Living tissues, such as muscle, autonomously grow and remodel themselves to adapt to their surrounding mechanical environment through metabolic processes. By contrast, typical synthetic materials cannot grow and reconstruct their structures once formed. We propose a strategy for developing “self-growing” polymeric materials that respond to repetitive mechanical stress through an effective mechanochemical transduction. Robust double-network hydrogels provided with a sustained monomer supply undergo self-growth, and the materials are substantially strengthened under repetitive loading through a structural destruction-reconstruction process. This strategy also endows the hydrogels with tailored functions at desired positions by mechanical stamping. This work may pave the way for the development of self-growing gel materials for applications such as soft robots and intelligent devices.
Recent developments in smart responsive composites have utilized various stimuli including heat, light, solvents, electricity, and magnetic fields to induce a change in material properties. Here, we report a thermodynamically driven mechanically responsive composite, exploiting irreversible phase-transformation (relaxation) of metastable undercooled liquid metal core shell particle fillers. Thermal and mechanical analysis reveals that as the composite is deformed, the particles transform from in...
Preface INTRODUCTION History and Overview Why Structures Fail Historical Perspective The Fracture Mechanics Approach to Design Effect of Material Properties on Fracture A Brief Review of Dimensional Analysis References FUNDAMENTAL CONCEPTS Linear Elastic Fracture Mechanics An Atomic View of Fracture Stress Concentration Effect of Flaws The Griffith Energy Balance The Energy Release Rate Instability and the R Curve Stress Analysis of Cracks Relationship Between K and G Plane Stress versus Plane S...
#1Jason F. Patrick(UIUC: University of Illinois at Urbana–Champaign)H-Index: 9
#2Maxwell J. Robb(UIUC: University of Illinois at Urbana–Champaign)H-Index: 26
Last. Scott R. White(UIUC: University of Illinois at Urbana–Champaign)H-Index: 93
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The lifetime of man-made materials is controlled largely by the wear and tear of everyday use, environmental stress and unexpected damage, which ultimately lead to failure and disposal. Smart materials that mimic the ability of living systems to autonomously protect, report, heal and even regenerate in response to damage could increase the lifetime, safety and sustainability of many manufactured items. There are several approaches to achieving these functions using polymer-based materials, but m...
#2Robert Göstl(TU/e: Eindhoven University of Technology)H-Index: 16
Last. Rint P. Sijbesma(TU/e: Eindhoven University of Technology)H-Index: 77
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Under mechanical stress, the hexaarylbiimidazole (HABI) motif can cleave to triphenylimidazolyl radicals when incorporated into a polymer matrix. The mechanically produced coloured radicals can initiate secondary radical reactions yielding polymer networks. Thus, the HABI mechanophore combines optical reporting of bond scission and reinforcement of polymers in a single molecular moiety.
Last. Roman Boulatov(University of Liverpool)H-Index: 28
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Incorporation of small reactive moieties, the reactivity of which depends on externally imposed load (so-called mechanophores) into polymer chains offers access to a broad range of stress-responsive materials. Here, we report that polymers incorporating spirothiopyran (STP) manifest both green mechanochromism and load-induced addition reactions in solution and solid. Stretching a macromolecule containing colorless STP converts it into green thiomerocyanine (TMC), the mechanically activated thiol...
The generation of acid under mechanical force is potentially useful for initiating proton-catalyzed changes in polymeric materials. Here we demonstrate that oxime sulfonates—known photoacid generators—are also acid generators when activated mechanically. NMR analysis of products suggests that the ultrasound-induced mechanochemical scission of the oxime sulfonate mechanophore also generates a ketone functional moiety, in addition to acid. Both acid and ketone moieties are useful for developing st...
Double network (DN) gels, consisting of a brittle first and flexible second network, have been known to be extremely tough and functional hydrogels. In a DN gel subjected to force, the brittle first network breaks prior to the fracture of the flexible network. This process, referred to as internal fracture, dissipates energy and increases the energy required to completely fracture DN gels. Such internal fracture macroscopically appears as a yielding-like phenomenon. The aim of this paper is to i...
#1Philipp Michael(MLU: Martin Luther University of Halle-Wittenberg)H-Index: 13
#2Wolfgang H. Binder(MLU: Martin Luther University of Halle-Wittenberg)H-Index: 55
“Click” chemistry represents one of the most powerful approaches for linking molecules in chemistry and materials science. Triggering this reaction by mechanical force would enable site- and stress-specific “click” reactions—a hitherto unreported observation. We introduce the design and realization of a homogeneous Cu catalyst able to activate through mechanical force when attached to suitable polymer chains, acting as a lever to transmit the force to the central catalytic system. Activation of ...
A tough and thin double-network gel membrane containing amino acid ionic liquids as a CO2 carrier exhibited superior CO2 permeability and stability under pressurized conditions.
