The net capturing method holds great potential for space debris removal due to its adaptability to the various target shapes and high fault tolerance.However,the capture mechanisms of current rope nets,which rely sole...The net capturing method holds great potential for space debris removal due to its adaptability to the various target shapes and high fault tolerance.However,the capture mechanisms of current rope nets,which rely solely on a passive wrap-ping mechanism,limit their capacity to capture objects within a specific size range and make it challenging to handle unexpected situations.Inspired by spider webs,which combine wrapping and adhering to capture prey of various sizes,we present a new type of net(envelope diameter:208.49 mm)for on-orbit capture.This net adopts a spiral symmetric structure similar to spider webs,incorporates electrostatic-microstructure hybrid adhesives,and increases the maximum contact area by 38.31%,allowing it to capture debris ranging from fragments smaller than the mesh size(envelope diam-eter:2.7 mm-4.4 mm)to larger objects(envelope diameter:270 mm),and effectively grasps flexible items(450 mm2),planar items(350 mm2)and three-dimensional items(160 mm3).Moreover,to validate the net's capability for wrapping and adhesion,simulations and experiments are demonstrated that this dual capture method can effectively handle various targets.展开更多
As a common electronic adhesive,ultraviolet(UV)curing polyurethane acrylate adhesive has both flexibility and wear resistance of polyurethane,excellent weather resistance and optical properties of acrylate.Despite the...As a common electronic adhesive,ultraviolet(UV)curing polyurethane acrylate adhesive has both flexibility and wear resistance of polyurethane,excellent weather resistance and optical properties of acrylate.Despite the extensive applications,it is still difficult to solve the problems caused by the shrinkage of adhesive.Here,a new type of photosensitive adhesive for bonding electronic components based on supramolecular interaction was designed and synthesized.The supramolecular interaction of cyclodextrin and adamantane moieties introduced into the adhesive polymer entitles the viscosity of the adhesive to rise rapidly during use,thereby preventing adhesive loss and dislocation of electronic components.UV light could further cure the adhesive and position the electronic components.The adhesive shrunk<2%when cured by UV light,so it can be used for electronic packaging and high-resolution,defect-free lithography.展开更多
Silicone-based pressure-sensitive adhesives(Si-PSAs)are valued for their thermal stability,flexibility,and biocompatibility,but their weak bonding strength restricts high-performance use.Polyurethane-modified Si-PSAs ...Silicone-based pressure-sensitive adhesives(Si-PSAs)are valued for their thermal stability,flexibility,and biocompatibility,but their weak bonding strength restricts high-performance use.Polyurethane-modified Si-PSAs enhance adhesion,however diisocyanates remain essential.The raw materials of isocyanates are toxic,and their synthesis involves phosgene.To make up for those shortcomings,a series of poly(hydroxy urethane-siloxane)PSAs,named as PHUSi here,were synthesized through the ring-opening reaction of cyclic carbonate-functionalized polysiloxanes(PSi_(x)-VEC_(z))with various aliphatic diamines.The PSi_(x)-VEC_(z) precursors were prepared via the hydrosilylation of hydrogen-containing polysiloxanes(PSi_(x)-H_(y))with 4-vinyl-1,3-dioxolan-2-one(VEC).The chemical structures of PSi_(x)-H_(y),PSi_(x)-VEC_(z) and PHUSi were characterized,and bonding properties of PHUSi were systematically evaluated.The influence of architectures on adhesive performance was elucidated through comprehensive analyses,including rheology,crosslink density assessment,and so on.These studies revealed that the tailored design of PHUSi adhesives combine the advantages of traditional Si-PSAs with enhanced adhesion while eliminating isocyanate toxicity.The optimized PHUSi formulation achieved remarkable 180°peel strength(76.5 N/m on skin)and maximum probe tack force(1.61 N),enabling secure 24 h attachment of flexible sensors to skin.These properties make PHUSi particularly suitable for medical applications,as demonstrated by successful implementation in flexible electrocardiogram devices,offering a biocompatible,high-performance adhesive.展开更多
Reuse/recycling of expensive components in next-generation optoelectronic systems(e.g.,flexible electronics and foldable displays)for sustainability purposes impose stringent requirements on optically clear adhesive(O...Reuse/recycling of expensive components in next-generation optoelectronic systems(e.g.,flexible electronics and foldable displays)for sustainability purposes impose stringent requirements on optically clear adhesive(OCA)with on-demand adhesion/deadhesion capability.Although some hot-melt OCAs have been developed,there still remain great challenges in balancing the mechanical property,adhesion/detachment and recyclability/reusability of the OCAs.Herein,we developed a debondable and robust polyurethane(PU)-based optically clear adhesive with both mechanical and chemical recyclability,overcoming the critical bottlenecks in sustainable advanced manufacturing.The ductile yet strong PU-based OCAs not only can adhere to various optically transparent glass and polymeric substrates(with a bonding strength high up to 5.0 MPa),but also exhibit deadhesion capability at high temperature owing to the thermally sensitive H-bonding interaction within the polymer network.The ondemand adhesion/deadhesion facilitates non-destructive detachment of functional assemblies and materials recycling/repair.The mechanical and chemical recyclability of PU-based OCAs can also effectively reduce the cost and address the endof-life issues.Moreover,the PU-based OCAs outperformed some commercial optical adhesives.In view of the straightforward synthesis,easy industrial scale-up and exceptional comprehensive properties,the PU-based OCAs will provide promising transformative solutions for advancing the circular economy and sustainability in next-generation optoelectronic devices.展开更多
The effect of antibacterial adhesive on the biological corrosion resistance of mortar in seawater environment was studied by means of scanning electron microscope,thermogravimetric analysis,X-ray diffraction,Fourier t...The effect of antibacterial adhesive on the biological corrosion resistance of mortar in seawater environment was studied by means of scanning electron microscope,thermogravimetric analysis,X-ray diffraction,Fourier transform infrared spectroscopy,and ultra-depth microscope.The results show that the antibacterial adhesive can effectively inhibit the growth of sulfur-oxidizing bacteria in seawater,hinder their metabolism to produce biological sulfate,and reduce the formation of destructive product gypsum.The mineral composition and thermal analysis showed that the peak value of plaster diffraction peak and the mass loss of plaster dehydration in antibacterial adhesive group were significantly lower than those in blank group(without protective coating group).In addition,the electric flux of chloride ions(>400 C)in the blank group of mortar samples was higher than that in the antibacterial adhesive group(<200 C),indicating that the antibacterial adhesive can effectively reduce the permeability of chloride ions in mortar,and thus hinder the Cl-erosion in seawater.展开更多
