A poly vinyl alcohol(PVA) scaffold with aligned porous is strengthened by in-situ combining with TiO2. The increased freezing rate can be used to further increase the strength of aligned porous materials. The streng...A poly vinyl alcohol(PVA) scaffold with aligned porous is strengthened by in-situ combining with TiO2. The increased freezing rate can be used to further increase the strength of aligned porous materials. The strengthened porous PVA exhibits aligned interconnected porous structures and shows a significant enhancement in tensile testing and compression strength testing.展开更多
With important application prospects, eutectic high entropy alloys have received extensive attention for their excellent strength and ductility in a large temperature range. The excellent casting characteristics of eu...With important application prospects, eutectic high entropy alloys have received extensive attention for their excellent strength and ductility in a large temperature range. The excellent casting characteristics of eutectic high entropy alloys make it possible to achieve well manufacturability of selective laser melting.For the first time, we have achieved crack-free eutectic high entropy alloy fabricated by selective laser melting, which has excellent mechanical properties in a wide temperature range from -196 ℃ to 760 ℃ due to ultra-fine eutectic lamellar spacing of 150–200 nm and lamellar colony of 2–6 μm. Specifically,the room temperature tensile strength exceeds 1400 MPa and the elongation is more than 20%, which significantly improved compared with those manufactured by other techniques with lower cooling rate.展开更多
Accumulation of organic contaminants on fullerene nanoparticles(nC(60)) may significantly affect the risks of C(60) in the environment.The objective of this study was to further understand how the interplay of n...Accumulation of organic contaminants on fullerene nanoparticles(nC(60)) may significantly affect the risks of C(60) in the environment.The objective of this study was to further understand how the interplay of nC(60) formation routes and humic acid modification affects contaminant adsorption of nC(60).Specifically,adsorption of 1,2,4,5-tetrachlorobenzene(a model nonionic,hydrophobic organic contaminant) on nC(60) was greatly affected by nC(60)formation route- the formation route significantly affected the aggregation properties of nC(60),thus affecting the available surface area and the extent of adsorption via the pore-filling mechanism.Depending on whether nC(60) was formed via the "top-down" route(i.e.,sonicating C(60) powder in aqueous solution) or "bottom-up" route(i.e.,phase transfer from an organic solvent) and the type of solvent involved(toluene versus tetrahydrofuran),modification of nC(60) with Suwannee River humic acid(SRHA) could either enhance or inhibit the adsorption affinity of nC(60).The net effect depended on the specific way in which SRHA interacted with C(60) monomers and/or C(60) aggregates of different sizes and morphology,which determined the relative importance of enhanced adsorption from SRHA modification via preventing C(60) aggregation and inhibited adsorption through blocking available adsorption sites.The findings further demonstrate the complex mechanisms controlling interactions between nC(60) and organic contaminants,and may have significant implications for the life-cycle analysis and risk assessment of C(60).展开更多
Solidification microstructure of powder fed laser additive manufactured Ti-6Al--2Zr--2Sn--3Mo--1.5Cr--2Nb titanium alloy was investigated, The results showed that by deliberately increasing the powder feed rate, parti...Solidification microstructure of powder fed laser additive manufactured Ti-6Al--2Zr--2Sn--3Mo--1.5Cr--2Nb titanium alloy was investigated, The results showed that by deliberately increasing the powder feed rate, partially melted powders were retained at the top of the molten pool, which can promote heteroge- neous nucleus. Thus, each cladding layer is composed of two regions: (i) randomly orientated cellular structure region caused by partially melted powders at the top of each cladding layer; and (ii) epitaxial cellular structure region adjacent to the fusion line. Usually, randomly orientated cellular structure region was totally remelted for a wide range of process conditions. The remelting effect ensures the continuity of epitaxial growth of cellular structure and leads to the formation of columnar β grains, In order to obtain equiaxed grains the scanning velocity and powder feed rate should be carefully selected to enlarge the randomly orientated cellular structure region,展开更多
An air superoleophobic/superhydrophilic composite coating with a unique structure was fabricated by oxidation and further modification of the copper mesh,and its design principle was clarified.This unique bird-nest-li...An air superoleophobic/superhydrophilic composite coating with a unique structure was fabricated by oxidation and further modification of the copper mesh,and its design principle was clarified.This unique bird-nest-like configuration gives it instant superhydrophilicity due to the high surface roughness and high polar surface free energy components,while air superoleophobicity is caused by its extremely low dispersive surface free energy components.Furthermore,a water-resistance mechanism was proposed whereby a polyelectrolyte plays a critical role in improving the water-resistance of fluorosurfactants.It can separate oil–water mixtures with high efficiency(98.72%)and high flux(25185 L·m−2·h−1),and can be reused.In addition,our composite coating had certain anti-acid,anti-alkali,anti-salt and anti-sand impact performance.More importantly,after being soaked in water for a long time or being exposed to the air for a long time,it still retained ultra-high air oil contact angle and showed excellent stability,which provided the possibility for practical applications.Thus,these findings offer the potential for significant practical applications in managing oily wastewater and marine oil spill incidents.展开更多
基金Supported by the Northwestern Polytechnical University under Grant No 158-QP-2016the Natural Science Basic Research Plan of Shaanxi Province under Grant No 2017JM5112
文摘A poly vinyl alcohol(PVA) scaffold with aligned porous is strengthened by in-situ combining with TiO2. The increased freezing rate can be used to further increase the strength of aligned porous materials. The strengthened porous PVA exhibits aligned interconnected porous structures and shows a significant enhancement in tensile testing and compression strength testing.
