We investigated the feasibility of obtaining large photoresponse in metal-semiconductor-metal(MSM) type single nanowire device where one contact can be blocking type. We showed that suitable modification of the blocki...We investigated the feasibility of obtaining large photoresponse in metal-semiconductor-metal(MSM) type single nanowire device where one contact can be blocking type. We showed that suitable modification of the blocking contact by deposition of a capping metal using focused electron beam(FEB) can lead to considerable enhancement of the photoresponse. The work was done in a single Cu:TCNQ nanowire device fabricated by direct growth of nanowires(NW) from pre-patterned Cu electrode which makes the contact ohmic with the other contact made from Au. Analysis of the data shows that the large photoresponse of the devices arises predominantly due to reduction of the barriers at the Au/NW blocking contact on illumination. This is caused by the diffusion of the photo generated carriers from the nanowires to the contact region. When the barrier height is further reduced by treating the contact with FEB deposited Pt, this results in a large enhancement in the device photoresponse.展开更多
Endowing stimuli-responsive materials with micro-nano structures is an intriguing strategy for the fabrication of superwetting surfaces;however,its application is limited by poor chemical/mechanical stability.Herein,a...Endowing stimuli-responsive materials with micro-nano structures is an intriguing strategy for the fabrication of superwetting surfaces;however,its application is limited by poor chemical/mechanical stability.Herein,a simple and versatile strategy was developed to fabricate durable polymeric superwetting surfaces with photoswitchable wettability on hierarchically structured metallic substrates.Inspired by nature,a novel functional terpolymer incorporating mussel-inspired catechol groups,photoresponsive azobenzene groups,and low-surface-energy fluorine-containing groups was synthesized via solution radical polymerization.The azobenzene-containing terpolymer possesses outstanding photoresponsiveness in both the solution and film states because of the trans-cis isomerization of the azobenzene moieties.After dip-coating with the mussel-inspired azo-copolymer,the as-prepared smart surfaces exhibited a photo-triggered change in wettability between high hydrophobicity and superhydrophilicity.More importantly,these superwetting surfaces with enhanced adhesion properties can tolerate harsh environmental conditions and repeated abrasion tests,thereby demonstrating excellent chemical robustness and mechanical durability.This study paves a new avenue for the convenient and large-scale fabrication of robust smart surfaces that could find widespread potential applications in microfluidic devices,water treatment,and functional coatings.展开更多
Face masks play a pivotal role in preventing infection transmission.However,the capture of infection-sourced particles in face masks poses challenges related to reuse,necessitating proper disposal.We developed a self-...Face masks play a pivotal role in preventing infection transmission.However,the capture of infection-sourced particles in face masks poses challenges related to reuse,necessitating proper disposal.We developed a self-sterilizable polypropylene-based membrane for face masks to address challenges associated with infection transmission prevention.The membrane,created using 3D printing,underwent functionalization with zinc oxide(ZnO)and polydopamine(PDA)-TEMPO to achieve broad-spectrum light absorption and facilitate self-sterilization through photocatalytic and photothermal effects upon light exposure.The hydrophobic surface(water contact angle:133±2°)minimized moisture accumulation,and the membrane exhibited robust mechanical properties,including shear strength(1.25±0.5kPa)and peel resistance strength(112.8±11.2kPa).The evaluation demonstrated stability in airflow(0-500cm^(3)/s)and excellent aerosol filtration efficiency(94.8±0.6%)for particles(PM 0.3,PM 2.5,PM 10),comparable to commercial masks.The membrane showed antibacterial efficacy over five uses in a simulated respiratory environment.Safety assessments confirmed biocompatibility through cytocompatibility and skin irritation assays.In conclusion,this membrane offers efficient filtration and photo-triggered sterilization,presenting a promising solution for next-generation face masks to address concerns related to reuse,disposal,and infection control.展开更多
Combining the stability of chemical crosslinking and the processability of physical crosslinking is a well-established strategy to design new materials with desirable stimuli–responsive properties. Herein, a series o...Combining the stability of chemical crosslinking and the processability of physical crosslinking is a well-established strategy to design new materials with desirable stimuli–responsive properties. Herein, a series of azobenzenebased thermotropic liquid crystalline polyesters were synthesized by introducing mesogenic dial named 4,4＇-bis（6-hydroxyhexyloxy）azobenzene（BHHAB）, 2-phenylsuccinic acid（PSA）, and different contents of 1,2,3-propanetricarboxylic acid（PTA） as the chemical crosslinker. All these polyesters showed good thermal stability and smectic liquid crystalline phase. Wide-angel X-ray diffraction（WAXD） and the fluorescence emission spectra confirmed the existence of π–πstacking interactions as the physical crosslinking in the polymer chains, particularly at the lower content of PTA. However, when the PTA content increased, the chemical crosslinking changed the chain conformation, and thus the intensity of physical crosslinking slackened gradually. Combining the physical and chemical crosslinking, these polyesters showed the thermoplastic processability, thermal shape memory, heat-assisted healing and photoresponsive behaviors. Taking advantages of these features, these multiple stimuli–responsive polymers can bring more chances for smart materials such as soft actuator.展开更多
A quadrature phase-shift keying(QPSK)coherent photodetector chip consisting of a 4×4 multimode interference 90°optical hybrid and a four-channel evanescent photodetector array is designed and fabricated with...A quadrature phase-shift keying(QPSK)coherent photodetector chip consisting of a 4×4 multimode interference 90°optical hybrid and a four-channel evanescent photodetector array is designed and fabricated with its photo-response in the L-band characterized.The metal organic chemical vapor deposition regrowth method is adopted to realize active–passive monolithic integration.The chip exhibits a low dark current below 100 nA for each photodetector in the array,a low excess loss of 0.85 dB,a common mode ratio rejection better than 13.6 dB,and a phase deviation within±10°over the 40 nm wavelength span.展开更多