Last. Hideyuki Otsuka(TITech: Tokyo Institute of Technology)H-Index: 57
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Visualization and quantitative evaluation of covalent bond scission in polymeric materials are highly important for understanding failure, fatigue, and deterioration mechanisms and improving the lifetime, durability, toughness, and reliability of the materials. The diarylbibenzofuranone-based mechanophore radical system enabled, through electron paramagnetic resonance spectroscopy, in situ quantitative evaluation of scission of the mechanophores and estimation of mechanical energy induced along ...
Last. Jie Feng(Zhejiang University of Technology)H-Index: 10
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Abstract Hydrogels with good antifouling and mechanical properties as well as biocompatibility have great application potential in the field of biomedicine. In this paper, a newly double network (DN) hydrogel was prepared based on zwitterionic material sulfobetaine methacrylate (SBMA) and natural polysaccharide, sodium alginate (SA). The PSBMA network is covalently crosslinked while the SA network is ionically crosslinked by Ca2+. The hybrid crosslinked double network structure endows the DN hyd...
#1Fuqiang Wan(WUT: Wuhan University of Technology)H-Index: 1
#2Hang Ping(WUT: Wuhan University of Technology)H-Index: 11
Last. Zhengyi Fu(WUT: Wuhan University of Technology)H-Index: 31
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Abstract Biological materials have excellent mechanical properties due to their organized structures from nano- to macro-scale. Artificial manufacture of materials with anisotropic microstructures still remains challenging. We described a stress-induced method to fabricate anisotropic alginate fibers. Organic-inorganic composite fibers were obtained by incorporating aligned hydroxyapatite (HAP) nanowires into the alginate fiber. Detailed structural characterization revealed the bone-like structu...
Last. Jianzhang Li(BFU: Beijing Forestry University)H-Index: 32
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Abstract The development of high-performance and sustainable bio-adhesive materials has attracted significant research attention in recent years. However, producing high-performance biopolymer materials with desirable mechanical and antibacterial properties remains a challenge. Herein, a mussel-mimetic strategy is reported to fabricate a soy protein (SP)-based composite film via aqueous co-assembly of 3-aminophenylboronic acid-functionalized cellulose nanofibril (AB@CNF) and hyperbranched polyes...
Owing to their unique chemical and physical properties, hydrogels are attracting increasing attention in both basic and translational biomedical studies. Although the classical hydrogels with static networks have been widely reported for decades, a growing number of recent studies have shown that structurally dynamic hydrogels can better mimic the dynamics and functions of natural extracellular matrix (ECM) in soft tissues. These synthetic materials with defined compositions can recapitulate key...
#1Erfan Dashtimoghadam(UNC: University of North Carolina at Chapel Hill)H-Index: 28
#2Farahnaz Fahimipour(UNC: University of North Carolina at Chapel Hill)H-Index: 13
Last. Sergei S. Sheiko(UNC: University of North Carolina at Chapel Hill)H-Index: 72
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Current materials used in biomedical devices do not match tissue’s mechanical properties and leach various chemicals into the body. These deficiencies pose significant health risks that are further exacerbated by invasive implantation procedures. Herein, we leverage the brush-like polymer architecture to design and administer minimally invasive injectable elastomers that cure in vivo into leachable-free implants with mechanical properties matching the surrounding tissue. This strategy allows tun...
#1Fuchuan Ding(UConn: University of Connecticut)H-Index: 4
#2Hao Ding(UConn: University of Connecticut)H-Index: 6
Last. Sonia E. Chavez(UConn: University of Connecticut)H-Index: 1
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Inspired by hook-and-loop fasteners, we designed a hydrogel network containing α-zirconium phosphate (ZrP) two-dimensional nanosheets with a high density of surface hydroxyl groups serving as nanopatches with numerous "hooks," while polymer chains with plentiful amine functional groups serve as "loops." Our multiscale molecular simulations confirm that both the high density of hydroxyl groups on nanosheets and the large number of amine functional groups on polymer chains are essential to achieve...
Last. Ke-Qing Zhao(SICNU: Sichuan Normal University)H-Index: 23
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Abstract null null Based on the need for whole biomass hydrogels in biomedical applications, a dual-crosslinked hydrogel based on natural product sodium alginate (SA) were prepared. Dual-crosslinked was formed by SA crosslinking with glutaraldehyde (GA) and calcium ion (Ca2+), and the introduction of carboxymethyl cellulose (CMC) into crosslinked network to obtain excellent water-induced shape memory property. The chemical and physical crosslinking net points, formed by GA and Ca2+, as the stati...
Abstract null null To develop the hydrogels with high mechanical strength and excellent conductivity is always a challenging topic. In this study, the ultra-strong hydroxypropyl cellulose (HPC)/polyvinyl alcohol (PVA) composite hydrogels were prepared by combination of the triple-network and mechanical training. The proposed composite hydrogels were achieved by physically crosslinking HPC with PVA to form the first crosslinking network, in which the HPC fibers could decrease the crosslinking den...