Nano-sized polyacrylonitrile （PAN） particles were prepared under the catalytic effect of in situ developed CoCl2/EDTA complex with ammonium persulfate as the initiator in the absence of any added emulsifier. The emu...Nano-sized polyacrylonitrile （PAN） particles were prepared under the catalytic effect of in situ developed CoCl2/EDTA complex with ammonium persulfate as the initiator in the absence of any added emulsifier. The emulsion polymerization was studied at varying concentrations of the initiator, monomer, complex and solvent over a temperature range of 30-70℃. The overall activation energy （Ea, 49.79 kJ/mol）, energy of dissociation of initiator （Ed, 82.68 kJ/mol）, number of micelles （0.163 × 10^18） and the viscosity average molecular weight of the polymer were computed. The distribution of particle sizes was determined by transmission electron microscopy （TEM）. It was found that the oil-in-water polymerization was stabilized by the presence of the CoCl2/EDTA in situ complex reducing the particle size into the nano order. The average diameters of PAN nano particles, obtained by TEM, were in the range of 50-150 nm at the maximum conversion. The experimental particle size was mainly dependent on the concentration of the complex and temperature.展开更多
Nonconventional luminescent materials(NLMs)are a type of organic luminescent materials that does not contain aromatic units.Due to the simplicity of the synthesis process,mild reaction conditions,good hydrophilicity a...Nonconventional luminescent materials(NLMs)are a type of organic luminescent materials that does not contain aromatic units.Due to the simplicity of the synthesis process,mild reaction conditions,good hydrophilicity and biological compatibility,NLMs have attracted much attention.Nevertheless,numerous reports indicate that NLMs can only effectively luminesce at high concentrations and in solid state,which limits their applicability in the field of cell imaging.This study addresses this limitation by designing and synthesizing oligomers P1,P2 and P3 using ethylene glycol diglycidyl ether and amine compounds containing ethylene groups.These oligomers exhibit remarkable luminescence efficiency reaching as high as 9.2%in dilute solutions(0.1 mg/m L),making them among the best NLMs in this category.Furthermore,the synthesized oligomers exhibit excitation wavelength-dependent and concentration-dependent luminescence intensity,fluorescence response to temperature and p H changes,as well as the ability to identify Fe^(3+),Cu^(2+)and Mo^(5+)in dilute solutions.These characteristics render them potentially useful in the for cell imaging.展开更多
The response of olive orchard with same age and type to irrigation with treated municipal wastewater and freshwater was investigated in three years. Physical and chemical properties of the treated municipal wastewater...The response of olive orchard with same age and type to irrigation with treated municipal wastewater and freshwater was investigated in three years. Physical and chemical properties of the treated municipal wastewater reuse in agriculture (the effluent) produced by the Sheikh Ejleen wastewater treatment plant in Gaza Strip, freshwater, soil, and olive oil were determined and compared with Palestinian and international standards. The biological oxygen?demand (BOD) of Sheikh Ejleen effluent is 60 mg·l-1, which indicates low quality effluent. The results indicate that most of olive oil quality parameters—including heavy metals and trace elements for both fruits irrigated with treated wastewater or irrigated with freshwater—fall within the acceptable standard limit values. Moreover, soil analysis shows that organic content and cation exchange capacity were improved in soil irrigated with treated wastewater in comparison with that irrigated with freshwater. The results also show that there is no trace elements or heavy metals accumulation in soil.展开更多
How to generate rake faces of nonconventional milling cutters (NCMC) with constant spiral angled and normal rake angled edges on NC machine tools is presented by use of a blunt cup grinder or a cup milling cutter. Mot...How to generate rake faces of nonconventional milling cutters (NCMC) with constant spiral angled and normal rake angled edges on NC machine tools is presented by use of a blunt cup grinder or a cup milling cutter. Motion functions of the NC machining system are mathematically deduced and exam- ed by a experiment. The research will provide theoretical and practical guidance for machining noncon- ventional tools on NC machine tools.展开更多
