4,4-Difluoro-4-bora-3a,4a-diaza-sindacene (BODIPY) is a sort of photofunctional dye which possesses advantages including strong light-capturing property, high photon-resistance, etc. Meso-N substituted aza-BODIPY is a...4,4-Difluoro-4-bora-3a,4a-diaza-sindacene (BODIPY) is a sort of photofunctional dye which possesses advantages including strong light-capturing property, high photon-resistance, etc. Meso-N substituted aza-BODIPY is a crucial derivative of BODIPY scaffold that has the favorable optical properties and a significant spectral redshift. The photophysical properties can be tuned by molecular design, and the attenuation path of the excited state energy release of absorbed light energy can be well controlled via structural modifications, enabling tailored application. It has been extensively employed in life medicine fields including fluorescence imaging diagnosis, photodynamic therapy photosensitizer and photothermal therapy reagent and so forth. Extensive research and review have been performed in these areas. However, BODIPYs/aza-BODIPYs have a significant role in energy, catalysis, optoelectronics, photo-responsive materials and other fields. Nevertheless, there are relatively few studies and reviews in these fields on the modification and application based on BODIPY/aza-BODIPY scaffold. Herein, in this review we summarized the application of BODIPY/aza-BODIPY in the aforementioned fields, with the molecular regulation of dye as the foundation and the utilization in the above fields as the objective, in the intention of providing inspiration for the exploration of innovative BODIPY/aza-BODIPY research in the field of light resource conversion and functional materials.展开更多
The design and synthesis of organic high-temperature reversible thermochromic materials is one of the difficult issues in the field of organic chromic materials.In this paper,four diacetylene monomers named DBA-PCDA,T...The design and synthesis of organic high-temperature reversible thermochromic materials is one of the difficult issues in the field of organic chromic materials.In this paper,four diacetylene monomers named DBA-PCDA,TBA-PCDA,DBE-PCDA and TBE-PCDA,each containing multiple diacetylene units,were synthesized from 10,12-pentacosadiynoic acid(PCDA)through the amidation or esterification reactions,using 4,4'-diaminobiphenyl,1,3,5-tris(4-aminophenyl)benzene,4,4'-dihydroxybiphenyl,and 1,3,5-tris(4-hydroxyphenyl)benzene as bridging units.The effects of functional groups that can form hydrogen bond andπ-πinteractions on the solid-state polymerization properties of monomers and the thermochromic properties of the corresponding PDAs were investigated.The results show that only DBA-PCDA and TBAPCDA,which contain functional groups that can form hydrogen bonding interactions,can be polymerized under 254-nm UV irradiation.The corresponding poly(DBA-PCDA)exhibits reversible thermochromic property even heated up to 200℃,showing a potential application in the field of high-temperature thermal indicator above 100℃.This work provides a new perspective to the development of PDA with high-temperature reversible thermochromic property.展开更多
The thermochromic mechanism and the structure-property regulation principle of reversible thermochromic polydiacetylene(PDA)materials have always been a challenging issue.In this work,a series of diacetylene monomers(...The thermochromic mechanism and the structure-property regulation principle of reversible thermochromic polydiacetylene(PDA)materials have always been a challenging issue.In this work,a series of diacetylene monomers(m-PCDA)containing phenyl and amide or carboxyl groups were synthesized from 10,12-pentacosadiynoic acid(PCDA)through the esterification or amidation reactions.The effects of the number and the distribution of the functional groups in m-PCDA molecules on their solid-state polymerization capability,and the thermochromic mechanism of their corresponding polymers(m-PDA)were investigated and discussed in detail.The results show that the m-PCDA monomers containing both benzene ring and groups that can form hydrogen bonding interactions have strong intermolecular interaction,and are easy to carry out the solid phase polymerization under 254-nm UV irradiation to obtain the corresponding new thermochromic m-PDA materials.The thermochromic behavior of m-PDA depends on its melting process.The initial color-change temperature(blue to red)is determined by the onset melting tem perature,and the temperature range in which reversible color recovery can be achieved by repeat heating-cooling treatment is determined by its melting range.According to the proposed thermochromic mechanism of PDA,various new PDA materials with precise thermochromic temperatu res and reversible thermochromic temperature ra nges can be designed and synthesized through the appropriate introduction of benzene ring and groups that can form hydrogen bonding interactions into the molecular structure of linear diacetylene monomer.This work provides a perspective to the precise molecular structure design and the property regulation of the reversible thermochromic PDA materials.展开更多
Thermochromic material is a kind of smart material whose color will vary as the result of the phase transition caused by the temperature change. The characteristics of thermochromic materials are the memory functions ...Thermochromic material is a kind of smart material whose color will vary as the result of the phase transition caused by the temperature change. The characteristics of thermochromic materials are the memory functions to the temperature, having great potential applications in aerospace, military, anticounterfeiting technology, construction and other fields. In recent years, many kinds of thermochromic materials have been prepared by different methods and their discoloration mechanisms are various according to published literatures. In this paper, the classification, discoloration mechanism, preparation methods, application fields and development trend of thermochromic materials are reviewed.展开更多
Silks have various advantages compared with synthetic polymer fibers,such as sustainability,mechanical properties,luster,as well as air and humidity permeability.However,the functionalization of silks has not yet been...Silks have various advantages compared with synthetic polymer fibers,such as sustainability,mechanical properties,luster,as well as air and humidity permeability.However,the functionalization of silks has not yet been fully developed.Functionalization techniques that retain or even improve the sustainability of silk production are required.To this end,a low-cost,effective,and scalable strategy to produce TCSs by integrating yarn-spinning and continuous dip coating technique is developed herein.TCSs with extremely long length(>10 km),high mechanical performance(strength of 443.1 MPa,toughness of 56.0 MJ m−3,comparable with natural cocoon silk),and good interfacial bonding were developed.TCSs can be automatically woven into arbitrary fabrics,which feature super-hydrophobicity as well as rapid and programmable thermochromic responses with good cyclic performance:the response speed reached to one second and remained stable after hundreds of tests.Finally,applications of TCS fabrics in temperature management and dynamic textile displays are demonstrated,confirming their application potential in smart textiles,wearable devices,flexible displays,and human–machine interfaces.Moreover,combination of the fabrication and the demonstrated applications is expected to bridge the gap between lab research and industry and accelerate the commercialization of TCSs.展开更多
