Massive efforts have been concentrated on the advance of eminent near-infrared(NIR) photothermal materials(PTMs) in the NIR-Ⅱ window(1000–1700 nm), especially organic PTMs because of their intrinsic biological safet...Massive efforts have been concentrated on the advance of eminent near-infrared(NIR) photothermal materials(PTMs) in the NIR-Ⅱ window(1000–1700 nm), especially organic PTMs because of their intrinsic biological safety compared with inorganic PTMs. However, so far, only a few NIR-Ⅱresponsive organic PTMs was explored, and their photothermal conversion efficiencies(PCEs) still remain relatively low. Herein, donor–acceptor conjugated diradical polymers with open-shell characteristics are explored for synergistically photothermal immunotherapy of metastatic tumors in the NIR-Ⅱ window. By employing side-chain regulation, the conjugated diradical polymer TTB-2 with obvious NIR-Ⅱ absorption was developed, and its nanoparticles realize a record-breaking PCE of 87.7% upon NIR-Ⅱ light illustration. In vitro and in vivo experiments demonstrate that TTB-2 nanoparticles show good tumor photoablation with navigation of photoacoustic imaging in the NIR-Ⅱ window, without any side-effect. Moreover, by combining with PD-1 antibody,the pulmonary metastasis of breast cancer is high-effectively prevented by the efficient photo-immunity effect. Thus, this study explores superior PTMs for cancer metastasis theranostics in the NIR-Ⅱ window, offering a new horizon in developing radical-characteristic NIR-Ⅱ photothermal materials.展开更多
By using one-dimensional tight-binding model modified to include electron-electric field interaction and electron-electron interaction,we theoretically explore the polarization process of exciton and biexciton in cis-...By using one-dimensional tight-binding model modified to include electron-electric field interaction and electron-electron interaction,we theoretically explore the polarization process of exciton and biexciton in cis-polyacetylene.The dynamical simulation is performed by adopting the non-adiabatic evolution approach.The results show that under the effect of moderate electric field,when the strength of electron-electron interaction is weak,the singlet exciton is stable but its polarization presents obvious oscillation.With the enhancement of interaction,it is dissociated into polaron pairs,the spin-flip of which can be observed through modulating the interaction strength.For the triplet exciton,the strong electron-electron interaction restrains its normal polarization,but it is still stable.In the case of biexciton,the strong electron-electron interaction not only dissociate it,but also flip its charge distribution.The yield of the possible states formed after the dissociation of exciton and biexciton is also calculated.展开更多
With tunable local electronic environment,high mass density of MN4sites,and ease of preparation,metal-organic conjugated coordinative polymer(CCP) with inherent electronic conductivity provides a promising alternative...With tunable local electronic environment,high mass density of MN4sites,and ease of preparation,metal-organic conjugated coordinative polymer(CCP) with inherent electronic conductivity provides a promising alternative to the well-known M-N-C electrocatalysts.Herein,the coordination reaction between Cu^(2+)and 1,2,4,5-tetraaminobenzene(TAB) was conducted on the surface of metallic Cu nanowires,forming a thin layer of CuN4-based CCP(Cu-TAB) on the Cu nanowire.More importantly,interfacial transfer of electrons from Cu core to the CuN4-based CCP nanoshell was observed within the resulting CuTAB@Cu,which was found to enrich the local electronic density of the CuN4sites.As such,the CuTAB@Cu demonstrates much improved affinity to the*COOH intermediate formed from the rate determining step;the energy barrier for C-C coupling,which is critical to convert CO_(2)into C2products,is also decreased.Accordingly,it delivers a current density of-9.1 mA cm^(-2)at a potential as high as 0.558 V(vs.RHE) in H-type cell and a Faraday efficiency of 46.4% for ethanol.This work emphasizes the profound role of interfacial interaction in tuning the local electronic structure and activating the CuN4-based CCPs for efficient electroreduction of CO_(2).展开更多
Chitosan-stavudine (d4T) conjugate with a succinic spacer was synthesized via carbodiimide coupling reaction and structurally characterized. In order to nanosize it for improving its therapeutic properties, the chit...Chitosan-stavudine (d4T) conjugate with a succinic spacer was synthesized via carbodiimide coupling reaction and structurally characterized. In order to nanosize it for improving its therapeutic properties, the chitosan-5'-O-succinyl-d4T conjugate was crosslinked with sodium tripolyphosphate (TPP) to obtain the chitosan-d4T conjugate nano-prodrug. The morphologies of chitosan-d4T conjugate nanoparticles were observed by transmission electron microscopy (TEM), and their zeta potential, particle size, and polydispersity (size distribution) were measured by the dynamic light scattering (DLS) techniques. In vitro drug release studies at pH 1.1 and pH 7.4 indicate that the crosslinked chitosan-d4T conjugate nano-prodrug can prevent the coupled d4T from leaking out before entering the target viral reservoirs and provide a mild sustained release without the burst release. The results reveal that constructing conjugated chitosan nano-prodrugs may be a promising approach for improving the therapy efficacy of drugs in antiviral treatment.展开更多