The emergence of nonconventional luminescent materials(NLMs)has attracted significant attention due to their sustainable synthesis and tunable optical properties.Yet,establishing a clear structure-emission relationshi...The emergence of nonconventional luminescent materials(NLMs)has attracted significant attention due to their sustainable synthesis and tunable optical properties.Yet,establishing a clear structure-emission relationship remains a challenge.In this work,we report a previously unknown class of NLMs:cross-linked protein crystals that exhibit intense photoluminescence(PL)in the visible range(425-680 nm).We systematically investigated seven natural protein crystals(concanavalin,catalase,lysozyme,hemoglobin,α-chymotrypsin,pepsin,and β-lactoglobulin)cross-linked with glutaraldehyde and demonstrated that cross-linking induces broadband emission that is absent in natural crystals.Focusing on polymorphic lysozyme crystals(tetragonal,orthorhombic,and monoclinic),we found excitation-dependent fluorescence with lifetimes in the nanosecond range and quantum yields up to 20%(in themonoclinic phase under 450 nmexcitation).Single-and two-photon spectroscopy,as well as pressure-and solvent-modulated PL studies,confirm that the emission is due to intermolecular through-space interactions(TSI)within the crystal lattice.Compression enhances TSI and redshifts the emission,whereas the solvent(DMSO)-induced swelling reduces TSI and causes a blue shift,establishing a direct structure-emission correlation.This work establishes protein crystals as programmableNLMswith tunable emission and provides a mechanistic framework for the design of nonconventional luminogens through protein crystal engineering.展开更多
The liver is a tolerogenic organ with exquisite mechanisms of immune regulation that ensure upkeep of local and systemic immune tolerance to self and foreign antigens, but that is also able to mount effective immune r...The liver is a tolerogenic organ with exquisite mechanisms of immune regulation that ensure upkeep of local and systemic immune tolerance to self and foreign antigens, but that is also able to mount effective immune responses against pathogens. The immune privilege of liver allografts was recognized first in pigs in spite of major histo-compatibility complex mismatch, and termed the ＂liver tolerance effect＂. Furthermore, liver transplants are spontaneously accepted with only low-dose immunosuppression, and induce tolerance for non-hepatic co-transplanted allografts of the same donor. Although this immunotolerogenic environment is favorable in the setting of organ transplantation, it is detrimental in chronic infectious liver diseases like hepatitis B or C, malaria, schistosomiasis or tumorigenesis, leading to pathogen persistence and weak anti-tumor effects. The liver is a primary site of T-cell activation, but it elicits poor or incomplete activation of T cells, leading to their abortive activation, exhaustion, suppression of their effector function and early death. This is exploited by pathogens and can impair pathogen control and clearance or allow tumor growth. Hepatic priming of T cells is mediated by a number of local conventional and nonconventional antigen-presenting cells （APCs）, which promote tolerance by immune deviation, induction of T-cell anergy or apoptosis, and generating and expanding regulatory T cells. This review will focus on the communication between classical and nonclassical APCs and lymphocytes in the liver in tolerance induction and will discuss recent insights into the role of innate lymphocytes in this process.展开更多
Nonconventional luminophores have attracted significant attention for their unique photophysical properties and potential applications in different areas.Unlike classic luminogens consisting of remarkably conjugated s...Nonconventional luminophores have attracted significant attention for their unique photophysical properties and potential applications in different areas.Unlike classic luminogens consisting of remarkably conjugated segments,nonconventional luminophores generally possess merely nonconjugated or short-conjugated structures based on electron-rich units.Fluorescence,phosphorescence,and even color tunable room temperature phosphorescence(RTP)could be readily obtained from these unique luminophores.Herein,we summarized recent advances in the phosphorescence of nonconventional luminophores,with focus on RTP and color tunable RTP.The clustering-triggered emission(CTE)mechanism could be applied to explain the luminescence as clustering-triggered phosphorescence(CTP).Furthermore,strategies toward the RTP regulation are summarized,and corresponding applications are demonstrated.展开更多
Nonconventional luminescent materials have been rising stars in organic luminophores due to their intrinsic characteristics,including water-solubility,biocompatibility,and environmental friendliness and have shown pot...Nonconventional luminescent materials have been rising stars in organic luminophores due to their intrinsic characteristics,including water-solubility,biocompatibility,and environmental friendliness and have shown potential applications in diverse fields.As an indispensable branch of nonconventional luminescent materials,polysiloxanes,which consist of electron-rich auxochromic groups,have exhibited outstanding photophysical properties due to the unique silicon atoms.The flexible Si-O bonds benefit the aggregation,and the empty 3d orbitals of Si atoms can generate coordination bonds including N→Si and O→Si,altering the electron delocalization of the material and improving the luminescent purity.Herein,we review the recent progress in luminescent polysiloxanes with different topologies and discuss the challenges and perspectives.With an emphasis on the driving force for the aggregation and the mechanism of tuned emissions,the role of Si atoms played in the nonconventional luminophores is highlighted.This review may provide new insights into the design of nonconventional luminescent materials and expand their further applications in sensing,biomedicine,lighting devices,etc.展开更多