Developing hydroscopic actuators with simultaneous high elasticity,shape programmability and tunable actuating behaviors are highly desired but still challenging.In this study,we propose an orthogonal composite design...Developing hydroscopic actuators with simultaneous high elasticity,shape programmability and tunable actuating behaviors are highly desired but still challenging.In this study,we propose an orthogonal composite design to develop such a material.The developed composite elastomer comprises carboxyl group-grafted polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene(SEBS-g-COOH)as the elastic substrate,and a synthesized azobenzene derivative as the functional filler(Azo12).By surface treatment using acidic and base solutions,the carboxyl groups on the surface can reversibly transform into carboxylate groups,which render the composite tunable hygroscopic actuating functionality.On another aspect,the added filler undergoes trans-to-cis isomerization when exposed to UV light irradiation,leading to liquefaction of the crystalline aggregates formed by Azo12 molecules.The liquefied Azo12 molecules can autonomously resotre their trans form and reform the crystalline structure.This reversible change in crystralline structure is utilized to realize the shape memory property,and 5 wt%of Azo12addition is adequate for the composite to exhibit photo-responsive shape memory behavior without compromising much of the elasricity.The regualtion of external geometry by shape memory effect is effective in altering the actuating behavior.The proposed method can be extend to designing different composites with the demonstrated functionalities.展开更多
Photo-responsive mechanical actuator is a class of stimuli-responsive materials transferring light to mechanical energy through macroscopic transformation.To fabricate photo-responsive mechanical actuator,soft polymer...Photo-responsive mechanical actuator is a class of stimuli-responsive materials transferring light to mechanical energy through macroscopic transformation.To fabricate photo-responsive mechanical actuator,soft polymeric materials crosslinked with functional bridging structures are desired.Supramolecular interaction is a relatively common way to fabricate crosslinked materials due to its excellent self-assembly performance.And azobenzene and derivatives are ideal candidates of photo-responsive materials because of the unique photo-induced trans-cis isomerization.Here,a new kind of crosslinked materials based on supramolecular interaction between 4,4'-dihydroxyazobenzene and chitosan is reported.Under 355 nm irradiation,the macroscopic bending of polymeric materials occurs rapidly due to the photo-isomerization of 4,4-dihydroxyazobenzene.Meanwhile,the photo-responsive mechanical actuator can also lift weight which is up to 200 times that of the actuator itself,and convert energy from light to mechanical work efficiently.This report suggests a new kind of photo-responsive actuator based on supramolecular interaction and may be helpful to contribute a theoretical basis to the design and synthesis of photo-responsive mechanical actuator suitable for large-scale manufacturing industrialization in future.展开更多
Solid-stated smart polymers responsive to external stimuli have attracted much attention for potential application in the field of photoelectron devices,logic gates,sensor,data storage and security.However,it is a big...Solid-stated smart polymers responsive to external stimuli have attracted much attention for potential application in the field of photoelectron devices,logic gates,sensor,data storage and security.However,it is a bigger challenge for polymers than that for small molecules in solid state to acquire stimuli-responsive properties,because polymers with high molecular weight are not as easy to change the packing structure as small molecules under external stimulation.Here,a D-A type alternating copolymer PTMF-o containing 3,4-bisthienylmaleimide(A unit)and fluorene(D unit)is designed and synthesized.Upon irradiation of sunlight,PTMF-o film exhibits a photo-response with the color altering from purple to colorless.It is attributed to the structure of copolymer transformed from ring-opening form(PTMF-o)to ring-closure form(PTMF-c),resulting from the oxidative photocyclization of 3,4-bisthienylmaleimide unit.Consequently,the ability of charge transfer(CT)from fluorene to 3,4-bisthienylmaleimide unit in PTMF-o can be easily weakened by light stimuli.PTMF-o film displays a WORM-type resistive storage performance for the strong CT.Interestingly,after exposure,the electrical memory behavior in situ transfers into FLASH type,due to weak CT in PTMF-c.PTMF-o film can also be employed as smart material to construct NAND and NOR logic gates by using light as input condition.The work provides a simple way to modify the electronic properties of polymers and realize stimuli-response in solid states.展开更多
Functional materials synthesized from bio-based building blocks are fascinating and challenging in the fields of chemistry and materials science.Herein,we present a versatile strategy for synthesizing bio-based stimul...Functional materials synthesized from bio-based building blocks are fascinating and challenging in the fields of chemistry and materials science.Herein,we present a versatile strategy for synthesizing bio-based stimulus-responsive polymers derived from itaconic acid(IA).Bearing an azobenzene-containing side chain,the IA-based epoxy polymer exhibited both photoresponsiveness and acid/base-stimulus responsiveness.With controllable manipulation of the stress field of the wrinkling IA-polymer film via the stress relaxation effect resulting from the reversible cis-trans isomerization of the azobenzene moieties or solvent-induced swelling of the film,various tailor-made patterned wrinkling surfaces were conveniently fabricated.More importantly,the azobenzene protonation/deprotonation yields a reversible visual color transformation between pale yellow and purple in the film,which allows these IA-based polymer-coated surfaces to be utilized as rewritable information storage media.Various elegant pattern information can be acid-printed and base-erased(within 10 s)for multiple cycles and legible for over one day under laboratory conditions.Notably,the aforementioned dual-stimulus responsiveness of the IA-based polymer film enables its surface to be applied in information encryption.This study not only paves a new avenue for the convenient fabrication of stimulus-responsive surfaces but also sheds light on the development of functional polymers through green engineering.展开更多
The focus of drug delivery is shifting toward smart drug carriers that release the cargo in response to a change in the microenvironment due to an internal or external trigger. As the most clinically successful nanosy...The focus of drug delivery is shifting toward smart drug carriers that release the cargo in response to a change in the microenvironment due to an internal or external trigger. As the most clinically successful nanosystem, liposomes naturally come under the spotlight of this trend. This review summarizes the latest development about the design and construction of photo-responsive liposomes with gold nanoparticles for the controlled drug release. Alongside, we overview the mechanism involved in this process and the representative applications.展开更多
Photo-responsive polymer materials from zero-dimensional micelles, two-dimensional surfaces to three-dimensional hydrogels have been designed, synthesized and applied for various biological fields including drug deliv...Photo-responsive polymer materials from zero-dimensional micelles, two-dimensional surfaces to three-dimensional hydrogels have been designed, synthesized and applied for various biological fields including drug delivery and cell manipulation. Many remarkable works have been reported, revealing the advantages of photo-responsive polymers such as noninvasion and spatiotemporal control. In this review, we briefly summarized the remarkable progress of photo-responsive polymers with irreversible or reversible moieties and their further biological applications. The future opportunities and challenges of photo-responsive polymer materials are also proposed.展开更多