By replacing hexyl chains in poly(3-hexylthiophene)(P3HT)with 2-propoxyethyls,four poly(3-(2-propoxyethyl)thiophene)(P3POET)homopolymers with comparable polydispersity indexes(PDI)and regioregularities were prepared h...By replacing hexyl chains in poly(3-hexylthiophene)(P3HT)with 2-propoxyethyls,four poly(3-(2-propoxyethyl)thiophene)(P3POET)homopolymers with comparable polydispersity indexes(PDI)and regioregularities were prepared herein in addition with step increment of about 7 kDa on numberaverage molecular weight(M_(n))from around 11 to 32 kDa(accordingly denoted as P11k,P18k,P25k,and P32k).When doped in film by FeCl_(3)at the optimized conditions,the maximum power factor(PF_(max))increases greatly from 4.3μW·m^(-1)·K^(-2)for P11k to 8.8μW·m^(-1)·K^(-2)for P18k,and further to 9.7μW·m^(-1)·K^(-2)for P25k,followed by a slight decrease to 9.2μW·m^(-1)·K^(-2)for P32k.The close Seebeck coefficients(S)at PF_(max)are observed in these doped polymer films due to their consistent frontier orbital energy levels and Fermi levels.The main contribution to this PF_(max)evolution thus comes from the corresponding conductivities(σ).Theσvariation of the doped films can be rationally correlated with their microstructure evolution.展开更多
A photocatalyst of nanometer TiO2/conjugated polymer complex was successfully synthesized and characterized by spectroscopic methods and photocatalytic experiments. The complex photocatalyst could be activated by abso...A photocatalyst of nanometer TiO2/conjugated polymer complex was successfully synthesized and characterized by spectroscopic methods and photocatalytic experiments. The complex photocatalyst could be activated by absorbing both ultraviolet and visible light (λ = 190-800 nm). Methylene blue (MB) could be degraded more efficiently on the complex photocatalyst than on the TiO2 under natural light. The conjugated polymer played a promoting role in the photocatalytic degradation of MB. The calcination temperature had an important effect in degradation of dye and could be summarized as 260℃ 〉 300 ℃ 〉 340 ℃ 〉 220 ℃ 〉 180 ℃.展开更多
The title polymers PMS 8Pz,M=Mn Ⅱ,Fe Ⅱ,Co Ⅱ,Ni Ⅱ,Cu Ⅱ,Zn Ⅱ,were synthesized by teaction of 2,3,5,6 tetracyano 1,4 dithiin with corresponding metal salts ,respectively.The styucture and properties of th...The title polymers PMS 8Pz,M=Mn Ⅱ,Fe Ⅱ,Co Ⅱ,Ni Ⅱ,Cu Ⅱ,Zn Ⅱ,were synthesized by teaction of 2,3,5,6 tetracyano 1,4 dithiin with corresponding metal salts ,respectively.The styucture and properties of these polyers were characterized by elemental analysis,transmission electron microscope,DTA,IR, UV Vis,fluorescence and EPR spectra. It has been found that these conjugated polymers have the property of intrinsic semiconductor. The conductivity σ 298K of these polymers is in the range of 10 -9  ̄10 -3 S · cm -1 under pressure 10.63 MPa and incremental in the metal orderMn < Co<Fe<Zn<Cu<Ni.\ The photosensitivity of the MS 8Pz to the CdS PVA films is incremental in the metal order Zn < Mn < Co < Fe < Cu < Ni.展开更多
Soft-stamped nanoimprint lithography(NIL) is considered as one of the most effective processes of nanoscale patterning because of its low cost and high throughput. In this work, this method is used to emboss the pol...Soft-stamped nanoimprint lithography(NIL) is considered as one of the most effective processes of nanoscale patterning because of its low cost and high throughput. In this work, this method is used to emboss the poly(9, 9-dioctylfluorene)film. By reducing the linewidth of the nanogratings on the stamp, the orientations of nanocrystals are confined along the grating vector in the nanoimprint process, where the confinement linewidth is comparable to the geometrical size of the nanocrystal. When the linewidth is about 400 nm, the poly(9, 9-dioctylfluorene)(PFO) nanocrystals could be orderly arranged in the nanogratings, so that both pattern transfer and well-aligned nanocrystal arrangement could be achieved in a single step by the soft-stamped NIL. The relevant mechanism of the nanocrystalline alignment in these nanogratings is fully discussed. The modulation of nanocrystal alignment is of benefit to the charge mobilities and other performances of PFO-based devices for the future applications.展开更多
A novel bipolar conjugated polymer containing triphenylamine and 1, 3, 4-oxadiazole units was synthesized by Suzuki reaction. Its structure and properties were characterized by NMR, IR, UV-Vis, PL spectroscopy and el...A novel bipolar conjugated polymer containing triphenylamine and 1, 3, 4-oxadiazole units was synthesized by Suzuki reaction. Its structure and properties were characterized by NMR, IR, UV-Vis, PL spectroscopy and electrochemical measurement. The photoluminescent spectroscopy and cyclic voltammograms measurement demonstrated that the resulting polymer shows blue emission (477 nm) and possesses both electron and hole-transporting property.展开更多
