A series of soluble poly(p-phenylene vinylene) (PPV) derivatives were synthesized through dehydrochlorination with the p-metaoxy phenol as starting materials. The electronic characteristics of PPV derivatives were stu...A series of soluble poly(p-phenylene vinylene) (PPV) derivatives were synthesized through dehydrochlorination with the p-metaoxy phenol as starting materials. The electronic characteristics of PPV derivatives were studied.展开更多
The incorporation of mechanophores,motifs that transform mechanical stimulus into chemical reaction or optical variation,allows creating materials with stressresponsive properties.The most widely used mechanophore gen...The incorporation of mechanophores,motifs that transform mechanical stimulus into chemical reaction or optical variation,allows creating materials with stressresponsive properties.The most widely used mechanophore generally features a weak bond,but its cleavage is typical an irreversible process.Here,we showed that this problem can be solved by folding–unfolding of a molecular tweezer.We systematically studied the mechanochromic properties of polyurethanes with cyano-substituted oligo(p-phenylene)vinylene(COP)tweezer(DPU).As a control experiment,a class of polyurethanes containing only a single COP moiety(MPU)was also prepared.The DPU showed prominent mechanochromic properties,due to the intramolecular folding–unfolding of COP tweezer under mechanical stimulus.The process was efficient,reversible and optical detectable.However,due to the disability to form either intramolecular folding or intermolecular aggregation,the MPU sample was mechanical inert.展开更多
A water-soluble oligo(p-phenylkene vinylene) [4,4′-(1,4-phenylene dithenylene)-bis-(N-methyl pyridinium iodide)] was synthesized by Witting reaction. The oligomer was characterized by NMR, elemental analysis, UV-visi...A water-soluble oligo(p-phenylkene vinylene) [4,4′-(1,4-phenylene dithenylene)-bis-(N-methyl pyridinium iodide)] was synthesized by Witting reaction. The oligomer was characterized by NMR, elemental analysis, UV-visible spectrum, surface photovoltage spectrum and fluorescence spectrum.展开更多
Recently,photodynamic therapy(PDT)has attracted wide attention due to its less susceptibility to drug resistance,broad-spectrum biocidal activity and biosafety in normal tissues.However,the traditional photosensitizer...Recently,photodynamic therapy(PDT)has attracted wide attention due to its less susceptibility to drug resistance,broad-spectrum biocidal activity and biosafety in normal tissues.However,the traditional photosensitizers(Ps)face the disadvantage of poor therapeutic efficacy due to the requirement of an aerobic environment to generate ^(1)O_(2) through Type Ⅱ pathway.Herein,we designed and synthesized a novel cationic conjugated oligomer oligo(phenylene vinylene)(OPV)and studied its antibacterial photodynamic activity against both Gram-negative Escherichia coli(E.coli)and Gram-positive bacteria methicillin-resistant Staphylococcus aureus(MRSA).Importantly,the OpV can rapidly produce reactive oxygen species(ROs)through double pathways,Type Ⅰ and Ⅱ mechanism under white light irradiation,and efficiently kill E.coli and MRSA at a nanomolar level.The dual type photosensitizing capability makes OPV promising for enhanced PDT to treat pathogens and tumors in complex environments.展开更多
The oligo phenylene vinylene(oligo PV)/SiO 2 composite film was prepared by the sol gel process. The surface photovoltage spectroscopy(SPS) and electric field induced surface photovoltage spectroscopy(EFISPS) had been...The oligo phenylene vinylene(oligo PV)/SiO 2 composite film was prepared by the sol gel process. The surface photovoltage spectroscopy(SPS) and electric field induced surface photovoltage spectroscopy(EFISPS) had been used to investigate the charge transport process in olige PV/SiO 2 heterostructured composite. The results show that the oligo PV / SiO 2 composite film not only can improve the stability of oligo PV, but also have some photoelectric activity.展开更多
