Green and recyclable solid acid catalysts are in urgent demand as a substitute for conventional liquid mineral acids.In this work,a series of novel sulfonic acid-functionalized core-shell Fe_(3)O_(4)@carbon microspher...Green and recyclable solid acid catalysts are in urgent demand as a substitute for conventional liquid mineral acids.In this work,a series of novel sulfonic acid-functionalized core-shell Fe_(3)O_(4)@carbon microspheres(Fe_(3)O_(4)@C-SO_(3)H)have been designed and synthesized as an efficient and recyclable heterogeneous acid catalyst.For the synthesis,core-shell Fe_(3)O_(4)@RF(resorcinol-formaldehyde)microspheres with tunable shell thickness were achieved by interfacial polymerization on magnetic Fe_(3)O_(4)microspheres.After high-temperature carbonization,the microspheres were eventually treated by surface sulfonation,re sulting in Fe_(3)O_(4)@C-x-SO_(3)H(x stands for carbonization temperature)microspheres with abundant surface SO_(3)H groups.The obtained microspheres possess uniform core-shell structure,partially-graphitized carbon skeletons,superparamagnetic property,high magnetization saturation value of 10.6 emu/g,and rich SO_(3)H groups.The surface acid amounts can be adju sted in the range of 0.59-1.04 mmol/g via sulfonation treatment of carbon shells with different graphitization degrees.The magnetic Fe_(3)O_(4)@C-x-SO_(3)H microspheres were utilized as a solid acid catalyst for the acetalization reaction between benzaldehyde and ethylene glycol,demonstrating high selectivity(97%)to benzaldehyde ethylene glycol acetal.More importantly,by applying an external magnetic field,the catalysts can be easily separated from the heterogeneous reaction solutions,which later show well preserved catalytic activity even after 9 cycles,revealing good recyclability and high stability.展开更多
Latent fingerprints are extremely vital for personal identification and criminalinvestigation,and potential information recognition techniques have been widelyused in the fields of information and communication electr...Latent fingerprints are extremely vital for personal identification and criminalinvestigation,and potential information recognition techniques have been widelyused in the fields of information and communication electronics.Although physicalpowder dusting methods have been frequently employed to develop latent fingerprintsand most of them are carried out by using single component powders ofmicron-sized fluorescent particles,magnetic powders,or metal particles,there isstill an enormous challenge in producing high-resolution image of latent fingerprintsat different backgrounds or substrates.Herein,a novel and effectivenanoimpregnation method is developed to synthesize bifunctional magnetic fluorescentmesoporous microspheres for latent fingerprints visualization by growthof mesoporous silica(mesoSiO_(2))on magical Fe_(3)O_(4) core and then deposition offluorescent YVO4:Eu^(3+)nanoparticles in the mesopores.The obtainedFe_(3)O_(4)@mesoSiO_(2)@YVO4:Eu^(3+)microspheres possess spatially isolated magneticcore and fluorescent shell which were insulated by mesoporous silica layer.Dueto their small particle size of submicrometer scale,high magnetization and lowmagnetic remanence as well as the combined magnetic and fluorescent properties,the microspheres show superior performance in visual latent fingerprint recognitionwith high contrast,high anti-interference,and sensitivity as well as goodretention on multifarious substrates regardless of surface permeability,roughness,refraction,colorfulness,and background fluorescence interference,and it makesthem ideal candidates for practical application in fingerprint visualization andeven magneto-optic information storage.展开更多
