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
Layer-by-layer (LbL) strategy has been developed to form bulk heterojunction (BHJ) structure for processing efficient organic solar cells (OSCs). Herein, LbL slot-die coating with twin boiling point solvents (TBPS) st...Layer-by-layer (LbL) strategy has been developed to form bulk heterojunction (BHJ) structure for processing efficient organic solar cells (OSCs). Herein, LbL slot-die coating with twin boiling point solvents (TBPS) strategy was developed to fabricate highly efficient OSCs, which matches with large-scale, high throughput roll-to-roll (R2R) industrialized mass process. The TBPS strategy could produce high-quality thin film without any additive, leading to the optimized vertical phase separation with interpenetrating nanostructures, as well as the enhanced charge transport and extraction. Thus, the power conversion efficiency up to 14.42% was achieved for [(2,6-(4,8-bis(5-(2-ethylhexyl-3-fluoro)thiophen-2-yl)-benzo [1,2-b:4,5-b′]dithiophene))-alt-(5,5-(1′,3′-di-2-thienyl-5′,7′-bis(2-ethylhexyl)benzo[1′,2′-c:4′,5′-c′]dithiophene-4,8-dione)]:2,2′-((2Z,2′Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3″:4″,5″]thieno[2′,3′:4,5]pyrrolo[3,2-g]thieno[2′,3′:4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene)) bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (PM6:Y6) OSCs fabricated via sequentially LbL slot-die coating using the TBPS strategy under ambient condition. The research provides a potential route for industrialized production of high-efficiency and large-area OSC devices.展开更多
Electrochemical sensing of carcinoembryonic antigen(CEA)on a gold electrode modified by the se- quential incorporation of the mediator,thionine(Thi),and gold nanoparticles(nano-Au),through co- valent linkage and elect...Electrochemical sensing of carcinoembryonic antigen(CEA)on a gold electrode modified by the se- quential incorporation of the mediator,thionine(Thi),and gold nanoparticles(nano-Au),through co- valent linkage and electrostatic interactions onto a self-assembled monolayer configuration is de- scribed in this paper.The enzyme,horseradish peroxidase(HRP),was employed to block the possible remaining active sites of the nano-Au monolayer,avoid the non-specific adsorption,instead of bovine serum albumin(BSA),and amplify the response of the antigen-antibody reaction.Electrochemical ex- periments indicated highly efficient electron transfer by the imbedded Thi mediator and adsorbed nano-Au.The HRP kept its activity after immobilization,and the studied electrode showed sensitive response to CEA and high stability during a long period of storage.The working range for the system was 2.5 to 80.0 ng/mL with a detection limit of 0.90 ng/mL.The model membrane system in this work is a potential biosensor for mimicking the other immunosensor and enzyme sensor.展开更多
Silver halide (AgX) microcrystal was used as template to synthesize hollow polyelectrolyte capsules. These hollow capsules were characterized by laser light scattering (LLS) used to measure the size of the capsules in...Silver halide (AgX) microcrystal was used as template to synthesize hollow polyelectrolyte capsules. These hollow capsules were characterized by laser light scattering (LLS) used to measure the size of the capsules in solution. The ratio of hydrodynamic radius (R h ) from dynamic LLS to the radius of gyration (Rg) from static LLS is almost unity, revealing that the entities are hollow in solution. The results suggest that the LLS method can be regarded as a good complement to the confocal laser scanning microscopy (CLSM) method for the characterization of small hollow capsules, and it possesses the advantage of not needing fluorescence labeling.展开更多