Materials with emission over the whole visible range(400-800 nm)have been obtained through incorporating single-colored CdTe nanocrystals(NCs)into a poly(p-phenylene vinylene)(PPV)precursor[the sulfonium polyelectroly...Materials with emission over the whole visible range(400-800 nm)have been obtained through incorporating single-colored CdTe nanocrystals(NCs)into a poly(p-phenylene vinylene)(PPV)precursor[the sulfonium polyelectrolyte precursor of PPV].Firstly,the quantum yield(QY)of the PPV precursor was improved to~50%via heat treatment of a mixed solution of the PPV precursor and poly(vinyl alcohol)(PVA)at 100°C for 3 min.Then,single-colored CdTe NCs were incorporated into the mixed solution.The introduction of the PVA was necessary to reduce the electrostatic interaction between the PPV precursor and CdTe NCs,which improved their compatibility.The reduced electrostatic interaction eliminated Förster resonance energy transfer(FRET)processes between NCs,as well as between NCs and the PPV precursor,which allowed the functional integration of the polymer and NCs.Consequently,polymer/NC composites with almost any Commission Internationale de L’Eclairage(CIE)coordinates can be achieved by simply changing the size and amount of the NCs.In particular,when the emission wavelength of the CdTe NCs was 559 nm,a pure white-light emitting material with CIE coordinates(0.337,0.332)was obtained.展开更多
This paper deals with the relationships between the structure of poly（p-phenylene vinylene）（PPV） film and treatment temperature and their mechanical properties.The chemical structures and aggregated structures of ...This paper deals with the relationships between the structure of poly（p-phenylene vinylene）（PPV） film and treatment temperature and their mechanical properties.The chemical structures and aggregated structures of PPV precursor（PPVpre） and PPV treated at three node temperatures（125,155 and 230 ℃） were investigated by FTIR spectrometry and X-ray diffraction.The results show that the content of trans-conformation and the size of the crystalline domains increased with the increase of treatment temperature.The mechanical performances of the corresponding polymers were studied by nanoindentation.The elastic modulus and hardness of PPV films decreased with the increases of the content of trans-conformation and the size of the crystalline domains.These results suggest that the conformation and the size of the crystalline domains are able to induce the elastic modulus and hardness variation of PPV films.展开更多
文摘A series of soluble poly(p-phenylene vinylene) (PPV) derivatives were synthesized through dehydrochlorination with the p-metaoxy phenol as starting materials. The electronic characteristics of PPV derivatives were studied.
基金This work was financially supported by the National Natural Science Foundation of China(Grant Nos.52103141 and 51803090)the Natural Science Foundation of Jiangsu Province(Grant Nos.BK20181025 and BK20191022)for financial support.
文摘The incorporation of mechanophores,motifs that transform mechanical stimulus into chemical reaction or optical variation,allows creating materials with stressresponsive properties.The most widely used mechanophore generally features a weak bond,but its cleavage is typical an irreversible process.Here,we showed that this problem can be solved by folding–unfolding of a molecular tweezer.We systematically studied the mechanochromic properties of polyurethanes with cyano-substituted oligo(p-phenylene)vinylene(COP)tweezer(DPU).As a control experiment,a class of polyurethanes containing only a single COP moiety(MPU)was also prepared.The DPU showed prominent mechanochromic properties,due to the intramolecular folding–unfolding of COP tweezer under mechanical stimulus.The process was efficient,reversible and optical detectable.However,due to the disability to form either intramolecular folding or intermolecular aggregation,the MPU sample was mechanical inert.
基金supported by the Major Basic Research Project(Grant No.2002CB613401)the Foundation of Jilin university.
文摘A water-soluble oligo(p-phenylkene vinylene) [4,4′-(1,4-phenylene dithenylene)-bis-(N-methyl pyridinium iodide)] was synthesized by Witting reaction. The oligomer was characterized by NMR, elemental analysis, UV-visible spectrum, surface photovoltage spectrum and fluorescence spectrum.
