A5039526043- Hydrogels: synthesis, properties, applications
- Advanced Materials and Mechanics
- Advanced Sensor and Energy Harvesting Materials
- Elasticity and Material Modeling
- Adhesion, Friction, and Surface Interactions
- Welding Techniques and Residual Stresses
- Force Microscopy Techniques and Applications
- Polymer composites and self-healing
- Advanced Welding Techniques Analysis
- Polymer Surface Interaction Studies
- Electrospun Nanofibers in Biomedical Applications
- biodegradable polymer synthesis and properties
- Tribology and Wear Analysis
- 3D Printing in Biomedical Research
- Rock Mechanics and Modeling
- Engineering and Environmental Studies
- Dielectric materials and actuators
- Copper Interconnects and Reliability
- Protein Structure and Dynamics
- Advancements in Materials Engineering
- Supramolecular Self-Assembly in Materials
- Injection Molding Process and Properties
- RNA Research and Splicing
- Cellular Mechanics and Interactions
- Micro and Nano Robotics
Hokkaido University
2018-2024
Sapporo Science Center
2018-2020
Working harder, getting stronger Self-healing polymers attempt to restore mechanical strength after deformation. Polymer gels tend be too soft for this occur. Matsuda et al. generated self-healing hydrogels composed of a double-network material (see the Perspective by Craig). A stress breaks more brittle two networks, while other retains stability. On breakage, fractured chains create radical initiators that polymerize new network material. With repeated breakage and supply monomers, gel...
Longer and stronger; stiff but not brittle Hydrogels are highly water-swollen, cross-linked polymers. Although they can be deformed, tend to weak, methods strengthen or toughen them reduce stretchability. Two papers now report strategies create tough deformable hydrogels (see the Perspective by Bosnjak Silberstein). Wang et al . introduced a toughening mechanism storing releasable extra chain length in part of double-network hydrogel. A high applied force triggered opening cycling strands...
Abstract Living organisms share the ability to grow various microstructures on their surface achieve functions. Here we present a force stamp method of hydrogels based force-triggered polymerisation mechanism double-network hydrogels. This allows fast spatial modulation morphology and chemistry hydrogel within seconds for on-demand We demonstrate oriented growth cells directional transportation water droplets engineered surfaces. chemically engineer surfaces provides new tool in addition...
Double network (DN) gels, consisting of a brittle first and flexible second network, have been known to be extremely tough functional hydrogels. In DN gel subjected force, the breaks prior fracture network. This process, referred as internal fracture, dissipates energy increases required completely gels. Such macroscopically appears yielding-like phenomenon. The aim this paper is investigate relationship between yield point molecular structure gels more deeply understand mechanism To achieve...
The double-network (DN) structure is a state-of-the-art strategy used for toughening soft materials. challenge widespread applications, however, the difficulty in synthesizing two interpenetrating networks with contrasting architecture, i.e., one network brittle and sparse other stretchable dense. Such structures are formed to toughen hydrogels via two-step sequential synthesis of highly swellable polyelectrolyte subsequent aqueous media; this approach not directly applicable fabricating...
In this work, we intended to investigate the relationship between swelling ratio Q and Young's modulus E of hydrogels from their contracted state extreme elucidate underlining molecular mechanism. For purpose, used tetra-poly(ethylene glycol) (tetra-PEG) gel, whose network parameters are well known, as polymer backbone, succeeded in tuning gel by a factor 1500 times while maintaining topological structure unchanged, using an approach combining stent method PEG dehydration method. A master...
Quantitative characterization of the energy dissipation zone around a crack tip is focal point in fracture mechanics soft materials. In this report, we present mechanochemical technique for visualization and quantification degree polymer strand scission damage tough double-network hydrogels. This uses mechanoradicals generated by covalent bond to initiate radical polymerization, which records internal fracturing during opening or propagation. We adopted mechanoradical polymerization...
High modulus, toughness, and fatigue resistance are usually difficult to be obtained simultaneously in rubbery materials. Here, we report that by superimposing the nanophase separation structure double network (DN) elastomers using immiscible polymers, fracture energy, energy release rate of threshold enhanced all together 13, 5, 5 times, respectively. We reveal interplay between DN brings two effects synergistically: (1) formation nanoclusters overstresses homogenizes sacrificial network,...