According to the one-dimensional tight-binding Su-Schrieffer-Heeger model, we have investigated the effects of charged polarons on the static polarizability, axx, and the second order hyperpolarizabilities, γxxxx, of...According to the one-dimensional tight-binding Su-Schrieffer-Heeger model, we have investigated the effects of charged polarons on the static polarizability, axx, and the second order hyperpolarizabilities, γxxxx, of conjugated polymers. Our results are consistent qualitatively with previous ab initio and semi-empirical calculations. The origin of the universal growth is discussed using a local-view formalism that is based on the local atomic charge derivatives. Furthermore, combining the Su Schrieffer-Heeger model and the extended Hubbard model, we have investigated systematically the effects of electron-electron interactions on αxx and γxxxx of charged polymer chains. For a fixed value of the nearest-neighbour interaction V, the values of αxx and γxxxx increase as the on-site Coulomb interaction U increases for U 〈 Uc and decrease with U for U 〉 Uc, where Uc is a critical value of U at which the static polarizability or the second order hypcrpolarizability reaches a maximal value of αxx or γxxxx. It is found that the effect of the e-e interaction on the value of αxx is dependent on the ratio between U and V for either a short or a long charged polymer. Whereas, that effect on the value of γxxxx is sensitive both to the ratio of U to V and to the size of the molecule.展开更多
The title copolymer(PDEBO) was synthesized. The thermal characteristics of the polymer were determined by means of DSC and TGA, revealing that the polymer has a good thermal stability. The X-ray diffraction measuremen...The title copolymer(PDEBO) was synthesized. The thermal characteristics of the polymer were determined by means of DSC and TGA, revealing that the polymer has a good thermal stability. The X-ray diffraction measurements of the thin films showed that the polymer is disorder. Electroluminescence(EL) in the green region of the spectrum with a maximum at 500 nm was observed from the polymer films sandwiched between indium-tin-oxide and an Al electrode.展开更多
The novel shish-kebab-type liquid crystalline cross-conjugated (p-phenylene)s-poly(p-phenylenevinylene)s hybrid was synthesized through Gilch polymerization. Their structures and properties were characterized by N...The novel shish-kebab-type liquid crystalline cross-conjugated (p-phenylene)s-poly(p-phenylenevinylene)s hybrid was synthesized through Gilch polymerization. Their structures and properties were characterized by NMR, GPC, DSC, X-ray diffraction and polarizing optical microscope (POM). ^1H-NMR investigation of the polymers indicates that the shish-kebab-structure has a strong ability to suppress the structural defects in the polymers. The polymers are enantiotropic liquid crystals. The melting point (Tm) of the polymers decreases when the length of the alkoxy tails of the mesogenic units increases. The mesophase was identified by X-ray diffraction method. They showed not only a smectic LC phase, but also a strong green fluorescence in chloroform. The maximum absorption band of the "kebabs" of the two, 5-bis(4'- alkoxyphenyl)benzene at 280 nm did not appear in absorption spectra of the polymers. The same phenomena were also observed in the fluorescence spectra. These results imply that the polymers have formed a cross-conjugated uniform structure and achieved an extended n-conjugation polymer.展开更多
Suzuki coupling reaction is widely used in the construction of conjugated polymers; however, there is still no report describing the mechanism and coupling of 9,10-phenanthrenequinone(PQ) building blocks via Suzuki ...Suzuki coupling reaction is widely used in the construction of conjugated polymers; however, there is still no report describing the mechanism and coupling of 9,10-phenanthrenequinone(PQ) building blocks via Suzuki reaction because PQ is sensitive to bases and light. Herein is reported the efficient Suzuki coupling of PQ with 9,10-dialkylfluorene with Na2CO3 as basic species and high molecular weight PQ-Alt-Dialkyl-Fluorene conjugated copolymer obtained in an yield of 42%. Based on the characterization data and well-accepted literature, we proposed a step-by-step mechanistic explanation for the formation of the PQ containing alternating conjugated copolymer.展开更多
Conjugated microporous polymers(CMPs) are a unique class of porous organic materials, which are constructed with π-conjugation structures leading to intrinsic micropores. The CMPs properties such as high surface area...Conjugated microporous polymers(CMPs) are a unique class of porous organic materials, which are constructed with π-conjugation structures leading to intrinsic micropores. The CMPs properties such as high surface area, intrinsic and rich micropores, interlocking and rigid structure, extensive π-conjugation and tunable band-gap, chemical and thermal stability, together with tailored functionalities, contribute to its abundant potential for application in fields such as photocatalysis, optoelectronics, energy storage, and chemical sensors. Recently, CMPs have gained importance in the field of membranes for chemical separation. In this review, we briefly discuss the historical development of CMPs, followed by a detailed description of the progress in state-of-the-art design, preparation, and application of CMPs in membranes. Additionally, we provide inference on the future prospects of CMPs as membranes.展开更多
A novel soluble conjugated copolymer (propionic acid)-co-(propargyl alcohol) (PA-co-OHP) has been synthesized for the first time using a new palladium acetylide catalyst Pd(PPh3)(2)(C=CC(CH3)(2)OH)(2)(PPB). Thin film ...A novel soluble conjugated copolymer (propionic acid)-co-(propargyl alcohol) (PA-co-OHP) has been synthesized for the first time using a new palladium acetylide catalyst Pd(PPh3)(2)(C=CC(CH3)(2)OH)(2)(PPB). Thin film resistive humidity sensor based oil the copolymer doped with HClO4 was prepared. The impedance of the sensor changed from 10(3)similar to 10(7) Omega in 95%similar to 30%RH, and the response of that is very quick (<6 sec.). Preliminary results show the copolymer is a promising humidity sensitive material.展开更多
