Science China Materials最新文献

Environmental pollutants, including gas phase pollutants, liquid organic pollutants, heavy metal ions, and pathogenic bacteria, pose a serious threat to our ecological environment and human health. Effectively addressing these pollutants has become one of the most urgent issues. Graphdiyne (GDY), as an emerging carbon material for environmental remediation, has unique acetylene bonds and abundant pore structures. The unique carbon atomic structure of sp/sp² hybrid endows it with tunable electronic structure and outstanding physical and chemical properties. This review summarizes the practical applications of GDY-based nanomaterials in the context of environmental pollution control, including carbon monoxide (CO) oxidation, ozone (O₃) decomposition, heavy metal ion detection and adsorption, organic pollutant degradation, and bacterial inactivation. Furthermore, the structure-performance relationship of GDY-based nanomaterials is analyzed, and the issues and challenges in the field of environmental remediation of GDY-based materials are indicated.

Hydrogels, a class of highly hydrated materials mimicking the extracellular matrix, offer tunable mechanical properties and serve as versatile platforms for functionalization, which have been used for wound dressing to prevent infection and fluid loss. However, their inherent moisture evaporation hampers both storage stability and service life in practical applications. Deep eutectic solvents (DESs), as a category of eco-friendly solvents, exhibit low vapor pressure, good conductivity, biodegradability, non-flammability, and affordability. Eutectogels using DESs as a solvent not only retain the mechanical strength and functionality of hydrogel systems but also circumvent the limitations imposed by water evaporation in conventional hydrogels, which presents a promising direction and material framework for more personalized and efficacious wound management strategies. In this study, we have successfully synthesized a novel ternary deep eutectic solvent composed of glycerol, zinc chloride, and choline chloride, and subsequently incorporated polymerizable double bonds to fabricate an eco-friendly, antimicrobial-sensing eutectogel. This gel possesses a unique combination of high mechanical strength, universal adhesion capabilities, persistent bactericidal activity, superior sensing properties, and excellent biocompatibility. Its potential application as a wound dressing was explored, with results demonstrating the ability of eutectogel to accelerate wound healing and prevent bacterial colonization at the wound site. These findings provide a solid theoretical foundation and a promising material platform for the development of next-generation intelligent wound dressings.

Hydrogen embrittlement remains a crucial concern in industries that rely on high-strength materials. Exposure to hydrogen poses a significant threat to the mechanical integrity of such materials. This review article briefly discusses the fundamentals of hydrogen embrittlement, including its mechanisms and the effects of various factors, such as chemical composition and environmental conditions. Several heat treatments have been developed to eliminate the risk of hydrogen embrittlement. Among various suggested heat treatments, the retrogression-reaging (RRA) treatment has proven effective in optimizing the balance between mechanical properties and resistance to hydrogen embrittlement. This review highlights the role of RRA treatment in modifying the microstructure of Al-Zn-Mg alloys to enhance their ability to resist hydrogen embrittlement, building on existing literature. An interesting aspect explored in this article is the intricate relationship between pre-deformation and subsequent RRA treatment. Additionally, the review discusses the use of RRA as a post-weld heat treatment to mitigate the susceptibility of weldments to hydrogen embrittlement. A comprehensive exploration of these topics is beneficial for a thorough understanding of the multifaceted functions of RRA treatment. However, despite its advantages, the widespread adoption of RRA treatment in the industry is hindered by certain challenges. This review addresses these challenges, offering insights into the latest strategies to overcome them.

The advancement of photo-curing three-dimensional (3D) printing technology has significantly enhanced the capabilities of advanced manufacturing across various fields. However, the robust cross-linking network of photopolymers limits its application in information encryption and exacerbates environmental issues. In this study, a degradable thermosetting photopolymer platform for information encryption was proposed by incorporating sulfite bonds into the polymer structure. Due to the autocatalytic behavior of sulfite bonds during hydrolysis under acidic conditions, the photopolymer can achieve complete degradation at 50°C within 45 min. Based on the degradability of the developed photopolymers, a highly secure degradation-UV dual information encryption system has been established using photo-curing-based 3D printing technology. Furthermore, the degradation products of these photopolymers, generated during the information decryption process, can be utilized to prepare high-performance solar thermoelectric generators with a power density of 325.7 µW cm⁻² (under one sun) after a simple one-step modification. This work not only inspires the development of multiple information encryption methods based on 3D printing but also provides a practical solution to address environmental challenges associated with plastic pollution.