To achieve fire-resistant epoxy resin(EP),a UiO-66-based novel flame retardant coating(CS@APP@UiO-66)was prepared by modifying UiO-66 with chitosan(CS)and ammonium polyphosphate(APP)through a layer-by-layer(LbL)self-a...To achieve fire-resistant epoxy resin(EP),a UiO-66-based novel flame retardant coating(CS@APP@UiO-66)was prepared by modifying UiO-66 with chitosan(CS)and ammonium polyphosphate(APP)through a layer-by-layer(LbL)self-assembly method,which was then introduced into an EP system to improve its fire safety.The results of scanning electron microscopy,X-ray diffraction and Fourier transform infrared spectroscopy show that the unsaturated Zr atoms in the UiO-66 framework provide many active sites conducive to modification,so that the UiO-66 particles,which originally had a regular octahedral structure,are more dispersed by LbL modification without causing doping or distortion issues.The thermogravimetric analysis results indicate that the char residue of EP/2%UiO-66 is increased by 2.52%compared with that of pure EP,indicating that the thermal properties of the EP composite are improved after modification.In addition,the cone test results indicate that EP/2%UiO-66-5L has good flame retardancy and smoke suppression properties,and the peak heat release rate,total smoke production and rate of CO generation values are 25.2%,5.7%and 38.5%lower than those of the unmodified EP.Moreover,it can be concluded from the Raman test that the graphitization degree of the modified EP composite is strengthened.The above results indicated that after the incorporation of CS@APP@UiO-66 into the EP composites,more char layers formed as physical barriers to prevent the transfer of mass and heat,thus reducing the speed of flame propagation.Therefore,the flame resistance and smoke suppression of the EP composites improved.These favorable characteristics,including high flame retardant efficiency and good smoke suppression,make LbL-functionalized UiO-66 promising for flame retardant polymer applications.展开更多
Understanding the mechanical properties of bionanofilms is important in terms of identifying their durability.The primary focus of this study is to examine the effect of water vapor annealed silk fibroin on the indent...Understanding the mechanical properties of bionanofilms is important in terms of identifying their durability.The primary focus of this study is to examine the effect of water vapor annealed silk fibroin on the indentation modulus and hardness of graphene oxide-silk fibroin(GO-SF)bionanofilms through nanoindentation experiments and finite element analysis(FEA).The GO-SF bionanofilms were fabricated using the layer-by-layer technique.The water vapor annealing process was employed to enhance the interfacial properties between the GO and SF layers,and the mechanical properties of the GO-SF bionanofilms were found to be affected by this process.By employing water vapor annealing,the indentation modulus and hardness of the GO-SF bionanofilms can be improved.Furthermore,the FEA models of the GO-SF bionanofilms were developed to simulate the details of the mechanical behaviors of the GO-SF bionanofilms.The difference in the stress and strain distribution inside the GO-SF bionanofilms before and after annealing was analyzed.In addition,the load-displacement curves that were obtained by the developed FEA model conformed well with the results from the nanoindentation tests.In summary,this study presents the mechanism of improving the indentation modulus and hardness of the GO-SF bionanofilms through the water vapor annealing process,which is established with the FEA simulation models.展开更多
Chitosan(CS), a kind of naturally produced polysaccharide with extraordinary biocompatibility and biodegradation, shows much potential to act as reducing and stabilizing agent in the synthesis of gold nanoparticles(Au...Chitosan(CS), a kind of naturally produced polysaccharide with extraordinary biocompatibility and biodegradation, shows much potential to act as reducing and stabilizing agent in the synthesis of gold nanoparticles(AuNPs) for drug delivery. To solve the poor solubility and expand the pharmaceutical applications of CS, various CS derivatives through rational design have been developed and further used to prepare, stabilize, and mediate self-assembling of gold materials. Herein, we chose sulfonic chitosan as a stabilizing reagent for the synthesis of highly stable