We have studied the electric-field-driven motion of a polaron by solving the time-dependent SchrSdinger equation nonadiabatically and the lattice equation of motion simultaneously. It is found that the polaron may exp...We have studied the electric-field-driven motion of a polaron by solving the time-dependent SchrSdinger equation nonadiabatically and the lattice equation of motion simultaneously. It is found that the polaron may experience two sequent transitions under high fields; one is the transition from the subsonic to the supersonic state, and the other from the supersonic to dissociated state. The acoustic mode is decoupled from the charge when the polaron moves at a speed faster than the sound speed, and then the optical mode is decoupled at the second transition to make the polaron dissociate completely.展开更多
Chiral polymers P-1 and P-2 were synthesized by the polymerization of (R)-3,3'-diiodo-2,2'-bisbutoxy-1,1'- binaphthyl (M- 1 ) with 2,5-di(4-ethynylphenyl)- 1,3,4-oxadiazole (M-3) and (R)-3,3'-diethylnyl-...Chiral polymers P-1 and P-2 were synthesized by the polymerization of (R)-3,3'-diiodo-2,2'-bisbutoxy-1,1'- binaphthyl (M- 1 ) with 2,5-di(4-ethynylphenyl)- 1,3,4-oxadiazole (M-3) and (R)-3,3'-diethylnyl-2,2'-bisbutoxy- 1,1 '-binaphthyl (M-2) with 1,2-di(4-bromophenyl)acetylene (M-4) under Sonogashira reaction, respectively. Both monomers and polymers were analyzed by NMR, MS, FT-IR, UV-Vis spectroscopy, DSC-TGA, fluorescence spectroscopy, GPC and CD spectroscopy. CD spectra of P-1 and P-2 are similar due to the same chiral center units and main chain structure. The long wavelengths CD effect of P-1 and P-2 can be regarded as the more extended conjugated structure and a highly rigid backbone in the polymer chain. Polymers have strong blue fluorescence due to the efficient energy migration from the extended n-electronic structure of the polymers to the chiral binaphthyl core and are expected to provide understanding of the relationship between molecular structure and fluorescent property of the chiral polymers.展开更多
^13C spin-lattice relaxation times (T1) of a conjugated polymer MEH-PPV in polymer/ layered silicate nanocomposites together with the steady state fluorescence emission and transient fluorescence decay measurements ...^13C spin-lattice relaxation times (T1) of a conjugated polymer MEH-PPV in polymer/ layered silicate nanocomposites together with the steady state fluorescence emission and transient fluorescence decay measurements have been investigated. The T1 values of the conjugated carbons decrease dramatically according to the reduction of polymer concentration in the nano composites, while the fluorescence life times (τ) show a linear prolonging tendency. The results are explained from the point of view of molecular dynamics.展开更多
Photoacoustic imaging(PAI)is a hybrid imaging method based on photoacoustic(PA)effects,which is able to capture the structure,function,and molecular information of biological tissues with high resolution.To date,thera...Photoacoustic imaging(PAI)is a hybrid imaging method based on photoacoustic(PA)effects,which is able to capture the structure,function,and molecular information of biological tissues with high resolution.To date,therapeutic techniques under the guidance of PAI have provided new strategies for accurate diagnosis and precise treatment of tumors.In particular,conjugated polymer nanoparticles have been extensively inspected for PA-based cancer theranostics largely due to their superior optical properties such as tunable spectrum and large absorption coefficient and their good biocompatibility,and abundant functional groups.This mini-review mainly focuses on the recent advances toward the development of novel conjugated polymer nanoparticles for PA-based multimodal imaging and cancer photothermal therapy.展开更多
Short wave near-infrared(SWIR,900-1700 nm)fluorescence imaging has attracted extensive research interest from scientists due to its high imaging quality.However,the variety of SWIR fluorescence imaging agents are quit...Short wave near-infrared(SWIR,900-1700 nm)fluorescence imaging has attracted extensive research interest from scientists due to its high imaging quality.However,the variety of SWIR fluorescence imaging agents are quite limited and the corresponding quantum efficiency is rela-tively low.In this work,a novel conjugated polymer PDTSDTBT was reported,consisting of a donor unit with a tetrahedral Si(sp3)named DTS and an acceptor unit named DTBT with branched side chains.The design approach of endowing the donor-acceptor structure with the branched side chains successfully increase the fluorescence quantum efficiency.The polymer was prepared into nanoparticles by nanoprecipitation.The PDTSDTBT nanoparticles showed an absorption peak of 626 nm and fluorescence emission peak of 924 nm.The quantum efficiency of the nanoparticles is 0.53%,which is higher than that of nanotube fluorophores(0.4%).The nanoparticles also demonstrate a photothermal effect,the temperature of nanoparticles solution could reach 45℃under excitation by 660 nm laser.Therefore,the PDTSDTBT nanoparticles is an excellent fluorescent imaging agent with potential photothermal applications.展开更多
基金The work was financially supported by the National Natural Science Foundation of China(No.52173135,22207024)Jiangsu Specially Appointed Professorship,Leading Talents of Innovation and Entrepreneurship of Gusu(ZXL2022496)the Suzhou Science and Technology Program(SKY2022039).
