Polyacrylic acid(PAA)hydrogel composites with different hexagonal boron nitride(h-BN)fillers were synthesized and successfully 3D-printed while their thermal conductivity was systematically *** the content of h-BN inc...
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Polyacrylic acid(PAA)hydrogel composites with different hexagonal boron nitride(h-BN)fillers were synthesized and successfully 3D-printed while their thermal conductivity was systematically *** the content of h-BN increasing from 0.1 wt%to 0.3 wt%,the thermal conductivity of the 3D-printed composites has been ***,through the shear force given by the 3D printer,a complete thermal conductivity path is obtained inside the hydrogel,which significantly improves the thermal conductivity of the h-BN hydrogel *** maximum thermal conductivity is 0.8808 W/(m·K),leading to a thermal conductive enhancement of 1000%,compared with the thermal conductivity of pure PAA *** study shows that using h-BN fillers can effectively and significantly improve the thermal conductivity of hydrogelbased materials while its 3D-printable ability has been maintained.
To satisfy the demand of zinc oxide（ZnO） with advanced muti-functional properties, significant efforts have been made in synthesizing ZnO with various structure and morphology. In particular, hydrothermal method has...
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To satisfy the demand of zinc oxide（ZnO） with advanced muti-functional properties, significant efforts have been made in synthesizing ZnO with various structure and morphology. In particular, hydrothermal method has attracted considerable attentions, in which Zn4CO3（OH）6·H2O（ZCHH） is commonly found as a metastable precursor. However, the formation and crystallization mechanisms of ZCHH are still lacking and urgently needed. In the present study, the crystallization pathway of ZCHH was systematically investigated, and the results demonstrate that the amorphous zinc carbonate（AZC） was an even more unstable precursor. AZC nanoparticles typically aggregated to form one-dimensional（1D） ZCHH nanorods, however, two-dimensional（2D） ZCHH nanofilms were obtained in the presence of a certain concentration of calcium ion. The results suggest that calcium ions could promote the partial dissolution of AZC and facilitate the aggregation of AZC nanoparticles to form crystalline nanofilm. Moreover, 2D ZnO nanofilms could be obtained by heat treatment of the ZCHH nanofilms. The calcium ion mediated nonclassical crystallization pathway provides inspiration for fabrication of ZnO with controlled morphology and offers new opportunities for inorganic regulated material synthesis.
Hexagonal BN-coated powders have been widely used in various engineering sectors,however,their pro-ductions are restricted by the complexity of gas-solid *** this study,guided by thermodynamics,a novel approach to syn...
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Hexagonal BN-coated powders have been widely used in various engineering sectors,however,their pro-ductions are restricted by the complexity of gas-solid *** this study,guided by thermodynamics,a novel approach to synthesize Layer-structured hexagonal BN(hBN)-coated high entropy diboride pow-ders in vacuum was developed,using metal salt Zr(NO_(3))4·5H_(2)O,HfCl_(4),NbC_(15),TaC_(15),C_(16)H_(36)O_(4)Ti,boric acid,and sucrose as raw *** adjusting the ratio of carbon to metal source(C/M),powders only consisting of two boride solid solutions and hBN were finally obtained,under an optimal process-ing condition of C/M=5.5 and synthesis temperature of 1400 ℃.Parts of hBN were found to coat on high-entropy metal diborides ceramic(HEB)particles,corresponding formation mechanism for core-shell structured powders was investigated,together with the liquid precursor assisted boro/carbothermal re-duction *** from as-synthesized core-shell powders,(Ti_(0.2)Zr_(0.2)Hf_(0.2)Nb_(0.2)Ta_(0.2))B2-11 vol%hBN ceramics were densified at 1900 ℃ under 50 MPa without holding,with a high relative density of 97.3%.
Due to its abundant sodium content and low cost,sodium-ion battery(SIB)has become an effective substitute and supplement for lithium-ion batteries,which has a broad development prospect in largescale energy storage **...
