltage of 2.5 V are realized, which are superior to almost all of the reported ultraflexible OLEDs with thicknesses below 10 μm. Based on versatile ultraflexible OLEDs, all-organic and skin-mounted displays are successfully realized by employing a conformable organic thin-film transistor (OTFT) as the driver. This work offers a feasible strategy for advancing OLEDs from flexible to ultraflexible, showing significant application potential in future epidermal electronics and conformal displays.

Immune priming modulates Galleria mellonella and Pseudomonas entomophila interaction. Antimicrobial properties of Kazal peptide Pr13a.

Galleria mellonella larvae repeatedly infected with Pseudomonas entomophila bacteria re-induced their immune response. Its parameters, i.e. the defence activities of cell-free hemolymph, the presence and activity of antimicrobial peptides, and the expression of immune-relevant genes were modulated after the re-challenge in comparison to non-primed infected larvae, resulting in better protection. No enhanced resistance was observed when the larvae were initially infected with other microorganisms, and larvae pre-infected with P. entomophila were not more resistant to further infection with other pathogens. Then, the peptide profiles of hemolymph from primed- and non-primed larvae infected with P. entomophila were compared by quantitative RP-HPLC (Reverse Phase - High Performance Liquid Chromatography). The level of carbonic anhydrase, anionic peptide-1, proline peptide-2, and finally, unknown so far, putative Kazal peptide Pr13a was higher in the primed infected animals than in the larvae infected with P. entomophila for the first time. The expression of the Pr13a gene increased two-fold after the infection, but only in the primed animals. To check whether the enhanced level of Pr13a could have physiological significance, the peptide was purified to homogeneity and checked for its defence properties. In fact, it had antibacterial activity: at the concentration of 15 µM and 7.5 µM it reduced the number of P. entomophila and Bacillus thuringiensis CFU, respectively, to about 40%. The antibacterial activity of Pr13a was correlated with changes observed on the surface of the peptide-treated bacteria, e.g. surface roughness and adhesion force. The presented results bring us closer to finding hemolymph constituents responsible for the effect of priming on the immune response in re-infected insects.

Enhanced cytocompatible gelatin/chondroitin sulfate/ionic liquid polyelectrolyte multilayers with virucidal activity against mouse hepatitis coronavirus

The cytotoxicity of ionic liquids (ILs) in solution, including aqueous 1-n-hexadecyl-3-methylimidazolium chloride (C16MImCl), 1-n-hexadecyl-3-methylimidazolium methane sulfonate (C16MImMeS), and 1-n-hexadecyl pyridinium chloride monohydrate (C16PyrCl⋅H2O) solutions and polyelectrolyte multilayers (PEMs) containing ILs were investigated against mouse hepatitis virus (MHV-3) and fibroblast cells (L929). C16MImMeS and C16PyrCl⋅H2O exhibited virucidal activity against MHV-3 after 30 s of exposure at 662.31 nM and 744.88 nM, respectively. However, these ILs demonstrated considerable toxicity against fibroblast cells (2.0 × 105 cells/well) at 583 nM (C16MImCl), 498 nM (C16MImMeS), and 559 nM (C16PyrCl⋅H2O), limiting their direct application in aqueous solutions. Therefore, these ILs were combined with PEMs consisting of alternating 15 layers of gelatin (GE) and chondroitin sulfate (CS) to address this limitation. The PEMs were deposited on oxidized poly(ethylene terephthalate) (PET) using the layer-by-layer (LbL) approach. The ILs altered the relative surface adhesion force, reducing it from 4.08 nN on GE/CS PEM to the range between 2.23 and 3.10 nN on the GE/CS IL PEMs. The ILs enhanced surface electrostatic forces while decreasing adhesion forces on the surfaces. Incorporating ILs into the PEMs proved a promising strategy as they reduced the toxicity of the ILs towards L929 cells while maintaining their virucidal efficacy. The GE/CS PEM without IL did not exhibit virucidal activity against MHV-3. In contrast, GE/CS PEMs combined with C16MImMeS showed virucidal activity after 24 h, inactivating 99.99 % of the virus. The PEMs associated with the ILs were cytocompatible toward the L929 cells after a 48-hour incubation period. GE/CS IL PEMs hold promise as cytocompatible surface coatings for solid materials due to their durability and ability to prevent viral growth.

