Porous carbon(PC)materials have unique structures and excellent physicochemical properties,which offer significant advantages in the field of electromagnetic wave(EMW)absorption materials.However,how to utilize availa...Porous carbon(PC)materials have unique structures and excellent physicochemical properties,which offer significant advantages in the field of electromagnetic wave(EMW)absorption materials.However,how to utilize available raw materials and practical preparation techniques is a major challenge for PC microwave absorption materials to achieve engineering applications.In this study,inexpensive coal tar pitch(CTP)was used as a carbon source to prepare PC microwave absorbers.Firstly,hyper-crosslinked polymers(HCPs)were prepared by selectively crosslinking the aromatic components in CTP via Friedel-Crafts reaction using chloroalkanes as crosslinking agents.Further,PC materials with uniform structure were also prepared by simple high-temperature carbonization.The effects of cross-linker type(CH_(2)Cl_(2),CHCl_(3) and CCl_(4))and carbonization temperature(600,700,and 800℃)on the microstructure,crystallization,dielectric and microwave absorption properties of PC materials were systematically studied.After modulation and optimization,all CTP-based PCs have uniform pore structure with a maximum specific surface area of 533.93 m^(2)/g.The PC with CHCl_(3) as cross-linking agent carbonized at 700℃ showed the exceptional microwave absorption performance,with the minimum refection loss(RL_(min))of−43.08 dB and the maximum effective absorption bandwidth(EAB_(max))of 5.44 GHz.Meanwhile,the RL_(min) of CCl_(4)-PC-800 also achieved−47.28 dB.This work has developed a simple and low-cost method for preparing PC microwave absorption materials,which has the potential to enable the mass production and engineering application of PCs,as well as facilitating processing technology innovation and high value-added utilization of CTP.展开更多
Using household detergents to clean oil stains has always caused global concerns,as these detergents negatively impact the ecosystem and are toxic.Therefore,it is essential to effectively attenuate the adhesion force ...Using household detergents to clean oil stains has always caused global concerns,as these detergents negatively impact the ecosystem and are toxic.Therefore,it is essential to effectively attenuate the adhesion force between oil stains and substrates to create an easy and detergent-saving cleaning pathway.To address this challenge,we herein develop a strategy to reduce the strength of oil adhesion on common substrates by∼20 times through a lamination layer,which contains phase-transitioned lysozyme nanofilm(PTL)and cellulose nanocrystals(CNCs).The resultant CNC/PTL coating significantly enhances the capability of cleaning oil stains in an underwater detergent-free manner;this strategy is applicable to edible oil packaging material and tableware,without impairing the usability and aesthetics of these materials.This coating exhibits excellent mechanical stability and regeneration characteristics through simple soaking,ensuring its robustness in real applications in an infinite life cycle.By eliminating 100%detergent in routine cleaning,the CNC/PTL coating demonstrated remarkable cost-effectiveness,saving 57.7%of water and 83.3%of energy when washing tableware only with water.This work presents an ingenious design to create oil-repellent packaging materials and tableware toward detergent-free water-cleaning pathways,thereby greatly reducing the negative environmental impact of surfactant emissions.展开更多
Graphitic carbon nitride(g-C_(3)N_(4))nanosheets have attracted widespread interest in the construction of advanced separation membranes.However,dense stacking and a single functionality have limited the membrane deve...Graphitic carbon nitride(g-C_(3)N_(4))nanosheets have attracted widespread interest in the construction of advanced separation membranes.However,dense stacking and a single functionality have limited the membrane development.Here,an advanced two-/three-dimensional(2D/3D)g-C_(3)N_(4)/TiO_(2)@MnO_(2) membrane is constructed by intercalating 3D TiO_(2)@MnO_(2) nanostructures into g-C_(3)N_(4) nanosheets.The 3D flower-like nanostructures broaden the transport channels of the composite membrane.The membrane can effectively separate five oil-in-water(O/W)emulsions,with a