Stimuli-responsive macrocycles are of importance for synthetic chemistry and smart materials. In this manuscript, we report two novel organoborane cyclophanes, which were successfully synthesized by ruthenium-catalyze...Stimuli-responsive macrocycles are of importance for synthetic chemistry and smart materials. In this manuscript, we report two novel organoborane cyclophanes, which were successfully synthesized by ruthenium-catalyzed olefin metathesis. They are composed of one/two boron-doped helicene π-skeletons and flexible alkyl chain linkers, thus representing a new kind of non-conjugated organoborane macrocycles. Their cyclic structures and photophysical properties, as well as Lewis acidity were theoretically and experimentally investigated. Notably, two enantiomers in one single crystal are observed for one organoborane cyclophane, owning to the presence of helical π-framework in its cyclic structure. Moreover, their Lewis acid-base adducts may dissociate in the excited state and thus display intriguing photo-responsive fluorescence properties, which can be further modulated by temperature. This study thus provides a novel design strategy for non-conjugated organoborane macrocycles, which may promote the development of stimuli-responsive macrocyclic materials with fascinating properties.展开更多
Dimension-controllable supramolecular organic frameworks(SOFs)with aggregation-enhanced fluorescence are hierarchically fabricated through the host-vip interactions of cucurbit[8]uril(CB[8])and coumarin-modified tet...Dimension-controllable supramolecular organic frameworks(SOFs)with aggregation-enhanced fluorescence are hierarchically fabricated through the host-vip interactions of cucurbit[8]uril(CB[8])and coumarin-modified tetraphenylethylene derivatives(TPEC).The three-dimensional layered SOFs could be constructed from the further stacking of two-dimensional mono-layered structures via simply regulating the self-assembly conditions including the culturing time and concentration.Upon light irradiation under the wavelength of 365 nm,the photodimerization of coumarin moieties occurred,which resulted in the transformation of the resultant TPECn/CB[8]4n two-dimensional SOFs into robust covalently-connected 2D polymers with molecular thickness.Interestingly,the supramolecular system of TPEC/CB[8]exhibited intriguing multicolor fluorescence emission from yellow to blue in the time range of 0-24 h at 365 nm irradiation,possessing potential applicability for photochromic fluorescence ink.展开更多
Direct alcohol fuel cells(DAFCs)have received wide attention as a new type of clean energy device because of their high energy conversion efficiency,portability,non-toxicity and pollution-free.Anode catalysts are the ...Direct alcohol fuel cells(DAFCs)have received wide attention as a new type of clean energy device because of their high energy conversion efficiency,portability,non-toxicity and pollution-free.Anode catalysts are the key factors affecting the performance of DAFCs.Recently studies show that using the optical activity of semiconductor materials as the carriers of traditional precious metal electrocatalysts,under the illumination of light sources,can greatly improve the electrocatalytic activity and stability of electrodes.In this review,the research progress of photo-responsive metal/semiconductor hybrids as the electrocatalysts for DAFCs in recent years is summarized,including:(1)Mechanism and advantages of photo-assistant electrochemical alcohol oxidation reaction,(2)me tal/semiconductor electrocatalyst for the different type of fuel cell reactions,(3)different kind of metals in photo-responsive metal/semiconductor hybrid nanostructure,(4)the personal prospects of the photo-responsive metal/semiconductor electrode for future application in DAFCs.展开更多
The exploration of novel photo/thermal-responsive nonvolatile memorizers will be beneficial for energysaving memories.Herein,new<110>-oriented perovskites using single template melamine,i.e.,[(MLAI-H_(2))(PbX_(4...The exploration of novel photo/thermal-responsive nonvolatile memorizers will be beneficial for energysaving memories.Herein,new<110>-oriented perovskites using single template melamine,i.e.,[(MLAI-H_(2))(PbX_(4))]_n(X=Br (α-1),Cl (α-2),MLAI=melamine) have been prepared and their structures upon irradiation of visible light have been investigated.They have been fabricated as nonvolatile memory devices with structures of ITO/[(MLAI-H_(2))(PbX_(4))]_n/PMMA/Ag (device-1:X=Br,device-2:X=Cl),which can exhibit unique visible light-triggered binary nonvolatile memory performances.Interestingly,the silent or working status can be monitored by visible chromisms.Furthermore,the light-triggered binary resistive switching mechanisms of these ITO/[(MLAI-H_(2))(PbX_(4))]_n/PMMA/Ag memory devices have been clarified in terms of EPR,fluorescence,and single-crystal structural analysis.The presence of light-activated traps in<110>-oriented[(MLAI-H_(2))(PbX_(4))]_n perovskites are dominated in the appearance of light-triggered resistive switching behaviors,based on which the inverted internal electrical fields can be established.According to the structural analysis,the more distorted PbX_6octahedra,higher corrugated<110>-oriented perovskite sheets,and more condensed organic-inorganic packing in Br-containing perovskite are beneficial for the stabilization of light-activated traps,which lead to the better resistive switching behavior of device-1.This work can pave a new avenue for the establishment of novel energy-saving nonvolatile memorizers used in aerospace or military industries.展开更多
Photo-responsive slippery lubricant-infused porous surface(SLIPS) for droplet manipulation is flexible, noncontact and non-destructive in droplet manipulation, which has promising applications in flexible robotics, mi...Photo-responsive slippery lubricant-infused porous surface(SLIPS) for droplet manipulation is flexible, noncontact and non-destructive in droplet manipulation, which has promising applications in flexible robotics, microfluidics,biomedicine, and chemical analysis. However, the repeated manipulations for droplets of SLIPSs are quite limited in the works reported so far, the poor durability of droplet manipulation severely limits the practical application of the surfaces. In this paper, an Fe3O4-doped polydimethylsiloxane(PDMS)-based SLIPS is proposed and implemented to achieve ultra-high repeated droplet manipulation numbers under near-infrared ray(NIR) laser irradiation. Firstly, a micron columnar array structure with micro-pits on the top side, as well as, a wall structure out of the array is designed on SLIPS to reserve the lubricant. Secondly, the prototype of the SLIPS is fabricated by a 3-step ultraviolet(UV) lithography, and subsequently immersed in silicone oil for more than 96 h to obtain the ultra-high durability slippery lubricant-infused porous surface(UD-SLIPS). With a power of 25 m W–85 m W NIR laser, the repeated manipulation of microdroplets(≤ 5 μL) in the scale of 1 cm can exceed more than 3000 times which is far beyond that in previous reports. Finally, the droplet manipulation performance of this photo-responsive UD-SLIPS and the influence of infusion time on durability are investigated. The mechanism of the PDMS swelling effect is found to be the key factor in improving the droplet manipulation durability of SLIPS. The findings of this work would be of great significance for the development of highly durable photo-responsive functional surfaces for droplet manipulation.展开更多