AuNPs(AuNP/SCSs) with diameters of about 3 nm. For investigating their surface electronic payload of charged drugs, the negatively charged fluorescence isothiocyanate(FITC) and positively charged Rhodamine B(Rb) were used as models to be modified on the surface of the AuNP/SCSs via a layer-by-layer(Lb L) method. With a basis of the fluorescence resonance energy transfer(FRET) principle, via adjusting the distance between AuNPs and fluorescent molecules by tuning the layers of charged polymers, the regulation of the fluorescence intensity of the fluorescent molecules has been achieved. In addition, the drug loading efficiency was investigated.展开更多
Active sites of two-dimensional(2D)electrocatalysts are often partially blocked owing to their inevitable stacking and hydrophobic polymeric binders in macroscale electrodes,therefore impeding their applications in ef...Active sites of two-dimensional(2D)electrocatalysts are often partially blocked owing to their inevitable stacking and hydrophobic polymeric binders in macroscale electrodes,therefore impeding their applications in efficient electrolyzers.Here,using layered double hydroxide(LDH)nanosheets as a model 2D electrocatalyst,we demonstrate that their performance toward water splitting can be boosted when they are electrostatically assembled into an organized structure pillared by hydrophilic polyelectrolytes or nanoparticles in a layer-by-layer(LbL)fashion.In particular,their mass activity on a planar electrode can be as large as 2.267 mA·μg^(-1) toward oxygen evolution reaction(OER),when NiFe-LDH nanosheets are electrostatically connected by poly(sodium 4-styrenesulfonate)(PSS),while drop-casted NiFe-LDH nanosheets only have a mass activity of 0.116 mA·μg^(-1).In addition,these homogeneous NiFe-LDH nanofilms can be easily deposited on three-dimensional(3D)surfaces with high areas,such as carbon cloths,to serve as practical electrodes with overpotentials of 328 mV at a current density of 100 mA·cm^(-2),and stability for 40 h.Furthermore,Pt nanoparticles can be LbL assembled with NiFe-LDH as bifunctional electrodes for synergistically boosted oxygen and hydrogen evolution reactions(HER),leading to successful overall water splitting powered by a 1.5 V battery.This study heralds the spatial control of 2D nanomaterials in nanoscale precision as an efficient strategy for the design of advanced electrocatalysts.展开更多
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This work was supported by the National Key Research and Development Program of China(No.2017YFA0206600)the Science and Technology Innovation Program of Hunan Province(No.2020RC4004)the Special Funding for the Construction of Innovative Provinces in Hunan Province(No.2020GK2024).
文摘Layer-by-layer (LbL) strategy has been developed to form bulk heterojunction (BHJ) structure for processing efficient organic solar cells (OSCs). Herein, LbL slot-die coating with twin boiling point solvents (TBPS) strategy was developed to fabricate highly efficient OSCs, which matches with large-scale, high throughput roll-to-roll (R2R) industrialized mass process. The TBPS strategy could produce high-quality thin film without any additive, leading to the optimized vertical phase separation with interpenetrating nanostructures, as well as the enhanced charge transport and extraction. Thus, the power conversion efficiency up to 14.42% was achieved for [(2,6-(4,8-bis(5-(2-ethylhexyl-3-fluoro)thiophen-2-yl)-benzo [1,2-b:4,5-b′]dithiophene))-alt-(5,5-(1′,3′-di-2-thienyl-5′,7′-bis(2-ethylhexyl)benzo[1′,2′-c:4′,5′-c′]dithiophene-4,8-dione)]:2,2′-((2Z,2′Z)-((12,13-bis(2-ethylhexyl)-3,9-diundecyl-12,13-dihydro-[1,2,5]thiadiazolo[3,4-e]thieno[2″,3″:4″,5″]thieno[2′,3′:4,5]pyrrolo[3,2-g]thieno[2′,3′:4,5]thieno[3,2-b]indole-2,10-diyl)bis(methanylylidene)) bis(5,6-difluoro-3-oxo-2,3-dihydro-1H-indene-2,1-diylidene))dimalononitrile (PM6:Y6) OSCs fabricated via sequentially LbL slot-die coating using the TBPS strategy under ambient condition. The research provides a potential route for industrialized production of high-efficiency and large-area OSC devices.