文摘Massive efforts have been concentrated on the advance of eminent near-infrared(NIR) photothermal materials(PTMs) in the NIR-Ⅱ window(1000–1700 nm), especially organic PTMs because of their intrinsic biological safety compared with inorganic PTMs. However, so far, only a few NIR-Ⅱresponsive organic PTMs was explored, and their photothermal conversion efficiencies(PCEs) still remain relatively low. Herein, donor–acceptor conjugated diradical polymers with open-shell characteristics are explored for synergistically photothermal immunotherapy of metastatic tumors in the NIR-Ⅱ window. By employing side-chain regulation, the conjugated diradical polymer TTB-2 with obvious NIR-Ⅱ absorption was developed, and its nanoparticles realize a record-breaking PCE of 87.7% upon NIR-Ⅱ light illustration. In vitro and in vivo experiments demonstrate that TTB-2 nanoparticles show good tumor photoablation with navigation of photoacoustic imaging in the NIR-Ⅱ window, without any side-effect. Moreover, by combining with PD-1 antibody,the pulmonary metastasis of breast cancer is high-effectively prevented by the efficient photo-immunity effect. Thus, this study explores superior PTMs for cancer metastasis theranostics in the NIR-Ⅱ window, offering a new horizon in developing radical-characteristic NIR-Ⅱ photothermal materials.
基金Project supported by the Natural Science Foundation of Shandong Province,China(Grant No.ZR2020MA070).
文摘By using one-dimensional tight-binding model modified to include electron-electric field interaction and electron-electron interaction,we theoretically explore the polarization process of exciton and biexciton in cis-polyacetylene.The dynamical simulation is performed by adopting the non-adiabatic evolution approach.The results show that under the effect of moderate electric field,when the strength of electron-electron interaction is weak,the singlet exciton is stable but its polarization presents obvious oscillation.With the enhancement of interaction,it is dissociated into polaron pairs,the spin-flip of which can be observed through modulating the interaction strength.For the triplet exciton,the strong electron-electron interaction restrains its normal polarization,but it is still stable.In the case of biexciton,the strong electron-electron interaction not only dissociate it,but also flip its charge distribution.The yield of the possible states formed after the dissociation of exciton and biexciton is also calculated.
基金The National Key Research and Development Program of China(2021YFA1502000 and 2022YFA1505300)the National Natural Science Foundation of China (22288102, 22072124)+1 种基金support from Beijing Synchrotron Radiation Facility (1W1B, BSRF)China Scholarship Council for the financial support。
文摘With tunable local electronic environment,high mass density of MN4sites,and ease of preparation,metal-organic conjugated coordinative polymer(CCP) with inherent electronic conductivity provides a promising alternative to the well-known M-N-C electrocatalysts.Herein,the coordination reaction between Cu^(2+)and 1,2,4,5-tetraaminobenzene(TAB) was conducted on the surface of metallic Cu nanowires,forming a thin layer of CuN4-based CCP(Cu-TAB) on the Cu nanowire.More importantly,interfacial transfer of electrons from Cu core to the CuN4-based CCP nanoshell was observed within the resulting CuTAB@Cu,which was found to enrich the local electronic density of the CuN4sites.As such,the CuTAB@Cu demonstrates much improved affinity to the*COOH intermediate formed from the rate determining step;the energy barrier for C-C coupling,which is critical to convert CO_(2)into C2products,is also decreased.Accordingly,it delivers a current density of-9.1 mA cm^(-2)at a potential as high as 0.558 V(vs.RHE) in H-type cell and a Faraday efficiency of 46.4% for ethanol.This work emphasizes the profound role of interfacial interaction in tuning the local electronic structure and activating the CuN4-based CCPs for efficient electroreduction of CO_(2).
基金Funded by the National Natural Science Foundation of China(Nos.20504018,20972014,20604010,20872010 and 20732004)the National Basic Research Program of China(No.2009CB930203)
文摘Chitosan-stavudine (d4T) conjugate with a succinic spacer was synthesized via carbodiimide coupling reaction and structurally characterized. In order to nanosize it for improving its therapeutic properties, the chitosan-5'-O-succinyl-d4T conjugate was crosslinked with sodium tripolyphosphate (TPP) to obtain the chitosan-d4T conjugate nano-prodrug. The morphologies of chitosan-d4T conjugate nanoparticles were observed by transmission electron microscopy (TEM), and their zeta potential, particle size, and polydispersity (size distribution) were measured by the dynamic light scattering (DLS) techniques. In vitro drug release studies at pH 1.1 and pH 7.4 indicate that the crosslinked chitosan-d4T conjugate nano-prodrug can prevent the coupled d4T from leaking out before entering the target viral reservoirs and provide a mild sustained release without the burst release. The results reveal that constructing conjugated chitosan nano-prodrugs may be a promising approach for improving the therapy efficacy of drugs in antiviral treatment.