Electronic technology, based on signal conversion induced by voltage stimulation, forms the core foundation of the state-of-the-art intelligent devices, tools, and equipment. Such conversions are inherently binary and limited because they rely solely on voltage, which presents challenges for many emerging frontier applications. Here, a two-dimensional ordered conjugated system of reduced graphene oxide/polypyrrole (rGO/PPy) has been developed. Multi-stimulus response signal adapters have been constructed, utilizing the electrical anisotropy inherent in the rGO/PPy system. This electrical anisotropy, derived from the quasi-two-dimensional geometry of rGO/PPy, enables the device to produce distinct electrical signals in response to various stimuli. With effective responses to light and pressure, the two most common input stimuli other than voltage, it can output quaternary/denary signals and visual optical signals, as well as enables information encryption using passive devices. Furthermore, the signal adapter demonstrates high cyclic stability under repeated pressure and/or light loading. The successful development of this low-cost, scalable signal adapter paves the way for the next-generation of intelligent systems, promising advancements in human-computer interaction, electronic skin, biological implant equipment, and related fields.

Traditional hydrogels-based actuators are hindered by limitations such as low deliverable forces (∼2 kPa) and sluggish actuation speeds, culminating in persistent issues with low work density (∼0.01 kJ/m³). Furthermore, achieving low hysteresis and high strength presents significant challenges in both their synthesis and applications. Herein, we developed poly(acrylic acid) hydrogels characterized by sparse cross-linking and high entanglement, effectively addressing these issues. Inspired by the energy conversion mechanisms of mammalian muscle fibers, the hydrogels were utilized for storing and releasing elastic potential energy in polymer network. Notably, we achieved a remarkable contractile force of 60.6 kPa, an ultrahigh work density of 30.8 kJ/m³, and an energy conversion efficiency of up to 53.8%. Furthermore, the hydrogels exhibit unique dual-state functionality, seamlessly transitioning between elasticity and plasticity, which paves the way for adaptable and precisely controllable energy release mechanisms. These features hold significant potential for diverse practical applications, providing a promising advancement for hydrogel actuators.

The presence of electromagnetic interference (EMI) leads to distortion of current and voltage waveforms, which reduces the accuracy and stability of sensor devices. The emergence of flexible electronic devices has broken the limits of physical space, as they can be bent and twisted at will. However, this characteristic exacerbates unwanted coupling of their internal sensing elements, which can interfere with each other. At present, the solution to EMI is based on electromagnetic shielding (EMS), but this method alone cannot solve internal EMI of flexible sensor devices. In this study, the gallium-based liquid metal (LM) circuits are printed on the Ecoflex@Fe film to realize a stretchable film with both EMS and wave-absorbing functions, which is expected to simultaneously address the effects of internal and external EMI. The results show that the shielding efficiency of the electromagnetic wave shielding and absorbing (EWSA) film is as high as 54.5 dB on one side, while the reflection loss on the other side is as low as −43.5 dB. In addition, the LM-based EWSA film maintains positive wave-absorbing and EMS properties during stretching in different directions and it can also effectively avoid EMI after 1000 times of stretching. Overall, the LM-based EWSA film, which enables broadband EMS and wave-absorption, provides a solution for the development of next-generation flexible electronic skin that eliminates both internal and external EMI.

Layered inorganic materials provide an essential platform for constructing new structural configurations of materials with exceptional properties. However, precise control over the interlayer molecular arrangement remains a significant challenge, impeding in-depth exploration in physics and chemistry realm. Herein, we demonstrated a new layered organic-inorganic superlattice composed of a S-Ta-S inorganic lattice and bilayer linear molecules, providing superhigh heat insulation. A series of interlayer-confined intercalations of alkylamines with increasing chain length in the layered inorganic materials were achieved through precisely ordered molecule design (TaS₂-Cn, n = 3, 6, 8, 12). Systematic spectral analysis reveals that as the length of the intercalated alkyl chain increases, the alkyl chain between layers becomes more ordered and linear, and the gauche conformation decreases. Furthermore, the more linear and ordered alkyl chain conformation results in lower thermal conductivity. The thermal conductivity of TaS₂-C12 is 0.426 W m⁻¹ K⁻¹, which is only one-third that of the pristine TaS₂ crystal. We anticipate that this layered organic-inorganic superlattice design will pave a new avenue for developing new organic-inorganic functional materials and probing the limits of ultralow thermal conductivity materials.