用DFT-B3LYP方法对低聚物(PF30T)_n[n(芴):n(硫芴)=2:1,物质的量之比,n=1～4],(PF50T)_n[n(芴):n(硫芴) =1:1,物质的量之比,n=1～4]体系全优化,得到两系列低聚物的电离能(IP_(a,v))、电子亲和势(EA_(a,v))、空穴抽取能(HEP)、电子抽取能...用DFT-B3LYP方法对低聚物(PF30T)_n[n(芴):n(硫芴)=2:1,物质的量之比,n=1～4],(PF50T)_n[n(芴):n(硫芴) =1:1,物质的量之比,n=1～4]体系全优化,得到两系列低聚物的电离能(IP_(a,v))、电子亲和势(EA_(a,v))、空穴抽取能(HEP)、电子抽取能(EEP),在此基础上用ZINDO和TD-DFT方法计算吸收光谱,分析了两个系列的HOMO-LUMO能隙随着n递增的变化趋势及硫芴含量对低聚物电子结构和光谱性质的影响,推断了高聚物的电子和光谱性质,用ab initio CIS方法优化了低聚物的S_1激发态结构并分析了其与发射光谱的关系,研究显示:2,8位引入的硫芴基团,破坏了链的共轭,而且随着硫芴含量的增加,HOMO-LUMO能隙变大,光谱蓝移:激发态结构趋于共面化。展开更多
The interface and surface properties of nano-hydroxyapatite(n-HA) and poly( 1, 4-phenylene sulfide)-poly (2,4-phenylene sulfide acid)(PPS-PPSA) copolymer composite were investigated. The results show that there are so...The interface and surface properties of nano-hydroxyapatite(n-HA) and poly( 1, 4-phenylene sulfide)-poly (2,4-phenylene sulfide acid)(PPS-PPSA) copolymer composite were investigated. The results show that there are some strong interface combinations of calcium ion (Ca2+ ), car-boxyl (-COO- ) and phosphate radicle ion (PO_4~3- ) between copolymer and n-HA in the composite. The presence of the 2,4-phenylene sulfide acid in copolymer can increase the affinity to n-HA, which causes the formation of chemical bindings between the PPS-PPSA copolymer and n-HA. XRD analysis and IR surface analysis indicate that n-HA is not encapsulated by copolymer but exposed on the surface of the composite, and has same structure and properties with the origi-nal n-HA. The presence of the interface chemical bindings between the PPS-PPSA copolymer and n-HA can increase the content of n-HA in composite but does not cause the decrease of the composite mechanical strength.展开更多
The medium band gap donor-acceptor （D-A） copolymer J61 based on bi（alkylthio-thienyl）benzodithiophene as donor unit and fluorobenzotriazole as acceptor unit and thiophene as n-bridge has demonstrated excellent pho...The medium band gap donor-acceptor （D-A） copolymer J61 based on bi（alkylthio-thienyl）benzodithiophene as donor unit and fluorobenzotriazole as acceptor unit and thiophene as n-bridge has demonstrated excellent photovoltaic performance as donor material in nonfullerene polymer solar cells （PSCs） with narrow bandgap n-type organic semiconductor ITIC as acceptor. For studying the effect of n-bridges on the photovoltaic performance of the D-A copolymers, here we synthesized a new D-A copolymer J61-F based on the same donor and acceptor units as J61 but with furan n-bridges instead of thiophene. J61-F possesses a deeper the highest occupied molecular orbital （HOMO） level at -5.45 eV in comparison with that （-5.32 eV） of J61. The non-fullerene PSCs based on J61-F：ITIC exhibited a maximum power conversion efficiency （PCE） of 8.24% with a higher open-circuit voltage （Voc） of 0.95 V, which is benefitted from the lower-lying HOMO energy level of J61-F donor material. The results indicate that main chain engineering by changing n-bridges is another effective way to tune the electronic energy levels of the conjugated D-A copolymers for the application as donor materials in non-fullerene PSCs.展开更多
Inherent brittleness and low heat resistance are the two major obstacles that hinder the wide applications of poly（L-lactide）（PLLA）. In this study,we report a fully biobased,highly toughened and heat-resistant PLL...Inherent brittleness and low heat resistance are the two major obstacles that hinder the wide applications of poly（L-lactide）（PLLA）. In this study,we report a fully biobased,highly toughened and heat-resistant PLLA ternary blend,which was prepared by dynamic vulcanization of PLLA with poly（D-lactide）（PDLA） and an unsaturated bioelastomer（UBE）. The results indicated that during dynamic vulcanization PDLA cocrystallized with PLLA to form stereocomplex（SC） crystallites,which not only enhanced the molecular entanglement but also accelerated the crystallization rate of PLLA matrix. With increase in the content of PDLA,the matrix molecular entanglement increased while phase-separation was enhanced,which enabled the impact strength to increase first and then decrease. The ternary blends containing 10 wt.% PDLA showed the highest impact strength. The presence of SC crystallites makes it possible to achieve a fully sustainable PLLA/VUB/PDLA ternary blend with highly crystalline matrix under conventional injection molding,due to the high nucleation efficiency of SC towards crystallization of PLLA. The highly crystalline ternary blend showed excellent heat resistance and better impact toughness than high impact polystyrene.展开更多