基金Funded by the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing,Wuhan Univesity of Technology。
文摘By replacing hexyl chains in poly(3-hexylthiophene)(P3HT)with 2-propoxyethyls,four poly(3-(2-propoxyethyl)thiophene)(P3POET)homopolymers with comparable polydispersity indexes(PDI)and regioregularities were prepared herein in addition with step increment of about 7 kDa on numberaverage molecular weight(M_(n))from around 11 to 32 kDa(accordingly denoted as P11k,P18k,P25k,and P32k).When doped in film by FeCl_(3)at the optimized conditions,the maximum power factor(PF_(max))increases greatly from 4.3μW·m^(-1)·K^(-2)for P11k to 8.8μW·m^(-1)·K^(-2)for P18k,and further to 9.7μW·m^(-1)·K^(-2)for P25k,followed by a slight decrease to 9.2μW·m^(-1)·K^(-2)for P32k.The close Seebeck coefficients(S)at PF_(max)are observed in these doped polymer films due to their consistent frontier orbital energy levels and Fermi levels.The main contribution to this PF_(max)evolution thus comes from the corresponding conductivities(σ).Theσvariation of the doped films can be rationally correlated with their microstructure evolution.
文摘A photocatalyst of nanometer TiO2/conjugated polymer complex was successfully synthesized and characterized by spectroscopic methods and photocatalytic experiments. The complex photocatalyst could be activated by absorbing both ultraviolet and visible light (λ = 190-800 nm). Methylene blue (MB) could be degraded more efficiently on the complex photocatalyst than on the TiO2 under natural light. The conjugated polymer played a promoting role in the photocatalytic degradation of MB. The calcination temperature had an important effect in degradation of dye and could be summarized as 260℃ 〉 300 ℃ 〉 340 ℃ 〉 220 ℃ 〉 180 ℃.
文摘The title polymers PMS 8Pz,M=Mn Ⅱ,Fe Ⅱ,Co Ⅱ,Ni Ⅱ,Cu Ⅱ,Zn Ⅱ,were synthesized by teaction of 2,3,5,6 tetracyano 1,4 dithiin with corresponding metal salts ,respectively.The styucture and properties of these polyers were characterized by elemental analysis,transmission electron microscope,DTA,IR, UV Vis,fluorescence and EPR spectra. It has been found that these conjugated polymers have the property of intrinsic semiconductor. The conductivity σ 298K of these polymers is in the range of 10 -9  ̄10 -3 S · cm -1 under pressure 10.63 MPa and incremental in the metal orderMn < Co<Fe<Zn<Cu<Ni.\ The photosensitivity of the MS 8Pz to the CdS PVA films is incremental in the metal order Zn < Mn < Co < Fe < Cu < Ni.
基金Project supported by the National Natural Science Foundation of China(Grant No.21204058)
文摘Soft-stamped nanoimprint lithography(NIL) is considered as one of the most effective processes of nanoscale patterning because of its low cost and high throughput. In this work, this method is used to emboss the poly(9, 9-dioctylfluorene)film. By reducing the linewidth of the nanogratings on the stamp, the orientations of nanocrystals are confined along the grating vector in the nanoimprint process, where the confinement linewidth is comparable to the geometrical size of the nanocrystal. When the linewidth is about 400 nm, the poly(9, 9-dioctylfluorene)(PFO) nanocrystals could be orderly arranged in the nanogratings, so that both pattern transfer and well-aligned nanocrystal arrangement could be achieved in a single step by the soft-stamped NIL. The relevant mechanism of the nanocrystalline alignment in these nanogratings is fully discussed. The modulation of nanocrystal alignment is of benefit to the charge mobilities and other performances of PFO-based devices for the future applications.
基金This work was supported by the National Natural Science Foundation of China (No. 29725410 and 29992530) and Chinese Academy of Sciences (KJ951-A1-501-01).
文摘A novel bipolar conjugated polymer containing triphenylamine and 1, 3, 4-oxadiazole units was synthesized by Suzuki reaction. Its structure and properties were characterized by NMR, IR, UV-Vis, PL spectroscopy and electrochemical measurement. The photoluminescent spectroscopy and cyclic voltammograms measurement demonstrated that the resulting polymer shows blue emission (477 nm) and possesses both electron and hole-transporting property.