In recent years, nonconventional luminogens free of aromatic groups have attracted extensive attention due to their academic importance and promising wide applications. Whilst previous studies generally focused on flu...In recent years, nonconventional luminogens free of aromatic groups have attracted extensive attention due to their academic importance and promising wide applications. Whilst previous studies generally focused on fluorescence from aliphatic amine or carbonylcontaining systems, less attention has been paid to room temperature phosphorescence(RTP) and the systems with predominant oxygen functionalities. In this work, photophysical properties of the polyhydroxy polymers, including microcrystalline cellulose(MCC), 2-hydroxyethyl cellulose(HEC), hydroxypropyl cellulose(HPC), and cellulose acetate(CA), were studied and compared. While MCC,HEC, and HPC solids showed bright emission alongside distinct RTP, CA demonstrated relatively low intensity of solid emission without noticeable RTP. Their emissions were explained in terms of the clustering-triggered emission(CTE) mechanism and conformation rigidification. Additionally, on account of its intrinsic emission, concentrated HEC aqueous solution could be used as the probe for the detection of 2,4,6-trinitrophenol(TNP).展开更多
This review summarizes the recent progress of efficient room temperature phosphorescence（RTP） from pure organic luminogens achieved by crystallization-induced phosphorescence（CIP）,with focus on the advances in our...This review summarizes the recent progress of efficient room temperature phosphorescence（RTP） from pure organic luminogens achieved by crystallization-induced phosphorescence（CIP）,with focus on the advances in our group.Besides homocrystals,mixed crystals and cocrystals are also discussed.Meanwhile,intriguing RTP emission from the luminogens without conventional chromophores is demonstrated.展开更多
Spherulites are generally fabricated from cooling polymer melts,while their fabrication under mild conditions or from small molecule materials has been barely reported.Besides,organic luminescent molecules typically s...Spherulites are generally fabricated from cooling polymer melts,while their fabrication under mild conditions or from small molecule materials has been barely reported.Besides,organic luminescent molecules typically suffer from low quantum yields in a solid state.Moreover,preparing material with interconnected and simultaneous changes in structural and fluorescent colors is challenging.Here,we present the first solution-derived spherulites with unique interconnected structural and fluorescent colors,self-assembled from stearoylated monosaccharides at room temperature.D-galactose stearoyl ester self-assembled into banded spherulites,containing twisted nanoplates and interconnected simultaneously changing structural and fluorescent colors.In comparison,D-mannose stearoyl ester can only form nonbanded spherulites,which contain oriented nanoplates and uniform structural and fluorescent colors.Such materials revealed a novel negative correlation between fluorescence and birefringence,termed alignment-promoted quenching propensity.Remarkably,the solid-state fluorescence quantum yields of galactose and mannosederived spherulites are as high as 49±2%and 51±2%respectively,approximately ten times higher than those of unmodified monosaccharides.These quantum yield values are among the highest of reported organic nonconventional fluorophores and even comparable to those of conventional aromatic chromophores.Moreover,these spherulites manifested an unexpected excitation-dependent multicolor photoluminescence with a broad-spectrum emission(410−620 nm).They show multiple peaks in the photoluminescent emission spectra and broad fluorescence lifetime distributions,which should be attributed to the clustering of a variety of oxygen-containing functional groups as emissive moieties.展开更多
Nonconventional fluorescent materials,which are nonaromatic or consist of isolated aromatic systems,have attracted extensive attention because of their aggregation-induced emission properties.The mechanism of nonconve...Nonconventional fluorescent materials,which are nonaromatic or consist of isolated aromatic systems,have attracted extensive attention because of their aggregation-induced emission properties.The mechanism of nonconventional fluorescence remains incompletely understood,hindering the prediction and modulation of its emission color.Achieving full-color tunability in such systems,particularly within elastomers,is highly challenging.Herein,fluorescent cross-linked polysiloxanes are synthesized using aliphatic amino-terminated polysiloxane and glutaraldehyde,exhibiting full-color emission that can be continuously tuned through thermal treatments within a single material system.Thermal treatment of cross-linked polysiloxanes enables precise control over the structural evolution of fluorophores from imines to 3-(2-piperidyl)pyridinium derivatives and their aggregation states.It enables the continuous and wide-range modulation of the emission color.Additionally,the intramolecular and intermolecular charge transfers of the novel unconventional fluorophore,3-(2-piperidyl)pyridinium derivatives,have been identified,which are of great significance for aggregation-induced bathochromic fluorescence.Prepared from all commercial chemicals,these cross-linked polysiloxanes show great potential for large-scale production and applications,especially as flexible fluorescent light-conversion layers and solvent-responsive smart materials.Furthermore,our research is expected to inspire the innovation of unconventional fluorophores in multiple dimensions.展开更多