基金financial support from the National Natural Science Foundation of China(Grants 21974084,22274095 and 22101310)Innovation Capability Support Program of Shaanxi(Program no.2021TD-42)Fundamental Research Funds for the Central Universities(No.GK202302004,GK202207013,and GK202101001).
文摘Recently,photodynamic therapy(PDT)has attracted wide attention due to its less susceptibility to drug resistance,broad-spectrum biocidal activity and biosafety in normal tissues.However,the traditional photosensitizers(Ps)face the disadvantage of poor therapeutic efficacy due to the requirement of an aerobic environment to generate ^(1)O_(2) through Type Ⅱ pathway.Herein,we designed and synthesized a novel cationic conjugated oligomer oligo(phenylene vinylene)(OPV)and studied its antibacterial photodynamic activity against both Gram-negative Escherichia coli(E.coli)and Gram-positive bacteria methicillin-resistant Staphylococcus aureus(MRSA).Importantly,the OpV can rapidly produce reactive oxygen species(ROs)through double pathways,Type Ⅰ and Ⅱ mechanism under white light irradiation,and efficiently kill E.coli and MRSA at a nanomolar level.The dual type photosensitizing capability makes OPV promising for enhanced PDT to treat pathogens and tumors in complex environments.
文摘The oligo phenylene vinylene(oligo PV)/SiO 2 composite film was prepared by the sol gel process. The surface photovoltage spectroscopy(SPS) and electric field induced surface photovoltage spectroscopy(EFISPS) had been used to investigate the charge transport process in olige PV/SiO 2 heterostructured composite. The results show that the oligo PV / SiO 2 composite film not only can improve the stability of oligo PV, but also have some photoelectric activity.
基金This work was supported by National Natural Science Foundation of China(NSFC)(Nos.20804008,20974038,50973039,and 20921003)National Program on Key Basic Research Project(973 Program)(Nos.2007CB936402 and 2009CB939701)the China Postdoctoral Science Foundation(No.20090450139).
文摘Materials with emission over the whole visible range(400-800 nm)have been obtained through incorporating single-colored CdTe nanocrystals(NCs)into a poly(p-phenylene vinylene)(PPV)precursor[the sulfonium polyelectrolyte precursor of PPV].Firstly,the quantum yield(QY)of the PPV precursor was improved to~50%via heat treatment of a mixed solution of the PPV precursor and poly(vinyl alcohol)(PVA)at 100°C for 3 min.Then,single-colored CdTe NCs were incorporated into the mixed solution.The introduction of the PVA was necessary to reduce the electrostatic interaction between the PPV precursor and CdTe NCs,which improved their compatibility.The reduced electrostatic interaction eliminated Förster resonance energy transfer(FRET)processes between NCs,as well as between NCs and the PPV precursor,which allowed the functional integration of the polymer and NCs.Consequently,polymer/NC composites with almost any Commission Internationale de L’Eclairage(CIE)coordinates can be achieved by simply changing the size and amount of the NCs.In particular,when the emission wavelength of the CdTe NCs was 559 nm,a pure white-light emitting material with CIE coordinates(0.337,0.332)was obtained.
基金Supported by the National Natural Science Foundation of China（No.51173155）.
文摘This paper deals with the relationships between the structure of poly（p-phenylene vinylene）（PPV） film and treatment temperature and their mechanical properties.The chemical structures and aggregated structures of PPV precursor（PPVpre） and PPV treated at three node temperatures（125,155 and 230 ℃） were investigated by FTIR spectrometry and X-ray diffraction.The results show that the content of trans-conformation and the size of the crystalline domains increased with the increase of treatment temperature.The mechanical performances of the corresponding polymers were studied by nanoindentation.The elastic modulus and hardness of PPV films decreased with the increases of the content of trans-conformation and the size of the crystalline domains.These results suggest that the conformation and the size of the crystalline domains are able to induce the elastic modulus and hardness variation of PPV films.