maximum flux of 3265.67±15.01 L·m^(-2)·h^(-1)·bar^(-1) and a maximum efficiency of 99.69%±0.45%for toluene-in-water emulsion(T/W).Meanwhile,the TiO_(2)@MnO_(2) acts as an excellent electron acceptor and provides positive spatial separation of electrons–holes(e^(-)–h^(+)).The formation of 2D/3D heterojunctions allows the material with wider light absorption and smaller bandgap(2.10 eV).These photoelectric properties give the membrane good degradation of three different pollutants,with about 100%degradation for methylene blue(MB)and malachite green(MG).The photocatalytic antibacterial efficiency of the membrane is also about 100%.After cyclic experiment,the membrane maintains its original separation and photocatalytic capabilities.The remarkable multifunctional and self-cleaning properties of the g-C_(3)N_(4) based membrane represent its potential value for complex wastewater treatment.展开更多
Conductive gels have shown vast potential as flexible sensors for applications in health monitoring,soft robots,and human-machine interfaces.Nevertheless,there remains a significant challenge to integrate low hysteres...Conductive gels have shown vast potential as flexible sensors for applications in health monitoring,soft robots,and human-machine interfaces.Nevertheless,there remains a significant challenge to integrate low hysteresis,environmental tolerance,and high sensitivity in one component for accurate and stable signal outputs.In this work,a conductive organohydrogel is prepared by the radical polymerization of 3-acrylamidophenylboronic acid(APBA)and acrylamide(AM)in the presence of MXene followed by a solvent-replacement strategy.The organohydrogel exhibits high stretchability(>900%),robust elasticity(residual strain<12%),superior environmental tolerance(−60 to 60°C),and long-term stability in an open environment(>60 days)owing to the presence of B-N coordination and multiple hydrogen-bonding interactions within the gel network.As a flexible sensor,it can precisely distinguish successive tiny(1%)and large tensile strains(700%)even stored at−20°C for 7 days,and output reliable electrical signals of electrocardiograms and electromyograms with neglectable attenuation when exposed at the ambient environment for one week.Moreover,the organohydrogel shows remarkable temperature sensitivity with temperature coefficient of resistance of−2.71%/°C,and can accurately differentiate the temperatures of different human body parts with tiny differences for health monitoring.Our work may give a solution to design reliable gel-based flexible sensors for various applications.展开更多
Nanofiltration technology has opened an efficient pathway to addressing the grand issue of wastewater purification.Polyethyleneimine(PEI),as a hydrophilic polymer,is a promising material to manufacture separation memb...Nanofiltration technology has opened an efficient pathway to addressing the grand issue of wastewater purification.Polyethyleneimine(PEI),as a hydrophilic polymer,is a promising material to manufacture separation membranes owing to its superiority.Here,we prepared a hyperbranched PEI-based separation mem-brane through the supramolecular hydrogen bond interaction for wastewater purification.The amino groups in the PEI molecule were partially oxidized to the nitro groups with sodium hypochlorite(NaClO).Moreover,the PEI molecu-lar chains can be regulated from the hyperbranched state to the internal nucle-ation state.Molecular dynamics simulation results further indicated the strong hydrogen bonds among the oxidized PEI(O-PEI)molecular chains and the decreased gyration radius of the O-PEI molecule due to the formation of the nitro groups.In addition,the wettability and zeta potential of O-PEI membranes can be controlled by adjusting the molecular weight and oxidation degree of the PEI molecules.Under the collective effect of size screening and charge repulsion,the O-PEI separation membrane displayed a wide range of purification capabilities for contaminations,such as dye molecules and salts.This work may offer a new strategy to fabricate hyperbranched O-PEI membranes for wastewater purifica-tion.展开更多
基金supported by the National Natural Science Foundation of China(No.22005039)the Innovation Capability Support Program of Shaanxi(No.2023-CX-TD-43)the Fundamental Research Funds for the Central Universities,CHD(Nos.300102313208,300102312403,and 300102314401).