Reversible self-assembly of nanoparticles remains challenging due to limited molecular mobility.Moreover,reported successful examples typically rely on inorganic-core nanoparticles that require surface pre-functionali...Reversible self-assembly of nanoparticles remains challenging due to limited molecular mobility.Moreover,reported successful examples typically rely on inorganic-core nanoparticles that require surface pre-functionalization with specific stimuli-responsive ligands.Here,we demonstrate reversible self-assembly of organic nanoparticles through the selective self-modulation of aliphatic chains,without the need for prior modification with external stimuli-responsive ligands.D-glucose 11-octadecylthioundecanoate(D-Glc-C11S18E)self-assembles into microspheres(3-6µm)comprising nanospheres(100-300 nm).Within these nanospheres,octadecylthioundecanoyl(C29)groups form interior crystalline domains(C29 lamella)while octadecyl(C18)chains organize at nanosphere interfaces(C18 lamella).Thermal triggering enables selective reversibility:at 50℃,the C18 lamella dissociates into disordered structures while the C29 lamella remains intact;cooling to 20℃regenerates the C18 lamella.In methanol,this process drives reversible microsphere-nanosphere morphological transitions(validated by scanning electron microscopy/dynamic light scattering),accompanied by a reversible fluorescence modulation.Both structural and optical modulations exhibit no apparent fatigue over 10 consecutive cycles.Energy decomposition analysis reveals stronger C29 binding energy(ΔE_(int)=-29.80 kcal/mol vs.C18’s-19.90 kcal/mol),explaining selective reversibility.Density functional theory calculations confirm the distinct highest occupied molecular orbital-lowest unoccupied molecular orbital gaps correlating with emission wavelengths.Leveraging the temperature/wavelength-dependent fluorescence,we constructed a multi-input logic gate.This work establishes a new insight for reversible assembly and enables smart and fatigue-resistant optoelectronic applications.展开更多
Intrinsic emission from unorthodox luminogens without traditional conjugated building blocks is drawing increasing attention.However,the emission mechanism is still controversial.Herein,we demonstrate the intriguing e...Intrinsic emission from unorthodox luminogens without traditional conjugated building blocks is drawing increasing attention.However,the emission mechanism is still controversial.Herein,we demonstrate the intriguing emission from perfluorosulfonate ionomers(PFSIs),which can be explained by the clustering triggered emission(CTE)mechanism.Despite being free of any conventional chromophores,PFSIs exhibit bright emission and multi-color phosphorescence(77 K)in concentrated solutions,powders and membranes with obvious aggregation-induced emission(AIE)characteristics.Clustered sulfonic acids are responsible for the light emission,and their connection and evolution are deeply explored via X-ray diffraction(XRD)and small angel X-ray scattering(SAXS),in which the electron overlap determined by the clustered status results in the extended conjugation and simultaneously rigidified conformations.These results demonstrate that it is feasible to use fluorescence analysis to explore the ionic cluster structure and evolution of PFSI,and it can be applied in the pure organic luminescent field as well.展开更多
文摘Nano-sized polyacrylonitrile （PAN） particles were prepared under the catalytic effect of in situ developed CoCl2/EDTA complex with ammonium persulfate as the initiator in the absence of any added emulsifier. The emulsion polymerization was studied at varying concentrations of the initiator, monomer, complex and solvent over a temperature range of 30-70℃. The overall activation energy （Ea, 49.79 kJ/mol）, energy of dissociation of initiator （Ed, 82.68 kJ/mol）, number of micelles （0.163 × 10^18） and the viscosity average molecular weight of the polymer were computed. The distribution of particle sizes was determined by transmission electron microscopy （TEM）. It was found that the oil-in-water polymerization was stabilized by the presence of the CoCl2/EDTA in situ complex reducing the particle size into the nano order. The average diameters of PAN nano particles, obtained by TEM, were in the range of 50-150 nm at the maximum conversion. The experimental particle size was mainly dependent on the concentration of the complex and temperature.