Polymeric materials which can undergo controlled degradation and recycling are of great significance for a sustainable society.Although tremendous progress has been made in the degradation and recycling of both thermo...Polymeric materials which can undergo controlled degradation and recycling are of great significance for a sustainable society.Although tremendous progress has been made in the degradation and recycling of both thermoplastic and thermoset plastics,the development of high-performance degradable polymer adhesives is rare.Here,we have prepared high-performance nucleobase-containing thioctic acid-based supramolecular polymer adhesives through free radical polymerization.The specific hydrogen-bonding interactions between complementary nucleobases greatly improve the weak cohesion of the thioctic acid-based polymers and enhance the environmental stability of the thioctic acidbased polymers simultaneously.Degradation of the nucleobase-containing thioctic acid-based supramolecular polymers is achieved by the reduction of the disulfide backbone,and the cycle of degradation and repolymerization is further achieved via oxidative polymerization.The adhesion strength of the nucleobase-containing thioctic acid-based supramolecular polymers after two cycles of degradation and repolymerization still reaches as high as 4.7±0.3 MPa.This work provides an approach for the development of environmentally stable and high-performance degradable thioctic acid-based adhesives.展开更多
As the most abundant aromatic bio-based polymer,lignin has great potential as a sustainable feedstock for building crosslinked thermoset polymers as bio-based adhesives.However,the potential of hardwood kraft lignin(H...As the most abundant aromatic bio-based polymer,lignin has great potential as a sustainable feedstock for building crosslinked thermoset polymers as bio-based adhesives.However,the potential of hardwood kraft lignin(HKL)is limited due to its poor crosslinking reactivity.Hence,for the first time,the present study reports the facile oxidation of HKL involving a redox reaction with silver-ammonia complexes([(AgNH3)2]+),primarily focusing on oxidation to produce reactive quinones and promote C-C linkages during reaction.This study aims to increases reactivity of oxidized HKL for effective crosslinking with monoethanolamine(MEA)for the development of bio-based wood adhesives.The characterization,including 13C-nuclear magnetic resonance(NMR)and Fourier transform infrared(FT-IR)spectroscopy,confirms the oxidation reaction,such as the formation of quinones(C=O)and subsequent crosslinking between the oxidized HKL molecules and MEA.Additionally,gel permeation chromatography(GPC)confirms the C-C and C-O linkages with increased molecular weight after oxidation,and is supported by differential scanning calorimetry(DSC)which shows the exothermic reaction due to the crosslinking of the oxidized HKL molecules via condensation to form C-C and C-O linkages.The crosslinked HKL/MEA-based adhesives underwent mild reaction and achieved a maximum dry shear strength of 0.77 MPa,which exceeds the standard requirement of 0.6 MPa.These findings demonstrate not only a one-pot oxidation for improving the reactivity of HKL using silver complexes,but also its facile crosslinking with MEA for sustainable bio-based wood adhesives.展开更多
This review is composed of three main parts each of which is written by well-known top specialists that have been,in a way or other,also the main participants of the majority of the developments reported.Thus,after a ...This review is composed of three main parts each of which is written by well-known top specialists that have been,in a way or other,also the main participants of the majority of the developments reported.Thus,after a general part covering the grand lines and more in-depth views of more recent tannin,lignin,carbohydrate and soy bioadhesives,somemix of the other bio raw materials with soy protein and soy flour and some other differently sourced bioadhesives for wood,this review presents a more in-depth part on starch-based wood adhesives and a more indepth part covering plant protein-based adhesives.It must be kept in mind that the review is focused on completely or almost completely biosourced adhesives,the fashionable adhesives derived from mixes of biosourced materials with synthetic resins having been intentionally excluded.This choice was made as the latter constitute only an intermediate interval,possibly temporary if even for a somewhat long times,towards a final full bioeconomy of scale in this field.This review also focuses on more recent results,mainly obtained in the last 10–20 years,thus on adhesive formulations really innovative and sometimes even non-traditional.In all these fields there is still a lot of possibility of innovation for relevant formulation as this field is still in rapid growth.展开更多
Photoinitiators(PIs), as the key substances for photopolymerized antibacterial film(PAF), affect the cure rate and color of PAF. Herein, two enone dyes were designed and synthesized by a facile approach. Among the can...Photoinitiators(PIs), as the key substances for photopolymerized antibacterial film(PAF), affect the cure rate and color of PAF. Herein, two enone dyes were designed and synthesized by a facile approach. Among the candidates, BDO1 has demonstrated the ability to initiate polymerization of acrylate monomers as single-component PI with the advantages of low mobility, outstanding photobleaching, excellent cytocompatibility, and suitability for light emitting diode(LED) light sources above 365 nm. Taking BDOs as examples, a novel method based on theoretical calculations aiming to assess the potential of enone molecules as single-component PIs was proposed. Finally, under the initiation of BDO1, tannic acid was photopolymerized to a colorless and transparent antibacterial film with high antibacterial ability, which indicated that BDO1 was expected to be used in environmentally friendly PAF.展开更多
Since 2009,perovskite solar cells(PSCs)have advanced significantly,achieving over 26%efficiency for single-junction devices and exceeding 34%for silicon-perovskite tandem cells.Despite these successes,the weak adhesio...Since 2009,perovskite solar cells(PSCs)have advanced significantly,achieving over 26%efficiency for single-junction devices and exceeding 34%for silicon-perovskite tandem cells.Despite these successes,the weak adhesion of C_(60)to perovskite layers,due to van der Waals interactions,hinders long-term stability.In this study,we introduce electron-deficient intermolecular adhesives(EDIAs)as a novel interlayer material to enhance adhesion between perovskite and C_(60)layers.Comprehensive analyses,including density functional theory calculations,microscopy,and spectroscopy,demonstrate that EDIAs,particularly NDI-C9-Ace comprising of three key functionalities:aπ-electron-deficient arene core,a hydrophobic passivation core,and a secondary-bond anchoring core,significantly improve bonding strength and recombination passivation.This leads to enhanced efficiency as well as enhanced mechanical and photochemical stability in PSCs.Long-term stability tests further confirm the superior durability of EDIA-enhanced devices.This study highlights EDIA as a promising strategy for enhancing the robustness and efficiency of PSCs.展开更多