基金the National Natural Science Foundation of China(Grant No.20675064)Natural Science Foundation of Chongqing City(Grant Nos.CSTC-2004BB4149 and 2005BB4100)the High Technology Project Foundation ofSouthwest University(XSGX02),China
文摘Electrochemical sensing of carcinoembryonic antigen(CEA)on a gold electrode modified by the se- quential incorporation of the mediator,thionine(Thi),and gold nanoparticles(nano-Au),through co- valent linkage and electrostatic interactions onto a self-assembled monolayer configuration is de- scribed in this paper.The enzyme,horseradish peroxidase(HRP),was employed to block the possible remaining active sites of the nano-Au monolayer,avoid the non-specific adsorption,instead of bovine serum albumin(BSA),and amplify the response of the antigen-antibody reaction.Electrochemical ex- periments indicated highly efficient electron transfer by the imbedded Thi mediator and adsorbed nano-Au.The HRP kept its activity after immobilization,and the studied electrode showed sensitive response to CEA and high stability during a long period of storage.The working range for the system was 2.5 to 80.0 ng/mL with a detection limit of 0.90 ng/mL.The model membrane system in this work is a potential biosensor for mimicking the other immunosensor and enzyme sensor.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 20204017 and 50373049) and theChinese Academy of Sciences (CMS-CX200308).
文摘Silver halide (AgX) microcrystal was used as template to synthesize hollow polyelectrolyte capsules. These hollow capsules were characterized by laser light scattering (LLS) used to measure the size of the capsules in solution. The ratio of hydrodynamic radius (R h ) from dynamic LLS to the radius of gyration (Rg) from static LLS is almost unity, revealing that the entities are hollow in solution. The results suggest that the LLS method can be regarded as a good complement to the confocal laser scanning microscopy (CLSM) method for the characterization of small hollow capsules, and it possesses the advantage of not needing fluorescence labeling.
基金support by the Textile Light Applied Basic Research Project(Grant No.J202107)the Doctor Project of Innovation and Entrepreneurship in Jiangsu Province(Grant No.JSSCBS20210821)+1 种基金the National Natural Science Foundation of China(Grant No.22205082)the Natural Science Foundation of Jiangsu Province(Grant No.BK20221098).
文摘To achieve fire-resistant epoxy resin(EP),a UiO-66-based novel flame retardant coating(CS@APP@UiO-66)was prepared by modifying UiO-66 with chitosan(CS)and ammonium polyphosphate(APP)through a layer-by-layer(LbL)self-assembly method,which was then introduced into an EP system to improve its fire safety.The results of scanning electron microscopy,X-ray diffraction and Fourier transform infrared spectroscopy show that the unsaturated Zr atoms in the UiO-66 framework provide many active sites conducive to modification,so that the UiO-66 particles,which originally had a regular octahedral structure,are more dispersed by LbL modification without causing doping or distortion issues.The thermogravimetric analysis results indicate that the char residue of EP/2%UiO-66 is increased by 2.52%compared with that of pure EP,indicating that the thermal properties of the EP composite are improved after modification.In addition,the cone test results indicate that EP/2%UiO-66-5L has good flame retardancy and smoke suppression properties,and the peak heat release rate,total smoke production and rate of CO generation values are 25.2%,5.7%and 38.5%lower than those of the unmodified EP.Moreover,it can be concluded from the Raman test that the graphitization degree of the modified EP composite is strengthened.The above results indicated that after the incorporation of CS@APP@UiO-66 into the EP composites,more char layers formed as physical barriers to prevent the transfer of mass and heat,thus reducing the speed of flame propagation.Therefore,the flame resistance and smoke suppression of the EP composites improved.These favorable characteristics,including high flame retardant efficiency and good smoke suppression,make LbL-functionalized UiO-66 promising for flame retardant polymer applications.
基金This work was supported by the National Research Foundation of Korea(NRF)grant that was funded by the Korea Government(MSIT)(No.NRF-2018R1C1B6002339).