基金financially supported by the National Natural Science Foundation of China(No.52163017)Project of Guangxi Natural Science Foundation(No.2021GXNSFAA220047)the project of Thousand Outstanding Young Teachers'Training in Higher Education Institutions of Guangxi and the Open Project Program of Guangxi Key Laboratory of Optical and Electronic Materials and Devices(No.20AA-2)。
文摘Nonconventional luminescent materials(NLMs)are a type of organic luminescent materials that does not contain aromatic units.Due to the simplicity of the synthesis process,mild reaction conditions,good hydrophilicity and biological compatibility,NLMs have attracted much attention.Nevertheless,numerous reports indicate that NLMs can only effectively luminesce at high concentrations and in solid state,which limits their applicability in the field of cell imaging.This study addresses this limitation by designing and synthesizing oligomers P1,P2 and P3 using ethylene glycol diglycidyl ether and amine compounds containing ethylene groups.These oligomers exhibit remarkable luminescence efficiency reaching as high as 9.2%in dilute solutions(0.1 mg/m L),making them among the best NLMs in this category.Furthermore,the synthesized oligomers exhibit excitation wavelength-dependent and concentration-dependent luminescence intensity,fluorescence response to temperature and p H changes,as well as the ability to identify Fe^(3+),Cu^(2+)and Mo^(5+)in dilute solutions.These characteristics render them potentially useful in the for cell imaging.
文摘The response of olive orchard with same age and type to irrigation with treated municipal wastewater and freshwater was investigated in three years. Physical and chemical properties of the treated municipal wastewater reuse in agriculture (the effluent) produced by the Sheikh Ejleen wastewater treatment plant in Gaza Strip, freshwater, soil, and olive oil were determined and compared with Palestinian and international standards. The biological oxygen?demand (BOD) of Sheikh Ejleen effluent is 60 mg·l-1, which indicates low quality effluent. The results indicate that most of olive oil quality parameters—including heavy metals and trace elements for both fruits irrigated with treated wastewater or irrigated with freshwater—fall within the acceptable standard limit values. Moreover, soil analysis shows that organic content and cation exchange capacity were improved in soil irrigated with treated wastewater in comparison with that irrigated with freshwater. The results also show that there is no trace elements or heavy metals accumulation in soil.
文摘How to generate rake faces of nonconventional milling cutters (NCMC) with constant spiral angled and normal rake angled edges on NC machine tools is presented by use of a blunt cup grinder or a cup milling cutter. Motion functions of the NC machining system are mathematically deduced and exam- ed by a experiment. The research will provide theoretical and practical guidance for machining noncon- ventional tools on NC machine tools.
基金support from the National Key R&D Program of China(2021YFF0502900)the National Natural Science Foundation of China(62127819,T2421003,62435011,32471230,W2431056)+2 种基金the Shenzhen Key Laboratory of Photonics and Biophotonics(ZDSYS20210623092006020)the Shenzhen Science and Technology Program(JCYJ20220818100202005)and the Fundamental Research Funds for the Central Universities(23GH02021).
文摘The emergence of nonconventional luminescent materials(NLMs)has attracted significant attention due to their sustainable synthesis and tunable optical properties.Yet,establishing a clear structure-emission relationship remains a challenge.In this work,we report a previously unknown class of NLMs:cross-linked protein crystals that exhibit intense photoluminescence(PL)in the visible range(425-680 nm).We systematically investigated seven natural protein crystals(concanavalin,catalase,lysozyme,hemoglobin,α-chymotrypsin,pepsin,and β-lactoglobulin)cross-linked with glutaraldehyde and demonstrated that cross-linking induces broadband emission that is absent in natural crystals.Focusing on polymorphic lysozyme crystals(tetragonal,orthorhombic,and monoclinic),we found excitation-dependent fluorescence with lifetimes in the nanosecond range and quantum yields up to 20%(in themonoclinic phase under 450 nmexcitation).Single-and two-photon spectroscopy,as well as pressure-and solvent-modulated PL studies,confirm that the emission is due to intermolecular through-space interactions(TSI)within the crystal lattice.Compression enhances TSI and redshifts the emission,whereas the solvent(DMSO)-induced swelling reduces TSI and causes a blue shift,establishing a direct structure-emission correlation.This work establishes protein crystals as programmableNLMswith tunable emission and provides a mechanistic framework for the design of nonconventional luminogens through protein crystal engineering.