文摘用DFT-B3LYP方法对低聚物(PF30T)_n[n(芴):n(硫芴)=2:1,物质的量之比,n=1～4],(PF50T)_n[n(芴):n(硫芴) =1:1,物质的量之比,n=1～4]体系全优化,得到两系列低聚物的电离能(IP_(a,v))、电子亲和势(EA_(a,v))、空穴抽取能(HEP)、电子抽取能(EEP),在此基础上用ZINDO和TD-DFT方法计算吸收光谱,分析了两个系列的HOMO-LUMO能隙随着n递增的变化趋势及硫芴含量对低聚物电子结构和光谱性质的影响,推断了高聚物的电子和光谱性质,用ab initio CIS方法优化了低聚物的S_1激发态结构并分析了其与发射光谱的关系,研究显示:2,8位引入的硫芴基团,破坏了链的共轭,而且随着硫芴含量的增加,HOMO-LUMO能隙变大,光谱蓝移:激发态结构趋于共面化。
文摘The interface and surface properties of nano-hydroxyapatite(n-HA) and poly( 1, 4-phenylene sulfide)-poly (2,4-phenylene sulfide acid)(PPS-PPSA) copolymer composite were investigated. The results show that there are some strong interface combinations of calcium ion (Ca2+ ), car-boxyl (-COO- ) and phosphate radicle ion (PO_4~3- ) between copolymer and n-HA in the composite. The presence of the 2,4-phenylene sulfide acid in copolymer can increase the affinity to n-HA, which causes the formation of chemical bindings between the PPS-PPSA copolymer and n-HA. XRD analysis and IR surface analysis indicate that n-HA is not encapsulated by copolymer but exposed on the surface of the composite, and has same structure and properties with the origi-nal n-HA. The presence of the interface chemical bindings between the PPS-PPSA copolymer and n-HA can increase the content of n-HA in composite but does not cause the decrease of the composite mechanical strength.
基金supported by the National Basic Research Program,Ministry of Science and Technology of China(2014CB643501)Beijing Nova program(Z171100001117074)+1 种基金the National Natural Science Foundation of China(91633301,91433117,21374124)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB12030200)
文摘The medium band gap donor-acceptor （D-A） copolymer J61 based on bi（alkylthio-thienyl）benzodithiophene as donor unit and fluorobenzotriazole as acceptor unit and thiophene as n-bridge has demonstrated excellent photovoltaic performance as donor material in nonfullerene polymer solar cells （PSCs） with narrow bandgap n-type organic semiconductor ITIC as acceptor. For studying the effect of n-bridges on the photovoltaic performance of the D-A copolymers, here we synthesized a new D-A copolymer J61-F based on the same donor and acceptor units as J61 but with furan n-bridges instead of thiophene. J61-F possesses a deeper the highest occupied molecular orbital （HOMO） level at -5.45 eV in comparison with that （-5.32 eV） of J61. The non-fullerene PSCs based on J61-F：ITIC exhibited a maximum power conversion efficiency （PCE） of 8.24% with a higher open-circuit voltage （Voc） of 0.95 V, which is benefitted from the lower-lying HOMO energy level of J61-F donor material. The results indicate that main chain engineering by changing n-bridges is another effective way to tune the electronic energy levels of the conjugated D-A copolymers for the application as donor materials in non-fullerene PSCs.
基金supported by the National Science Foundation of China (51673158)the Opening Project of Key Laboratory of Polymer Processing Engineering (South China University of Technology),Ministry of Education (KFKT02)the Fundamental Research Funds for the Central Universities (XDJK2017A016 and XDJK2017C022)
文摘Inherent brittleness and low heat resistance are the two major obstacles that hinder the wide applications of poly（L-lactide）（PLLA）. In this study,we report a fully biobased,highly toughened and heat-resistant PLLA ternary blend,which was prepared by dynamic vulcanization of PLLA with poly（D-lactide）（PDLA） and an unsaturated bioelastomer（UBE）. The results indicated that during dynamic vulcanization PDLA cocrystallized with PLLA to form stereocomplex（SC） crystallites,which not only enhanced the molecular entanglement but also accelerated the crystallization rate of PLLA matrix. With increase in the content of PDLA,the matrix molecular entanglement increased while phase-separation was enhanced,which enabled the impact strength to increase first and then decrease. The ternary blends containing 10 wt.% PDLA showed the highest impact strength. The presence of SC crystallites makes it possible to achieve a fully sustainable PLLA/VUB/PDLA ternary blend with highly crystalline matrix under conventional injection molding,due to the high nucleation efficiency of SC towards crystallization of PLLA. The highly crystalline ternary blend showed excellent heat resistance and better impact toughness than high impact polystyrene.