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Due to its abundant sodium content and low cost,sodium-ion battery(SIB)has become an effective substitute and supplement for lithium-ion batteries,which has a broad development prospect in largescale energy storage ***-super-ionic conductor(NASICON)structural materials have stable 3D skeleton structures and open Na+transport channels,which is a very promising SIB cathode *** in the typical NASICON material Na_(3)V_(2)(PO_(4))_(3)(NVP),the number of electrons involved in NVP per formula unit is less than 2 at the stable voltage window,which limits the further improvement of battery *** this work,we report another NASICON structured Na_(3)V_(4/3)Cr_(2/3)(PO_(4))_(3)@C(NVCP@C),which is obtained by Cr-doped NVP through spray *** taking full advantage of the voltage platforms of V^(5+/4+),V^(4+/3+),and V^(3+/2+)in the window of 1.5-4.4 V,NVCP@C delivered a high discharge capacity(175 mAh g^(-1))and durable cyclability(86%capacity retention for 2000 cycles).In-situ X-ray diffraction results demonstrate that the reversible structural evolution accompanies by solid-solution reaction and two-phase reaction mechanisms co-exist during charge/discharge *** coupled with Na^(+)preembedded hard carbon(HC),the assembled NVCP@C//HC full cell delivers a high capacity(105 mAh g^(-1))and long cycling performance(70%after 1000 cycles).This Cr-doped NVP method offers new insights into the design of high-energy NASICON-structured cathode materials.
The fact that single dielectric loss materials have disadvantages of excessive conductivities and impedance mismatches has given rise to a large effort to develop effective strategies to fabricate electromagnetic wave...
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The fact that single dielectric loss materials have disadvantages of excessive conductivities and impedance mismatches has given rise to a large effort to develop effective strategies to fabricate electromagnetic wave(EMW)absorbing materials comprised of components that bring about a balance between dielectric loss and magnetic ***,little is known about the essential features that regulate EMW absorption *** study focused on the development of a new EMW absorbing material and gaining information about factors that govern EMW absorption *** materials at the center of the effort are light weight and porous cobalt sulfonated phthalocyanine-reduced graphene oxide(CoSPcrGO)aerogels that were synthesized by using a simple hydrothermal method followed by *** properties of these materials that contribute to the electromagnetic balance between dielectric and magnetic loss were elucidated by first formulating a reasonable hypothesis about how the relative orien-tation of the components in CoSPc-rGO govern p-conjugation and electron transfer from rGO to CoSPc,which is proposed to be a key factor contributing to the regulation of the electromagnetic *** relaxation process of materials was analyzed in detail using a variety of approaches including theoretical calculation,spectroscopic measurements,and experimental and simulation *** fabricated CoSPc-rGO aerogels that contain an ultra-low content of 4%were found to exhibit an extraordinary microwave absorption performance associated with a strong reflection loss of-53.23 dB and a broad effective absorption bandwidth of 8.04 *** results of this study should provide an effective guide for new designs of composite materials for EMW absorption.
La_(4)NiLiO_(8)-coated NCM622 samples were prepared through a sol-gel method,and the electrochemical performance as cathode materials was *** is revealed that part of the introduced La^(3+)ions produce a coating layer...
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La_(4)NiLiO_(8)-coated NCM622 samples were prepared through a sol-gel method,and the electrochemical performance as cathode materials was *** is revealed that part of the introduced La^(3+)ions produce a coating layer on the surface of NCM622 particles,while the rest occupy the 3b position of the *** optimized sample exhibits a capacity retention of 96.54%after 100 cycles under 1C rate with a discharge specific capacity of 117.54 mAh·g^(-1)under 5C rate,much higher than those of the unmodified *** results show that the addition of La^(3+)ion can greatly improve the cyclic stability and the rate performance of NCM622.
Emerging technological advances are reshaping the casting sector in latest *** technology is evolving towards intelligent casting paradigm that involves automation,greenization and intelligentization,which attracts mo...
