Widely used disposable plastic tableware is usually buried or directly discharged into the natural environment after using, which poses potential threats to the natural environment and human health. ...To solve this problem, nondegradable plastic tableware needs to be replaced by tableware composed of biodegradable structural materials with both food safety and the excellent mechanical and thermal properties. Here, a food‐safe sargassum cellulose nanofiber (SCNF) is extracted from common seaweed in an efficient and low energy consuming way under mild reaction conditions. Then, by assembling the SCNF into a dense bulk material, a strong sargassum cellulose nanofiber structural material (SCNSM) with high strength (283 MPa) and high thermal stability (>160 °C) can be prepared. The SCNSM also possesses good machinability, which can be processed into tableware with different shapes, e.g., knives and forks. The overall performance of the SCNSM‐based tableware is better than commercial plastic, wood‐based, and poly(lactic acid) tableware, which shows great application potential in the tableware field.
A food‐safe sargassum cellulose nanofiber (SCNF) is extracted through an efficient and low energy consuming way. Then, by assembling the SCNF into a dense bulk material, a strong structural material can be prepared. It possesses good machinability, which can be processed into tableware with better overall performance than that of commercial tableware, showing great application potential in the tableware field.
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.
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.
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.
Cellulose nanofiber (CNF) possesses excellent intrinsic properties, and many CNF-based high-performance structural and functional materials have been developed recently. However, the coordination of ...the mechanical properties and functionality is still a considerable challenge. Here, a CNF-based structural material is developed by a bioinspired gradient structure design using hollow magnetite nanoparticles and the phosphorylation-modified CNF as building blocks, which simultaneously achieves a superior mechanical performance and electromagnetic wave absorption (EMA) ability. Benefiting from the gradient design, the flexural strength of the structural material reached ∼205 MPa. Meanwhile, gradient design improves impedance matching, contributing to the high EMA ability (−59.5 dB) and wide effective absorption width (5.20 GHz). Besides, a low coefficient of thermal expansion and stable storage modulus was demonstrated as the temperature changes. The excellent mechanical, thermal, and EMA performance exhibited great potential for application in stealth equipment and electromagnetic interference protecting electronic packaging materials.
Aerogels. In their Research Article (e202211099), Qing‐Fang Guan, Shu‐Hong Yu et al. present a surface nanocrystallization method to construct wood‐inspired, large‐size composite aerogels.
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.
Aerogels. In their Research Article (e202211099), Qing‐Fang Guan, Shu‐Hong Yu et al. present a surface nanocrystallization method to construct wood‐inspired, large‐size composite aerogels.
Background：Obstructive sleep apnea syndrome （OSAS） has been shown to generate hypertension and endothelial dysfunction.Retinal vessel is the only vessel that can be observed directly and ...noninvasively;retinal vascular abnormalities can serve as a predictive marker for the occurrence,clinical course,and prognosis of cardiovascular and cerebrovascular diseases.The objective of this study was to identify the effect of OSAS severity on the morphological changes of retinal vessels.Methods：Adult patients complained of snoring were included in this study.The patients＆#39; general information,polysomnography,and fundus photography parameters including central retinal artery equivalent （CRAE）,central retinal vein equivalent （CRVE）,and arteriole-to-venule ratio （AVR） were collected.Patients were divided into four groups according to their apnea-hypopnea index （AHI） results：Group Ⅰ,AHI ≤5/h;Group ll,5/h 〈 AHI ≤30/h;Group Ⅲll,30/h 〈 AHI ≤60/h;and Group Ⅳ,AHI 〉60/h.Results：A total of 133 patients were included in this study with 111 males （83.5%） and 22 females （16.5%）.Mean age was 41.6 ± 9.9 years,and the mean body mass index was 28.1 ± 4.0 kg/m2.AHI ranged between 0 and 130.8/h with a mean of 39.l ± 30.7/h.There were 24,34,35,and 40 patients in Group Ⅰ,Group Ⅱ,Group Ⅲ,and Group Ⅳ,respectively.Significant differences were found for AHI （F =388.368,P 〈 0.001）,minimal pulse oxygen saturation （F-91.902,P 〈 0.001）,and arousal index （F =31.014,P 〈 0.001） among four groups;no significant differences were found for CRAE （F=0.460,P =0.599） and CRVE （F =0.404,P =0.586） among groups;there were significant differences for AVR between Group l and Group Ⅳ （63.6 ± 5.1% vs.67.2 ± 5.5%,P =0.010） Group Ⅱ and Group Ⅳ （64.5 ± 6.0% vs.67.2 ± 5.5%,P =0.030）,and Group ll and Group Ⅳ （64.7 ± 4.1% vs.67.2 ± 5.5%,P=0.043）.A main group-by-AHI effect was found on the AVR：patients with higher AHI showed higher AVR results （r =0.225,P =0.009）.Multivariate logistic regression analysis was used for multi-variable factors.A group-by-age effect was found on the AVR：younger patients showed higher AVR results （β =-0.001,P =0.020）.Conclusions：This study indicated that increased AVR of retinal vessel can be observed in extremely severe OSAS patients.For patients with OSAS,retinal vascular abnormalities may become an early indication for further cardiovascular abnormalities.
（90-x）TeO2-xZnO-lOBi203 （x = 15, 17.5, 20 and 22.5, in mol%） and 70TeOz-2OZnO-（10-y）Bi2O3-y Na2O （y = 1, 3, 5, 7, and 10, in mol%） glasses, and the corresponding Ag paste were prepared in order to ...prove that the Te-based glass frit could be applied to Ag pastes to fabricate Ag electrode. The relationship between structure and properties of the glasses was analyzed. The effects of glass frit on the microstructure, adhesion force, and resistivity of the Ag electrode were studied. The microstructure of Ag electrodes and the phase analysis of interface between Ag electrodes and the Si wafer were investigated using SEM and XRD. Finally, the 70TeO2-20ZnO-5Bi2O3-5Na2O glass showed better performance in the paste. What is more, Ag crystallites could be found on the Si wafer. These results suggested that the Te-based glass frit could react with SiNx anti-reflecting coating and Si to serve as a medium for forming Ag crystallites.
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