This paper describes the research on the materials and design methods for advanced smart radiator devices （SRDs） on large-area flexible substrates utilized on spacecraft. The functional material is thermochromic van...This paper describes the research on the materials and design methods for advanced smart radiator devices （SRDs） on large-area flexible substrates utilized on spacecraft. The functional material is thermochromic vanadium dioxide. The coating design of SRD is similar to the design of broadband filter coatings in a mid-infrared region. The multilayer coatings have complex structures. Coating materials must be highly transparent in a required spectrum region and also mechanically robust enough to endure the influence from the rigorous environments of outer space. The number of layers must be very small, suitable for the deposition on large-area flexible substrates. All the coatings are designed initially based on optical calculation and practical experience, and then optimized by the TFCALC software. Several designs are described and compared with each other. The results show that the emittance variability of the designed SRDs is great than 400%, more advanced than the reported ones.展开更多
Cutting-edge heat spreaders for soft and planar electronics require not only high thermal conductivity and a certain degree of flexibility but also remarkable self-adhesion without thermal interface materials, elastic...Cutting-edge heat spreaders for soft and planar electronics require not only high thermal conductivity and a certain degree of flexibility but also remarkable self-adhesion without thermal interface materials, elasticity, arbitrary elongation along with soft devices, and smart properties involving thermal self-healing, thermochromism and so on. Nacre-like composites with excellent in-plane heat dissipation are ideal as heat spreaders for thin and planar electronics. However, the intrinsically poor viscoelasticity, i.e., adhesion and elasticity, prevents them from simultaneous self-adhesion and arbitrary elongation along with current flexible devices as well as incurring high interfacial thermal impedance. In this paper, we propose a soft thermochromic composite(STC) membrane with a layered structure, considerable stretchability, high in-plane thermal conductivity(~30 Wm^(-1) K^(-1)), low thermal contact resistance(~12 mm^2 KW^(-1), 4–5 times lower than that of silver paste), strong yet sustainable adhesion forces(~4607 Jm^(-2), 2220 Jm^(-2) greater than that of epoxy paste) and self-healing efficiency. As a self-adhesive heat spreader, it implements efficient cooling of various soft electronics with a temperature drop of 20℃ than the polyimide case. In addition to its self-healing function, the chameleon-like behavior of STC facilitates temperature monitoring by the naked eye, hence enabling smart thermal management.展开更多
Black nanostructured BiOCI microspheres were directly synthesized by a hydrothermal method. The black ball- like BiOCI microspheres and black flower-like BiOCI microspheres were obtained using different surfactant. Th...Black nanostructured BiOCI microspheres were directly synthesized by a hydrothermal method. The black ball- like BiOCI microspheres and black flower-like BiOCI microspheres were obtained using different surfactant. The color of the BiOCI microspheres turned from black to white when being annealed at 400 ℃ in air for 3 h and could be recovered to black by exposure to ultraviolet light for a few hours. The photocatalytic activity of both the black and the white BiOCI microspheres was characterized by the photo-degradation of methyl orange dye under visible light irradiation. The black ball-like nanostructure BiOCI displayed the best photocatalytic activity, compared with the white BiOCI and the black flower-like BiOCI. It can degrade the methyl orange dye to 20% within 70 min under visible light irradiation. The high activity of the BiOCI ball-like sphere may own to its special morphology, strong absorption in visible light range and the existence of oxygen vacancies.展开更多
To investigate the feasibility of developing biobased and biodegradable thermochromic fibers,poly(lactic acid)(PLA)fibers with visual temperature indicator functionality were fabricated using a scalable melt spinning ...To investigate the feasibility of developing biobased and biodegradable thermochromic fibers,poly(lactic acid)(PLA)fibers with visual temperature indicator functionality were fabricated using a scalable melt spinning technique(spinning speed 800 m/min),where PLA and thermochromic microcapsules were used as fiber-forming polymers and color indicators,respectively.The effect of thermochromic microcapsules on the mechanical properties and reversible color-changing function of PLA fibers was systematically investigated to achieve high tenacity and sensitive color-changing function.The difference in the fiber performance was connected to changes in the multilayer structure.The results show that PLA fibers exhibit excellent tenacity of 3.7-4.7 cN/dtex and reversible and stable thermochromic behavior over 31℃.The high fraction of mesophase within TPLA-1 fiber plays an important role in its tenacity.Meanwhile,the low-concentration of microcapsules(~1 wt%)with good dispersion could act as a nucleating agent inside the PLA matrix and contribute to the formation of microcrystals in the amorphous between primary lamellae,which is also beneficial to maintain the tenacity of the fibers.The agglomeration of high-concentration microcapsules within PLA fibers hampered the formation of mesophase,resulting in a decrease in fiber tenacity.Aside from the content of microcapsules,the agglomeration of high-concentration microcapsules(>5 wt%)is the main reason that limits the substantial increase in fiber color depth.This study opens up new possibilities for degradable thermochromic fibers produced using standard industrial spinning technology.展开更多