基金supported by the National Key R&D Program of China (No.2018YFC0310400)the Research Fund of the State Key Laboratory of Solidification Processing,China (No.2020TS-06,2021-TS-02)。
文摘With important application prospects, eutectic high entropy alloys have received extensive attention for their excellent strength and ductility in a large temperature range. The excellent casting characteristics of eutectic high entropy alloys make it possible to achieve well manufacturability of selective laser melting.For the first time, we have achieved crack-free eutectic high entropy alloy fabricated by selective laser melting, which has excellent mechanical properties in a wide temperature range from -196 ℃ to 760 ℃ due to ultra-fine eutectic lamellar spacing of 150–200 nm and lamellar colony of 2–6 μm. Specifically,the room temperature tensile strength exceeds 1400 MPa and the elongation is more than 20%, which significantly improved compared with those manufactured by other techniques with lower cooling rate.
基金supported by the Ministry of Science and Technology(No.2014CB932001)the National Natural Science Foundation of China(Nos.21237002 and 21425729)
文摘Accumulation of organic contaminants on fullerene nanoparticles(nC(60)) may significantly affect the risks of C(60) in the environment.The objective of this study was to further understand how the interplay of nC(60) formation routes and humic acid modification affects contaminant adsorption of nC(60).Specifically,adsorption of 1,2,4,5-tetrachlorobenzene(a model nonionic,hydrophobic organic contaminant) on nC(60) was greatly affected by nC(60)formation route- the formation route significantly affected the aggregation properties of nC(60),thus affecting the available surface area and the extent of adsorption via the pore-filling mechanism.Depending on whether nC(60) was formed via the "top-down" route(i.e.,sonicating C(60) powder in aqueous solution) or "bottom-up" route(i.e.,phase transfer from an organic solvent) and the type of solvent involved(toluene versus tetrahydrofuran),modification of nC(60) with Suwannee River humic acid(SRHA) could either enhance or inhibit the adsorption affinity of nC(60).The net effect depended on the specific way in which SRHA interacted with C(60) monomers and/or C(60) aggregates of different sizes and morphology,which determined the relative importance of enhanced adsorption from SRHA modification via preventing C(60) aggregation and inhibited adsorption through blocking available adsorption sites.The findings further demonstrate the complex mechanisms controlling interactions between nC(60) and organic contaminants,and may have significant implications for the life-cycle analysis and risk assessment of C(60).
基金supported by the National Natural Science Foundation of China (Grant Nos. 51105311 and 51475380)the National High Technology Research and Development Program of China (Grant No. 2013AA031103)
文摘Solidification microstructure of powder fed laser additive manufactured Ti-6Al--2Zr--2Sn--3Mo--1.5Cr--2Nb titanium alloy was investigated, The results showed that by deliberately increasing the powder feed rate, partially melted powders were retained at the top of the molten pool, which can promote heteroge- neous nucleus. Thus, each cladding layer is composed of two regions: (i) randomly orientated cellular structure region caused by partially melted powders at the top of each cladding layer; and (ii) epitaxial cellular structure region adjacent to the fusion line. Usually, randomly orientated cellular structure region was totally remelted for a wide range of process conditions. The remelting effect ensures the continuity of epitaxial growth of cellular structure and leads to the formation of columnar β grains, In order to obtain equiaxed grains the scanning velocity and powder feed rate should be carefully selected to enlarge the randomly orientated cellular structure region,
基金supported by the Science and Technology Department of Sichuan Province(2021YFG0275).
文摘An air superoleophobic/superhydrophilic composite coating with a unique structure was fabricated by oxidation and further modification of the copper mesh,and its design principle was clarified.This unique bird-nest-like configuration gives it instant superhydrophilicity due to the high surface roughness and high polar surface free energy components,while air superoleophobicity is caused by its extremely low dispersive surface free energy components.Furthermore,a water-resistance mechanism was proposed whereby a polyelectrolyte plays a critical role in improving the water-resistance of fluorosurfactants.It can separate oil–water mixtures with high efficiency(98.72%)and high flux(25185 L·m−2·h−1),and can be reused.In addition,our composite coating had certain anti-acid,anti-alkali,anti-salt and anti-sand impact performance.More importantly,after being soaked in water for a long time or being exposed to the air for a long time,it still retained ultra-high air oil contact angle and showed excellent stability,which provided the possibility for practical applications.Thus,these findings offer the potential for significant practical applications in managing oily wastewater and marine oil spill incidents.