Search

Fatigue performance and self-repairing activity of asphalt binders are two properties that highly influence the fatigue cracking response of asphalt pavement. There are still numerous gaps in knowledge to fill linked with these two characteristics. For instance, current parameters fail to accommodate these two bitumen phenomena fully. This study aims to propose a new procedure to address this issue utilizing the linear amplitude sweep (LAS) test, LAS with rest period (RP) (LASH) test, and simplified viscoelastic continuum damage (S-VECD) model. This research work used four different types of asphalt binders: neat asphalt (NA), self-healing thermoplastic polyurethane (STPU)-modified bitumen (STPB), self-healing poly (dimethyl siloxane) crosslinked with urea bond (IPA1w)-modified bitumen (IPAB), and styrene–butadiene–styrene (SBS)-modified bitumen (SBSB). Before the testing process, all the materials were subjected to short-term and long-term aging. The new procedure showed a superior capacity to analyze and accommodate all bitumen fatigue performances and self-repairing activities compared to the current method. Another finding proved that asphalt binders with a higher self-restoration behavior failed to show a better fatigue performance. Moreover, the higher fatigue performance increments produced by STPU and IPA1w in NA concerning the control bitumen were 123.7% and 143.7%, respectively. Those values were obtained with 1.0% STPU and 0.5% IPA1w in NA. A breakthrough finding demonstrated that asphalt binder fatigue response is augmented when the RP was applied at a higher damage intensity (S) value. STPB and IPAB reached their highest increments of fatigue response, containing 1.0% of STPU and 0.5% of IPA1w, respectively. Those augmentations were 207.54% and 232.64%, respectively. [ABSTRACT FROM AUTHOR]

The environmental problem of "white pollution" caused by traditional non-degradable plastics is becoming increasingly serious. Thus, the development of degradable and recyclable plastics attracts lots of attention from researchers. However, the currently reported plastics have limitations in eliminating pollution in the sea and achieving the balance between ductility and strength. Herein, a recyclable, degradable and water-soluble plastic with robust toughness is prepared based on the supramolecular covalent adaptive network, which is synthesized through crosslinking copolymer and poly(vinyl alcohol) PVA chains with dynamic boronic ester/hydrogen bonds and doping the lignin component via forming hydrogen bonds between polymer chains. Such a plastic exhibits excellent mechanical properties, showing a toughness of up to 148 MJ m−3 due to the combination of supramolecular and covalent adaptive networks. Significantly, the water dissolution rates and mechanical properties of plastics can be tuned over a wide range by adjusting the molar masses and hydrolysis degrees of PVA and changing the water contents. In addition, the plastic displays superior functions, such as antimicrobial, anti-UV and antioxidant properties, making it promising for applications in plenty of fields. This work paves a creative path for designing recyclable and degradable plastics with high performance to reduce "white pollution". [ABSTRACT FROM AUTHOR]

Quasi‐solid aqueous zinc ion batteries (AZIBs) based on flexible hydrogel electrolytes are promising substitutions of lithium‐ion batteries owing to their intrinsic safety, low cost, eco‐friendliness and wearability. However, it remains a challenge to lower the freezing point without sacrificing the fundamental advantages of hydrogel electrolytes such as conductivity and mechanical properties. Herein, an all‐around hydrogel electrolyte is constructed through a convenient energy dissipation strategy via the rapid and reversible intramolecular/intermolecular ligand exchanges between Zn2+ and alterdentate ligands. The as‐obtained hydrogel exhibits excellent mechanical properties, fatigue resistance, high Zn‐ion conductivity (38.2 mS cm−1), good adhesion (19.1 kPa), and ultra‐low freezing point (−97 °C). Due to the alterdentate ligands help to improve the zinc ion solvation structure and guide uniform Zn deposition, the Zn||Zn symmetric cells show stable plating/stripping behavior and long‐term cycle stability. The Zn||V2O5 full cells exhibit large capacity of 230.6 mAh g−1 and high capacity retention of 75.2% after 1000 cycles. Furthermore, flexible AZIBs operate stably even under extreme conditions including low temperature (−40 °C) and large bending angle (180°). The mechanically damage‐resistant hydrogel can also be utilized in flexible strain sensors. This work offers a facile strategy for developing mechanically deformation‐resistant, dendrite‐free, and environmentally adaptable AZIBs. [ABSTRACT FROM AUTHOR]

Silicone elastomers are broadly used in various fields because of their unique properties, such as flexibility, durable dielectric insulation, and excellent stability in hash environments. As a result, three‐dimensional (3D) printing of silicone elastomers is frequently required to construct personalized structures. However, existing 3D‐printing of silicone elastomers are less accurate, difficult to maintain shape, or require doping modification with thixotropic agents. Moreover, common 3D‐printable silicone elastomers do not have self‐healing capability, so they have to be discarded upon damaging. Herein, by introducing hydrogen bonds to improve the shape retention ability and induce network reversibility, we have developed a self‐healing polydimethylsiloxane elastomer, which can be readily 3D‐printed by fused deposition modeling (FDM) technology. We believe that this new silicone elastomer would be useful in the field of biomedical materials, flexible electronics, medical inserts, soft robots and so on. [ABSTRACT FROM AUTHOR]

Bitumen, which is widely used in various applications, is facing the challenge of being unsustainable. Many strategies are proposed to recycle or replace bitumen. However, most of them can not address the unsustainability of bitumen from the roots. On the other hand, sulfur exists widely on the earth as a kind of industrial waste despite its extensive applications. Herein, a series of bitumen‐like polymers from elemental sulfur is obtained through an inverse vulcanization reaction. The sulfur‐containing polymers exhibit self‐healing, non‐toxic, and adjustable properties depending on the working environment. Based on these features, the applications of sulfur‐containing polymers in self‐healing waterproof sealants, impact‐resistance or shock‐absorption devices, and non‐Newtonian speed bumps are demonstrated. With the method of synthesizing multifunctional bitumen‐like polymers from sulfur wastes, a feasible way is provided to solve simultaneously the challenging problem of bitumen's unsustainability as well as sulfur's utilization, with the advantages including easy massed‐fabrication, non‐toxicity, extremely low cost (≈2 cents per gram) and environment friendliness. [ABSTRACT FROM AUTHOR]