Nowadays,the employing of molecular imprinting technique in the analysis and separation of proteins from complex biological samples has been widely favored by researchers.To enrich the types of surface protein imprint...Nowadays,the employing of molecular imprinting technique in the analysis and separation of proteins from complex biological samples has been widely favored by researchers.To enrich the types of surface protein imprinted materials and expand the application fields of graphene materials,novel surface molecular imprinted polymers(MIPs)based on magnetic graphene microspheres Fe_(3)O_(4)@r GO@MIPs are first synthesized in this paper.Fe_(3)O_(4)@r GO@MIPs are prepared by oxidative self-polymerization of dopamine on the surface of magnetic graphene(Fe_(3)O_(4)@r GO)composite microspheres.Bovine serum albumin(BSA)is selected as protein template.Fe_(3)O_(4)@r GO microspheres with wrinkled flower-like structure are obtained by compounding Fe_(3)O_(4)and graphene oxide in an appropriate ratio via the method of high-temperature reduction self-assembly.The microspheres exhibit promising dispersibility,high external surface area,rich pore structure,and sufficient magnetic properties.These advantages not only prevent the agglomeration of imprinted microspheres in the aqueous phase,which is conducive to contact and static adsorption,but also increase the amount of protein imprinting.Additionally,sufficient magnetic properties ensure fast and effective separation of the adsorbents.While the adsorption capacity is increased,the separation procedure becomes simple.The binding capacity of Fe_(3)O_(4)@r GO@MIPs for BSA can reach 317.58 mg/g within 60 min,and the imprinting factor(IF)is 4.24.More importantly,Fe_(3)O_(4)@r GO@MIPs can specifically recognize the target BSA from the mixed proteins and the actual sample.There is no significant decrease in the adsorption amount,IF,and magnetic properties after eight runs.It is promising to be used in the separation of proteins from the actual biological samples.展开更多
1 Rusults Most enzymes, including lipase, play a key role in biotechnology, but their usage is quite limited because of poor recovery, yield, limited re-usability and rapid inactivation in the soluble state. Immobiliz...1 Rusults Most enzymes, including lipase, play a key role in biotechnology, but their usage is quite limited because of poor recovery, yield, limited re-usability and rapid inactivation in the soluble state. Immobilization enzymes offer advantages over free enzymes because of the availability of a choice of batch or continuous processes, rapid termination of reactions, controlled product formation, ease of enzyme removal from the reaction mixture, and adaptability to various engineering designs.In this ...展开更多
基金financially supported by the National Natural Science Foundation of China(Nos.21875044,52073064,22005058 and 22005057)National Key R&D Program of China(No.2020YFB2008600)+3 种基金Key Basic Research Program of Science and Technology Commission of Shanghai Municipality(No.20JC1415300)Program of Shanghai Academic Research Leader(No.19XD1420300)China Post-doctoral Science Foundation(Nos.2020M670973,BX20200085)the State Key Laboratory of Transducer Technology of China(No.SKT1904)。
文摘Green and recyclable solid acid catalysts are in urgent demand as a substitute for conventional liquid mineral acids.In this work,a series of novel sulfonic acid-functionalized core-shell Fe_(3)O_(4)@carbon microspheres(Fe_(3)O_(4)@C-SO_(3)H)have been designed and synthesized as an efficient and recyclable heterogeneous acid catalyst.For the synthesis,core-shell Fe_(3)O_(4)@RF(resorcinol-formaldehyde)microspheres with tunable shell thickness were achieved by interfacial polymerization on magnetic Fe_(3)O_(4)microspheres.After high-temperature carbonization,the microspheres were eventually treated by surface sulfonation,re sulting in Fe_(3)O_(4)@C-x-SO_(3)H(x stands for carbonization temperature)microspheres with abundant surface SO_(3)H groups.The obtained microspheres possess uniform core-shell structure,partially-graphitized carbon skeletons,superparamagnetic property,high magnetization saturation value of 10.6 emu/g,and rich SO_(3)H groups.The surface acid amounts can be adju sted in the range of 0.59-1.04 mmol/g via sulfonation treatment of carbon shells with different graphitization degrees.The magnetic Fe_(3)O_(4)@C-x-SO_(3)H microspheres were utilized as a solid acid catalyst for the acetalization reaction between benzaldehyde and ethylene glycol,demonstrating high selectivity(97%)to benzaldehyde ethylene glycol acetal.More importantly,by applying an external magnetic field,the catalysts can be easily separated from the heterogeneous reaction solutions,which later show well preserved catalytic activity even after 9 cycles,revealing good recyclability and high stability.