p,p'-Diaminodiphenylmethane-Schiff bases (SB) of general formula (R)-phCH=N- ph-CH2-ph-N=CHph(R), where R is p-NO2, m-NO2, p-OH, o-OH, p-Cl, -H, p-OCH3, and sul- phonamide Schiff bases (SB) of general formula (R)-...p,p'-Diaminodiphenylmethane-Schiff bases (SB) of general formula (R)-phCH=N- ph-CH2-ph-N=CHph(R), where R is p-NO2, m-NO2, p-OH, o-OH, p-Cl, -H, p-OCH3, and sul- phonamide Schiff bases (SB) of general formula (R)-phCH=N-ph-SO2NH2, where R is p-NO2, m-NO2, p-OH, o-OH, p-Cl, -H, p-OCH3, were synthesized and their structure have been characterized by the melting pointing, 1HNMR, MS, and elemental analysis. They are thermolabile and undergo thermo-chromism and thermal decomposition after melting. The TG. and DSC measurement were recorded in dynamic air and interpreted.展开更多
Both thermochromic and photochromic coating have attracted many attentions due to their widely applications,but the low stability is a big obstacle.Inspired by the lotus leaf,to endow the chromic coating with superhyd...Both thermochromic and photochromic coating have attracted many attentions due to their widely applications,but the low stability is a big obstacle.Inspired by the lotus leaf,to endow the chromic coating with superhydrophobicity is a possible solution.In this research,a dual response coating was prepared by adding photochromic and thermochromic particles simultaneously.The prepared sample demonstrated at least four-state color switching,which can be successfully used in tactile imaging,multi-color fabric,erasable record,and security labels.The superhydrophobicity was achieved by introducing vinyl-terminated polydimethylsiloxane,which not only offers low surface energy but also can cross-link with the particles to increase the adhesion.Thus,the prepared sample maintained superhydrophobicity after various kinds of destruction(such as sandpaper abrasion,corrosive liquid attack,ultrasonic treatment,UV irradiation,and high-speed drops/turbulent jets impact).Even though the superhydrophobicity can be destroyed by plasma etching,it can be recovered after 12 h at room temperature.展开更多
Boiling of water, for purification, commonly practiced in the world, has many problems associated with it like danger of scalding, scaling in the vessels, removal of useful minerals and blandness of taste etc. Water c...Boiling of water, for purification, commonly practiced in the world, has many problems associated with it like danger of scalding, scaling in the vessels, removal of useful minerals and blandness of taste etc. Water can be made safe for drinking simply by heating at 65℃ for 6 minutes. A colour indicating strip was developed which changes colour from red to purple at 67℃. Use of this strip can help in pasteurizing water without the above problems and with considerable energy saving.展开更多
In this study, gold nanoparticles and thermochromic composite films modified screen-printed carbon electrodes (TM-AuNPsSPCEs) were developed as a platform for the simultaneous detection of protein and temperature. The...In this study, gold nanoparticles and thermochromic composite films modified screen-printed carbon electrodes (TM-AuNPsSPCEs) were developed as a platform for the simultaneous detection of protein and temperature. The TM-AuNPs composited film had better sensitivity resulting from the gold nanoparticles amplification effect. A phase transition model analysis of TM-AuNPs films found that the TM-AuNPs films had three-phase transition intervals (<45℃, 45℃ to 80℃ and >80℃) which accommodated the temperature requirements for protein denaturation. When used to detect different concentrations of haemoglobin (Hb) solution, the TM-AuNPs modified SPCEs had a better sensitivity in detecting the different concentrations in comparison to TM and AuNP modified SPCEs which showed no clear sensitivity towards the different Hb concentrations. The dual detection and excellent sensitivity show a good application prospect for the study of the TM-AuNPs composite film.展开更多
Thermochromic glazing theoretically has the potential to lead to a large reduction in energy demand in modern buildings by allowing the transmission of visible light for day lighting whilst reducing unwanted solar gai...Thermochromic glazing theoretically has the potential to lead to a large reduction in energy demand in modern buildings by allowing the transmission of visible light for day lighting whilst reducing unwanted solar gain during the cooling season, but allowing useful solar gain in the heating season. In this study building simulation is used to examine the effect of the thermochromic transition hysteresis width on the energy demand characteristics of a model system in a variety of climates. The results are also compared against current industry standard glazing products. The results suggest that in a warm climate with a low transition temperature and hysteresis width energy demand can be reduced by up to 54% compared to standard double glazing.展开更多
Thermochromic polymers will play an extremely important role in the next future. The physical background of thermochromism and the state of development of thermochromic polymers based on light absorption effects are r...Thermochromic polymers will play an extremely important role in the next future. The physical background of thermochromism and the state of development of thermochromic polymers based on light absorption effects are reported. In detail, the interactions between the polymer matrix and the thermochromic composite - composed of leuco or indicator dyes - are discussed on a molecular level. Thermochromic hydrogels with extremely high transparency, an outstanding switching behavior from colorless to colored or between different colors is presented. Preparation of thermosetting and thermoplastic polymers, including the resulting optical, and, for the first time, the mechanical properties are discussed in relation to matrix tuned high-resistant microcapsules.展开更多
Multifunctional lead-free double perovskites demonstrate remarkable potential towards applications in various fields.Herein,an environmentally-friendly,low-cost,high-throughput Cs_(2)NaFeCl_(6) single crystal with exc...Multifunctional lead-free double perovskites demonstrate remarkable potential towards applications in various fields.Herein,an environmentally-friendly,low-cost,high-throughput Cs_(2)NaFeCl_(6) single crystal with exceedingly high thermal stability is designed and grown.It obtains a cubic lattice system in the temperature range of 80-500 K,accompanied by a completely reversible chromatic variation ranging from yellow to black.Importantly,the intriguing thermochromism is proved to own extremely high reproducibility(over 1000 cycles)without a hysteretic effect,originating from its structural flexibility that including(i)the noteworthy distortion/deformation of[NaCl_(6)]5−and[FeCl_(6)]3−octahedra;(ii)order-disorder arrangement transition of[NaCl_(6)]5−and[FeCl6]3−octahedra as the function of temperature.This study paves the way towards a new class of smart windows and camouflage coatings with an unprecedented colour range based on a Cs_(2)NaFeCl_(6) perovskite.展开更多