The role of the adhesive layer in the ballistic performance of ceramic multi-layer armour system is complex and multi-faceted,often with trade-offs between single-and multi-hit performance.However,research focused on ...The role of the adhesive layer in the ballistic performance of ceramic multi-layer armour system is complex and multi-faceted,often with trade-offs between single-and multi-hit performance.However,research focused on untangling the underlying impact of varying adhesive cohesive or adhesion properties is limited and sometimes appears to provide conflicting conclusions.Comparison between the available studies is also often difficult due to variations in armour systems or ballistic testing being conducted.This review scrutinises the available research,identifying six critical properties of an adhesive layer in determining ballistic performance:elastic modulus,fracture strain,acoustic impedance,tensile bond strength,shear bond strength,and thickness.The impact of each of these properties on ballistic performance is discussed in detail,with clear description of the underlying processes involved,allowing clear optimisation goals to be established depending on the ceramic armour specification.展开更多
This study aims to investigate the failure modes at the interface of semi-flexible pavement(SFP)materials.The cohesive and wetting properties of asphalt materials,as well as two types of grout(early strength cement gr...This study aims to investigate the failure modes at the interface of semi-flexible pavement(SFP)materials.The cohesive and wetting properties of asphalt materials,as well as two types of grout(early strength cement grout-ELS and high strength cement grout-CHS),were evaluated through pull-out tests and contact angle experiments.The rheological properties of the grout/asphalt mortar were assessed using dynamic shear rheometer(DSR)testing.The interaction coefficient,complex shear modulus,and complex viscosity coefficients of the grout/asphalt mortar were calculated to analyze the interaction between the grout and asphalt.Failure modes were identified through image analysis of semi-circular bending test(SCB)specimens.Results indicate that ELS specimens exhibit a lower grout/asphalt interface failure ratio compared to CHS specimens,due to the superior wettability and interaction of ELS grout.As the temperature increases,the proportions of cement fracture and aggregate failure decrease,while the proportion of asphalt cohesive failure surfaces increases.Furthermore,the bonding strength of SBS-modified asphalt with the grout exceeds that of pure asphalt.展开更多
The advancement of functional adhesives featuring recyclable and repairable properties is of great significance in interfacial science and engineering.Herein,a series of high-strength,recyclable fluorine-containing ad...The advancement of functional adhesives featuring recyclable and repairable properties is of great significance in interfacial science and engineering.Herein,a series of high-strength,recyclable fluorine-containing adhesives(ESOx-FPF)were designed and synthesized by crosslinking two prepolymers,FPF-B(derived from side-chain fluorinated diol,isocyanate,and aminoboric acid)and ESO-B(synthesized from biobased epoxy soybean oil and aminoboric acid),through dynamic boro-oxygen bonds.The resulting adhesive exhibited an optimal tensile strength of 42 MPa and the shear strength on steel plates reached as high as 3.89 MPa.More importantly,benefiting from the dynamic reversibility of the boron-oxygen bonds along with the hydrogen bonds interaction,ESOx-FPF can be welded with the assistance of solvents and recycled for multiple cycles.The outstanding healing efficiency and excellent reprocessability of these functional adhesives were confirmed by mechanical testing.Moreover,the as-prepared adhesives demonstrated universal and remarkable adhesion to various substrates,such as aromatic polyamide,aluminum plates and polycarbonate,meanwhile,they could be easily disassembled and recycled using ethanol without damaging the substrates surface.This study not only provides a simple strategy for the synthesis of eco-friendly adhesives with weldable and recyclable properties,but also sheds light on the development of other functional materials utilizing dynamic covalent chemistry.展开更多
Gecko-inspired van der Waals force-based adhesion technology demonstrates significant potential for robotic operations.While superior adhesion is achieved under parallel contact during testing,engineering operations o...Gecko-inspired van der Waals force-based adhesion technology demonstrates significant potential for robotic operations.While superior adhesion is achieved under parallel contact during testing,engineering operations often involve non-parallel contact,weakening adhesion,and compromising task stability and efficiency.Stable attachment under such non-parallel contacts remains challenging.Inspired by the soft muscle and rigid bone in the gecko’s sole,this study proposes a self-adaptive core-shell dry adhesive by embedding a thin,rigid piece into a soft,thick elastomer comprising a top adhesion tip with a mushroom-like geometry for interfacial adhesion based on the van der Waals force and a bottom core-shell configuration for interface stress regulation.Unlike traditional core-shell structures with a fixed“dead core,”the proposed“live core”rotates within the soft shell,mimicking skeletal joints.This enables stress equalization at the interface and facilitates adaptive contact to macroscopic interfacial angle errors.This innovative core-shell configuration demonstrates an adhesion strength 100 times higher than conventional homogeneous structures under non-parallel contact and offers anti-overturning ability by mitigating torsional effects.The proposed strategy can advance the development of gecko-inspired adhesion-based devices and systems.展开更多
The ability of queens and males of most ant species to disperse by flight has fundamentally contributed to the group’s evolutionary and ecological success and is a determining factor to take into account for biogeogr...The ability of queens and males of most ant species to disperse by flight has fundamentally contributed to the group’s evolutionary and ecological success and is a determining factor to take into account for biogeographic studies(Wagner and Liebherr 1992;Peeters and Ito 2001;Helms 2018).展开更多
Hydrogel-based flexible sensors are emerging as ideal candidates for wearable devices and soft robotics.However,most current hydrogels possess limited physicochemical properties,which hinder their practical applicatio...Hydrogel-based flexible sensors are emerging as ideal candidates for wearable devices and soft robotics.However,most current hydrogels possess limited physicochemical properties,which hinder their practical application in long-term and complex scenarios.Herein,inspired by the unique structure of the barnacle,we design multifunctional poly(DMAPA-co-PHEA)hydrogels(CP hydrogels)by employing multiple physical crosslinks in the presence of Ag nanoparticles and NaCl additives.Owing to the synergistic effect of cation-πinteractions,hydrophobic interactions,and ionic bonds,the CP hydrogels exhibit high stretchability(strain up to 1430%),strong adhesion(22.8 kPa),satisfactory antibacterial activity,stable anti-icing ability(<20 kPa after 20 icing-deicing cycles),and high electrical conductivity(18.5 mS/cm).Additionally,the CP hydrogels show fast and sensitive responsiveness and cycling stability and can attach directly to human skin to accurately detect both human motions and tiny physiological signals as a flexible wearable sensor.Collectively,this work significantly contributes a straightforward and efficient design strategy for the development of multifunctional hydrogels,broadening their application scenarios.展开更多
