Herein, the effect of fluoropolymer binders on the properties of polymer-bonded explosives(PBXs) was comprehensively investigated. To this end, fluorinated semi-interpenetrating polymer networks(semiIPNs) were prepare...Herein, the effect of fluoropolymer binders on the properties of polymer-bonded explosives(PBXs) was comprehensively investigated. To this end, fluorinated semi-interpenetrating polymer networks(semiIPNs) were prepared using different catalyst amounts(denoted as F23-CLF-30-D). The involved curing and phase separation processes were monitored using Fourier-transform infrared spectroscopy, differential scanning calorimetry, a haze meter and a rheometer. Curing rate constant and activation energy were calculated using a theoretical model and numerical method, respectively. Results revealed that owing to its co-continuous micro-phase separation structure, the F23-CLF-30-D3 semi-IPN exhibited considerably higher tensile strength and elongation at break than pure fluororubber F2314 and the F23-CLF-30-D0 semi-IPN because the phase separation and curing rates matched in the initial stage of curing.An arc Brazilian test revealed that F23-CLF-30-D-based composites used as mock materials for PBXs exhibited excellent mechanical performance and storage stability. Thus, the matched curing and phase separation rates play a crucial role during the fabrication of high-performance semi-IPNs;these factors can be feasibly controlled using an appropriate catalyst amount.展开更多
The development of high-performance non-fullerene acceptors with extended exciton diffusion lengths has positioned the sequential layer-by-layer(LBL)solution processing technique as a promising approach for fabricatin...The development of high-performance non-fullerene acceptors with extended exciton diffusion lengths has positioned the sequential layer-by-layer(LBL)solution processing technique as a promising approach for fabricating high-performance and large-area organic solar cells(OSCs).This method allows for the independent dissolution and deposition of donor and acceptor materials,enabling precise morphology control.In this review,we provide a comprehensive overview of the LBL processing technique,focusing on the morphology of the active layer.The swelling intercalation phase-separation(SIPS)model is introduced as the mainstream theory of morphology evolution,with a detailed discussion on vertical phase separation.We summarize recent strategies for morphology optimization.Additionally,we review the progress in LBL-based large-area device and module fabrication,as well as green processing approaches.Finally,we highlight current challenges and future prospects,paving the way for the commercialization of LBL-processed OSCs.展开更多
A systematic study of air gap distance effects on the structure and properties of poly(vinyl butyral)hollow fiber membrane via thermally induced phase separation(TIPS)has been carried out.The results show that the hol...A systematic study of air gap distance effects on the structure and properties of poly(vinyl butyral)hollow fiber membrane via thermally induced phase separation(TIPS)has been carried out.The results show that the hollow fiber membrane prepared at air gap zero has no skin layer; the pore size near the outer surface is larger than that near the inner surface; and the special pore channel-like structure near the outer surface is formed,which is quite different with the typical sponge-like structure caused by TIPS and the finger-like structure caused by non-solvent induced phase separation(NIPS),because of the synergistic action of non-solvent induced phase separation at air gap zero.The pore size gradually decreases from outer surface layer to the intermediate layer,but increases gradually from intermediate layer to the inner surface layer.With the increase of air gap distance,the pore size near the outer surface gets smaller and a dense skin layer is formed,and the pore size gradually increases from the outer surface layer to the inner surface layer.Water permeability of the hollow fiber membrane decreases with air gap distance,the water permeability decreases sharply from 45.50×10-7 to 4.52×10-7 m3/(m2·s·kPa)as air gap increases from 0 to 10 mm at take-up speed of 0.236 m/s,further decreases from 4.52×10-7 to 1.00×10-8 m3/(m2·s·kPa)as the air gap increases from 10 to 40 mm.Both the breaking strength and the elongation increase with the increase of air gap distance.The breaking strength increases from 2.25 MPa to 4.19 MPa and the elongation increases from 33.9% to 132.6% as air gap increases from 0 mm to 40 mm at take-up speed 0.236 m/s.展开更多