A series of thermochromic polypropylene foils were prepared by embedding various leuco dye-developer-solvent systems in the polymer matrix. Bisphenol A, laurylgallate, ethylgallate and p-hydroxybenzoic acid methyl est...A series of thermochromic polypropylene foils were prepared by embedding various leuco dye-developer-solvent systems in the polymer matrix. Bisphenol A, laurylgallate, ethylgallate and p-hydroxybenzoic acid methyl ester were used as developers, crystal violet lactone and 3,3-bis-（1-n-butyl-2-methyl-3-indolyl）-phthalide as dyes and l-octanoic acid methyl ester as solvent. The molar ratio between the three components of the investigated leuco dye-developer-solvent systems was kept constant. All obtained polypropylene foils exhibit an excellent thermochromic behavior. The foils, prepared by extrusion technology, switch from color to colorless with increasing temperature. The influence of molecular structure of the developer on the intensity of the colored state and the influence of a developer-surfactant complex on the resulting thermochromic properties were investigated. The results are presented and discussed in detail according to a molecular model suggesting that the ring-opening process of the leuco dye is triggered by the formation of dye-developer complexes via H-bondings.展开更多
Polydiacetylene(PDA)is one kind of the conjugated polymer with layered structure,which can serve as a host to accommodate the vip components through intercalation.In these intercalated PDAs,some of them were reporte...Polydiacetylene(PDA)is one kind of the conjugated polymer with layered structure,which can serve as a host to accommodate the vip components through intercalation.In these intercalated PDAs,some of them were reported to have a nearly perfect organized structure and perform completely reversible thermochromism.Till now,these reported intercalated PDAs were made by only introducing a single component for intercalation.Here,we chose 10,12-pentacosadiynoic acid(PCDA)as the monomer,of which the carboxyl-terminal groups can interact with either Tb^3+ ions or melamines(MAs).When the feeding molar ratio of PCDA,MA,and Tb^3+ ion was 3:267:1,only Tb^3+ ions were intercalated though excess MAs existed.Such Tb^3+- intercalated poly-PCDA exhibited completely reversible thermochromism,where almost all the carboxyl groups interacted with Tb^3+ ions to form the nearly perfect structure.When the feeding molar ratio of PCDA,MA,and Tb^3+ ion was 3:267:0.6,both Tb^3+ ions and MAs were intercalated.There existed some defects in the imperfect MA-intercalated domains and at the domain boundaries.The MA/Tb^3+- intercalated poly-PCDA exhibits partially reversible thermochromism,where the backbones near the defects are hard to return the initial conformation,while the rest,those at nearly perfect organized domains,are still able to restore the initial conformation.展开更多
The stoichiometric vanadium（IV） oxide thin films were obtained by controlling the temperature, time and pressure of annealing. The thermochromic phase transition and the IR thermochromic property of 400 nm and 900 n...The stoichiometric vanadium（IV） oxide thin films were obtained by controlling the temperature, time and pressure of annealing. The thermochromic phase transition and the IR thermochromic property of 400 nm and 900 nm VO2 thin films in the 7.5 μm-14 μm region were discussed. The derived VO2 thin film samples were characterized by Raman, XRD, XPS, AFM, SEM, and DSC. The resistance and infrared emissivity of VO2 thin films under different temperature were measured, and the thermal images of films were obtained using infrared imager. The results show that the VO2 thin film annealed at 550 ℃ for 10 hours through aqueous sol-gel process is pure and uniform. The 900 nm VO2 thin film exhibits better IR thermochromic property than the 400 nm VO2 thin film. The resistance of 900 nm VO2 film can change by 4 orders of magnitude and the emissivity can change by 0.6 during the phase transition, suggesting the outstanding IR thermochromic property. The derived VO2 thin film can control its infrared radiation intensity and lower its apparent temperature actively when the real temperature increases, which may be applied in the field of energy saving, thermal control and camouflage.展开更多
Multifunctional switchable materials are attracting tremendous interest because of their great application potential in signal processing,information encryption,and smart devices.Here,we reported an organic-inorganic ...Multifunctional switchable materials are attracting tremendous interest because of their great application potential in signal processing,information encryption,and smart devices.Here,we reported an organic-inorganic hybrid thermochromic ferroelastic crystal,[TMIm][CuCl_(4)](TMIm=1,1,3,3-tetramethylimidazolidinium),which undergoes two reversible phase transitions at 333 K and 419 K,respectively.Intriguingly,these three phases experience a remarkable ferroelastic-paraelastic-ferroelastic(2/m-mmm-2/m)transition,which remains relatively unexplored in ferroelastics.Moreover,the ferroelastic domains can be simultaneously switched under temperature and stress stimuli.Meanwhile,[TMIm][CuCl_(4)]exhibits thermochromic phenomenon,endowing it with extra spectral encryption possibilities during information processing.Combined with dielectric switching behavior,[TMIm][Cu Cl_(4)]are promising for practical applications in memory devices,next-generation sensors,and encryption technology.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22078201,U1908202)Liaoning&Shenyang Key Laboratory of Functional Dye and Pigment(Nos.2021JH13/10200018,21-104-0-23)。
文摘4,4-Difluoro-4-bora-3a,4a-diaza-sindacene (BODIPY) is a sort of photofunctional dye which possesses advantages including strong light-capturing property, high photon-resistance, etc. Meso-N substituted aza-BODIPY is a crucial derivative of BODIPY scaffold that has the favorable optical properties and a significant spectral redshift. The photophysical properties can be tuned by molecular design, and the attenuation path of the excited state energy release of absorbed light energy can be well controlled via structural modifications, enabling tailored application. It has been extensively employed in life medicine fields including fluorescence imaging diagnosis, photodynamic therapy photosensitizer and photothermal therapy reagent and so forth. Extensive research and review have been performed in these areas. However, BODIPYs/aza-BODIPYs have a significant role in energy, catalysis, optoelectronics, photo-responsive materials and other fields. Nevertheless, there are relatively few studies and reviews in these fields on the modification and application based on BODIPY/aza-BODIPY scaffold. Herein, in this review we summarized the application of BODIPY/aza-BODIPY in the aforementioned fields, with the molecular regulation of dye as the foundation and the utilization in the above fields as the objective, in the intention of providing inspiration for the exploration of innovative BODIPY/aza-BODIPY research in the field of light resource conversion and functional materials.