Wound dressings with tissue adhesion,good mechanical,antioxidant and anti-inflammatory performance are urgently needed.In this work,we present a multifunctional selenium nanoparticles(SeNPs)/citric acid/gelatin/hydrox...Wound dressings with tissue adhesion,good mechanical,antioxidant and anti-inflammatory performance are urgently needed.In this work,we present a multifunctional selenium nanoparticles(SeNPs)/citric acid/gelatin/hydroxysuccinimide-grafted polyacrylic acid nanocomposite hydrogel adhesive(SCA) specifically designed for wound healing applications.The SCA was prepared via a one-pot processing,where SeNPs synthesized via chemical reduction were incorporated.These SeNPs not only endowed SCA with robust wet adhesion ability,excellent stretchability,and skin-matched elasticity modulus by serving as a physical crosslinker to modulate swelling equilibrium and molecular slippage,but also enhanced the biocompatibility and free radical scavenging capacity of SCA.Furthermore,in vivo evaluation of full-thickness cutaneous defects of rats revealed that SCA effectively reduced inflammation,promoted wound closure,and increased collagen deposition.All these results demonstrated that the developed SCA offers a promising therapeutic strategy for wound healing applications.展开更多
Brittle materials,such as silicon,glass,and ceramics,are widely used in engineering via adhesive bonding.The assessment of adhesive strength of brittle materials to other adherends is essential for their applications....Brittle materials,such as silicon,glass,and ceramics,are widely used in engineering via adhesive bonding.The assessment of adhesive strength of brittle materials to other adherends is essential for their applications.Compared with metals and composites,for which standard testing methods have been established,the experimental method for brittle adherends has been much less explored.During the adhesive strength test,the brittleness of these materials makes them prone to failure,rather than the interface.It remains a challenge to measure the adhesive strength of brittle adherends.Here we develop an experimental method to address this issue by using a strap joint specimen with a backing layer.We use a single crystal silicon wafer and two PCB(printed circuit board)strips as adherends to make a strap joint specimen.A steel backing layer is glued to the silicon wafer to prevent the failure of silicon.This method enables the measurement of adhesive strength up to 35 MPa.In contrast,that without backing layer can only measure the adhesive strength below 10 MPa.It is found that the backing layer can reduce the stress in the silicon remarkably,while it has much less effect on the stress in the adhesive layer.We confirm that the backing layer has a negligible effect on the measured adhesive strength but expands the working space greatly.Combining finite element analysis and experiments,we establish the phase diagram for the failure modes.This work provides guidance for the measurement of adhesive strength of brittle materials.展开更多
Soft actuators are inherently flexible and compliant,traits that enhance their adaptability to diverse environments and tasks.However,their low structural stiffness can lead to unpredictable and uncontrollable complex...Soft actuators are inherently flexible and compliant,traits that enhance their adaptability to diverse environments and tasks.However,their low structural stiffness can lead to unpredictable and uncontrollable complex deformations when substantial force is required,compromising their load-bearing capacity.This work proposes a novel method that uses gecko setae-inspired adhesives as interlayer films to construct a layer jamming structure to adjust the stiffness of soft actuators.The mechanical behavior of a single tilted microcylinder was analyzed using the energy method to determine the adhesion force of the adhesives.The gecko-inspired adhesive was designed under the guidance of the adhesion force model.Testing under various loads and directions revealed that the tilted characteristic of microcylinders can enhance the adhesion force in its grasping direction.The adhesive demonstrated excellent adhesion performance compared to other typical adhesives.A tunable stiffness actuator using gecko setae-inspired adhesives(TSAGA),was developed with these adhesives serving as interlayer films.The stiffness model of TSAGA was derived by analyzing its axial compression force.The results of stiffness test indicate that the adhesives serve as interlayer films can adjust the stiffness in response to applied load.TSAGA was compared with other typical soft actuators in order to evaluate the stiffness performance,and the results indicate that TSAGA exhibits the highest stiffness and the widest tunable stiffness range.This demonstrates the superior performance of the setae-inspired adhesives as interlayer films in terms of stiffness adjustment.展开更多
The main raw material utilized in wood adhesives comes from petrochemical extractives.However,due to the excessive dependence on petrochemical resources and the adverse impact on the ecosystem and human wellbeing,ther...The main raw material utilized in wood adhesives comes from petrochemical extractives.However,due to the excessive dependence on petrochemical resources and the adverse impact on the ecosystem and human wellbeing,there is an increasing trend to develop byproduct protein-based adhesives in the current global food safety context.In this research,flaxseed meal was subjected to pretreatment,and trimethylolpropane triglycidyl ether(TTE)and ethylenediamine(EN)were utilized as crosslinkers to establish a more compact adhesive layer and to prevent water intrusion.The pretreatment decreased the FM/UB viscosity by 60%compared to FM.The combination of CD analysis indicated that the Urea-NaOH pretreatment effectively stretched the flaxseed meal protein.According to Fourier transform infrared(FTIR)spectroscopy,X-ray diffraction(XRD),and differential scanning calorimetry(DSC)were used to analyze the resulting adhesive’s reaction mechanism and thermal response.Furthermore,the physical properties of the adhesive were characterized using wet shear strength testing and SEM observation.Remarkably,the dry bond strength increased from 0.72 to 2.12 MPa,representing a 194.4%increase.The wet bonding strength of the adhesive was improved from 0.22 to 1.21 MPa,representing a 550%increase compared to the original flaxseed protein-based adhesive,which far exceeded the minimum requirement for plywood of Type II(≥0.7 MPa,by GB/T 9846-2015).This study demonstrated an eco-friendly and sustainable method for the development of protein adhesives as viable substitutes for petrochemical resins.展开更多
基金the New Chongqing Innovative Young Talent Project under Grant 2024NSCQ-qncxX0468Dreams Foundation of Jianghuai Advance Technology Center under Grant 2023-ZM01Z007.
