We have developed a facile strategy to fabricate model multicolor hydrogels via a straightforward mixing process of poly acrylonitrile-grafted methacrylamide(PANMAM),polymethacrylic acid(PMAA)and doped lanthanide(Eu/T...We have developed a facile strategy to fabricate model multicolor hydrogels via a straightforward mixing process of poly acrylonitrile-grafted methacrylamide(PANMAM),polymethacrylic acid(PMAA)and doped lanthanide(Eu/Tb)and zinc ions to form the interpenetrating dual-polymer gel networks.The hydrogels exhibit excellent tunability of multi-spectrum emission colors(including white light)by simply varying the stoichiometry of metal ions.Furthermore,taking the advantage of different metal ion response mechanisms,we have demonstrated the reversible acidity/alkalinity stimuli-responsive behaviors of white-light-emitting hydrogel(WLE gel).Meanwhile,the unique cross-linked network formed through hydrogen-bonding,metal-ligand coordination and ionic interaction is introduced to achieve favorable mechanical strength of hydrogels.These properties enable the possibility in obtaining fluorescent patterns on hydrogels,which are promising candidate for encrypted information with improved security.展开更多
Fluorescence-based white-light-emitting diodes （WLEDs） were fabricated using blue GaN chips and green- and red-emitting CdSe/CdS/ZnS quantum dots （QDs）. The coordinate and color temperature of the WLEDs could be v...Fluorescence-based white-light-emitting diodes （WLEDs） were fabricated using blue GaN chips and green- and red-emitting CdSe/CdS/ZnS quantum dots （QDs）. The coordinate and color temperature of the WLEDs could be varied because of the size-tunable emission of CdSe QDs from 510 to 620 nm. Warm and cold white emissions were confirmed with the color temperature ranging from 4000 to 9000 K. Color coordinates were analyzed at different bias. The fast enhancement of blue emission resulted in the shift of color coordinates to the cold side. The stability of white emission during operation was analyzed; stable spectra were achieved within 90 min.展开更多
Photoluminescence （PL） and colorimetric properties of white-light emission SrAl2Si2O8：Eu2＋,Mn2＋ phosphor were tuned effectively through incorporating Si–N bond to the host in the form of Si3N4. A maximum solubil...Photoluminescence （PL） and colorimetric properties of white-light emission SrAl2Si2O8：Eu2＋,Mn2＋ phosphor were tuned effectively through incorporating Si–N bond to the host in the form of Si3N4. A maximum solubility of Si–N bond in SrAl2–xSi2＋xO8–xNx was estimated theoretically to be in a value of x=1.0. Under 365 nm irradiation, a distinct red-shift of blue band emission from 406 to 473 nm for Eu2＋ and an enhancement of yellow band emission peaked at ~565 nm for Mn2＋ were observed with the increase of Si–N content. These effects resulted from partial substitution of Si–N for Al1–O1 and Al4–O2 sites in SrAl2Si2O8 lattice. Eventually, a white emission with CIE chromaticity coordinates （0.287, 0.337） and color rendering index （CRI） 78.3 for SrAl2Si2O8：Eu2＋,Mn2＋ phosphor were achieved upon optimization to a suitable amount of Si–N.展开更多
Carbon dots(CDs)have gradually become a widely favored type of fluorescent nanomaterials with unlimited and promising applications.This work reports a means of breaking the shackle of method to develop new red and whi...Carbon dots(CDs)have gradually become a widely favored type of fluorescent nanomaterials with unlimited and promising applications.This work reports a means of breaking the shackle of method to develop new red and white CDs by introducing free radicals.The resulting white emissive CDs in this strategy are employed to demonstrate electroluminescent white-light-emitting diodes(WLEDs)and achieve a record-high external quantum efficiency(0.95%)of one-step-produced white CDs(WCD)-LEDs,which dramatically simplifies the whole fabrication processes of WLEDs.With additional passivation treatment,the red CDs(RCD2)with excellent properties such as N and S co-doping,bright(quantum yield=49%)and stable photoluminescence(PL),large positive zeta potential(+20.5 mV),and two-photon fluorescence are obtained.Such RCD2 are used for rapid staining(5 min)of yeast cells.The two CDs synthesized via this method have outstanding performance in different aspects,which provides new promise of CDs for further functionalization and applications.展开更多
Crystalline cluster-assembled materials(CAMs)are emerging as types of exploratory fabrications due to their atomically precise structures and intriguing chemical/physical properties,as well as their lumines-cent funct...Crystalline cluster-assembled materials(CAMs)are emerging as types of exploratory fabrications due to their atomically precise structures and intriguing chemical/physical properties,as well as their lumines-cent function.展开更多