The smart emulsification and demulsification system with the light response is a useful tool in various industries,including green chemistry,catalytic reaction,pharmaceuticals,and environmental remediation.Herein,an i...The smart emulsification and demulsification system with the light response is a useful tool in various industries,including green chemistry,catalytic reaction,pharmaceuticals,and environmental remediation.Herein,an ionic liquid crystal compound with a light triggered switch based on the azobenzene group[(4-{3-methyl-1-[3-(8-octyloxyoctyl)oxy-4-oxobutanoyl]imidazo-lium-1-yl}octyl)oxy]-N-(4-methylphenyl)benzene-1,2-diazene bromide(MOIAzo),was designed and synthesized,which could cause reversible transition between emulsification and demulsification through the light trigger.The ionic liquid has an efficient photoinduced liquefaction process,which dramatically lowers the melting point of ionic liquids from 79 to 9.2 oC.This significantly broadens the liquid state temperature of the ionic liquid crystal.The ionic liquid crystal MOIAzo exhibits both photoinduced and thermally induced nematic liquid crystal properties.The smart emulsion system was effectively employed in an eco-friendly water-saving dyeing process of cationic dyes for cationic dyeable polyester(CDP)fabrics,which used only half the amount of water compared with the conventional water bath dyeing method.After dyeing,the oil and water phases can be efficiently separated through the light irradiation,and the oil phase can be reused for the subsequent dyeing process.This novel smart emulsion dyeing method greatly reduces the water consumption and wastewater discharge.MOIAzo as a lighttriggered ionic liquid molecule opens up new dimensions in green chemistry.展开更多
A three-transistor active pixel sensor and its double sampling readout circuit implemented by a switch capacitor amplifier are designed. The circuit is embedded in a 64 × 64 pixel array CMOS image sensor and succ...A three-transistor active pixel sensor and its double sampling readout circuit implemented by a switch capacitor amplifier are designed. The circuit is embedded in a 64 × 64 pixel array CMOS image sensor and success-fully taped out with a Chartered 0.35μm process. The pixel pitch is 8μm × 8μm with a fill factor of 57%, the photo-sensitivity is 0.8V/（lux · s） ,and the dynamic range is 50dB. Theoretical analysis and test results indicate that as the process is scaled down, a smaller pixel pitch reduces the sensitivity. A deep junction n-well/p-substrate photodiode with a reasonable fill factor and high sensitivity are more appropriate for submicron processes.展开更多
[Objective] This study compared the leaf photosynthetic characteristics of Turpan grape cultivated in greenhouses and open field to provide a scientific basis for the high-quality and high-yield cultivation of grape. ...[Objective] This study compared the leaf photosynthetic characteristics of Turpan grape cultivated in greenhouses and open field to provide a scientific basis for the high-quality and high-yield cultivation of grape. [Method] Two precocious grape varieties as experimental materials were cultivated in greenhouses and open field, and their net photosynthetic rates （Pn）, photo-response curves and CO2 response curves were determined using Li-400XT portable photosynthesis system. [Result] The leaf Pn of the two varieties cultivated in open field was higher than that in greenhouse. The Pn of Hongqitezao cultivated in open field was the highest, up to 19.79 μmol/（m^2·s）; in the photo-response curves, Hongqitezao cultivated in greenhouse had the largest Pnmax and apparent quantum yield （AQY）, while the Flame Seedless in greenhouse had the smallest light compensation point （LCP）. The light saturation point （LSP） value of greenhouse cultivation was higher than that of open field cultivation. In the CO2 response test, the dark respiration rate （Rd） and Pnmax of greenhouse cultivation were higher than those of open field cultivation, and the carboxylation efficiency （CE） of greenhouse cultivation was lower than that of open field cultivation; the CO2 compensation point （CCP） and CO2 saturation point （CSP） of greenhouse cultivation were lower than those of open field cultivation. [Conclusion] The utilization of elevated light in greenhouse cultivation was more efficient than in open field cultivation; however, the utilization of elevated CO2 in greenhouse cultivation was weaker than tin open field cultivation.展开更多
Magnetotactic bacteria(MTB)synthesize intracellular magnetic organelles,magnetosomes,which consist of magnetic crystals that are enveloped in a membrane.Magnetosomes are organized into a chain(s)and confer on cells a ...Magnetotactic bacteria(MTB)synthesize intracellular magnetic organelles,magnetosomes,which consist of magnetic crystals that are enveloped in a membrane.Magnetosomes are organized into a chain(s)and confer on cells a magnetic dipolar moment.This magnetic property allows MTB cells to align and swim along geomagnetic field lines,a movement referred to as magnetotaxis.Some MTB species change their swim direction in response to illumination by UV,violet and blue light.Here we analyzed the polarity of morphology,magnetism,and motion in Mediterranean multicellular magnetotactic prokaryotes,also called,magnetoglobules or MMP.The magnetoglobules were assembled from 60-80 cells into an asymmetric ellipsoidal morphology with a relative narrow and large end.They swam dominantly northward,parallel to the direction of the magnetic field,with the narrow-end as the leading side.In response to a reversal in the direction of the magnetic field,they aligned quickly along the magnetic field lines and kept swimming northward.Interestingly,under constant illumination,385-nm UV light,magnetoglobules changed their swimming direction southward anti-parallel to the direction of the magnetic field,with the large-end as the leading side.The change from a northward to southward direction occurred along with an increase of swimming speed.A minimum of 35-mW/cm^(2) irradiance of UV light was sufficient to trigger the swimming re-orientation.UV radiation also triggered the unidirectional division of magnetoglobules.Together these results revealed a coordination of the polarity of magnetoglobule morphology,magnetic moment,and swimming orientation,in response to magnetic and optical stimuli.The UV triggered the reversal of magnetotaxis and magnetoglobule division indicating the ecological significance of light for multicellular magnetotactic prokaryotes.展开更多
基金Nanomission,Department of Science and Technology,Govt. of India for financial support as sponsored project:Theme Unit of Excellence in Nanodevice Technology
文摘We investigated the feasibility of obtaining large photoresponse in metal-semiconductor-metal(MSM) type single nanowire device where one contact can be blocking type. We showed that suitable modification of the blocking contact by deposition of a capping metal using focused electron beam(FEB) can lead to considerable enhancement of the photoresponse. The work was done in a single Cu:TCNQ nanowire device fabricated by direct growth of nanowires(NW) from pre-patterned Cu electrode which makes the contact ohmic with the other contact made from Au. Analysis of the data shows that the large photoresponse of the devices arises predominantly due to reduction of the barriers at the Au/NW blocking contact on illumination. This is caused by the diffusion of the photo generated carriers from the nanowires to the contact region. When the barrier height is further reduced by treating the contact with FEB deposited Pt, this results in a large enhancement in the device photoresponse.
