Most research on copolymers with fluorinated monomers has focused on the relationship between fluorinated monomer content and the corresponding surface structure. However,the influence of the non-fluorinated block on ...Most research on copolymers with fluorinated monomers has focused on the relationship between fluorinated monomer content and the corresponding surface structure. However,the influence of the non-fluorinated block on the surface structure of the copolymer film is unknown. Various molecular weight poly(butyl methacrylates) (PBMA) end-capped with 2-perfluorooctylethyl methacrylate (FMA) units (PBMA-ec-FMA) have been synthesized by atom transfer radical polymerization (ATRP). The effect of the PBMA block length on the surface structure and properties of the polymers both in the solid state and in solution was investigated using various techniques. X-ray photoelectron spectroscopy (XPS),sum frequency generation (SFG) vibrational spectroscopy and X-ray diffraction (XRD) analyses indicated that longer PBMA blocks enhanced both the enrichment of the fluorinated moieties and the order of the packing orientation of the perfluoroalkyl side chains on the surface. This enhancement was attributed mainly to the molecular aggregate structure of the end-capped polymers with long PBMA blocks in the solution and to the interfacial structure at the air/liquid interface,which favors the -(CF2)7CF3 moieties self-assembling on the polymer surface during film formation. This observation suggests that the polyacrylate block structure in fluorinated diblock copolymers,in addition to the fluorinated monomer content,plays an important role in structure formation on the solid surface.展开更多
Triblock copolymer of poly（p-dioxanone） and polyethylene glycol end-capped with pyrene moieties（（Py-PPDO）_2-b-PEG） was synthesized and used as modifier for multi-wall carbon nanotubes（MWCNTs）.Nano-aggregates（...Triblock copolymer of poly（p-dioxanone） and polyethylene glycol end-capped with pyrene moieties（（Py-PPDO）_2-b-PEG） was synthesized and used as modifier for multi-wall carbon nanotubes（MWCNTs）.Nano-aggregates（（Py-PPDO）_2-b-PEG@MWCNTs） with shish-kebab like partially wrapped morphology and very good stability were obtained by incorporating the copolymer with MWCNTs.The bare MWCNT sections of（Py-PPDO）_2-b-PEG@MWCNTs were able to induce n-n interactions with graphene（GE） and resulted in a novel GE/（Py-PPDO）_2-b-PEG@MWCNTs hybrid.The dispersity of GE in solution or polymer matrix was therefore greatly improved.The PCL nanocomposite films using GE/（Py-PPDO）_2-bPEG@MWCNTs as hybrid nanofiller exhibited obviously improved mechanical properties especially at very low hybrid nanofiller content.The influence of the nanofiller content and feed ratio of GE/MWCNTs on the mechanical properties of composites films was evaluated.When the feed ratio of GE to MWCNTs is 2：8 and the total loading of nanofiller is only 0.01 wt%,the tensile strength of the composite film increased by 163%and the elongation at break increased by 17% compared to those of neat PCL These results can be attributed to fine dispersion of the nanofillers in PCL matrix and the hybrid interactions between GE and MWCNTs.Therefore,this work provides a novel method for preparing polymer nanocomposites with high mechanical performance and low nanofiller loading.展开更多