Liquid crystalline （LC） polymers with a shish-kebab-type moiety on their cross-conjugated （p-phenylene）s-poly（p- phenylenevinylene）s main chains were synthesized through Gilch polymerization in order to develop ...Liquid crystalline （LC） polymers with a shish-kebab-type moiety on their cross-conjugated （p-phenylene）s-poly（p- phenylenevinylene）s main chains were synthesized through Gilch polymerization in order to develop a kind of polymers available for linearly polarized white-light-emitting from single chain. In this system, the 2,5-bis（4＇-alkoxyphenyl）benzene as the ＂kebabs＂ connects with poly（p-phenylenevinylene） （PPV） main chain backbone using its molecular gravity center and the PPV as the ＂shish＂ or ＂skewer＂ （the ＂shish-kebab＂）. The polymers possess desirable properties such as excellent solubility and liquid crystalline properties. To drop the ＂kebabs＂ of the 2,5-bis（4＇-alkoxyphenyl）benzene into the orientation microgroove of aligned polyimide film, not only the ＂shish＂ of polymer main chain can be aligned by the virtue of orientation of ＂kebabs＂ but also the uniform cross-conjugated structure between the ＂kebabs＂ and ＂shish＂ can be broken. Then, the alignment of the polymer main chain showed yellow light emission and was also accompanied by orientation of the LC side chains showing blue light emission, this gave rise to a notable linearly polarized white fluorescence.展开更多
A series of Ca10Na(PO4)7:Ce3+/Tb3+/Mn2+(CNPO:Ce3+/Tb3+/Mn2+) phosphors with high brightness were synthesized by high-temperature solid-state method. X-ray diffraction(XRD), scanning electron microscopy(SEM), diffuse r...A series of Ca10Na(PO4)7:Ce3+/Tb3+/Mn2+(CNPO:Ce3+/Tb3+/Mn2+) phosphors with high brightness were synthesized by high-temperature solid-state method. X-ray diffraction(XRD), scanning electron microscopy(SEM), diffuse reflectance spectra(DRS), photo luminescence(PL) spectra, luminescence decay curves and thermally stability were performed to characterize the as-prepared samples. For Ce3+-doped samples, an intense and broad band emission is present under 265 nm excitation. When Ce3+and Tb3+are codoped, energy transfer(ET) process from Ce3+ to Tb3+ is demonstrated with electric dipole-dipole interaction. The internal and external quantum efficiencies(QEs) of CNPO:0.15 Ce3+, 0.04 Tb3+, 0.005 Mn2+are measured to 76.79% and 54.11% under 265 nm excitation and temperature-dependent PL intensity can remain 51.78% at 150 ℃ of its initial intensity at 25 ℃. It is indicated that single-phased white lightemitting CNPO:Ce3+/Tb3+/Mn2+phosphor can serve as a promising phosphor for illumination devices.展开更多
基金The financial support of this work by the National Natural Science Foundation of China(No.51973026)the Jilin Provincial Education Departments(No.JJKH20201169KJ)。
文摘We have developed a facile strategy to fabricate model multicolor hydrogels via a straightforward mixing process of poly acrylonitrile-grafted methacrylamide(PANMAM),polymethacrylic acid(PMAA)and doped lanthanide(Eu/Tb)and zinc ions to form the interpenetrating dual-polymer gel networks.The hydrogels exhibit excellent tunability of multi-spectrum emission colors(including white light)by simply varying the stoichiometry of metal ions.Furthermore,taking the advantage of different metal ion response mechanisms,we have demonstrated the reversible acidity/alkalinity stimuli-responsive behaviors of white-light-emitting hydrogel(WLE gel).Meanwhile,the unique cross-linked network formed through hydrogen-bonding,metal-ligand coordination and ionic interaction is introduced to achieve favorable mechanical strength of hydrogels.These properties enable the possibility in obtaining fluorescent patterns on hydrogels,which are promising candidate for encrypted information with improved security.
基金supported by the National High Technology Research and Development Program 863 of China (2011AA050509)National Natural Science Foundation of China (61106039)+1 种基金National Postdoctoral Foundation(2011049015)Jilin Province Youth Foundation(201101025)
文摘Fluorescence-based white-light-emitting diodes （WLEDs） were fabricated using blue GaN chips and green- and red-emitting CdSe/CdS/ZnS quantum dots （QDs）. The coordinate and color temperature of the WLEDs could be varied because of the size-tunable emission of CdSe QDs from 510 to 620 nm. Warm and cold white emissions were confirmed with the color temperature ranging from 4000 to 9000 K. Color coordinates were analyzed at different bias. The fast enhancement of blue emission resulted in the shift of color coordinates to the cold side. The stability of white emission during operation was analyzed; stable spectra were achieved within 90 min.