基金supported by the Natural Science Foundation of Shandong Province(No.ZR2022MB034)the Development Program Project of the Young Innovation Team of Institutions of Higher Learning in Shandong Province。
文摘Endowing stimuli-responsive materials with micro-nano structures is an intriguing strategy for the fabrication of superwetting surfaces;however,its application is limited by poor chemical/mechanical stability.Herein,a simple and versatile strategy was developed to fabricate durable polymeric superwetting surfaces with photoswitchable wettability on hierarchically structured metallic substrates.Inspired by nature,a novel functional terpolymer incorporating mussel-inspired catechol groups,photoresponsive azobenzene groups,and low-surface-energy fluorine-containing groups was synthesized via solution radical polymerization.The azobenzene-containing terpolymer possesses outstanding photoresponsiveness in both the solution and film states because of the trans-cis isomerization of the azobenzene moieties.After dip-coating with the mussel-inspired azo-copolymer,the as-prepared smart surfaces exhibited a photo-triggered change in wettability between high hydrophobicity and superhydrophilicity.More importantly,these superwetting surfaces with enhanced adhesion properties can tolerate harsh environmental conditions and repeated abrasion tests,thereby demonstrating excellent chemical robustness and mechanical durability.This study paves a new avenue for the convenient and large-scale fabrication of robust smart surfaces that could find widespread potential applications in microfluidic devices,water treatment,and functional coatings.
基金supported by Key Scientific Research Projects of Colleges and Universities in Henan Province(No.23ZX016)University Innovation Research and Training Program(No.202110467004)the Distinguished Professor Program of Institutions of Higher Learning in Henan Province,National Key R&D Program of China(No.2019YFE0101200).
文摘Face masks play a pivotal role in preventing infection transmission.However,the capture of infection-sourced particles in face masks poses challenges related to reuse,necessitating proper disposal.We developed a self-sterilizable polypropylene-based membrane for face masks to address challenges associated with infection transmission prevention.The membrane,created using 3D printing,underwent functionalization with zinc oxide(ZnO)and polydopamine(PDA)-TEMPO to achieve broad-spectrum light absorption and facilitate self-sterilization through photocatalytic and photothermal effects upon light exposure.The hydrophobic surface(water contact angle:133±2°)minimized moisture accumulation,and the membrane exhibited robust mechanical properties,including shear strength(1.25±0.5kPa)and peel resistance strength(112.8±11.2kPa).The evaluation demonstrated stability in airflow(0-500cm^(3)/s)and excellent aerosol filtration efficiency(94.8±0.6%)for particles(PM 0.3,PM 2.5,PM 10),comparable to commercial masks.The membrane showed antibacterial efficacy over five uses in a simulated respiratory environment.Safety assessments confirmed biocompatibility through cytocompatibility and skin irritation assays.In conclusion,this membrane offers efficient filtration and photo-triggered sterilization,presenting a promising solution for next-generation face masks to address concerns related to reuse,disposal,and infection control.
基金supported by the National Natural Science Foundation of China (51721091)the Sichuan Province Youth Science and Technology Innovation Team (2017TD0006)
文摘Combining the stability of chemical crosslinking and the processability of physical crosslinking is a well-established strategy to design new materials with desirable stimuli–responsive properties. Herein, a series of azobenzenebased thermotropic liquid crystalline polyesters were synthesized by introducing mesogenic dial named 4,4＇-bis（6-hydroxyhexyloxy）azobenzene（BHHAB）, 2-phenylsuccinic acid（PSA）, and different contents of 1,2,3-propanetricarboxylic acid（PTA） as the chemical crosslinker. All these polyesters showed good thermal stability and smectic liquid crystalline phase. Wide-angel X-ray diffraction（WAXD） and the fluorescence emission spectra confirmed the existence of π–πstacking interactions as the physical crosslinking in the polymer chains, particularly at the lower content of PTA. However, when the PTA content increased, the chemical crosslinking changed the chain conformation, and thus the intensity of physical crosslinking slackened gradually. Combining the physical and chemical crosslinking, these polyesters showed the thermoplastic processability, thermal shape memory, heat-assisted healing and photoresponsive behaviors. Taking advantages of these features, these multiple stimuli–responsive polymers can bring more chances for smart materials such as soft actuator.
基金supported by the National Key Research and Development Program of China(No.2020YFB1805701)the National Natural Foundation of China(Nos.61934003,61635010,and 61674136)the Beijing Natural Science Foundation(No.4194093).
文摘A quadrature phase-shift keying(QPSK)coherent photodetector chip consisting of a 4×4 multimode interference 90°optical hybrid and a four-channel evanescent photodetector array is designed and fabricated with its photo-response in the L-band characterized.The metal organic chemical vapor deposition regrowth method is adopted to realize active–passive monolithic integration.The chip exhibits a low dark current below 100 nA for each photodetector in the array,a low excess loss of 0.85 dB,a common mode ratio rejection better than 13.6 dB,and a phase deviation within±10°over the 40 nm wavelength span.