基金Project supported by the National Natural Science Foundation of China(Grant No.10574037)the Program for New Century Excellent Talents in University of Ministry of Education of China(Grant No.NCET-05-0262)+3 种基金the Hebei Provincial Outstanding Youth Science Fund(Grant No.A2009001512)the Key Project of Ministry of Education of China(Grant No.210021)the Natural Science Fund of Hebei Province,China(Grant No.A2010000357)the Educational Commission of Hebei Province, China(Grant No.2007124)
文摘According to the one-dimensional tight-binding Su-Schrieffer-Heeger model, we have investigated the effects of charged polarons on the static polarizability, axx, and the second order hyperpolarizabilities, γxxxx, of conjugated polymers. Our results are consistent qualitatively with previous ab initio and semi-empirical calculations. The origin of the universal growth is discussed using a local-view formalism that is based on the local atomic charge derivatives. Furthermore, combining the Su Schrieffer-Heeger model and the extended Hubbard model, we have investigated systematically the effects of electron-electron interactions on αxx and γxxxx of charged polymer chains. For a fixed value of the nearest-neighbour interaction V, the values of αxx and γxxxx increase as the on-site Coulomb interaction U increases for U 〈 Uc and decrease with U for U 〉 Uc, where Uc is a critical value of U at which the static polarizability or the second order hypcrpolarizability reaches a maximal value of αxx or γxxxx. It is found that the effect of the e-e interaction on the value of αxx is dependent on the ratio between U and V for either a short or a long charged polymer. Whereas, that effect on the value of γxxxx is sensitive both to the ratio of U to V and to the size of the molecule.
基金Supported by the National Natural Science Foundation of China(No.2 99740 2 5 ) and Zhejiang Provincial Nature Science Foundation(No.5 9910 0 ) State Key L aboratory of Silicon MaterialsL aboratory of Organnic Solids,Institute of Chemistry,Chinese Acade
文摘The title copolymer(PDEBO) was synthesized. The thermal characteristics of the polymer were determined by means of DSC and TGA, revealing that the polymer has a good thermal stability. The X-ray diffraction measurements of the thin films showed that the polymer is disorder. Electroluminescence(EL) in the green region of the spectrum with a maximum at 500 nm was observed from the polymer films sandwiched between indium-tin-oxide and an Al electrode.
基金This work was supported by the National Natural Science Foundation of China (No. 20574064).
文摘The novel shish-kebab-type liquid crystalline cross-conjugated (p-phenylene)s-poly(p-phenylenevinylene)s hybrid was synthesized through Gilch polymerization. Their structures and properties were characterized by NMR, GPC, DSC, X-ray diffraction and polarizing optical microscope (POM). ^1H-NMR investigation of the polymers indicates that the shish-kebab-structure has a strong ability to suppress the structural defects in the polymers. The polymers are enantiotropic liquid crystals. The melting point (Tm) of the polymers decreases when the length of the alkoxy tails of the mesogenic units increases. The mesophase was identified by X-ray diffraction method. They showed not only a smectic LC phase, but also a strong green fluorescence in chloroform. The maximum absorption band of the "kebabs" of the two, 5-bis(4'- alkoxyphenyl)benzene at 280 nm did not appear in absorption spectra of the polymers. The same phenomena were also observed in the fluorescence spectra. These results imply that the polymers have formed a cross-conjugated uniform structure and achieved an extended n-conjugation polymer.
基金the National Natural Science Foundation of China(Nos.20573040, 20474024, 20125421, 90101026 and 50303007)National Basic Research Program of China(Nos.2002CB6134003 and 2003CB314703) and PCSIRT
文摘Suzuki coupling reaction is widely used in the construction of conjugated polymers; however, there is still no report describing the mechanism and coupling of 9,10-phenanthrenequinone(PQ) building blocks via Suzuki reaction because PQ is sensitive to bases and light. Herein is reported the efficient Suzuki coupling of PQ with 9,10-dialkylfluorene with Na2CO3 as basic species and high molecular weight PQ-Alt-Dialkyl-Fluorene conjugated copolymer obtained in an yield of 42%. Based on the characterization data and well-accepted literature, we proposed a step-by-step mechanistic explanation for the formation of the PQ containing alternating conjugated copolymer.
基金supported by the King Abdullah University of Science and Technology,Saudi Arabia,under the competitive research grant URF/1/3769-01。
文摘Conjugated microporous polymers(CMPs) are a unique class of porous organic materials, which are constructed with π-conjugation structures leading to intrinsic micropores. The CMPs properties such as high surface area, intrinsic and rich micropores, interlocking and rigid structure, extensive π-conjugation and tunable band-gap, chemical and thermal stability, together with tailored functionalities, contribute to its abundant potential for application in fields such as photocatalysis, optoelectronics, energy storage, and chemical sensors. Recently, CMPs have gained importance in the field of membranes for chemical separation. In this review, we briefly discuss the historical development of CMPs, followed by a detailed description of the progress in state-of-the-art design, preparation, and application of CMPs in membranes. Additionally, we provide inference on the future prospects of CMPs as membranes.
文摘A novel soluble conjugated copolymer (propionic acid)-co-(propargyl alcohol) (PA-co-OHP) has been synthesized for the first time using a new palladium acetylide catalyst Pd(PPh3)(2)(C=CC(CH3)(2)OH)(2)(PPB). Thin film resistive humidity sensor based oil the copolymer doped with HClO4 was prepared. The impedance of the sensor changed from 10(3)similar to 10(7) Omega in 95%similar to 30%RH, and the response of that is very quick (<6 sec.). Preliminary results show the copolymer is a promising humidity sensitive material.