文摘The liver is a tolerogenic organ with exquisite mechanisms of immune regulation that ensure upkeep of local and systemic immune tolerance to self and foreign antigens, but that is also able to mount effective immune responses against pathogens. The immune privilege of liver allografts was recognized first in pigs in spite of major histo-compatibility complex mismatch, and termed the ＂liver tolerance effect＂. Furthermore, liver transplants are spontaneously accepted with only low-dose immunosuppression, and induce tolerance for non-hepatic co-transplanted allografts of the same donor. Although this immunotolerogenic environment is favorable in the setting of organ transplantation, it is detrimental in chronic infectious liver diseases like hepatitis B or C, malaria, schistosomiasis or tumorigenesis, leading to pathogen persistence and weak anti-tumor effects. The liver is a primary site of T-cell activation, but it elicits poor or incomplete activation of T cells, leading to their abortive activation, exhaustion, suppression of their effector function and early death. This is exploited by pathogens and can impair pathogen control and clearance or allow tumor growth. Hepatic priming of T cells is mediated by a number of local conventional and nonconventional antigen-presenting cells （APCs）, which promote tolerance by immune deviation, induction of T-cell anergy or apoptosis, and generating and expanding regulatory T cells. This review will focus on the communication between classical and nonclassical APCs and lymphocytes in the liver in tolerance induction and will discuss recent insights into the role of innate lymphocytes in this process.
基金supported by the National Natural Science Foundation of China(51822303,52073172)the Natural Science Foundation of Shanghai(20ZR1429400)+1 种基金“Shuguang Program”(20SG11)cosponsored by Shanghai Education Development Foundation and Shanghai Municipal Education Commissionthe State Key Laboratory of BioFibers and Eco-Textiles(Qingdao University,KF2020107)。
文摘Nonconventional luminophores have attracted significant attention for their unique photophysical properties and potential applications in different areas.Unlike classic luminogens consisting of remarkably conjugated segments,nonconventional luminophores generally possess merely nonconjugated or short-conjugated structures based on electron-rich units.Fluorescence,phosphorescence,and even color tunable room temperature phosphorescence(RTP)could be readily obtained from these unique luminophores.Herein,we summarized recent advances in the phosphorescence of nonconventional luminophores,with focus on RTP and color tunable RTP.The clustering-triggered emission(CTE)mechanism could be applied to explain the luminescence as clustering-triggered phosphorescence(CTP).Furthermore,strategies toward the RTP regulation are summarized,and corresponding applications are demonstrated.
基金Guangdong Basic and Applied Basic Research Foundation,Grant/Award Number:2020A1515110540Key Research and Development Program of Shaanxi,Grant/Award Number:2022SF-599+1 种基金Fundamental Research Funds for the Central Universities,Grant/Award Number:D5000230114National Natural Science Foundation of China,Grant/Award Number:22175143。
文摘Nonconventional luminescent materials have been rising stars in organic luminophores due to their intrinsic characteristics,including water-solubility,biocompatibility,and environmental friendliness and have shown potential applications in diverse fields.As an indispensable branch of nonconventional luminescent materials,polysiloxanes,which consist of electron-rich auxochromic groups,have exhibited outstanding photophysical properties due to the unique silicon atoms.The flexible Si-O bonds benefit the aggregation,and the empty 3d orbitals of Si atoms can generate coordination bonds including N→Si and O→Si,altering the electron delocalization of the material and improving the luminescent purity.Herein,we review the recent progress in luminescent polysiloxanes with different topologies and discuss the challenges and perspectives.With an emphasis on the driving force for the aggregation and the mechanism of tuned emissions,the role of Si atoms played in the nonconventional luminophores is highlighted.This review may provide new insights into the design of nonconventional luminescent materials and expand their further applications in sensing,biomedicine,lighting devices,etc.