Poly （vinyl butyral） （PVB） hollow fiber membranes were fabricated via thermally induced phase separation （TIPS）. The effects of coagulation bath temperature （CBT） on the structure and performance of membranes ...Poly （vinyl butyral） （PVB） hollow fiber membranes were fabricated via thermally induced phase separation （TIPS）. The effects of coagulation bath temperature （CBT） on the structure and performance of membranes were investigated in detail. The morphologies of the membranes were studied by scanning electron microscopy （SEM）, the performances of water permeability, rejection, breaking strength and elongation were measured, respectively. The results indicate that all the membranes have the asymmetric morphology and the thickness of the skin layer decreases and the pore size of the outer layer increases with the increase of CBT. The permeability of membranes prepared at air gap 1.0 cm and take-up speed 0.253 m/s increases from 1.047×10-7 to 5.909×10-7 m3/（m2·s-kPa） with the CBT increasing from 20 ℃ to 40℃, and sharply increases to 35.226×10 7 m3/（m2.s.kPa）once the CBT arrives at 50 ℃. While the carbonic ink rejections have no significant decrease, totally exceed 98%, but that of acid-maleic acid copolymer greatly decreases with the increase of CBT. Both the breaking strength and elongation decrease with the increase of CBT.展开更多
The low-cost Fe-Cu,Fe-Ni,and Cu-based high-entropy alloys exhibit a widespread utilization prospect.However,these potential applications have been limited by their low strength.In this study,a novel Fe_(31)Cu_(31)Ni_(...The low-cost Fe-Cu,Fe-Ni,and Cu-based high-entropy alloys exhibit a widespread utilization prospect.However,these potential applications have been limited by their low strength.In this study,a novel Fe_(31)Cu_(31)Ni_(28)Al_(4)Ti_(3)Co_(3) immiscible high-entropy alloy(HEA)was developed.After vacuum arc melting and copper mold suction casting,this HEA exhibits a unique phase separation microstructure,which consists of striped Cu-rich regions and Fe-rich region.Further magnification of the striped Cu-rich region reveals that it is composed of a Cu-rich dot-like phase and a Fe-rich region.The aging alloy is further strengthened by a L1_(2)-Ni_(3)(AlTi)nanoprecipitates,achieving excellent yield strength(1185 MPa)and uniform ductility(~8.8%).The differential distribution of the L1_(2) nanoprecipitate in the striped Cu-rich region and the external Fe-rich region increased the strength difference between these two regions,which increased the strain gradient and thus improved hetero-deformation induced(HDI)hardening.This work provides a new route to improve the HDI hardening of Fe-Cu alloys.展开更多
基金supported by Wuxi HIT New Material Research Institute and China Academy of Engineering Physics。
文摘Herein, the effect of fluoropolymer binders on the properties of polymer-bonded explosives(PBXs) was comprehensively investigated. To this end, fluorinated semi-interpenetrating polymer networks(semiIPNs) were prepared using different catalyst amounts(denoted as F23-CLF-30-D). The involved curing and phase separation processes were monitored using Fourier-transform infrared spectroscopy, differential scanning calorimetry, a haze meter and a rheometer. Curing rate constant and activation energy were calculated using a theoretical model and numerical method, respectively. Results revealed that owing to its co-continuous micro-phase separation structure, the F23-CLF-30-D3 semi-IPN exhibited considerably higher tensile strength and elongation at break than pure fluororubber F2314 and the F23-CLF-30-D0 semi-IPN because the phase separation and curing rates matched in the initial stage of curing.An arc Brazilian test revealed that F23-CLF-30-D-based composites used as mock materials for PBXs exhibited excellent mechanical performance and storage stability. Thus, the matched curing and phase separation rates play a crucial role during the fabrication of high-performance semi-IPNs;these factors can be feasibly controlled using an appropriate catalyst amount.
基金Project(22408404)supported by the National Natural Science Foundation of China。
文摘The development of high-performance non-fullerene acceptors with extended exciton diffusion lengths has positioned the sequential layer-by-layer(LBL)solution processing technique as a promising approach for fabricating high-performance and large-area organic solar cells(OSCs).This method allows for the independent dissolution and deposition of donor and acceptor materials,enabling precise morphology control.In this review,we provide a comprehensive overview of the LBL processing technique,focusing on the morphology of the active layer.The swelling intercalation phase-separation(SIPS)model is introduced as the mainstream theory of morphology evolution,with a detailed discussion on vertical phase separation.We summarize recent strategies for morphology optimization.Additionally,we review the progress in LBL-based large-area device and module fabrication,as well as green processing approaches.Finally,we highlight current challenges and future prospects,paving the way for the commercialization of LBL-processed OSCs.