基金financially supported by the National Natural Science Foundation of China(Nos.51803115 and 21636006)the Fundamental Research Funds for the Central Universities(Nos.GK201901001,2021CSLY008,2021CSZL003 and GK202103032)the Innovation Capability Support Program of Shaanxi(No.2020TD-024)。
文摘Developing hydroscopic actuators with simultaneous high elasticity,shape programmability and tunable actuating behaviors are highly desired but still challenging.In this study,we propose an orthogonal composite design to develop such a material.The developed composite elastomer comprises carboxyl group-grafted polystyrene-block-poly(ethylene-co-butylene)-block-polystyrene(SEBS-g-COOH)as the elastic substrate,and a synthesized azobenzene derivative as the functional filler(Azo12).By surface treatment using acidic and base solutions,the carboxyl groups on the surface can reversibly transform into carboxylate groups,which render the composite tunable hygroscopic actuating functionality.On another aspect,the added filler undergoes trans-to-cis isomerization when exposed to UV light irradiation,leading to liquefaction of the crystalline aggregates formed by Azo12 molecules.The liquefied Azo12 molecules can autonomously resotre their trans form and reform the crystalline structure.This reversible change in crystralline structure is utilized to realize the shape memory property,and 5 wt%of Azo12addition is adequate for the composite to exhibit photo-responsive shape memory behavior without compromising much of the elasricity.The regualtion of external geometry by shape memory effect is effective in altering the actuating behavior.The proposed method can be extend to designing different composites with the demonstrated functionalities.
基金supported by the National Natural Science Foundation of China(Nos.51703112,51673106)Natural Science Foundation of Shandong Province(Nos.ZR2017BEM040,ZR2016BQ28)+1 种基金Open Fund of the State Key Laboratory of Luminescent Materials and Devices(No.2017-skllmd-10,South China University of Technology)China Postdoctoral Science Foundation(No.2017M622152).
文摘Photo-responsive mechanical actuator is a class of stimuli-responsive materials transferring light to mechanical energy through macroscopic transformation.To fabricate photo-responsive mechanical actuator,soft polymeric materials crosslinked with functional bridging structures are desired.Supramolecular interaction is a relatively common way to fabricate crosslinked materials due to its excellent self-assembly performance.And azobenzene and derivatives are ideal candidates of photo-responsive materials because of the unique photo-induced trans-cis isomerization.Here,a new kind of crosslinked materials based on supramolecular interaction between 4,4'-dihydroxyazobenzene and chitosan is reported.Under 355 nm irradiation,the macroscopic bending of polymeric materials occurs rapidly due to the photo-isomerization of 4,4-dihydroxyazobenzene.Meanwhile,the photo-responsive mechanical actuator can also lift weight which is up to 200 times that of the actuator itself,and convert energy from light to mechanical work efficiently.This report suggests a new kind of photo-responsive actuator based on supramolecular interaction and may be helpful to contribute a theoretical basis to the design and synthesis of photo-responsive mechanical actuator suitable for large-scale manufacturing industrialization in future.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.22075044 and 21574021)the Natural Science Foundation of Fujian Provinee(No.2018J01670)+1 种基金Educational Commission of Fujian Province(No.JAT170129)the Scientific Research Starting Foundation for researchers with PhD of Fujian Normal University.
文摘Solid-stated smart polymers responsive to external stimuli have attracted much attention for potential application in the field of photoelectron devices,logic gates,sensor,data storage and security.However,it is a bigger challenge for polymers than that for small molecules in solid state to acquire stimuli-responsive properties,because polymers with high molecular weight are not as easy to change the packing structure as small molecules under external stimulation.Here,a D-A type alternating copolymer PTMF-o containing 3,4-bisthienylmaleimide(A unit)and fluorene(D unit)is designed and synthesized.Upon irradiation of sunlight,PTMF-o film exhibits a photo-response with the color altering from purple to colorless.It is attributed to the structure of copolymer transformed from ring-opening form(PTMF-o)to ring-closure form(PTMF-c),resulting from the oxidative photocyclization of 3,4-bisthienylmaleimide unit.Consequently,the ability of charge transfer(CT)from fluorene to 3,4-bisthienylmaleimide unit in PTMF-o can be easily weakened by light stimuli.PTMF-o film displays a WORM-type resistive storage performance for the strong CT.Interestingly,after exposure,the electrical memory behavior in situ transfers into FLASH type,due to weak CT in PTMF-c.PTMF-o film can also be employed as smart material to construct NAND and NOR logic gates by using light as input condition.The work provides a simple way to modify the electronic properties of polymers and realize stimuli-response in solid states.
基金supported by the Natural Science Foundation of Shandong Province(No.ZR2022MB034)。
文摘Functional materials synthesized from bio-based building blocks are fascinating and challenging in the fields of chemistry and materials science.Herein,we present a versatile strategy for synthesizing bio-based stimulus-responsive polymers derived from itaconic acid(IA).Bearing an azobenzene-containing side chain,the IA-based epoxy polymer exhibited both photoresponsiveness and acid/base-stimulus responsiveness.With controllable manipulation of the stress field of the wrinkling IA-polymer film via the stress relaxation effect resulting from the reversible cis-trans isomerization of the azobenzene moieties or solvent-induced swelling of the film,various tailor-made patterned wrinkling surfaces were conveniently fabricated.More importantly,the azobenzene protonation/deprotonation yields a reversible visual color transformation between pale yellow and purple in the film,which allows these IA-based polymer-coated surfaces to be utilized as rewritable information storage media.Various elegant pattern information can be acid-printed and base-erased(within 10 s)for multiple cycles and legible for over one day under laboratory conditions.Notably,the aforementioned dual-stimulus responsiveness of the IA-based polymer film enables its surface to be applied in information encryption.This study not only paves a new avenue for the convenient fabrication of stimulus-responsive surfaces but also sheds light on the development of functional polymers through green engineering.
文摘The focus of drug delivery is shifting toward smart drug carriers that release the cargo in response to a change in the microenvironment due to an internal or external trigger. As the most clinically successful nanosystem, liposomes naturally come under the spotlight of this trend. This review summarizes the latest development about the design and construction of photo-responsive liposomes with gold nanoparticles for the controlled drug release. Alongside, we overview the mechanism involved in this process and the representative applications.
基金supported by the National Natural Science Foundation of China (Nos. 21425314, 21501184, 20141061)Beijing Municipal Science & Technology Commission (No. Z161100000116037)+1 种基金the Top-Notch Young Talents Program of ChinaYouth Innovation Promotion Association, CAS (No. 2017036)
文摘Photo-responsive polymer materials from zero-dimensional micelles, two-dimensional surfaces to three-dimensional hydrogels have been designed, synthesized and applied for various biological fields including drug delivery and cell manipulation. Many remarkable works have been reported, revealing the advantages of photo-responsive polymers such as noninvasion and spatiotemporal control. In this review, we briefly summarized the remarkable progress of photo-responsive polymers with irreversible or reversible moieties and their further biological applications. The future opportunities and challenges of photo-responsive polymer materials are also proposed.