The high fracture energy of tough soft materials can be attributed to the large dissipation zone around crack tip. Hence, quantitative characterization is key matter mechanics. In this study, we quantified in damage a double-network (DN) hydrogel using mechanochemical technique based on mechanoradical polymerization combined with confocal fluorescence microscopy. We found that, addition relatively narrow yield region, wide preyielding region and intrinsic also has contribution energy....
The cyclic stretching measurements in various geometries including uniaxial, planar, unequal, and equal biaxial extension reveal the distinctive features of internal fracture double network (DN) hydrogels with high toughness, which are composed rigid brittle first soft ductile second network. initial modulus, residual strain after unloading, dissipated energy (D), dissipation factor (Δ; ratio D to input energy), ultimate elongation strands (λi,m*) each loading–unloading cycle evaluated as a...
Double-network (DN) gels and elastomers, which consist of two (or more) rubbery polymer networks with contrasting physical properties, have received significant attention as they are extremely tough soft materials. The first network DN materials should be more brittle weaker than the second network. In this paper, we re-examined structural requirements covalently cross-linked established a nonprestretching strategy. While prestretching strands has been considered necessary for preparation...
Soft tissue engineering requires antifouling materials that are biocompatible and mechanically flexible.
Significance Fracture in soft materials often couples a wide range of time and length scales. To date, research is mostly focused at the meso- macroscale which continuum mechanics approach expected to work, deformation surrounding crack tip can be directly observed. Yet understanding network scale very limited. A relevant question how does chain dynamics control fracture rate-independent materials? Here, we study role polymer on nonlinear behaviors double-network gels. We believe this work...
Abstract Macromolecular crowding (MMC) in cells is a hot topic biology; therefore, well-characterized measurement standards for the evaluation of nano-environment MMC solutions are necessary. We propose to use polarization-dependent fluorescence correlation spectroscopy (Pol-FCS) macromolecular solutions. Pol-FCS can simultaneously measure relaxation times rotational and translational diffusion fluorescent molecules at same position, even living with low damage. In this report, differences...
Double-network (DN) gels are unique mechanochemical materials owing to their structures that can be dynamically remodelled during use. The mechanical energy applied DN is efficiently transferred the chemical bonds of brittle network, generating mechanoradicals initiate polymerisation pre-loaded monomers, thereby remodelling materials. To attain continuous or growth in response repetitive stimuli, a sustainable supply reagents such dynamic essential. In this study, inspired by vascular...
Anisotropy of strain-induced internal damage in tough double network (DN) hydrogels is characterized by a sequence two tensile experiments. Firstly, the virgin DN gels are subjected to single biaxial loading-unloading cycle using various combinations maximum strains λx,m and λy,m x- y-directions (λx,m ≥ λy,m). Secondly, rectangular subsamples, which cut out from unloaded specimens so that long axis can have an angle (θ) relative larger pre-strain (x-)axis, stretched uniaxially along axis....
Double-network (DN) hydrogels have attracted considerable attention owing to their unique mechanism show extraordinary mechanical strength and toughness. Although the toughening of DN gels, breaking relatively stiff brittle first network as sacrificial bonds, is widely accepted, microstructure morphology evolution internal damage hardly been revealed. In this study, we study structures in partially damaged gels by using microelectrode technique (MET) based on Donnan effect polyelectrolyte...
Mechanical yielding of double-network (DN) hydrogels is a distinctive feature out the classical polymer networks, which links to toughening DN gels. Previous studies have focused on effect swelling yield point; however, strain and stress could not be decoupled from each other restricted solid understanding micromechanical model yielding. In this study, we investigated point various gels where first network parameters (preparation concentration, strand arm length connectivity) been...
Quantitative characterization of the energy dissipative zone around crack tip is central issue in fracture mechanics soft materials. In this research, we present a mechanochemical technique to visualize bond scission first network damage tough double-network hydrogels. The mechanoradicals generated by polymer chain are employed initiate polymerization thermoresponsive polymer, which visualized fluorophore. This records spatial distribution internal fracturing from fractured surface bulk,...