Petroleum-based plastics are useful but they pose a great threat to the environment and human health. It is highly desirable yet challenging to develop sustainable structural materials with excellent ...mechanical and thermal properties for plastic replacement. Here, inspired by nacre's multiscale architecture, we report a simple and efficient so called "directional deforming assembly" method to manufacture high-performance structural materials with a unique combination of high strength (281 MPa), high toughness (11.5 MPa m
), high stiffness (20 GPa), low coefficient of thermal expansion (7 × 10
K
) and good thermal stability. Based on all-natural raw materials (cellulose nanofiber and mica microplatelet), the bioinspired structural material possesses better mechanical and thermal properties than petroleum-based plastics, making it a high-performance and eco-friendly alternative structural material to substitute plastics.
The widespread use of disposable plastic straws cause serious environmental problems and poses potential threats to human health, while paper straws, their most used alternatives, are not so ...satisfactory due to poor mechanical performance and unpleasant user experience. Here, a new kind of edible and microplastic‐free straw made from bacterial cellulose (BC) by biosynthesis is reported. Through the alginate coating, this BC‐based straw achieves better mechanical performance than paper straws and avoids additional adhesives. Owing to the 3D nanofiber network and strong interlayer connection, the comprehensive performance of this BC‐based straw surpasses that of commercially available counterparts, satisfying the requirements for practical use. Of particular note, the edible character provides a better user experience and a new end‐of‐life option for the straws, making the BC‐based straw a healthier and more eco‐friendly substitute for plastic straws.
A sustainable, microplastic‐free, ultrastrong, and edible straw is fabricated through biosynthesis. This bacterial cellulose‐based straw demonstrates great sustainability and excellent mechanical performance, representing an ideal substitute for plastic straws and a powerful competitor for paper straws. The 3D network of bacterial cellulose endows the straw with the ability to carry functional substances like flavor molecules, providing a better user experience.
Undoubtedly humidity is a non-negligible and sensitive problem for cellulose, which is usually regarded as one disadvantage to cellulose-based materials because of the uncontrolled deformation and ...mechanical decline. But the lack of an in-depth understanding of the interfacial behavior of nanocellulose in particular makes it challenging to maintain anticipated performance for cellulose-based materials under varied relative humidity (RH). Starting from multiscale mechanics, we herein carry out first-principles calculations and large-scale molecular dynamics simulations to demonstrate the humidity-mediated interface in hierarchical cellulose nanocrystals (CNCs) and associated deformation modes. More intriguingly, the simulations and subsequent experiments reveal that water molecules (moisture) as the interfacial media can strengthen and toughen nanocellulose simultaneously within a suitable range of RH. From the perspective of interfacial design in materials, the anomalous mechanical behavior of nanocellulose with humidity-mediated interfaces indicates that flexible hydrogen bonds (HBs) play a pivotal role in the interfacial sliding. The difference between CNC–CNC HBs and CNC–water–CNC HBs triggers the humidity-mediated interfacial slipping in nanocellulose, resulting in the arising of a pronounced strain hardening stage and the suppression of strain localization during uniaxial tension. This inelastic deformation of nanocellulose with humidity-mediated interfaces is similar to the Velcro-like behavior of a wet wood cell wall. Our investigations give evidence that the humidity-mediated interface can promote the mechanical enhancement of nanocellulose, which would provide a promising strategy for the bottom-up design of cellulose-based materials with tailored mechanical properties.
An All‐Natural Wood‐Inspired Aerogel Han, Zi‐Meng; Sun, Wen‐Bin; Yang, Kun‐Peng ...
Angewandte Chemie International Edition,
February 1, 2023, 2023-Feb-01, 2023-02-00, 20230201, Volume:
62, Issue:
6
Journal Article
Peer reviewed
The oriented pore structure of wood endows it with a variety of outstanding properties, among which the low thermal conductivity has attracted researchers to develop wood‐like aerogels as excellent ...thermal insulation materials. However, the increasing demands of environmental protection have put forward new and strict requirements for the sustainability of aerogels. Here, we report an all‐natural wood‐inspired aerogel consisting of all‐natural ingredients and develop a method to activate the surface‐inert wood particles to construct the aerogel. The obtained wood‐inspired aerogel has channel structure similar to that of natural wood, endowing it with superior thermal insulation properties to most existing commercial sponges. In addition, remarkable fire retardancy and complete biodegradability are integrated. With the above outstanding performances, this sustainable wood‐inspired aerogel will be an ideal substitute for the existing commercial thermal insulation materials.
An interesting surface nanocrystallization method was developed to make the surface‐inert and weakly interacting wood particles better assemble to construct the aerogel. This bottom‐up method allows the preparation of large‐size composite aerogels. The wood‐inspired oriented channel structure endows the obtained aerogel with superior thermal insulation properties to natural wood and most existing commercial sponges.
Flexible supercapacitors represent an attractive technology for the next generation of wearable consumer electronics as power sources but usually suffer from relatively low energy density. It is ...highly desired to construct high‐performance electrodes for the practical applications of supercapacitors. Here, inspired by the natural structure of the spider web, an elaborate design of binder is reported through a biosynthesis process to construct flexible electrodes with both excellent mechanical properties and electrochemical performance. Through this strategy, a spider‐web‐inspired 3D structural binder enables large ion‐accessible surface area and high packing density of active electrode material as well as efficient ion transport pathways. As a result, a high areal capacitance of 4.62 F cm‐2 and a high areal energy density of 0.18 mW h cm‐2 is achieved in the composite electrodes and symmetric supercapacitors, respectively, demonstrating a promising potential to construct flexible energy storage devices for diverse practical applications.