文摘The net capturing method holds great potential for space debris removal due to its adaptability to the various target shapes and high fault tolerance.However,the capture mechanisms of current rope nets,which rely solely on a passive wrap-ping mechanism,limit their capacity to capture objects within a specific size range and make it challenging to handle unexpected situations.Inspired by spider webs,which combine wrapping and adhering to capture prey of various sizes,we present a new type of net(envelope diameter:208.49 mm)for on-orbit capture.This net adopts a spiral symmetric structure similar to spider webs,incorporates electrostatic-microstructure hybrid adhesives,and increases the maximum contact area by 38.31%,allowing it to capture debris ranging from fragments smaller than the mesh size(envelope diam-eter:2.7 mm-4.4 mm)to larger objects(envelope diameter:270 mm),and effectively grasps flexible items(450 mm2),planar items(350 mm2)and three-dimensional items(160 mm3).Moreover,to validate the net's capability for wrapping and adhesion,simulations and experiments are demonstrated that this dual capture method can effectively handle various targets.
基金support from the National Natural Science Foundation of China(No.22308279)Guangdong Basic and Applied Basic Research Foundation(No.2021A1515110695)Natural Science Foundation of Chongqing(No.2023NSCQMSX2773).
文摘As a common electronic adhesive,ultraviolet(UV)curing polyurethane acrylate adhesive has both flexibility and wear resistance of polyurethane,excellent weather resistance and optical properties of acrylate.Despite the extensive applications,it is still difficult to solve the problems caused by the shrinkage of adhesive.Here,a new type of photosensitive adhesive for bonding electronic components based on supramolecular interaction was designed and synthesized.The supramolecular interaction of cyclodextrin and adamantane moieties introduced into the adhesive polymer entitles the viscosity of the adhesive to rise rapidly during use,thereby preventing adhesive loss and dislocation of electronic components.UV light could further cure the adhesive and position the electronic components.The adhesive shrunk<2%when cured by UV light,so it can be used for electronic packaging and high-resolution,defect-free lithography.
基金financially supported by the Shandong Provincial Natural Science Foundation,China(Nos.ZR2022MB051 and ZR2021MB112)Postdoctoral Science Foundation of China(No.2022M712343)+2 种基金Jinan City University Integration Development Strategy Project(No.JNSX2024030)Key Laboratory of Special Functional Aggregates of the Ministry of Education,Shandong University(No.JJT-2023-02)Shandong SD-Link New Material Technology Co.,LTD.
文摘Silicone-based pressure-sensitive adhesives(Si-PSAs)are valued for their thermal stability,flexibility,and biocompatibility,but their weak bonding strength restricts high-performance use.Polyurethane-modified Si-PSAs enhance adhesion,however diisocyanates remain essential.The raw materials of isocyanates are toxic,and their synthesis involves phosgene.To make up for those shortcomings,a series of poly(hydroxy urethane-siloxane)PSAs,named as PHUSi here,were synthesized through the ring-opening reaction of cyclic carbonate-functionalized polysiloxanes(PSi_(x)-VEC_(z))with various aliphatic diamines.The PSi_(x)-VEC_(z) precursors were prepared via the hydrosilylation of hydrogen-containing polysiloxanes(PSi_(x)-H_(y))with 4-vinyl-1,3-dioxolan-2-one(VEC).The chemical structures of PSi_(x)-H_(y),PSi_(x)-VEC_(z) and PHUSi were characterized,and bonding properties of PHUSi were systematically evaluated.The influence of architectures on adhesive performance was elucidated through comprehensive analyses,including rheology,crosslink density assessment,and so on.These studies revealed that the tailored design of PHUSi adhesives combine the advantages of traditional Si-PSAs with enhanced adhesion while eliminating isocyanate toxicity.The optimized PHUSi formulation achieved remarkable 180°peel strength(76.5 N/m on skin)and maximum probe tack force(1.61 N),enabling secure 24 h attachment of flexible sensors to skin.These properties make PHUSi particularly suitable for medical applications,as demonstrated by successful implementation in flexible electrocardiogram devices,offering a biocompatible,high-performance adhesive.
基金supported by the National Natural Science Foundation of China(52222302)。
文摘Reuse/recycling of expensive components in next-generation optoelectronic systems(e.g.,flexible electronics and foldable displays)for sustainability purposes impose stringent requirements on optically clear adhesive(OCA)with on-demand adhesion/deadhesion capability.Although some hot-melt OCAs have been developed,there still remain great challenges in balancing the mechanical property,adhesion/detachment and recyclability/reusability of the OCAs.Herein,we developed a debondable and robust polyurethane(PU)-based optically clear adhesive with both mechanical and chemical recyclability,overcoming the critical bottlenecks in sustainable advanced manufacturing.The ductile yet strong PU-based OCAs not only can adhere to various optically transparent glass and polymeric substrates(with a bonding strength high up to 5.0 MPa),but also exhibit deadhesion capability at high temperature owing to the thermally sensitive H-bonding interaction within the polymer network.The ondemand adhesion/deadhesion facilitates non-destructive detachment of functional assemblies and materials recycling/repair.The mechanical and chemical recyclability of PU-based OCAs can also effectively reduce the cost and address the endof-life issues.Moreover,the PU-based OCAs outperformed some commercial optical adhesives.In view of the straightforward synthesis,easy industrial scale-up and exceptional comprehensive properties,the PU-based OCAs will provide promising transformative solutions for advancing the circular economy and sustainability in next-generation optoelectronic devices.
基金Funded by the National Natural Science Foundation of China(Nos.52278269,52278268,52178264)Tianjin Outstanding Young Scholars Science Fund Project(No.22JCJQJC00020)Key Project of Tianjin Natural Science Foundation(No.23JCZDJC00430)。
文摘The effect of antibacterial adhesive on the biological corrosion resistance of mortar in seawater environment was studied by means of scanning electron microscope,thermogravimetric analysis,X-ray diffraction,Fourier transform infrared spectroscopy,and ultra-depth microscope.The results show that the antibacterial adhesive can effectively inhibit the growth of sulfur-oxidizing bacteria in seawater,hinder their metabolism to produce biological sulfate,and reduce the formation of destructive product gypsum.The mineral composition and thermal analysis showed that the peak value of plaster diffraction peak and the mass loss of plaster dehydration in antibacterial adhesive group were significantly lower than those in blank group(without protective coating group).In addition,the electric flux of chloride ions(>400 C)in the blank group of mortar samples was higher than that in the antibacterial adhesive group(<200 C),indicating that the antibacterial adhesive can effectively reduce the permeability of chloride ions in mortar,and thus hinder the Cl-erosion in seawater.