Fog collection efficiency of superhydrophobic surfaces with different water adhesion prepared by laser grid texturing

Superhydrophobic surfaces are widely used in fog collection areas due to their water adhesion properties. Unfortunately, the relationship between the water adhesion and the fog collection efficiency of superhydrophobic surfaces has seldom been reported in the literature. Therefore, it is still a challenge to conduct scientific design of superhydrophobic surfaces for fog collection. In this work, superhydrophobic titanium alloy surfaces with different water adhesions were fabricated by laser grid texturing combined with silicone oil heat treatment. As the texturing interval increased from 50 µm to 500 µm, the adhesion force of the superhydrophobic surfaces correspondingly increased from 2.4 µN to 104.9 µN. The results show that the superhydrophobic surfaces with the texturing interval of 100 µm have the highest fog collection efficiency of 415.5 mg·cm−2·h−1. The reason is that an appropriate adhesion force (7.6 µN) of the superhydrophobic surface can effectively suppress the coalescence-induced droplets jumping. Furthermore, it can also facilitate the removal of condensed droplets by decreasing the critical size of droplets sliding.

Time Dependence of the Graphene Surface Adhesion Force of the Sphere-Plane Contact at Different Relative Humidities.

Graphene has a promising application prospect in integrated circuits and microelectromechanical systems, and sphere-plane contacts are their common contact types. At present, it is difficult to explain the time dependence of the adhesion force of the sphere-plane contact by conventional theory. Therefore, a single rough peak of sphere-plane contact adhesion force model based on variable water contact angle theory and Bradley contact theory was established; the aim is to reveal the changing law of graphene adhesion force. Then, the time dependence of the graphene surface adhesion force at different humidity levels was investigated by using an atomic force microscopy spherical probe. Finally, a quantitative comparative analysis of the theory and experiment was performed. The results show that the theoretical adhesion force was in good agreement with the experimental measurement results. The time dependence of graphene surface adhesion was not obvious within a relative humidity of 45-55%. When the relative humidity was greater than 65%, the graphene surface adhesion first increased and then decreased with dwell time and finally tended to be stable. Because of the increase in relative humidity, the capillary condensation effect increases, and then the adhesion force increases with the development of the meniscus. When the water film was generated on the sample surface, the adhesion force decreased until the meniscus achieved equilibrium.

Magneto-responsive wettability-switchable surfaces for in-situ large distance droplets capturing-releasing-bouncing

In this paper, superhydrophobic magnetically responsive micro-plate arrays (SMMAs) with reverse switching wettability were studied for in-situ capturing, releasing, and directional bouncing of droplets over a large distance. A novel method for producing superhydrophobic pattern on one side surface of the micro-plates by laser texturing at 90 degree bending state, created water contact angle of 151°, a rolling angle of < 10°, and a maximum surface adhesion force of 35.5 μN. Reversible switching between droplets (volume 5–40 μL) capturing with high adhesion force (high surface energy) and droplet releasing with low adhesion force were achieved spontaneously. The instantaneous response of the SMMAs to magnetic field provided a guarantee for the directional bouncing of droplets in long distance. Droplets transportation up to 40 μL, directional bouncing of 5 μL droplets with a vertical bounce height of 4.5 mm and a horizontal bounce distance of 24.7 mm have been achieved. This work provides a novel approach for flexible droplets manipulation and multifunctional operation of droplets for non-contact, remote-driven and non-destructive reagent transfer applications.