A spider‐web‐inspired composite electrode is developed by biosynthesis process. With the 3D structural binder, electrode material particles are tightly entangled in the bacterial cellulose 3D framework, endowing electrodes with excellent mechanical performance and facilitated ion diffusion. Thereby, spider‐web‐inspired composite electrodes exhibit high areal capacitance and demonstrate excellent rate capability, making them promising wearable and portable electronic applications.
The exploration of extreme environments has become necessary for understanding and changing nature. However, the development of functional materials suitable for extreme conditions is still ...insufficient. Herein, a kind of nacre‐inspired bacterial cellulose (BC)/synthetic mica (S‐Mica) nanopaper with excellent mechanical and electrical insulating properties that has excellent tolerance to extreme conditions is reported. Benefited from the nacre‐inspired structure and the 3D network of BC, the nanopaper exhibits excellent mechanical properties, including high tensile strength (375 MPa), outstanding foldability, and bending fatigue resistance. In addition, S‐Mica arranged in layers endows the nanopaper with remarkable dielectric strength (145.7 kV mm−1) and ultralong corona resistance life. Moreover, the nanopaper is highly resistant to alternating high and low temperatures, UV light, and atomic oxygen, making it an ideal candidate for extreme environment‐resistant materials.
A nacre‐inspired nanopaper is fabricated through an aerosol‐assisted biosynthesis (AABS) strategy. Based on the AABS strategy and biomimetic structure design, the nanopaper has excellent mechanical properties, high dielectric strength, and ultralong corona resistance time. The dielectric‐mechanical comprehensive performance of the nanopaper is far beyond that of various commercial mica papers.
Plastic packaging materials are widely used because of their advantages of light weight, low cost, and convenience, especially as victuals packaging materials. Approximately 146 million metric tons ...of plastics were used for packaging in 2015, but most of these plastics had already been discarded and followed by serious white pollution. What's worse, the victuals packaging materials, especially polystyrene (PS) foam containers, can release microplastics (MPs) during daily usage. Through the combination of various appropriate chemical (eg, spectroscopy) and physical (eg, microscopy) characterization and analysis, the existence of MPs is proved and MPs can be intuitively observed. Although the impacts of MPs on ecosystems and human health are still under discussion, existing studies have shown that MPs can be integrated into habitats through soil transportation, affecting the health of various terrestrial invertebrates. Faced with this shocking reality, reducing the use of PS foam containers at high temperatures and developing healthy materials to substitute these plastics are promising solutions.
Based on the various appropriate chemical (e.g., spectroscopy) and physical (e.g., microscope) characterization and analysis, this paper provides sufficient evidence for the fact that the victuals packaging materials, especially polystyrene foam containers, can release microplastics (MPs) during daily usage. MPs have various sizes and irregularly shapes, which have potential threats to the ecosystems and human health.
Background Coronary collateral circulation (CCC) reduces the degree of myocardial ischemia and improves prognosis of patients with severe coronary artery stenosis, but CCC development varies ...significantly among different patients. The influencing factors of CCC development still remain clear, but the increase of inflammation response and inflammatory markers is associated with CCC. The C-reactive protein to albumin ratio (CAR) is a newly reported indicator of inflammation, which has been shown in several studies to be superior to C-reactive protein (CRP) and albumin (ALB) in reflecting cardiovascular inflammation. At present, there are few studies on the correlation between CAR level and CCC development. Objective To investigate the correlation between CAR and CCC development in unstable angina pectoris (UAP) patients. Methods One hundred and thirty-five UAP patients who underwent percutaneous coronary intervention during their hospitalization in the Cardiology Department of the First Affiliated Hospital of S
Water purification by solar distillation is considered a promising technology for producing clean water from undrinkable water resources. A solar steam generator is a central part of a solar ...distillation process to separate water and contaminants. Here, we report an efficient and sustainable hierarchical solar steam generator (HSSG) with reduced vaporization enthalpy based on bacterial cellulose (BC) nanocomposites. The nanomaterials are assembled with BC nanofibers produced by bacteria in situ to form nanocomposites. Using this method, we construct functional BC nanocomposites inside and on the natural porous structure of wood. Our HSSG integrates solar-to-vapor efficiency improvement and vaporization enthalpy reduction by integrating the hierarchical multifunctional BC nanocomposites with the natural porous structure of wood. Because of the biomimetic design, hierarchical structure and reduced vaporization enthalpy of HSSG, a high evaporation rate of 2.9 kg m–2 h–1 and solar-to-vapor efficiency of 80% is achieved.
Abstract
High-performance functional fibers play a critical role in various indispensable fields, including sensing, monitoring, and display. It is desirable yet challenging to develop conductive ...fibers with excellent mechanical properties for practical applications. Herein, inspired by the exquisite fascicle structure of skeletal muscle, we constructed a high-performance bacterial cellulose (BC)/carbon nanotube (CNT) conductive fiber through in situ biosynthesis and enhancement of structure and interaction. The biosynthesis strategy achieves the in situ entanglement of CNTs in the three-dimensional network of BC through the deposition of CNTs during the growth of BC. The structure enhancement through physical wet drawing and the interaction enhancement through chemical treatment facilitate orientation and bridging of components, respectively. Owing to the ingenious design, the obtained composite fibers integrate high strength (939 MPa), high stiffness (52.3 GPa), high fatigue resistance, and stable electrical performance, making them competitive for constructing fiber-based smart devices for practical applications.
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