基金supported by the National Natural Science Foundation of China(No.51973205)the Fundamental Research Funds for the Central Universities(Nos.WK9110000066,WK3450000005 and WK3450000006)。
文摘The design and synthesis of organic high-temperature reversible thermochromic materials is one of the difficult issues in the field of organic chromic materials.In this paper,four diacetylene monomers named DBA-PCDA,TBA-PCDA,DBE-PCDA and TBE-PCDA,each containing multiple diacetylene units,were synthesized from 10,12-pentacosadiynoic acid(PCDA)through the amidation or esterification reactions,using 4,4'-diaminobiphenyl,1,3,5-tris(4-aminophenyl)benzene,4,4'-dihydroxybiphenyl,and 1,3,5-tris(4-hydroxyphenyl)benzene as bridging units.The effects of functional groups that can form hydrogen bond andπ-πinteractions on the solid-state polymerization properties of monomers and the thermochromic properties of the corresponding PDAs were investigated.The results show that only DBA-PCDA and TBAPCDA,which contain functional groups that can form hydrogen bonding interactions,can be polymerized under 254-nm UV irradiation.The corresponding poly(DBA-PCDA)exhibits reversible thermochromic property even heated up to 200℃,showing a potential application in the field of high-temperature thermal indicator above 100℃.This work provides a new perspective to the development of PDA with high-temperature reversible thermochromic property.
基金financially supported by the National Natural Science Foundation of China(No.51973205)the Fundamental Research Funds for the Central Universities(Nos.WK9110000066,WK3450000005 and WK3450000006)。
文摘The thermochromic mechanism and the structure-property regulation principle of reversible thermochromic polydiacetylene(PDA)materials have always been a challenging issue.In this work,a series of diacetylene monomers(m-PCDA)containing phenyl and amide or carboxyl groups were synthesized from 10,12-pentacosadiynoic acid(PCDA)through the esterification or amidation reactions.The effects of the number and the distribution of the functional groups in m-PCDA molecules on their solid-state polymerization capability,and the thermochromic mechanism of their corresponding polymers(m-PDA)were investigated and discussed in detail.The results show that the m-PCDA monomers containing both benzene ring and groups that can form hydrogen bonding interactions have strong intermolecular interaction,and are easy to carry out the solid phase polymerization under 254-nm UV irradiation to obtain the corresponding new thermochromic m-PDA materials.The thermochromic behavior of m-PDA depends on its melting process.The initial color-change temperature(blue to red)is determined by the onset melting tem perature,and the temperature range in which reversible color recovery can be achieved by repeat heating-cooling treatment is determined by its melting range.According to the proposed thermochromic mechanism of PDA,various new PDA materials with precise thermochromic temperatu res and reversible thermochromic temperature ra nges can be designed and synthesized through the appropriate introduction of benzene ring and groups that can form hydrogen bonding interactions into the molecular structure of linear diacetylene monomer.This work provides a perspective to the precise molecular structure design and the property regulation of the reversible thermochromic PDA materials.
基金the National Natural Science Foundation of China(Grant Nos.51372200 and 51772243)the Foundation of the State Key Laboratory of Solidification Processing in NWPU(Grant No.SKLSP201753)+2 种基金Scientific Research Plan Projects of Shaanxi Education Department(Grant No.16JK1551)Technology Innovation Programme of Xi’an University of Technology(Grant No.2016CX030)China Postdoctoral Science Foundation(Grant No.2016M592824)
文摘Thermochromic material is a kind of smart material whose color will vary as the result of the phase transition caused by the temperature change. The characteristics of thermochromic materials are the memory functions to the temperature, having great potential applications in aerospace, military, anticounterfeiting technology, construction and other fields. In recent years, many kinds of thermochromic materials have been prepared by different methods and their discoloration mechanisms are various according to published literatures. In this paper, the classification, discoloration mechanism, preparation methods, application fields and development trend of thermochromic materials are reviewed.