The effects of end-capped modifications of a polymer donor with high molecular weight on non-fullerene solar cells are largely ignored,even if the chain-end-functionalized method of conjugated polymers is an effective...The effects of end-capped modifications of a polymer donor with high molecular weight on non-fullerene solar cells are largely ignored,even if the chain-end-functionalized method of conjugated polymers is an effective strategy in modulating polymeric optical-electronic properties.In this study,we design and synthesize an end-capped polymer,PM6TPO,via a reaction with the parent polymer PM6.Meanwhile,the conventional detection methods of X-ray photoelectron spectroscopy(XPS),matrix-assisted laser desorption/ionization time-of-flight(MALDI-TOF),and ^(1)H nuclear magnetic resonance(^(1)H NMR) were replaced by simple solution-based inductively coupled plasma-mass spectrometry(ICP-MS) to evaluate the end-capped efficacy of PM6TPO.By introducing end-capped groups on a high molecular weight polymer donor,we could finely tune the aggregated behavior,strengthen the miscibility between the donor and acceptor without sacrificing the strong aggregated properties,and reduce the non-radiative recombination with a lower energy loss.Therefore,the PM6TPO-based organic solar cell(OSC)realized a higher open-circuit voltage of 0.843 V and PCE of 17.26% than that of the non-end-capped parent polymer,PM6(0.824 V and 16.21%,respectively).This work not only provides a straightforward method for verifying the end-capped efficacy of a high molecular weight polymer but also indicates a new research direction for improving the photovoltaic performance of non-fullerene-based solar cells.展开更多
以偶氮二异丁腈、十二胺为主要原料,通过Pinner反应制备了一种两端各带有12个碳烷基链的水溶性偶氮引发剂——2,2'-偶氮二异丁基十二脒盐酸盐AIBL.采用核磁氢谱、元素分析及液相色谱对AIBL进行了结构及纯度表征,采用TGA、DSC和紫外...以偶氮二异丁腈、十二胺为主要原料,通过Pinner反应制备了一种两端各带有12个碳烷基链的水溶性偶氮引发剂——2,2'-偶氮二异丁基十二脒盐酸盐AIBL.采用核磁氢谱、元素分析及液相色谱对AIBL进行了结构及纯度表征,采用TGA、DSC和紫外分光光度计研究了其热分解现象和热分解动力学,采用表面张力仪对其表面活性进行了测定.结果表明,所合成的引发剂AIBL具有预想的结构和较高的纯度,其热分解反应属于一级反应,热分解活化能为134.80 k J/mol,70℃下水中的半衰期约为4 h;AIBL在水溶液中具有表面活性,其临界胶束浓度为0.13 g/L,对应的表面张力为33.57 m N/m.以丙烯酰胺为单体、AIBL为引发剂制备了水溶性端基疏水聚合物SPAM.采用溴化法研究其转化率,应用乌氏黏度法、零切黏度法以及荧光探针对其缔合作用进行了研究.结果表明,AIBL具有良好的引发丙烯酰胺聚合的能力;相对于不带疏水长链的引发剂所合成的聚合物PAM,SPAM具有明显的疏水缔合效应,这说明AIBL成功地将疏水长链引入到聚合物的端基中,从而形成端基疏水聚合物.展开更多
基金Supported by the National Natural Science Foundation of China (Grant Nos. 50573069 & 20704038) Program for Changjiang Scholars and Innovative Re-search Team in University (Grant No. IRT 0654)
文摘Most research on copolymers with fluorinated monomers has focused on the relationship between fluorinated monomer content and the corresponding surface structure. However,the influence of the non-fluorinated block on the surface structure of the copolymer film is unknown. Various molecular weight poly(butyl methacrylates) (PBMA) end-capped with 2-perfluorooctylethyl methacrylate (FMA) units (PBMA-ec-FMA) have been synthesized by atom transfer radical polymerization (ATRP). The effect of the PBMA block length on the surface structure and properties of the polymers both in the solid state and in solution was investigated using various techniques. X-ray photoelectron spectroscopy (XPS),sum frequency generation (SFG) vibrational spectroscopy and X-ray diffraction (XRD) analyses indicated that longer PBMA blocks enhanced both the enrichment of the fluorinated moieties and the order of the packing orientation of the perfluoroalkyl side chains on the surface. This enhancement was attributed mainly to the molecular aggregate structure of the end-capped polymers with long PBMA blocks in the solution and to the interfacial structure at the air/liquid interface,which favors the -(CF2)7CF3 moieties self-assembling on the polymer surface during film formation. This observation suggests that the polyacrylate block structure in fluorinated diblock copolymers,in addition to the fluorinated monomer content,plays an important role in structure formation on the solid surface.