基金supported by the National Natural Science Foundation of China(Nos.22273098,22373003,22103002 and 52033001)the Key Project of Anhui Province Science and Technology Innovation Platform(No.202305a12020030)the financial support from the Anhui Provincial Natural Science Foundation(No.2408085Y004)。
文摘Polymeric materials which can undergo controlled degradation and recycling are of great significance for a sustainable society.Although tremendous progress has been made in the degradation and recycling of both thermoplastic and thermoset plastics,the development of high-performance degradable polymer adhesives is rare.Here,we have prepared high-performance nucleobase-containing thioctic acid-based supramolecular polymer adhesives through free radical polymerization.The specific hydrogen-bonding interactions between complementary nucleobases greatly improve the weak cohesion of the thioctic acid-based polymers and enhance the environmental stability of the thioctic acidbased polymers simultaneously.Degradation of the nucleobase-containing thioctic acid-based supramolecular polymers is achieved by the reduction of the disulfide backbone,and the cycle of degradation and repolymerization is further achieved via oxidative polymerization.The adhesion strength of the nucleobase-containing thioctic acid-based supramolecular polymers after two cycles of degradation and repolymerization still reaches as high as 4.7±0.3 MPa.This work provides an approach for the development of environmentally stable and high-performance degradable thioctic acid-based adhesives.
基金supported by the National Research Foundation(NRF)of Korea,funded by the Korean Government(MSIT)(Grant No.RS-2023-00240043).
文摘As the most abundant aromatic bio-based polymer,lignin has great potential as a sustainable feedstock for building crosslinked thermoset polymers as bio-based adhesives.However,the potential of hardwood kraft lignin(HKL)is limited due to its poor crosslinking reactivity.Hence,for the first time,the present study reports the facile oxidation of HKL involving a redox reaction with silver-ammonia complexes([(AgNH3)2]+),primarily focusing on oxidation to produce reactive quinones and promote C-C linkages during reaction.This study aims to increases reactivity of oxidized HKL for effective crosslinking with monoethanolamine(MEA)for the development of bio-based wood adhesives.The characterization,including 13C-nuclear magnetic resonance(NMR)and Fourier transform infrared(FT-IR)spectroscopy,confirms the oxidation reaction,such as the formation of quinones(C=O)and subsequent crosslinking between the oxidized HKL molecules and MEA.Additionally,gel permeation chromatography(GPC)confirms the C-C and C-O linkages with increased molecular weight after oxidation,and is supported by differential scanning calorimetry(DSC)which shows the exothermic reaction due to the crosslinking of the oxidized HKL molecules via condensation to form C-C and C-O linkages.The crosslinked HKL/MEA-based adhesives underwent mild reaction and achieved a maximum dry shear strength of 0.77 MPa,which exceeds the standard requirement of 0.6 MPa.These findings demonstrate not only a one-pot oxidation for improving the reactivity of HKL using silver complexes,but also its facile crosslinking with MEA for sustainable bio-based wood adhesives.
文摘This review is composed of three main parts each of which is written by well-known top specialists that have been,in a way or other,also the main participants of the majority of the developments reported.Thus,after a general part covering the grand lines and more in-depth views of more recent tannin,lignin,carbohydrate and soy bioadhesives,somemix of the other bio raw materials with soy protein and soy flour and some other differently sourced bioadhesives for wood,this review presents a more in-depth part on starch-based wood adhesives and a more indepth part covering plant protein-based adhesives.It must be kept in mind that the review is focused on completely or almost completely biosourced adhesives,the fashionable adhesives derived from mixes of biosourced materials with synthetic resins having been intentionally excluded.This choice was made as the latter constitute only an intermediate interval,possibly temporary if even for a somewhat long times,towards a final full bioeconomy of scale in this field.This review also focuses on more recent results,mainly obtained in the last 10–20 years,thus on adhesive formulations really innovative and sometimes even non-traditional.In all these fields there is still a lot of possibility of innovation for relevant formulation as this field is still in rapid growth.
基金financially supported by National Natural Science Foundation of China (Nos. 21925802, 22338005)Liaoning Binhai Laboratory (No. LBLB-2023–03)the Fundamental Research Funds for the Central Universities (No. DUT22LAB601)。
文摘Photoinitiators(PIs), as the key substances for photopolymerized antibacterial film(PAF), affect the cure rate and color of PAF. Herein, two enone dyes were designed and synthesized by a facile approach. Among the candidates, BDO1 has demonstrated the ability to initiate polymerization of acrylate monomers as single-component PI with the advantages of low mobility, outstanding photobleaching, excellent cytocompatibility, and suitability for light emitting diode(LED) light sources above 365 nm. Taking BDOs as examples, a novel method based on theoretical calculations aiming to assess the potential of enone molecules as single-component PIs was proposed. Finally, under the initiation of BDO1, tannic acid was photopolymerized to a colorless and transparent antibacterial film with high antibacterial ability, which indicated that BDO1 was expected to be used in environmentally friendly PAF.
基金supported by National Research Foundation of Korea(NRF)(RS-2024-00336766 and RS-2023-00301974)support of the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(RS-2023-00220748)。
文摘Since 2009,perovskite solar cells(PSCs)have advanced significantly,achieving over 26%efficiency for single-junction devices and exceeding 34%for silicon-perovskite tandem cells.Despite these successes,the weak adhesion of C_(60)to perovskite layers,due to van der Waals interactions,hinders long-term stability.In this study,we introduce electron-deficient intermolecular adhesives(EDIAs)as a novel interlayer material to enhance adhesion between perovskite and C_(60)layers.Comprehensive analyses,including density functional theory calculations,microscopy,and spectroscopy,demonstrate that EDIAs,particularly NDI-C9-Ace comprising of three key functionalities:aπ-electron-deficient arene core,a hydrophobic passivation core,and a secondary-bond anchoring core,significantly improve bonding strength and recombination passivation.This leads to enhanced efficiency as well as enhanced mechanical and photochemical stability in PSCs.Long-term stability tests further confirm the superior durability of EDIA-enhanced devices.This study highlights EDIA as a promising strategy for enhancing the robustness and efficiency of PSCs.