基金Project supported by the Major Program of the National Natural Science Foundation of China (Grant Nos 10474056, 90403110 and 10574082).
文摘We have studied the electric-field-driven motion of a polaron by solving the time-dependent SchrSdinger equation nonadiabatically and the lattice equation of motion simultaneously. It is found that the polaron may experience two sequent transitions under high fields; one is the transition from the subsonic to the supersonic state, and the other from the supersonic to dissociated state. The acoustic mode is decoupled from the charge when the polaron moves at a speed faster than the sound speed, and then the optical mode is decoupled at the second transition to make the polaron dissociate completely.
基金This work was supported by the National Natural Science Foundation of China (No. 20474028)Jiangsu Provincial Natural Science Foundation (No. BK2004086)
文摘Chiral polymers P-1 and P-2 were synthesized by the polymerization of (R)-3,3'-diiodo-2,2'-bisbutoxy-1,1'- binaphthyl (M- 1 ) with 2,5-di(4-ethynylphenyl)- 1,3,4-oxadiazole (M-3) and (R)-3,3'-diethylnyl-2,2'-bisbutoxy- 1,1 '-binaphthyl (M-2) with 1,2-di(4-bromophenyl)acetylene (M-4) under Sonogashira reaction, respectively. Both monomers and polymers were analyzed by NMR, MS, FT-IR, UV-Vis spectroscopy, DSC-TGA, fluorescence spectroscopy, GPC and CD spectroscopy. CD spectra of P-1 and P-2 are similar due to the same chiral center units and main chain structure. The long wavelengths CD effect of P-1 and P-2 can be regarded as the more extended conjugated structure and a highly rigid backbone in the polymer chain. Polymers have strong blue fluorescence due to the efficient energy migration from the extended n-electronic structure of the polymers to the chiral binaphthyl core and are expected to provide understanding of the relationship between molecular structure and fluorescent property of the chiral polymers.
基金supported by the National Natural Science Foundation of China(Grant No.20023003).
文摘^13C spin-lattice relaxation times (T1) of a conjugated polymer MEH-PPV in polymer/ layered silicate nanocomposites together with the steady state fluorescence emission and transient fluorescence decay measurements have been investigated. The T1 values of the conjugated carbons decrease dramatically according to the reduction of polymer concentration in the nano composites, while the fluorescence life times (τ) show a linear prolonging tendency. The results are explained from the point of view of molecular dynamics.
基金We acknowledge financial support from grants MYRG2014-00093-FHS,MYRG 2015-00036-FHS,MYRG2016-00110-FHS and MYRG2018-00081-FHS from the University of Macao in Macao and grants FDCT 0011/2018/A1 and FDCT 025/2015/A1 from the Macao government.
文摘Photoacoustic imaging(PAI)is a hybrid imaging method based on photoacoustic(PA)effects,which is able to capture the structure,function,and molecular information of biological tissues with high resolution.To date,therapeutic techniques under the guidance of PAI have provided new strategies for accurate diagnosis and precise treatment of tumors.In particular,conjugated polymer nanoparticles have been extensively inspected for PA-based cancer theranostics largely due to their superior optical properties such as tunable spectrum and large absorption coefficient and their good biocompatibility,and abundant functional groups.This mini-review mainly focuses on the recent advances toward the development of novel conjugated polymer nanoparticles for PA-based multimodal imaging and cancer photothermal therapy.
基金supported by the National Natural Science Foundation of China(21807062,21976099 and 31570355)the Shandong Provincial Natural Science Foundation(ZR2018BB014)+2 种基金the Source Innovation Project of Qingdao(171183jch)Qingdao Postdoctoral Applied Research Project(2018111)National College Students Innova-tion and Entrepreneurship Training Program(201910429007)
文摘Short wave near-infrared(SWIR,900-1700 nm)fluorescence imaging has attracted extensive research interest from scientists due to its high imaging quality.However,the variety of SWIR fluorescence imaging agents are quite limited and the corresponding quantum efficiency is rela-tively low.In this work,a novel conjugated polymer PDTSDTBT was reported,consisting of a donor unit with a tetrahedral Si(sp3)named DTS and an acceptor unit named DTBT with branched side chains.The design approach of endowing the donor-acceptor structure with the branched side chains successfully increase the fluorescence quantum efficiency.The polymer was prepared into nanoparticles by nanoprecipitation.The PDTSDTBT nanoparticles showed an absorption peak of 626 nm and fluorescence emission peak of 924 nm.The quantum efficiency of the nanoparticles is 0.53%,which is higher than that of nanotube fluorophores(0.4%).The nanoparticles also demonstrate a photothermal effect,the temperature of nanoparticles solution could reach 45℃under excitation by 660 nm laser.Therefore,the PDTSDTBT nanoparticles is an excellent fluorescent imaging agent with potential photothermal applications.