文摘Porous carbon(PC)materials have unique structures and excellent physicochemical properties,which offer significant advantages in the field of electromagnetic wave(EMW)absorption materials.However,how to utilize available raw materials and practical preparation techniques is a major challenge for PC microwave absorption materials to achieve engineering applications.In this study,inexpensive coal tar pitch(CTP)was used as a carbon source to prepare PC microwave absorbers.Firstly,hyper-crosslinked polymers(HCPs)were prepared by selectively crosslinking the aromatic components in CTP via Friedel-Crafts reaction using chloroalkanes as crosslinking agents.Further,PC materials with uniform structure were also prepared by simple high-temperature carbonization.The effects of cross-linker type(CH_(2)Cl_(2),CHCl_(3) and CCl_(4))and carbonization temperature(600,700,and 800℃)on the microstructure,crystallization,dielectric and microwave absorption properties of PC materials were systematically studied.After modulation and optimization,all CTP-based PCs have uniform pore structure with a maximum specific surface area of 533.93 m^(2)/g.The PC with CHCl_(3) as cross-linking agent carbonized at 700℃ showed the exceptional microwave absorption performance,with the minimum refection loss(RL_(min))of−43.08 dB and the maximum effective absorption bandwidth(EAB_(max))of 5.44 GHz.Meanwhile,the RL_(min) of CCl_(4)-PC-800 also achieved−47.28 dB.This work has developed a simple and low-cost method for preparing PC microwave absorption materials,which has the potential to enable the mass production and engineering application of PCs,as well as facilitating processing technology innovation and high value-added utilization of CTP.
基金National Science Fund for Distinguished Young Scholars,Grant/Award Number:52225301National Key R&D Program of China,Grant/Award Numbers:2020YFA0710400,2020YFA0710402+2 种基金111 Project,Grant/Award Number:B14041Innovation Capability Support Program of Shaanxi,Grant/Award Number:2020TD-024International Science and Technology Cooperation Program of Shaanxi Province,Grant/Award Number:2022KWZ-24。
文摘Using household detergents to clean oil stains has always caused global concerns,as these detergents negatively impact the ecosystem and are toxic.Therefore,it is essential to effectively attenuate the adhesion force between oil stains and substrates to create an easy and detergent-saving cleaning pathway.To address this challenge,we herein develop a strategy to reduce the strength of oil adhesion on common substrates by∼20 times through a lamination layer,which contains phase-transitioned lysozyme nanofilm(PTL)and cellulose nanocrystals(CNCs).The resultant CNC/PTL coating significantly enhances the capability of cleaning oil stains in an underwater detergent-free manner;this strategy is applicable to edible oil packaging material and tableware,without impairing the usability and aesthetics of these materials.This coating exhibits excellent mechanical stability and regeneration characteristics through simple soaking,ensuring its robustness in real applications in an infinite life cycle.By eliminating 100%detergent in routine cleaning,the CNC/PTL coating demonstrated remarkable cost-effectiveness,saving 57.7%of water and 83.3%of energy when washing tableware only with water.This work presents an ingenious design to create oil-repellent packaging materials and tableware toward detergent-free water-cleaning pathways,thereby greatly reducing the negative environmental impact of surfactant emissions.
基金supported by the Fundamental Research Funds for the Central Universities,CHD(Nos.300102312403 and 300102313208)the Shaanxi Key Research&Development Project(No.2022GY-403)+1 种基金the Innovation Capability Support Program of Shaanxi(No.2023-CX-TD-43)the China Postdoctoral Science Foundation(No.2020M683395).