基金funding for this research was provided by Netherlands Ministry of Defence
文摘The role of the adhesive layer in the ballistic performance of ceramic multi-layer armour system is complex and multi-faceted,often with trade-offs between single-and multi-hit performance.However,research focused on untangling the underlying impact of varying adhesive cohesive or adhesion properties is limited and sometimes appears to provide conflicting conclusions.Comparison between the available studies is also often difficult due to variations in armour systems or ballistic testing being conducted.This review scrutinises the available research,identifying six critical properties of an adhesive layer in determining ballistic performance:elastic modulus,fracture strain,acoustic impedance,tensile bond strength,shear bond strength,and thickness.The impact of each of these properties on ballistic performance is discussed in detail,with clear description of the underlying processes involved,allowing clear optimisation goals to be established depending on the ceramic armour specification.
基金Funded by the Science and Technology Program Special Fund of Jiangsu Province(Frontier Leading Technology Basic Research)Major Projects(No.BK20222004)the National Natural Science Foundation of China(No.52078241)the New Cornerstone Science Foundation through the XPLORER PRIZE。
文摘This study aims to investigate the failure modes at the interface of semi-flexible pavement(SFP)materials.The cohesive and wetting properties of asphalt materials,as well as two types of grout(early strength cement grout-ELS and high strength cement grout-CHS),were evaluated through pull-out tests and contact angle experiments.The rheological properties of the grout/asphalt mortar were assessed using dynamic shear rheometer(DSR)testing.The interaction coefficient,complex shear modulus,and complex viscosity coefficients of the grout/asphalt mortar were calculated to analyze the interaction between the grout and asphalt.Failure modes were identified through image analysis of semi-circular bending test(SCB)specimens.Results indicate that ELS specimens exhibit a lower grout/asphalt interface failure ratio compared to CHS specimens,due to the superior wettability and interaction of ELS grout.As the temperature increases,the proportions of cement fracture and aggregate failure decrease,while the proportion of asphalt cohesive failure surfaces increases.Furthermore,the bonding strength of SBS-modified asphalt with the grout exceeds that of pure asphalt.
基金financially supported by the Natural Science Foundation of Shandong Province(No.ZR2022MB034)。
文摘The advancement of functional adhesives featuring recyclable and repairable properties is of great significance in interfacial science and engineering.Herein,a series of high-strength,recyclable fluorine-containing adhesives(ESOx-FPF)were designed and synthesized by crosslinking two prepolymers,FPF-B(derived from side-chain fluorinated diol,isocyanate,and aminoboric acid)and ESO-B(synthesized from biobased epoxy soybean oil and aminoboric acid),through dynamic boro-oxygen bonds.The resulting adhesive exhibited an optimal tensile strength of 42 MPa and the shear strength on steel plates reached as high as 3.89 MPa.More importantly,benefiting from the dynamic reversibility of the boron-oxygen bonds along with the hydrogen bonds interaction,ESOx-FPF can be welded with the assistance of solvents and recycled for multiple cycles.The outstanding healing efficiency and excellent reprocessability of these functional adhesives were confirmed by mechanical testing.Moreover,the as-prepared adhesives demonstrated universal and remarkable adhesion to various substrates,such as aromatic polyamide,aluminum plates and polycarbonate,meanwhile,they could be easily disassembled and recycled using ethanol without damaging the substrates surface.This study not only provides a simple strategy for the synthesis of eco-friendly adhesives with weldable and recyclable properties,but also sheds light on the development of other functional materials utilizing dynamic covalent chemistry.
基金supported by the National Natural Science Foundation(52025055,52175546,and 52405624)the Shaanxi University Youth Innovation Team.
文摘Gecko-inspired van der Waals force-based adhesion technology demonstrates significant potential for robotic operations.While superior adhesion is achieved under parallel contact during testing,engineering operations often involve non-parallel contact,weakening adhesion,and compromising task stability and efficiency.Stable attachment under such non-parallel contacts remains challenging.Inspired by the soft muscle and rigid bone in the gecko’s sole,this study proposes a self-adaptive core-shell dry adhesive by embedding a thin,rigid piece into a soft,thick elastomer comprising a top adhesion tip with a mushroom-like geometry for interfacial adhesion based on the van der Waals force and a bottom core-shell configuration for interface stress regulation.Unlike traditional core-shell structures with a fixed“dead core,”the proposed“live core”rotates within the soft shell,mimicking skeletal joints.This enables stress equalization at the interface and facilitates adaptive contact to macroscopic interfacial angle errors.This innovative core-shell configuration demonstrates an adhesion strength 100 times higher than conventional homogeneous structures under non-parallel contact and offers anti-overturning ability by mitigating torsional effects.The proposed strategy can advance the development of gecko-inspired adhesion-based devices and systems.
基金funded by the“Departments of Excellence”program of the Italian Ministry for University and Research(MIUR,2018-2022 and MUR,2023-2027).
文摘The ability of queens and males of most ant species to disperse by flight has fundamentally contributed to the group’s evolutionary and ecological success and is a determining factor to take into account for biogeographic studies(Wagner and Liebherr 1992;Peeters and Ito 2001;Helms 2018).
基金financial support from the Guangdong Basic and Applied Basic Research Foundation(No.2023A1515012218)Macao Science and Technology Development Fund(Nos.FDCT 0009/2020/AMJ,0027/2023/RIB1)+1 种基金National Natural Science Foundation of China(No.32301104)Fundamental Research Funds for the Central Universities,Sun Yat-sen University(No.23ptpy165).