基金Project(21176264)supported by the National Natural Science Foundation of ChinaProject(11JJ2010)supported by the Natural Science Foundation of Hunan Province,China
文摘A systematic study of air gap distance effects on the structure and properties of poly(vinyl butyral)hollow fiber membrane via thermally induced phase separation(TIPS)has been carried out.The results show that the hollow fiber membrane prepared at air gap zero has no skin layer; the pore size near the outer surface is larger than that near the inner surface; and the special pore channel-like structure near the outer surface is formed,which is quite different with the typical sponge-like structure caused by TIPS and the finger-like structure caused by non-solvent induced phase separation(NIPS),because of the synergistic action of non-solvent induced phase separation at air gap zero.The pore size gradually decreases from outer surface layer to the intermediate layer,but increases gradually from intermediate layer to the inner surface layer.With the increase of air gap distance,the pore size near the outer surface gets smaller and a dense skin layer is formed,and the pore size gradually increases from the outer surface layer to the inner surface layer.Water permeability of the hollow fiber membrane decreases with air gap distance,the water permeability decreases sharply from 45.50×10-7 to 4.52×10-7 m3/(m2·s·kPa)as air gap increases from 0 to 10 mm at take-up speed of 0.236 m/s,further decreases from 4.52×10-7 to 1.00×10-8 m3/(m2·s·kPa)as the air gap increases from 10 to 40 mm.Both the breaking strength and the elongation increase with the increase of air gap distance.The breaking strength increases from 2.25 MPa to 4.19 MPa and the elongation increases from 33.9% to 132.6% as air gap increases from 0 mm to 40 mm at take-up speed 0.236 m/s.
基金Project(21176264)supported by the National Natural Science Foundation of ChinaProject(11JJ2010)supported by the Hunan Provincial Natural Science Foundation of China
文摘Poly （vinyl butyral） （PVB） hollow fiber membranes were fabricated via thermally induced phase separation （TIPS）. The effects of coagulation bath temperature （CBT） on the structure and performance of membranes were investigated in detail. The morphologies of the membranes were studied by scanning electron microscopy （SEM）, the performances of water permeability, rejection, breaking strength and elongation were measured, respectively. The results indicate that all the membranes have the asymmetric morphology and the thickness of the skin layer decreases and the pore size of the outer layer increases with the increase of CBT. The permeability of membranes prepared at air gap 1.0 cm and take-up speed 0.253 m/s increases from 1.047×10-7 to 5.909×10-7 m3/（m2·s-kPa） with the CBT increasing from 20 ℃ to 40℃, and sharply increases to 35.226×10 7 m3/（m2.s.kPa）once the CBT arrives at 50 ℃. While the carbonic ink rejections have no significant decrease, totally exceed 98%, but that of acid-maleic acid copolymer greatly decreases with the increase of CBT. Both the breaking strength and elongation decrease with the increase of CBT.
基金Projects(52001083,52171111,U2141207)supported by the National Natural Science Foundation of ChinaProject(LH2020E060)supported by the Natural Science Foundation of Heilongjiang,China。
文摘The low-cost Fe-Cu,Fe-Ni,and Cu-based high-entropy alloys exhibit a widespread utilization prospect.However,these potential applications have been limited by their low strength.In this study,a novel Fe_(31)Cu_(31)Ni_(28)Al_(4)Ti_(3)Co_(3) immiscible high-entropy alloy(HEA)was developed.After vacuum arc melting and copper mold suction casting,this HEA exhibits a unique phase separation microstructure,which consists of striped Cu-rich regions and Fe-rich region.Further magnification of the striped Cu-rich region reveals that it is composed of a Cu-rich dot-like phase and a Fe-rich region.The aging alloy is further strengthened by a L1_(2)-Ni_(3)(AlTi)nanoprecipitates,achieving excellent yield strength(1185 MPa)and uniform ductility(~8.8%).The differential distribution of the L1_(2) nanoprecipitate in the striped Cu-rich region and the external Fe-rich region increased the strength difference between these two regions,which increased the strain gradient and thus improved hetero-deformation induced(HDI)hardening.This work provides a new route to improve the HDI hardening of Fe-Cu alloys.