基金supported by the National Natural Science Foundation of China (Nos. 22175074, 21822507)。
文摘Stimuli-responsive macrocycles are of importance for synthetic chemistry and smart materials. In this manuscript, we report two novel organoborane cyclophanes, which were successfully synthesized by ruthenium-catalyzed olefin metathesis. They are composed of one/two boron-doped helicene π-skeletons and flexible alkyl chain linkers, thus representing a new kind of non-conjugated organoborane macrocycles. Their cyclic structures and photophysical properties, as well as Lewis acidity were theoretically and experimentally investigated. Notably, two enantiomers in one single crystal are observed for one organoborane cyclophane, owning to the presence of helical π-framework in its cyclic structure. Moreover, their Lewis acid-base adducts may dissociate in the excited state and thus display intriguing photo-responsive fluorescence properties, which can be further modulated by temperature. This study thus provides a novel design strategy for non-conjugated organoborane macrocycles, which may promote the development of stimuli-responsive macrocyclic materials with fascinating properties.
基金supported by Anhui Province Natural Science Funds(2008085QE209)K2020-03 from the State Key Laboratory of Molecular Engineering of Polymers(Fudan University)。
文摘Dimension-controllable supramolecular organic frameworks(SOFs)with aggregation-enhanced fluorescence are hierarchically fabricated through the host-vip interactions of cucurbit[8]uril(CB[8])and coumarin-modified tetraphenylethylene derivatives(TPEC).The three-dimensional layered SOFs could be constructed from the further stacking of two-dimensional mono-layered structures via simply regulating the self-assembly conditions including the culturing time and concentration.Upon light irradiation under the wavelength of 365 nm,the photodimerization of coumarin moieties occurred,which resulted in the transformation of the resultant TPECn/CB[8]4n two-dimensional SOFs into robust covalently-connected 2D polymers with molecular thickness.Interestingly,the supramolecular system of TPEC/CB[8]exhibited intriguing multicolor fluorescence emission from yellow to blue in the time range of 0-24 h at 365 nm irradiation,possessing potential applicability for photochromic fluorescence ink.
基金the National Natural Science Foundation of China(Nos.21603111,51702173)Guangdong Basic and Applied Basic Research Foundation(No.2020B1515020038)the Pearl River Talent Recruitment Program of Guangdong Province(No.2019QN01L148)。
文摘Direct alcohol fuel cells(DAFCs)have received wide attention as a new type of clean energy device because of their high energy conversion efficiency,portability,non-toxicity and pollution-free.Anode catalysts are the key factors affecting the performance of DAFCs.Recently studies show that using the optical activity of semiconductor materials as the carriers of traditional precious metal electrocatalysts,under the illumination of light sources,can greatly improve the electrocatalytic activity and stability of electrodes.In this review,the research progress of photo-responsive metal/semiconductor hybrids as the electrocatalysts for DAFCs in recent years is summarized,including:(1)Mechanism and advantages of photo-assistant electrochemical alcohol oxidation reaction,(2)me tal/semiconductor electrocatalyst for the different type of fuel cell reactions,(3)different kind of metals in photo-responsive metal/semiconductor hybrid nanostructure,(4)the personal prospects of the photo-responsive metal/semiconductor electrode for future application in DAFCs.
基金financially supported by the Natural Science Foundation of Fujian Province(Nos.2021J02007,2021J01553)Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China(No.2021ZR148)。
文摘The exploration of novel photo/thermal-responsive nonvolatile memorizers will be beneficial for energysaving memories.Herein,new<110>-oriented perovskites using single template melamine,i.e.,[(MLAI-H_(2))(PbX_(4))]_n(X=Br (α-1),Cl (α-2),MLAI=melamine) have been prepared and their structures upon irradiation of visible light have been investigated.They have been fabricated as nonvolatile memory devices with structures of ITO/[(MLAI-H_(2))(PbX_(4))]_n/PMMA/Ag (device-1:X=Br,device-2:X=Cl),which can exhibit unique visible light-triggered binary nonvolatile memory performances.Interestingly,the silent or working status can be monitored by visible chromisms.Furthermore,the light-triggered binary resistive switching mechanisms of these ITO/[(MLAI-H_(2))(PbX_(4))]_n/PMMA/Ag memory devices have been clarified in terms of EPR,fluorescence,and single-crystal structural analysis.The presence of light-activated traps in<110>-oriented[(MLAI-H_(2))(PbX_(4))]_n perovskites are dominated in the appearance of light-triggered resistive switching behaviors,based on which the inverted internal electrical fields can be established.According to the structural analysis,the more distorted PbX_6octahedra,higher corrugated<110>-oriented perovskite sheets,and more condensed organic-inorganic packing in Br-containing perovskite are beneficial for the stabilization of light-activated traps,which lead to the better resistive switching behavior of device-1.This work can pave a new avenue for the establishment of novel energy-saving nonvolatile memorizers used in aerospace or military industries.
基金Project supported by the National Major Scientific Research Instrument Development Project of China (Grant No. 51927804)the National Natural Science Foundation of China (Grant No. 62275216)the Science and Technology Innovation Team Project of Shaanxi Province (Grant Nos. S2018-ZC-TD-0061 and 2023-CX-TD-06)。
文摘Photo-responsive slippery lubricant-infused porous surface(SLIPS) for droplet manipulation is flexible, noncontact and non-destructive in droplet manipulation, which has promising applications in flexible robotics, microfluidics,biomedicine, and chemical analysis. However, the repeated manipulations for droplets of SLIPSs are quite limited in the works reported so far, the poor durability of droplet manipulation severely limits the practical application of the surfaces. In this paper, an Fe3O4-doped polydimethylsiloxane(PDMS)-based SLIPS is proposed and implemented to achieve ultra-high repeated droplet manipulation numbers under near-infrared ray(NIR) laser irradiation. Firstly, a micron columnar array structure with micro-pits on the top side, as well as, a wall structure out of the array is designed on SLIPS to reserve the lubricant. Secondly, the prototype of the SLIPS is fabricated by a 3-step ultraviolet(UV) lithography, and subsequently immersed in silicone oil for more than 96 h to obtain the ultra-high durability slippery lubricant-infused porous surface(UD-SLIPS). With a power of 25 m W–85 m W NIR laser, the repeated manipulation of microdroplets(≤ 5 μL) in the scale of 1 cm can exceed more than 3000 times which is far beyond that in previous reports. Finally, the droplet manipulation performance of this photo-responsive UD-SLIPS and the influence of infusion time on durability are investigated. The mechanism of the PDMS swelling effect is found to be the key factor in improving the droplet manipulation durability of SLIPS. The findings of this work would be of great significance for the development of highly durable photo-responsive functional surfaces for droplet manipulation.