Investigation of Adhesion Force of Silver and Gold-Coated Surfaces with Different Thicknesses on Silicon Substrate

Investigation of Adhesion Force of Silver and Gold-Coated Surfaces with Different Thicknesses on Silicon Substrate

Piranha-etched titanium nanostructure reduces biofilm formation in vitro

ObjectivesNano-modified surfaces for dental implants may improve gingival fibroblast adhesion and antibacterial characteristics through cell-surface interactions. The present study investigated how a nanocavity titanium surface impacts the viability and adhesion of human gingival fibroblasts (HGF-1) and compared its response to Porphyromonas gingivalis with those of marketed implant surfaces.Material and methodsCommercial titanium and zirconia disks, namely, sandblasted and acid-etched titanium (SLA), sandblasted and acid-etched zirconia (ZLA), polished titanium (PT) and polished zirconia (ZrP), and nanostructured disks (NTDs) were tested. Polished titanium disks were etched with a 1:1 combination of 98% H2SO4 and 30% H2O2 (piranha etching) for 5 h at room temperature to produce the NTDs. Atomic force microscopy was used to measure the surface topography, roughness, adhesion force, and work of adhesion. MTT assays and immunofluorescence staining were used to examine cell viability and adhesion after incubation of HGF-1 cells on the disk surfaces. After incubation with P. gingivalis, conventional culture, live/dead staining, and SEM were used to determine the antibacterial properties of NTD, SLA, ZLA, PT, and ZrP.ResultsEtching created nanocavities with 10–20-nm edge-to-edge diameters. Chemical etching increased the average surface roughness and decreased the surface adherence, while polishing and flattening of ZrP increased adhesion. However, only the NTDs inhibited biofilm formation and bacterial adherence. The NTDs showed antibacterial effects and P. gingivalis vitality reductions. The HGF-1 cells demonstrated greater viability on the NTDs compared to the controls.ConclusionNanocavities with 10–20-nm edge-to-edge diameters on titanium disks hindered P. gingivalis adhesion and supported the adhesion of gingival fibroblasts when compared to the surfaces of currently marketed titanium or zirconia dental implants.Clinical relevanceThis study prepared an effective antibacterial nanoporous surface, assessed its effects against oral pathogens, and demonstrated that surface characteristics on a nanoscale level influenced oral pathogens and gingival fibroblasts.Clinical trial registration: not applicable

Enhancing droplets deposition on superhydrophobic plant leaves by bio-based surfactant: Experimental characterization and molecular dynamics simulations

The bouncing and splashing of pesticide droplets on the superhydrophobic plant leaves is the main reason for the low pesticide utilization rate and the main source of environmental pollution. In this study, we report a bio-based surfactant Nonyl β-D-glucopyranoside (DG) which could efficiently inhibit droplet bouncing and improve the retention and deposition on superhydrophobic plant leaves. The traditional surfactants N, N, N-trimethyl-1-dodecanaminium bromide (DTAB), and p-Octyl polyethylene glycol phenyl ether (TX-100) were used to explore the mechanism. The dynamic surface tension, surfactant aggregates, and adhesive force were investigated. Also, molecular dynamics (MD) simulations are displayed to prove the deposition mechanism. The bio-based surfactant DG with lower dynamic surface tension can diffuse and adsorb to the plant leaves rapidly. The rod-like micelles of DG interacted with the plant leaves covered with DG molecules and pinned the gas/liquid/solid three-phase contact lines to dissipate energy. This work has provided a green and efficient strategy to improve the retention of pesticide droplets on the leaves of the plant.

Membrane-bound transcription factor LRRC4 inhibits glioblastoma cell motility

Membrane-bound transcription factors (MTFs) have been observed in many types of organisms, such as plants, animals and microorganisms. However, the routes of MTF nuclear translocation are not well understood. Here, we reported that LRRC4 is a novel MTF that translocates to the nucleus as a full-length protein via endoplasmic reticulum-Golgi transport, which is different from the previously described nuclear entry mechanism. A ChIP-seq assay showed that LRRC4 target genes were mainly involved in cell motility. We confirmed that LRRC4 bound to the enhancer element of the RAP1GAP gene to activate its transcription and inhibited glioblastoma cell movement by affecting cell contraction and polarization. Furthermore, atomic force microscopy (AFM) confirmed that LRRC4 or RAP1GAP altered cellular biophysical properties, such as the surface morphology, adhesion force and cell stiffness. Thus, we propose that LRRC4 is an MTF with a novel route of nuclear translocation. Our observations demonstrate that LRRC4-null glioblastoma led to disordered RAP1GAP gene expression, which increased cellular movement. Re-expression of LRRC4 enabled it to suppress tumors, and this is a potential for targeted treatment in glioblastoma.