基金financially supported by the National Natural Science Foundation of China (Nos. 51603050 and 51863006)the Natural Science Foundation of Guangxi (Nos. 2016GXNSFBA380196, 2016GXNSFBA380064)+1 种基金Guangxi University Young and Middle-aged Teachers Basic Ability Promotion Project (No. KY2016YB316)The Open Project Foundation of Guangxi Ministry-Province Jointly-Constructed Cultivation Base for State Key Laboratory of Processing for Non-ferrous Metal and Featured Materials (15-KF-10)
文摘In recent years, nonconventional luminogens free of aromatic groups have attracted extensive attention due to their academic importance and promising wide applications. Whilst previous studies generally focused on fluorescence from aliphatic amine or carbonylcontaining systems, less attention has been paid to room temperature phosphorescence(RTP) and the systems with predominant oxygen functionalities. In this work, photophysical properties of the polyhydroxy polymers, including microcrystalline cellulose(MCC), 2-hydroxyethyl cellulose(HEC), hydroxypropyl cellulose(HPC), and cellulose acetate(CA), were studied and compared. While MCC,HEC, and HPC solids showed bright emission alongside distinct RTP, CA demonstrated relatively low intensity of solid emission without noticeable RTP. Their emissions were explained in terms of the clustering-triggered emission(CTE) mechanism and conformation rigidification. Additionally, on account of its intrinsic emission, concentrated HEC aqueous solution could be used as the probe for the detection of 2,4,6-trinitrophenol(TNP).
基金financially supported by the National Natural Science Foundation of China(No.51473092)the Shanghai Rising-Star Program(No.15QA1402500)the SMC-Chenxing Young Scholar Program of Shanghai Jiao Tong University
文摘This review summarizes the recent progress of efficient room temperature phosphorescence（RTP） from pure organic luminogens achieved by crystallization-induced phosphorescence（CIP）,with focus on the advances in our group.Besides homocrystals,mixed crystals and cocrystals are also discussed.Meanwhile,intriguing RTP emission from the luminogens without conventional chromophores is demonstrated.
基金EU,Grant/Award Number:NEuM(ZW7-85191973)German Research Foundation(DFG),Grant/Award Numbers:ZH 546/8-1,INST186/1397-1/FUGG,INST208/761-1FUGG+3 种基金Lower Saxony Ministry of Science and Culture,Grant/Award Number:INST186/1397-1/FUGGChina Scholarship CouncilNatural Sciences and Engineering Research Council of CanadaAlexander von Humboldt Foundation。
文摘Spherulites are generally fabricated from cooling polymer melts,while their fabrication under mild conditions or from small molecule materials has been barely reported.Besides,organic luminescent molecules typically suffer from low quantum yields in a solid state.Moreover,preparing material with interconnected and simultaneous changes in structural and fluorescent colors is challenging.Here,we present the first solution-derived spherulites with unique interconnected structural and fluorescent colors,self-assembled from stearoylated monosaccharides at room temperature.D-galactose stearoyl ester self-assembled into banded spherulites,containing twisted nanoplates and interconnected simultaneously changing structural and fluorescent colors.In comparison,D-mannose stearoyl ester can only form nonbanded spherulites,which contain oriented nanoplates and uniform structural and fluorescent colors.Such materials revealed a novel negative correlation between fluorescence and birefringence,termed alignment-promoted quenching propensity.Remarkably,the solid-state fluorescence quantum yields of galactose and mannosederived spherulites are as high as 49±2%and 51±2%respectively,approximately ten times higher than those of unmodified monosaccharides.These quantum yield values are among the highest of reported organic nonconventional fluorophores and even comparable to those of conventional aromatic chromophores.Moreover,these spherulites manifested an unexpected excitation-dependent multicolor photoluminescence with a broad-spectrum emission(410−620 nm).They show multiple peaks in the photoluminescent emission spectra and broad fluorescence lifetime distributions,which should be attributed to the clustering of a variety of oxygen-containing functional groups as emissive moieties.
基金supported by the National Natural Science Foundation of China(Grants 51373179,51073163,51803218,and 51373184).