基金supported by National Natural Science Foundation of China(Grant No.22278069,21978046)Textile Vision Basic Research Program(J202005).
文摘The smart emulsification and demulsification system with the light response is a useful tool in various industries,including green chemistry,catalytic reaction,pharmaceuticals,and environmental remediation.Herein,an ionic liquid crystal compound with a light triggered switch based on the azobenzene group[(4-{3-methyl-1-[3-(8-octyloxyoctyl)oxy-4-oxobutanoyl]imidazo-lium-1-yl}octyl)oxy]-N-(4-methylphenyl)benzene-1,2-diazene bromide(MOIAzo),was designed and synthesized,which could cause reversible transition between emulsification and demulsification through the light trigger.The ionic liquid has an efficient photoinduced liquefaction process,which dramatically lowers the melting point of ionic liquids from 79 to 9.2 oC.This significantly broadens the liquid state temperature of the ionic liquid crystal.The ionic liquid crystal MOIAzo exhibits both photoinduced and thermally induced nematic liquid crystal properties.The smart emulsion system was effectively employed in an eco-friendly water-saving dyeing process of cationic dyes for cationic dyeable polyester(CDP)fabrics,which used only half the amount of water compared with the conventional water bath dyeing method.After dyeing,the oil and water phases can be efficiently separated through the light irradiation,and the oil phase can be reused for the subsequent dyeing process.This novel smart emulsion dyeing method greatly reduces the water consumption and wastewater discharge.MOIAzo as a lighttriggered ionic liquid molecule opens up new dimensions in green chemistry.
文摘A three-transistor active pixel sensor and its double sampling readout circuit implemented by a switch capacitor amplifier are designed. The circuit is embedded in a 64 × 64 pixel array CMOS image sensor and success-fully taped out with a Chartered 0.35μm process. The pixel pitch is 8μm × 8μm with a fill factor of 57%, the photo-sensitivity is 0.8V/（lux · s） ,and the dynamic range is 50dB. Theoretical analysis and test results indicate that as the process is scaled down, a smaller pixel pitch reduces the sensitivity. A deep junction n-well/p-substrate photodiode with a reasonable fill factor and high sensitivity are more appropriate for submicron processes.
基金Supported by Key Technology Integration and Demonstration of Xinjiang Characteristic Fruit Trees’ High Efficiency and Safe Production,Science and Technical Plan Project of Xinjiang Uygur Autonomous Region(201130102-1)Earmarked Fund for China Agriculture Research System(CARS-30)Financial Aid from Key Fruit Trees Subject of Xinjiang Uygur Autonomous Region~~
文摘[Objective] This study compared the leaf photosynthetic characteristics of Turpan grape cultivated in greenhouses and open field to provide a scientific basis for the high-quality and high-yield cultivation of grape. [Method] Two precocious grape varieties as experimental materials were cultivated in greenhouses and open field, and their net photosynthetic rates （Pn）, photo-response curves and CO2 response curves were determined using Li-400XT portable photosynthesis system. [Result] The leaf Pn of the two varieties cultivated in open field was higher than that in greenhouse. The Pn of Hongqitezao cultivated in open field was the highest, up to 19.79 μmol/（m^2·s）; in the photo-response curves, Hongqitezao cultivated in greenhouse had the largest Pnmax and apparent quantum yield （AQY）, while the Flame Seedless in greenhouse had the smallest light compensation point （LCP）. The light saturation point （LSP） value of greenhouse cultivation was higher than that of open field cultivation. In the CO2 response test, the dark respiration rate （Rd） and Pnmax of greenhouse cultivation were higher than those of open field cultivation, and the carboxylation efficiency （CE） of greenhouse cultivation was lower than that of open field cultivation; the CO2 compensation point （CCP） and CO2 saturation point （CSP） of greenhouse cultivation were lower than those of open field cultivation. [Conclusion] The utilization of elevated light in greenhouse cultivation was more efficient than in open field cultivation; however, the utilization of elevated CO2 in greenhouse cultivation was weaker than tin open field cultivation.
基金Supported by the Excellence Initiative of Aix-Marseille University-A^(*)Midex,a French“Investissements d’Avenir”programme,the National Key Research and Development Program of China(No.2018YFC0309904)the National Natural Science Foundation of China(No.41920104009)grants from French CNRS for LIA-MagMC。
文摘Magnetotactic bacteria(MTB)synthesize intracellular magnetic organelles,magnetosomes,which consist of magnetic crystals that are enveloped in a membrane.Magnetosomes are organized into a chain(s)and confer on cells a magnetic dipolar moment.This magnetic property allows MTB cells to align and swim along geomagnetic field lines,a movement referred to as magnetotaxis.Some MTB species change their swim direction in response to illumination by UV,violet and blue light.Here we analyzed the polarity of morphology,magnetism,and motion in Mediterranean multicellular magnetotactic prokaryotes,also called,magnetoglobules or MMP.The magnetoglobules were assembled from 60-80 cells into an asymmetric ellipsoidal morphology with a relative narrow and large end.They swam dominantly northward,parallel to the direction of the magnetic field,with the narrow-end as the leading side.In response to a reversal in the direction of the magnetic field,they aligned quickly along the magnetic field lines and kept swimming northward.Interestingly,under constant illumination,385-nm UV light,magnetoglobules changed their swimming direction southward anti-parallel to the direction of the magnetic field,with the large-end as the leading side.The change from a northward to southward direction occurred along with an increase of swimming speed.A minimum of 35-mW/cm^(2) irradiance of UV light was sufficient to trigger the swimming re-orientation.UV radiation also triggered the unidirectional division of magnetoglobules.Together these results revealed a coordination of the polarity of magnetoglobule morphology,magnetic moment,and swimming orientation,in response to magnetic and optical stimuli.The UV triggered the reversal of magnetotaxis and magnetoglobule division indicating the ecological significance of light for multicellular magnetotactic prokaryotes.