基金China Postdoctoral Science Foundation,Grant/Award Numbers:2021M690660,2021TQ0066Key Basic Research Program of Science and Technology Commission of Shanghai Municipality,Grant/Award Number:20JC1415300+1 种基金National Natural Science Foundation of China,Grant/Award Numbers:21701153,21875044Program of Shanghai Academic Research Leader,Grant/Award Number:19XD1420300。
文摘Latent fingerprints are extremely vital for personal identification and criminalinvestigation,and potential information recognition techniques have been widelyused in the fields of information and communication electronics.Although physicalpowder dusting methods have been frequently employed to develop latent fingerprintsand most of them are carried out by using single component powders ofmicron-sized fluorescent particles,magnetic powders,or metal particles,there isstill an enormous challenge in producing high-resolution image of latent fingerprintsat different backgrounds or substrates.Herein,a novel and effectivenanoimpregnation method is developed to synthesize bifunctional magnetic fluorescentmesoporous microspheres for latent fingerprints visualization by growthof mesoporous silica(mesoSiO_(2))on magical Fe_(3)O_(4) core and then deposition offluorescent YVO4:Eu^(3+)nanoparticles in the mesopores.The obtainedFe_(3)O_(4)@mesoSiO_(2)@YVO4:Eu^(3+)microspheres possess spatially isolated magneticcore and fluorescent shell which were insulated by mesoporous silica layer.Dueto their small particle size of submicrometer scale,high magnetization and lowmagnetic remanence as well as the combined magnetic and fluorescent properties,the microspheres show superior performance in visual latent fingerprint recognitionwith high contrast,high anti-interference,and sensitivity as well as goodretention on multifarious substrates regardless of surface permeability,roughness,refraction,colorfulness,and background fluorescence interference,and it makesthem ideal candidates for practical application in fingerprint visualization andeven magneto-optic information storage.
基金the National Natural Science Foundation of China(No.21704084,21975206)the Shaanxi Innovative Talents Promotion Plan-the Young Star of Science and Technology Project(No.2019KJXX-67)。
文摘Nowadays,the employing of molecular imprinting technique in the analysis and separation of proteins from complex biological samples has been widely favored by researchers.To enrich the types of surface protein imprinted materials and expand the application fields of graphene materials,novel surface molecular imprinted polymers(MIPs)based on magnetic graphene microspheres Fe_(3)O_(4)@r GO@MIPs are first synthesized in this paper.Fe_(3)O_(4)@r GO@MIPs are prepared by oxidative self-polymerization of dopamine on the surface of magnetic graphene(Fe_(3)O_(4)@r GO)composite microspheres.Bovine serum albumin(BSA)is selected as protein template.Fe_(3)O_(4)@r GO microspheres with wrinkled flower-like structure are obtained by compounding Fe_(3)O_(4)and graphene oxide in an appropriate ratio via the method of high-temperature reduction self-assembly.The microspheres exhibit promising dispersibility,high external surface area,rich pore structure,and sufficient magnetic properties.These advantages not only prevent the agglomeration of imprinted microspheres in the aqueous phase,which is conducive to contact and static adsorption,but also increase the amount of protein imprinting.Additionally,sufficient magnetic properties ensure fast and effective separation of the adsorbents.While the adsorption capacity is increased,the separation procedure becomes simple.The binding capacity of Fe_(3)O_(4)@r GO@MIPs for BSA can reach 317.58 mg/g within 60 min,and the imprinting factor(IF)is 4.24.More importantly,Fe_(3)O_(4)@r GO@MIPs can specifically recognize the target BSA from the mixed proteins and the actual sample.There is no significant decrease in the adsorption amount,IF,and magnetic properties after eight runs.It is promising to be used in the separation of proteins from the actual biological samples.
文摘1 Rusults Most enzymes, including lipase, play a key role in biotechnology, but their usage is quite limited because of poor recovery, yield, limited re-usability and rapid inactivation in the soluble state. Immobilization enzymes offer advantages over free enzymes because of the availability of a choice of batch or continuous processes, rapid termination of reactions, controlled product formation, ease of enzyme removal from the reaction mixture, and adaptability to various engineering designs.In this ...