文摘Nonconventional fluorescent materials,which are nonaromatic or consist of isolated aromatic systems,have attracted extensive attention because of their aggregation-induced emission properties.The mechanism of nonconventional fluorescence remains incompletely understood,hindering the prediction and modulation of its emission color.Achieving full-color tunability in such systems,particularly within elastomers,is highly challenging.Herein,fluorescent cross-linked polysiloxanes are synthesized using aliphatic amino-terminated polysiloxane and glutaraldehyde,exhibiting full-color emission that can be continuously tuned through thermal treatments within a single material system.Thermal treatment of cross-linked polysiloxanes enables precise control over the structural evolution of fluorophores from imines to 3-(2-piperidyl)pyridinium derivatives and their aggregation states.It enables the continuous and wide-range modulation of the emission color.Additionally,the intramolecular and intermolecular charge transfers of the novel unconventional fluorophore,3-(2-piperidyl)pyridinium derivatives,have been identified,which are of great significance for aggregation-induced bathochromic fluorescence.Prepared from all commercial chemicals,these cross-linked polysiloxanes show great potential for large-scale production and applications,especially as flexible fluorescent light-conversion layers and solvent-responsive smart materials.Furthermore,our research is expected to inspire the innovation of unconventional fluorophores in multiple dimensions.
基金supporting the project‘NEuM’(ZW7-85191973)Cheng Li thanks the China Scholarship Council(CSC)for the financial support of his PhD grant.Qiyun Tang acknowledges the financial support from the National Natural Science Foundation of China under Grant Number 12374207the Natural Science Foundation of Jiangsu Province,BK20233001.
文摘Reversible self-assembly of nanoparticles remains challenging due to limited molecular mobility.Moreover,reported successful examples typically rely on inorganic-core nanoparticles that require surface pre-functionalization with specific stimuli-responsive ligands.Here,we demonstrate reversible self-assembly of organic nanoparticles through the selective self-modulation of aliphatic chains,without the need for prior modification with external stimuli-responsive ligands.D-glucose 11-octadecylthioundecanoate(D-Glc-C11S18E)self-assembles into microspheres(3-6µm)comprising nanospheres(100-300 nm).Within these nanospheres,octadecylthioundecanoyl(C29)groups form interior crystalline domains(C29 lamella)while octadecyl(C18)chains organize at nanosphere interfaces(C18 lamella).Thermal triggering enables selective reversibility:at 50℃,the C18 lamella dissociates into disordered structures while the C29 lamella remains intact;cooling to 20℃regenerates the C18 lamella.In methanol,this process drives reversible microsphere-nanosphere morphological transitions(validated by scanning electron microscopy/dynamic light scattering),accompanied by a reversible fluorescence modulation.Both structural and optical modulations exhibit no apparent fatigue over 10 consecutive cycles.Energy decomposition analysis reveals stronger C29 binding energy(ΔE_(int)=-29.80 kcal/mol vs.C18’s-19.90 kcal/mol),explaining selective reversibility.Density functional theory calculations confirm the distinct highest occupied molecular orbital-lowest unoccupied molecular orbital gaps correlating with emission wavelengths.Leveraging the temperature/wavelength-dependent fluorescence,we constructed a multi-input logic gate.This work establishes a new insight for reversible assembly and enables smart and fatigue-resistant optoelectronic applications.
基金supported by the Petrochina Petrochemical Research Institute(LH-17-02-07-05)Open Foundation from State Key Laboratory of Fluorinated Functional Membrane Material。
文摘Intrinsic emission from unorthodox luminogens without traditional conjugated building blocks is drawing increasing attention.However,the emission mechanism is still controversial.Herein,we demonstrate the intriguing emission from perfluorosulfonate ionomers(PFSIs),which can be explained by the clustering triggered emission(CTE)mechanism.Despite being free of any conventional chromophores,PFSIs exhibit bright emission and multi-color phosphorescence(77 K)in concentrated solutions,powders and membranes with obvious aggregation-induced emission(AIE)characteristics.Clustered sulfonic acids are responsible for the light emission,and their connection and evolution are deeply explored via X-ray diffraction(XRD)and small angel X-ray scattering(SAXS),in which the electron overlap determined by the clustered status results in the extended conjugation and simultaneously rigidified conformations.These results demonstrate that it is feasible to use fluorescence analysis to explore the ionic cluster structure and evolution of PFSI,and it can be applied in the pure organic luminescent field as well.