文摘Hydrogel-based flexible sensors are emerging as ideal candidates for wearable devices and soft robotics.However,most current hydrogels possess limited physicochemical properties,which hinder their practical application in long-term and complex scenarios.Herein,inspired by the unique structure of the barnacle,we design multifunctional poly(DMAPA-co-PHEA)hydrogels(CP hydrogels)by employing multiple physical crosslinks in the presence of Ag nanoparticles and NaCl additives.Owing to the synergistic effect of cation-πinteractions,hydrophobic interactions,and ionic bonds,the CP hydrogels exhibit high stretchability(strain up to 1430%),strong adhesion(22.8 kPa),satisfactory antibacterial activity,stable anti-icing ability(<20 kPa after 20 icing-deicing cycles),and high electrical conductivity(18.5 mS/cm).Additionally,the CP hydrogels show fast and sensitive responsiveness and cycling stability and can attach directly to human skin to accurately detect both human motions and tiny physiological signals as a flexible wearable sensor.Collectively,this work significantly contributes a straightforward and efficient design strategy for the development of multifunctional hydrogels,broadening their application scenarios.
基金supported by National Natural Science Foundation of China(No.52403042)China Postdoctoral Science Foundation(No.2023M742472)。
文摘Wound dressings with tissue adhesion,good mechanical,antioxidant and anti-inflammatory performance are urgently needed.In this work,we present a multifunctional selenium nanoparticles(SeNPs)/citric acid/gelatin/hydroxysuccinimide-grafted polyacrylic acid nanocomposite hydrogel adhesive(SCA) specifically designed for wound healing applications.The SCA was prepared via a one-pot processing,where SeNPs synthesized via chemical reduction were incorporated.These SeNPs not only endowed SCA with robust wet adhesion ability,excellent stretchability,and skin-matched elasticity modulus by serving as a physical crosslinker to modulate swelling equilibrium and molecular slippage,but also enhanced the biocompatibility and free radical scavenging capacity of SCA.Furthermore,in vivo evaluation of full-thickness cutaneous defects of rats revealed that SCA effectively reduced inflammation,promoted wound closure,and increased collagen deposition.All these results demonstrated that the developed SCA offers a promising therapeutic strategy for wound healing applications.
基金supported by the National Key R&D Program of China(2021YFB3201700).
文摘Brittle materials,such as silicon,glass,and ceramics,are widely used in engineering via adhesive bonding.The assessment of adhesive strength of brittle materials to other adherends is essential for their applications.Compared with metals and composites,for which standard testing methods have been established,the experimental method for brittle adherends has been much less explored.During the adhesive strength test,the brittleness of these materials makes them prone to failure,rather than the interface.It remains a challenge to measure the adhesive strength of brittle adherends.Here we develop an experimental method to address this issue by using a strap joint specimen with a backing layer.We use a single crystal silicon wafer and two PCB(printed circuit board)strips as adherends to make a strap joint specimen.A steel backing layer is glued to the silicon wafer to prevent the failure of silicon.This method enables the measurement of adhesive strength up to 35 MPa.In contrast,that without backing layer can only measure the adhesive strength below 10 MPa.It is found that the backing layer can reduce the stress in the silicon remarkably,while it has much less effect on the stress in the adhesive layer.We confirm that the backing layer has a negligible effect on the measured adhesive strength but expands the working space greatly.Combining finite element analysis and experiments,we establish the phase diagram for the failure modes.This work provides guidance for the measurement of adhesive strength of brittle materials.
基金supported by Jiangsu Special Project for Frontier Leading Base Technology(Grant Nos.BK20192004)Fundamental Research Funds for Central Universities(Grant Nos.B240201190)+3 种基金Changzhou Social Development Science and Technology Support Project(Grant Nos.CE20225037)Changzhou Science and Technology Project(Grant Nos.CM20223014)Suzhou Key Industrial Technology Innovation Forward-Looking Application Research Project(Grant Nos.SYG202143)Changzhou Science and Technology Project(Grant Nos.CJ20241061).
文摘Soft actuators are inherently flexible and compliant,traits that enhance their adaptability to diverse environments and tasks.However,their low structural stiffness can lead to unpredictable and uncontrollable complex deformations when substantial force is required,compromising their load-bearing capacity.This work proposes a novel method that uses gecko setae-inspired adhesives as interlayer films to construct a layer jamming structure to adjust the stiffness of soft actuators.The mechanical behavior of a single tilted microcylinder was analyzed using the energy method to determine the adhesion force of the adhesives.The gecko-inspired adhesive was designed under the guidance of the adhesion force model.Testing under various loads and directions revealed that the tilted characteristic of microcylinders can enhance the adhesion force in its grasping direction.The adhesive demonstrated excellent adhesion performance compared to other typical adhesives.A tunable stiffness actuator using gecko setae-inspired adhesives(TSAGA),was developed with these adhesives serving as interlayer films.The stiffness model of TSAGA was derived by analyzing its axial compression force.The results of stiffness test indicate that the adhesives serve as interlayer films can adjust the stiffness in response to applied load.TSAGA was compared with other typical soft actuators in order to evaluate the stiffness performance,and the results indicate that TSAGA exhibits the highest stiffness and the widest tunable stiffness range.This demonstrates the superior performance of the setae-inspired adhesives as interlayer films in terms of stiffness adjustment.
文摘The main raw material utilized in wood adhesives comes from petrochemical extractives.However,due to the excessive dependence on petrochemical resources and the adverse impact on the ecosystem and human wellbeing,there is an increasing trend to develop byproduct protein-based adhesives in the current global food safety context.In this research,flaxseed meal was subjected to pretreatment,and trimethylolpropane triglycidyl ether(TTE)and ethylenediamine(EN)were utilized as crosslinkers to establish a more compact adhesive layer and to prevent water intrusion.The pretreatment decreased the FM/UB viscosity by 60%compared to FM.The combination of CD analysis indicated that the Urea-NaOH pretreatment effectively stretched the flaxseed meal protein.According to Fourier transform infrared(FTIR)spectroscopy,X-ray diffraction(XRD),and differential scanning calorimetry(DSC)were used to analyze the resulting adhesive’s reaction mechanism and thermal response.Furthermore,the physical properties of the adhesive were characterized using wet shear strength testing and SEM observation.Remarkably,the dry bond strength increased from 0.72 to 2.12 MPa,representing a 194.4%increase.The wet bonding strength of the adhesive was improved from 0.22 to 1.21 MPa,representing a 550%increase compared to the original flaxseed protein-based adhesive,which far exceeded the minimum requirement for plywood of Type II(≥0.7 MPa,by GB/T 9846-2015).This study demonstrated an eco-friendly and sustainable method for the development of protein adhesives as viable substitutes for petrochemical resins.