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Emerging technological advances are reshaping the casting sector in latest *** technology is evolving towards intelligent casting paradigm that involves automation,greenization and intelligentization,which attracts more and more attention from the academic and industry *** this paper,the main features of casting technology were briefly summarized and forecasted,and the recent developments of key technologies and the innovative efforts made in promoting intelligent casting process were ***,the technical visions of intelligent casting process were also put *** key technologies for intelligent casting process comprise 3D printing technologies,intelligent mold technologies and intelligent process control *** future,the intelligent mold that derived from mold with sensors,control devices and actuators will probably incorporate the Internet of Things,online inspection,embedded simulation,decision-making and control system,and other technologies to form intelligent cyber-physical casting system,which may pave the way to realize intelligent *** is promising that the intelligent casting process will eventually achieve the goal of real-time process optimization and full-scale control,with the defects,microstructure,performance,and service life of the fabricated castings can be accurately predicted and tailored.
Laser etching and laser chemical vapor deposition(LCVD)techniques were proposed for the rapid preparation of high-purity,strongly bonded SiC porous micro-nano-coatings on quartz *** laser serves as an external driving...
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Laser etching and laser chemical vapor deposition(LCVD)techniques were proposed for the rapid preparation of high-purity,strongly bonded SiC porous micro-nano-coatings on quartz *** laser serves as an external driving force for the vertical growth of SiC whiskers,facilitating the formation of a porous nanostructure that resembles coral models found in the macroscopic biological *** porous nanostructures are beneficial for reducing thermal expansion mismatch and relieving residual *** is capable of eliminating the cracks on the surface of SiC coatings as well as enhancing the bonding of SiC coatings with quartz substrates to avoid coating detachment.
We synthesized photo-responsive carboxymethyl chitosan(CMC-MA)via free radical polymerization and utilized nanoclay laponite(LAP)as an inorganic crosslinking agent to develop an injectable and 3D-printable CMC-MA/LAP ...
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We synthesized photo-responsive carboxymethyl chitosan(CMC-MA)via free radical polymerization and utilized nanoclay laponite(LAP)as an inorganic crosslinking agent to develop an injectable and 3D-printable CMC-MA/LAP *** determined the optimal ratio of 2.5 w/v%CMC-MA/7.5 w/v%LAP based on injection molding,compression modulus,swelling properties,rheological properties,and 3D printing properties of the hydrogel ***-vitro cytocompatibility experiments showed that both CMC-MA and CMC-MA/LAP hydrogel had no inhibitory effect on cell proliferation and can promote cell growth when cultured on the surface of the hydrogel ***,the hydrogel containing LAP particles significantly facilitated cell adhesion(>60%)compared with the hydrogel without LAP(20%).Our findings demonstrate that the CMC-MA/LAP hydrogel has great potential for tissue repair in neural tissue engineering.
The catalytic alcohol dehydrogenation to carboxylic acids has been demonstrated as an atom-economic and environmental-friendly synthetic ***,the reported catalysts either require relatively complicated synthesis or ex...
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The catalytic alcohol dehydrogenation to carboxylic acids has been demonstrated as an atom-economic and environmental-friendly synthetic ***,the reported catalysts either require relatively complicated synthesis or exhibit high activity only in the presence of a ***,it is still in high demand to obtain catalysts that feature facile synthesis and perform well even without any ***,a series of nanostructured bimetallic Zn/Co species embedded in N-doped hierarchical porous carbon were fabricated in a facile and green *** significantly,the best-performing material(Zn/Co@NC-800)was identified as the first heterogeneous catalyst to enable this transformation under solvent-free ***,the as-prepared composites were comprehensively investigated to de-termine their structural and morphological properties,which rationalized the superiority of Zn/Co@NC-800 over the other synthesized *** studies signified that Co sites(both Co^(0)and Co^(2+))and N species(mainly pyridinic N)were probably involved in this process,functioning as the Lewis acid site and basic site,***,this study could provide a simple and sustainable method for carboxylic acid synthesis.
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