基金Project supported by the National Natural Science Foundation of China (50802062, 21076161, 50872091)Key Discipline of Materials Physics and Chemistry (Tianjin, China) (2006ZD30)
文摘Photoluminescence （PL） and colorimetric properties of white-light emission SrAl2Si2O8：Eu2＋,Mn2＋ phosphor were tuned effectively through incorporating Si–N bond to the host in the form of Si3N4. A maximum solubility of Si–N bond in SrAl2–xSi2＋xO8–xNx was estimated theoretically to be in a value of x=1.0. Under 365 nm irradiation, a distinct red-shift of blue band emission from 406 to 473 nm for Eu2＋ and an enhancement of yellow band emission peaked at ~565 nm for Mn2＋ were observed with the increase of Si–N content. These effects resulted from partial substitution of Si–N for Al1–O1 and Al4–O2 sites in SrAl2Si2O8 lattice. Eventually, a white emission with CIE chromaticity coordinates （0.287, 0.337） and color rendering index （CRI） 78.3 for SrAl2Si2O8：Eu2＋,Mn2＋ phosphor were achieved upon optimization to a suitable amount of Si–N.
基金support from the National Natural Science Foundation of China(Nos.21974101 and 22174102).
文摘Carbon dots(CDs)have gradually become a widely favored type of fluorescent nanomaterials with unlimited and promising applications.This work reports a means of breaking the shackle of method to develop new red and white CDs by introducing free radicals.The resulting white emissive CDs in this strategy are employed to demonstrate electroluminescent white-light-emitting diodes(WLEDs)and achieve a record-high external quantum efficiency(0.95%)of one-step-produced white CDs(WCD)-LEDs,which dramatically simplifies the whole fabrication processes of WLEDs.With additional passivation treatment,the red CDs(RCD2)with excellent properties such as N and S co-doping,bright(quantum yield=49%)and stable photoluminescence(PL),large positive zeta potential(+20.5 mV),and two-photon fluorescence are obtained.Such RCD2 are used for rapid staining(5 min)of yeast cells.The two CDs synthesized via this method have outstanding performance in different aspects,which provides new promise of CDs for further functionalization and applications.
基金This work was supported financially by the National Science Fund for Distinguished Young Scholars(21825106)the National Natural Science Foundation of China(21671175 and 21501150)+1 种基金the Program for Science&Technology Innovation Talents in Universities of Henan Province(164100510005)the Open Foundation of Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured Materials,Guangxi University(2019GXYSOF12).
文摘Crystalline cluster-assembled materials(CAMs)are emerging as types of exploratory fabrications due to their atomically precise structures and intriguing chemical/physical properties,as well as their lumines-cent function.
基金financially supported by the National Natural Science Foundation of China(No.20574064)
文摘Liquid crystalline （LC） polymers with a shish-kebab-type moiety on their cross-conjugated （p-phenylene）s-poly（p- phenylenevinylene）s main chains were synthesized through Gilch polymerization in order to develop a kind of polymers available for linearly polarized white-light-emitting from single chain. In this system, the 2,5-bis（4＇-alkoxyphenyl）benzene as the ＂kebabs＂ connects with poly（p-phenylenevinylene） （PPV） main chain backbone using its molecular gravity center and the PPV as the ＂shish＂ or ＂skewer＂ （the ＂shish-kebab＂）. The polymers possess desirable properties such as excellent solubility and liquid crystalline properties. To drop the ＂kebabs＂ of the 2,5-bis（4＇-alkoxyphenyl）benzene into the orientation microgroove of aligned polyimide film, not only the ＂shish＂ of polymer main chain can be aligned by the virtue of orientation of ＂kebabs＂ but also the uniform cross-conjugated structure between the ＂kebabs＂ and ＂shish＂ can be broken. Then, the alignment of the polymer main chain showed yellow light emission and was also accompanied by orientation of the LC side chains showing blue light emission, this gave rise to a notable linearly polarized white fluorescence.
基金supported by National Natural Science Foundation of China(51302182)Natural Science Foundation of Shanxi Province(201601d011030)
文摘A series of Ca10Na(PO4)7:Ce3+/Tb3+/Mn2+(CNPO:Ce3+/Tb3+/Mn2+) phosphors with high brightness were synthesized by high-temperature solid-state method. X-ray diffraction(XRD), scanning electron microscopy(SEM), diffuse reflectance spectra(DRS), photo luminescence(PL) spectra, luminescence decay curves and thermally stability were performed to characterize the as-prepared samples. For Ce3+-doped samples, an intense and broad band emission is present under 265 nm excitation. When Ce3+and Tb3+are codoped, energy transfer(ET) process from Ce3+ to Tb3+ is demonstrated with electric dipole-dipole interaction. The internal and external quantum efficiencies(QEs) of CNPO:0.15 Ce3+, 0.04 Tb3+, 0.005 Mn2+are measured to 76.79% and 54.11% under 265 nm excitation and temperature-dependent PL intensity can remain 51.78% at 150 ℃ of its initial intensity at 25 ℃. It is indicated that single-phased white lightemitting CNPO:Ce3+/Tb3+/Mn2+phosphor can serve as a promising phosphor for illumination devices.