基金supported by the National Natural Science Foundation of China(Nos.51973116,U1832109,21935002,52003156)the Users with Excellence Program of Hefei Science Center CAS(2019HSC-UE003)+1 种基金the starting grant of ShanghaiTech UniversityState Key Laboratory for Modification of Chemical Fibers and Polymer Materials。
文摘Silks have various advantages compared with synthetic polymer fibers,such as sustainability,mechanical properties,luster,as well as air and humidity permeability.However,the functionalization of silks has not yet been fully developed.Functionalization techniques that retain or even improve the sustainability of silk production are required.To this end,a low-cost,effective,and scalable strategy to produce TCSs by integrating yarn-spinning and continuous dip coating technique is developed herein.TCSs with extremely long length(>10 km),high mechanical performance(strength of 443.1 MPa,toughness of 56.0 MJ m−3,comparable with natural cocoon silk),and good interfacial bonding were developed.TCSs can be automatically woven into arbitrary fabrics,which feature super-hydrophobicity as well as rapid and programmable thermochromic responses with good cyclic performance:the response speed reached to one second and remained stable after hundreds of tests.Finally,applications of TCS fabrics in temperature management and dynamic textile displays are demonstrated,confirming their application potential in smart textiles,wearable devices,flexible displays,and human–machine interfaces.Moreover,combination of the fabrication and the demonstrated applications is expected to bridge the gap between lab research and industry and accelerate the commercialization of TCSs.
基金Project supported by the National Natural Science Foundation of China （Grant No 60676033）.
文摘This paper describes the research on the materials and design methods for advanced smart radiator devices （SRDs） on large-area flexible substrates utilized on spacecraft. The functional material is thermochromic vanadium dioxide. The coating design of SRD is similar to the design of broadband filter coatings in a mid-infrared region. The multilayer coatings have complex structures. Coating materials must be highly transparent in a required spectrum region and also mechanically robust enough to endure the influence from the rigorous environments of outer space. The number of layers must be very small, suitable for the deposition on large-area flexible substrates. All the coatings are designed initially based on optical calculation and practical experience, and then optimized by the TFCALC software. Several designs are described and compared with each other. The results show that the emittance variability of the designed SRDs is great than 400%, more advanced than the reported ones.
基金the financial support from the National Science Foundation of China (NSFC) (No.52103178)Science and Technology Project of Sichuan Province (No. 2023NSFSC0997)+2 种基金Sixth Two-hundred Talent B plan of Sichuan Universitysupport by the Australian Research Council Discovery Program (DP190103290)Australian Research Council Future Fellowships (FT200100730, FT210100804)。
文摘Cutting-edge heat spreaders for soft and planar electronics require not only high thermal conductivity and a certain degree of flexibility but also remarkable self-adhesion without thermal interface materials, elasticity, arbitrary elongation along with soft devices, and smart properties involving thermal self-healing, thermochromism and so on. Nacre-like composites with excellent in-plane heat dissipation are ideal as heat spreaders for thin and planar electronics. However, the intrinsically poor viscoelasticity, i.e., adhesion and elasticity, prevents them from simultaneous self-adhesion and arbitrary elongation along with current flexible devices as well as incurring high interfacial thermal impedance. In this paper, we propose a soft thermochromic composite(STC) membrane with a layered structure, considerable stretchability, high in-plane thermal conductivity(~30 Wm^(-1) K^(-1)), low thermal contact resistance(~12 mm^2 KW^(-1), 4–5 times lower than that of silver paste), strong yet sustainable adhesion forces(~4607 Jm^(-2), 2220 Jm^(-2) greater than that of epoxy paste) and self-healing efficiency. As a self-adhesive heat spreader, it implements efficient cooling of various soft electronics with a temperature drop of 20℃ than the polyimide case. In addition to its self-healing function, the chameleon-like behavior of STC facilitates temperature monitoring by the naked eye, hence enabling smart thermal management.
基金supported by the National Natural Science Foundation of China (NSFC) (No.51172012)
文摘Black nanostructured BiOCI microspheres were directly synthesized by a hydrothermal method. The black ball- like BiOCI microspheres and black flower-like BiOCI microspheres were obtained using different surfactant. The color of the BiOCI microspheres turned from black to white when being annealed at 400 ℃ in air for 3 h and could be recovered to black by exposure to ultraviolet light for a few hours. The photocatalytic activity of both the black and the white BiOCI microspheres was characterized by the photo-degradation of methyl orange dye under visible light irradiation. The black ball-like nanostructure BiOCI displayed the best photocatalytic activity, compared with the white BiOCI and the black flower-like BiOCI. It can degrade the methyl orange dye to 20% within 70 min under visible light irradiation. The high activity of the BiOCI ball-like sphere may own to its special morphology, strong absorption in visible light range and the existence of oxygen vacancies.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.21D110124/008)the Prospective Applied Basic Research Program of Suzhou City(No.SYG202041)Science and Technology Guidance Project of China Textile Industry Federation(No.2021003)。
文摘To investigate the feasibility of developing biobased and biodegradable thermochromic fibers,poly(lactic acid)(PLA)fibers with visual temperature indicator functionality were fabricated using a scalable melt spinning technique(spinning speed 800 m/min),where PLA and thermochromic microcapsules were used as fiber-forming polymers and color indicators,respectively.The effect of thermochromic microcapsules on the mechanical properties and reversible color-changing function of PLA fibers was systematically investigated to achieve high tenacity and sensitive color-changing function.The difference in the fiber performance was connected to changes in the multilayer structure.The results show that PLA fibers exhibit excellent tenacity of 3.7-4.7 cN/dtex and reversible and stable thermochromic behavior over 31℃.The high fraction of mesophase within TPLA-1 fiber plays an important role in its tenacity.Meanwhile,the low-concentration of microcapsules(~1 wt%)with good dispersion could act as a nucleating agent inside the PLA matrix and contribute to the formation of microcrystals in the amorphous between primary lamellae,which is also beneficial to maintain the tenacity of the fibers.The agglomeration of high-concentration microcapsules within PLA fibers hampered the formation of mesophase,resulting in a decrease in fiber tenacity.Aside from the content of microcapsules,the agglomeration of high-concentration microcapsules(>5 wt%)is the main reason that limits the substantial increase in fiber color depth.This study opens up new possibilities for degradable thermochromic fibers produced using standard industrial spinning technology.