文摘Understanding the mechanical properties of bionanofilms is important in terms of identifying their durability.The primary focus of this study is to examine the effect of water vapor annealed silk fibroin on the indentation modulus and hardness of graphene oxide-silk fibroin(GO-SF)bionanofilms through nanoindentation experiments and finite element analysis(FEA).The GO-SF bionanofilms were fabricated using the layer-by-layer technique.The water vapor annealing process was employed to enhance the interfacial properties between the GO and SF layers,and the mechanical properties of the GO-SF bionanofilms were found to be affected by this process.By employing water vapor annealing,the indentation modulus and hardness of the GO-SF bionanofilms can be improved.Furthermore,the FEA models of the GO-SF bionanofilms were developed to simulate the details of the mechanical behaviors of the GO-SF bionanofilms.The difference in the stress and strain distribution inside the GO-SF bionanofilms before and after annealing was analyzed.In addition,the load-displacement curves that were obtained by the developed FEA model conformed well with the results from the nanoindentation tests.In summary,this study presents the mechanism of improving the indentation modulus and hardness of the GO-SF bionanofilms through the water vapor annealing process,which is established with the FEA simulation models.
基金supported by the National Natural Science Foundation of China (30900337, 31470916, 81673390)Jiangsu Provincial Natural Science Foundation (BK20150689)+2 种基金the Fundamental Research Funds for the Central Universities (2015PT036)the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Open Project Program of MOE Key Laboratory of Drug Quality Control and Pharmacovigilance (DQCP2015MS01)
文摘Chitosan(CS), a kind of naturally produced polysaccharide with extraordinary biocompatibility and biodegradation, shows much potential to act as reducing and stabilizing agent in the synthesis of gold nanoparticles(AuNPs) for drug delivery. To solve the poor solubility and expand the pharmaceutical applications of CS, various CS derivatives through rational design have been developed and further used to prepare, stabilize, and mediate self-assembling of gold materials. Herein, we chose sulfonic chitosan as a stabilizing reagent for the synthesis of highly stable AuNPs(AuNP/SCSs) with diameters of about 3 nm. For investigating their surface electronic payload of charged drugs, the negatively charged fluorescence isothiocyanate(FITC) and positively charged Rhodamine B(Rb) were used as models to be modified on the surface of the AuNP/SCSs via a layer-by-layer(Lb L) method. With a basis of the fluorescence resonance energy transfer(FRET) principle, via adjusting the distance between AuNPs and fluorescent molecules by tuning the layers of charged polymers, the regulation of the fluorescence intensity of the fluorescent molecules has been achieved. In addition, the drug loading efficiency was investigated.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.52273076,52111540268,and 12004195)the 111 Project(No.B18030)in China+1 种基金The authors also acknowledge the financial support by Haihe Laboratory of Sustainable Chemical Transformations(No.YYJC202101)Open Research Fund Program of the State Key Laboratory of Low Dimensional Quantum Physics(No.KF202113).
文摘Active sites of two-dimensional(2D)electrocatalysts are often partially blocked owing to their inevitable stacking and hydrophobic polymeric binders in macroscale electrodes,therefore impeding their applications in efficient electrolyzers.Here,using layered double hydroxide(LDH)nanosheets as a model 2D electrocatalyst,we demonstrate that their performance toward water splitting can be boosted when they are electrostatically assembled into an organized structure pillared by hydrophilic polyelectrolytes or nanoparticles in a layer-by-layer(LbL)fashion.In particular,their mass activity on a planar electrode can be as large as 2.267 mA·μg^(-1) toward oxygen evolution reaction(OER),when NiFe-LDH nanosheets are electrostatically connected by poly(sodium 4-styrenesulfonate)(PSS),while drop-casted NiFe-LDH nanosheets only have a mass activity of 0.116 mA·μg^(-1).In addition,these homogeneous NiFe-LDH nanofilms can be easily deposited on three-dimensional(3D)surfaces with high areas,such as carbon cloths,to serve as practical electrodes with overpotentials of 328 mV at a current density of 100 mA·cm^(-2),and stability for 40 h.Furthermore,Pt nanoparticles can be LbL assembled with NiFe-LDH as bifunctional electrodes for synergistically boosted oxygen and hydrogen evolution reactions(HER),leading to successful overall water splitting powered by a 1.5 V battery.This study heralds the spatial control of 2D nanomaterials in nanoscale precision as an efficient strategy for the design of advanced electrocatalysts.