文摘Graphitic carbon nitride(g-C_(3)N_(4))nanosheets have attracted widespread interest in the construction of advanced separation membranes.However,dense stacking and a single functionality have limited the membrane development.Here,an advanced two-/three-dimensional(2D/3D)g-C_(3)N_(4)/TiO_(2)@MnO_(2) membrane is constructed by intercalating 3D TiO_(2)@MnO_(2) nanostructures into g-C_(3)N_(4) nanosheets.The 3D flower-like nanostructures broaden the transport channels of the composite membrane.The membrane can effectively separate five oil-in-water(O/W)emulsions,with a maximum flux of 3265.67±15.01 L·m^(-2)·h^(-1)·bar^(-1) and a maximum efficiency of 99.69%±0.45%for toluene-in-water emulsion(T/W).Meanwhile,the TiO_(2)@MnO_(2) acts as an excellent electron acceptor and provides positive spatial separation of electrons–holes(e^(-)–h^(+)).The formation of 2D/3D heterojunctions allows the material with wider light absorption and smaller bandgap(2.10 eV).These photoelectric properties give the membrane good degradation of three different pollutants,with about 100%degradation for methylene blue(MB)and malachite green(MG).The photocatalytic antibacterial efficiency of the membrane is also about 100%.After cyclic experiment,the membrane maintains its original separation and photocatalytic capabilities.The remarkable multifunctional and self-cleaning properties of the g-C_(3)N_(4) based membrane represent its potential value for complex wastewater treatment.
基金supported by the National Natural Science Foundation of China(Nos.52173139 and 52322309)the“Young Talent Support Plan”of Xi'an Jiaotong University,Innovation Capability Support Program of Shaanxi(No.2023-CXTD-43)+1 种基金Fundamental Research Funds for the Central Universities,CHD(No.300102314401)the Natural Science Foundation of Shaanxi Province(No.2024JC-YBQN-0586).
文摘Conductive gels have shown vast potential as flexible sensors for applications in health monitoring,soft robots,and human-machine interfaces.Nevertheless,there remains a significant challenge to integrate low hysteresis,environmental tolerance,and high sensitivity in one component for accurate and stable signal outputs.In this work,a conductive organohydrogel is prepared by the radical polymerization of 3-acrylamidophenylboronic acid(APBA)and acrylamide(AM)in the presence of MXene followed by a solvent-replacement strategy.The organohydrogel exhibits high stretchability(>900%),robust elasticity(residual strain<12%),superior environmental tolerance(−60 to 60°C),and long-term stability in an open environment(>60 days)owing to the presence of B-N coordination and multiple hydrogen-bonding interactions within the gel network.As a flexible sensor,it can precisely distinguish successive tiny(1%)and large tensile strains(700%)even stored at−20°C for 7 days,and output reliable electrical signals of electrocardiograms and electromyograms with neglectable attenuation when exposed at the ambient environment for one week.Moreover,the organohydrogel shows remarkable temperature sensitivity with temperature coefficient of resistance of−2.71%/°C,and can accurately differentiate the temperatures of different human body parts with tiny differences for health monitoring.Our work may give a solution to design reliable gel-based flexible sensors for various applications.
基金This work was supported by the K.C.Wong Education Foundation(GJTD-2019-13)National Key Research and Develop-ment Program of China(2019YFC1606600)+1 种基金Shaanxi Key Research and Development Project(2020ZDLGY13-08),the Open Research Fund of Key Laboratory of Marine Materials and Related Technologies(2013DP173296,2019K03)Shaanxi Key Research and Development Project(2021GY199).
文摘Nanofiltration technology has opened an efficient pathway to addressing the grand issue of wastewater purification.Polyethyleneimine(PEI),as a hydrophilic polymer,is a promising material to manufacture separation membranes owing to its superiority.Here,we prepared a hyperbranched PEI-based separation mem-brane through the supramolecular hydrogen bond interaction for wastewater purification.The amino groups in the PEI molecule were partially oxidized to the nitro groups with sodium hypochlorite(NaClO).Moreover,the PEI molecu-lar chains can be regulated from the hyperbranched state to the internal nucle-ation state.Molecular dynamics simulation results further indicated the strong hydrogen bonds among the oxidized PEI(O-PEI)molecular chains and the decreased gyration radius of the O-PEI molecule due to the formation of the nitro groups.In addition,the wettability and zeta potential of O-PEI membranes can be controlled by adjusting the molecular weight and oxidation degree of the PEI molecules.Under the collective effect of size screening and charge repulsion,the O-PEI separation membrane displayed a wide range of purification capabilities for contaminations,such as dye molecules and salts.This work may offer a new strategy to fabricate hyperbranched O-PEI membranes for wastewater purifica-tion.