文摘p,p'-Diaminodiphenylmethane-Schiff bases (SB) of general formula (R)-phCH=N- ph-CH2-ph-N=CHph(R), where R is p-NO2, m-NO2, p-OH, o-OH, p-Cl, -H, p-OCH3, and sul- phonamide Schiff bases (SB) of general formula (R)-phCH=N-ph-SO2NH2, where R is p-NO2, m-NO2, p-OH, o-OH, p-Cl, -H, p-OCH3, were synthesized and their structure have been characterized by the melting pointing, 1HNMR, MS, and elemental analysis. They are thermolabile and undergo thermo-chromism and thermal decomposition after melting. The TG. and DSC measurement were recorded in dynamic air and interpreted.
基金supported by the National Nature Science Foundation of China(51977079,51607067)the Central Guid-ance on Local Science and Technology Development Fund of Hebei Province(226Z1204G)+2 种基金the Top Young Innovative Talents of Colleges and universities of Higher Learning Institutions of Hebei(BJ2021095)Youth Elite Scientists Sponsorship Program by the Chinese Society for Electrical Engineering(CSEE-YESS-2017002)the Funda-mental Research Funds for the Central Universities(2020MS115,2017MS149).
文摘Both thermochromic and photochromic coating have attracted many attentions due to their widely applications,but the low stability is a big obstacle.Inspired by the lotus leaf,to endow the chromic coating with superhydrophobicity is a possible solution.In this research,a dual response coating was prepared by adding photochromic and thermochromic particles simultaneously.The prepared sample demonstrated at least four-state color switching,which can be successfully used in tactile imaging,multi-color fabric,erasable record,and security labels.The superhydrophobicity was achieved by introducing vinyl-terminated polydimethylsiloxane,which not only offers low surface energy but also can cross-link with the particles to increase the adhesion.Thus,the prepared sample maintained superhydrophobicity after various kinds of destruction(such as sandpaper abrasion,corrosive liquid attack,ultrasonic treatment,UV irradiation,and high-speed drops/turbulent jets impact).Even though the superhydrophobicity can be destroyed by plasma etching,it can be recovered after 12 h at room temperature.
文摘Boiling of water, for purification, commonly practiced in the world, has many problems associated with it like danger of scalding, scaling in the vessels, removal of useful minerals and blandness of taste etc. Water can be made safe for drinking simply by heating at 65℃ for 6 minutes. A colour indicating strip was developed which changes colour from red to purple at 67℃. Use of this strip can help in pasteurizing water without the above problems and with considerable energy saving.
文摘In this study, gold nanoparticles and thermochromic composite films modified screen-printed carbon electrodes (TM-AuNPsSPCEs) were developed as a platform for the simultaneous detection of protein and temperature. The TM-AuNPs composited film had better sensitivity resulting from the gold nanoparticles amplification effect. A phase transition model analysis of TM-AuNPs films found that the TM-AuNPs films had three-phase transition intervals (<45℃, 45℃ to 80℃ and >80℃) which accommodated the temperature requirements for protein denaturation. When used to detect different concentrations of haemoglobin (Hb) solution, the TM-AuNPs modified SPCEs had a better sensitivity in detecting the different concentrations in comparison to TM and AuNP modified SPCEs which showed no clear sensitivity towards the different Hb concentrations. The dual detection and excellent sensitivity show a good application prospect for the study of the TM-AuNPs composite film.
文摘Thermochromic glazing theoretically has the potential to lead to a large reduction in energy demand in modern buildings by allowing the transmission of visible light for day lighting whilst reducing unwanted solar gain during the cooling season, but allowing useful solar gain in the heating season. In this study building simulation is used to examine the effect of the thermochromic transition hysteresis width on the energy demand characteristics of a model system in a variety of climates. The results are also compared against current industry standard glazing products. The results suggest that in a warm climate with a low transition temperature and hysteresis width energy demand can be reduced by up to 54% compared to standard double glazing.
文摘Thermochromic polymers will play an extremely important role in the next future. The physical background of thermochromism and the state of development of thermochromic polymers based on light absorption effects are reported. In detail, the interactions between the polymer matrix and the thermochromic composite - composed of leuco or indicator dyes - are discussed on a molecular level. Thermochromic hydrogels with extremely high transparency, an outstanding switching behavior from colorless to colored or between different colors is presented. Preparation of thermosetting and thermoplastic polymers, including the resulting optical, and, for the first time, the mechanical properties are discussed in relation to matrix tuned high-resistant microcapsules.
基金The research was funded by the National Natural Science Foundation of China(No.51802120,51872126,22075103,51672111)Guangdong Basic and Applied Basic Research Foundation for Distinguished Young Scholar(No.2019B151502030)+7 种基金Natural Science Foundation of Guangdong Province(No.2018030310181)the Science and Technology Plan Project of Guangzhou(No.202002030159)Guangdong Basic and Applied Basic Research Foundation for Young Scholar(No.2020A1515111057)‘100 Talents Program of Hebei Province’(No.E2014100008)the Fundamental Research Funds for the Central Universities(No.21619406)X.Y.thanks for the Special Funds for the Cultivation of Guangdong College Students'Scientific and Technological Innovation("Climbing Program"Special Funds)(No.pdjh2019a0055)J.Fan also thanks for the project support for"Young Top talents"in the Pearl River Talent Project of Guangdong Province(2017GC010424)the Guangdong Provincial Innovation and Entrepreneurship Project(grant 2016ZT06D081).
文摘Multifunctional lead-free double perovskites demonstrate remarkable potential towards applications in various fields.Herein,an environmentally-friendly,low-cost,high-throughput Cs_(2)NaFeCl_(6) single crystal with exceedingly high thermal stability is designed and grown.It obtains a cubic lattice system in the temperature range of 80-500 K,accompanied by a completely reversible chromatic variation ranging from yellow to black.Importantly,the intriguing thermochromism is proved to own extremely high reproducibility(over 1000 cycles)without a hysteretic effect,originating from its structural flexibility that including(i)the noteworthy distortion/deformation of[NaCl_(6)]5−and[FeCl_(6)]3−octahedra;(ii)order-disorder arrangement transition of[NaCl_(6)]5−and[FeCl6]3−octahedra as the function of temperature.This study paves the way towards a new class of smart windows and camouflage coatings with an unprecedented colour range based on a Cs_(2)NaFeCl_(6) perovskite.
基金This work was financially supported by the Bundesministerium fur Bildung und Arbeit (No. 0329820E).
文摘A series of thermochromic polypropylene foils were prepared by embedding various leuco dye-developer-solvent systems in the polymer matrix. Bisphenol A, laurylgallate, ethylgallate and p-hydroxybenzoic acid methyl ester were used as developers, crystal violet lactone and 3,3-bis-（1-n-butyl-2-methyl-3-indolyl）-phthalide as dyes and l-octanoic acid methyl ester as solvent. The molar ratio between the three components of the investigated leuco dye-developer-solvent systems was kept constant. All obtained polypropylene foils exhibit an excellent thermochromic behavior. The foils, prepared by extrusion technology, switch from color to colorless with increasing temperature. The influence of molecular structure of the developer on the intensity of the colored state and the influence of a developer-surfactant complex on the resulting thermochromic properties were investigated. The results are presented and discussed in detail according to a molecular model suggesting that the ring-opening process of the leuco dye is triggered by the formation of dye-developer complexes via H-bondings.
基金supported by the Programs of the Shanghai Pujiang Program(No.18PJ1401500)the National Natural Science Foundation of China(No.21801046,No.51721002,No.21574025 and No.21871057)the Ministry of Science and Technology(2016YFA0203302)。
文摘Polydiacetylene(PDA)is one kind of the conjugated polymer with layered structure,which can serve as a host to accommodate the vip components through intercalation.In these intercalated PDAs,some of them were reported to have a nearly perfect organized structure and perform completely reversible thermochromism.Till now,these reported intercalated PDAs were made by only introducing a single component for intercalation.Here,we chose 10,12-pentacosadiynoic acid(PCDA)as the monomer,of which the carboxyl-terminal groups can interact with either Tb^3+ ions or melamines(MAs).When the feeding molar ratio of PCDA,MA,and Tb^3+ ion was 3:267:1,only Tb^3+ ions were intercalated though excess MAs existed.Such Tb^3+- intercalated poly-PCDA exhibited completely reversible thermochromism,where almost all the carboxyl groups interacted with Tb^3+ ions to form the nearly perfect structure.When the feeding molar ratio of PCDA,MA,and Tb^3+ ion was 3:267:0.6,both Tb^3+ ions and MAs were intercalated.There existed some defects in the imperfect MA-intercalated domains and at the domain boundaries.The MA/Tb^3+- intercalated poly-PCDA exhibits partially reversible thermochromism,where the backbones near the defects are hard to return the initial conformation,while the rest,those at nearly perfect organized domains,are still able to restore the initial conformation.
文摘The stoichiometric vanadium（IV） oxide thin films were obtained by controlling the temperature, time and pressure of annealing. The thermochromic phase transition and the IR thermochromic property of 400 nm and 900 nm VO2 thin films in the 7.5 μm-14 μm region were discussed. The derived VO2 thin film samples were characterized by Raman, XRD, XPS, AFM, SEM, and DSC. The resistance and infrared emissivity of VO2 thin films under different temperature were measured, and the thermal images of films were obtained using infrared imager. The results show that the VO2 thin film annealed at 550 ℃ for 10 hours through aqueous sol-gel process is pure and uniform. The 900 nm VO2 thin film exhibits better IR thermochromic property than the 400 nm VO2 thin film. The resistance of 900 nm VO2 film can change by 4 orders of magnitude and the emissivity can change by 0.6 during the phase transition, suggesting the outstanding IR thermochromic property. The derived VO2 thin film can control its infrared radiation intensity and lower its apparent temperature actively when the real temperature increases, which may be applied in the field of energy saving, thermal control and camouflage.
基金supported by the National Natural Science Foundation of China(Nos.21975114,11904151 and 22105094)。
文摘Multifunctional switchable materials are attracting tremendous interest because of their great application potential in signal processing,information encryption,and smart devices.Here,we reported an organic-inorganic hybrid thermochromic ferroelastic crystal,[TMIm][CuCl_(4)](TMIm=1,1,3,3-tetramethylimidazolidinium),which undergoes two reversible phase transitions at 333 K and 419 K,respectively.Intriguingly,these three phases experience a remarkable ferroelastic-paraelastic-ferroelastic(2/m-mmm-2/m)transition,which remains relatively unexplored in ferroelastics.Moreover,the ferroelastic domains can be simultaneously switched under temperature and stress stimuli.Meanwhile,[TMIm][CuCl_(4)]exhibits thermochromic phenomenon,endowing it with extra spectral encryption possibilities during information processing.Combined with dielectric switching behavior,[TMIm][Cu Cl_(4)]are promising for practical applications in memory devices,next-generation sensors,and encryption technology.