基金financially supported by the National Natural Science Foundation of China(No.21474066)the Foundation for Young Scientists of State Key Laboratory of Polymer Materials Engineering(No.sklpme2014-3-09)
文摘Triblock copolymer of poly（p-dioxanone） and polyethylene glycol end-capped with pyrene moieties（（Py-PPDO）_2-b-PEG） was synthesized and used as modifier for multi-wall carbon nanotubes（MWCNTs）.Nano-aggregates（（Py-PPDO）_2-b-PEG@MWCNTs） with shish-kebab like partially wrapped morphology and very good stability were obtained by incorporating the copolymer with MWCNTs.The bare MWCNT sections of（Py-PPDO）_2-b-PEG@MWCNTs were able to induce n-n interactions with graphene（GE） and resulted in a novel GE/（Py-PPDO）_2-b-PEG@MWCNTs hybrid.The dispersity of GE in solution or polymer matrix was therefore greatly improved.The PCL nanocomposite films using GE/（Py-PPDO）_2-bPEG@MWCNTs as hybrid nanofiller exhibited obviously improved mechanical properties especially at very low hybrid nanofiller content.The influence of the nanofiller content and feed ratio of GE/MWCNTs on the mechanical properties of composites films was evaluated.When the feed ratio of GE to MWCNTs is 2：8 and the total loading of nanofiller is only 0.01 wt%,the tensile strength of the composite film increased by 163%and the elongation at break increased by 17% compared to those of neat PCL These results can be attributed to fine dispersion of the nanofillers in PCL matrix and the hybrid interactions between GE and MWCNTs.Therefore,this work provides a novel method for preparing polymer nanocomposites with high mechanical performance and low nanofiller loading.
基金financially supported by the Beijing Natural Science Foundation (2212032)the National Natural Science Foundation of China (21774003, 51873221, 52073292, 51673207, 51373183)+1 种基金the Key Laboratory of Bioinspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, the Chinese Academy of Sciences, Beijing Municipal Science & Technology Commission (Z181100004418012)the Beihang University Youth Talent Support Program (YWF-18-BJ-J-218)。
文摘The effects of end-capped modifications of a polymer donor with high molecular weight on non-fullerene solar cells are largely ignored,even if the chain-end-functionalized method of conjugated polymers is an effective strategy in modulating polymeric optical-electronic properties.In this study,we design and synthesize an end-capped polymer,PM6TPO,via a reaction with the parent polymer PM6.Meanwhile,the conventional detection methods of X-ray photoelectron spectroscopy(XPS),matrix-assisted laser desorption/ionization time-of-flight(MALDI-TOF),and ^(1)H nuclear magnetic resonance(^(1)H NMR) were replaced by simple solution-based inductively coupled plasma-mass spectrometry(ICP-MS) to evaluate the end-capped efficacy of PM6TPO.By introducing end-capped groups on a high molecular weight polymer donor,we could finely tune the aggregated behavior,strengthen the miscibility between the donor and acceptor without sacrificing the strong aggregated properties,and reduce the non-radiative recombination with a lower energy loss.Therefore,the PM6TPO-based organic solar cell(OSC)realized a higher open-circuit voltage of 0.843 V and PCE of 17.26% than that of the non-end-capped parent polymer,PM6(0.824 V and 16.21%,respectively).This work not only provides a straightforward method for verifying the end-capped efficacy of a high molecular weight polymer but also indicates a new research direction for improving the photovoltaic performance of non-fullerene-based solar cells.
文摘以偶氮二异丁腈、十二胺为主要原料,通过Pinner反应制备了一种两端各带有12个碳烷基链的水溶性偶氮引发剂——2,2'-偶氮二异丁基十二脒盐酸盐AIBL.采用核磁氢谱、元素分析及液相色谱对AIBL进行了结构及纯度表征,采用TGA、DSC和紫外分光光度计研究了其热分解现象和热分解动力学,采用表面张力仪对其表面活性进行了测定.结果表明,所合成的引发剂AIBL具有预想的结构和较高的纯度,其热分解反应属于一级反应,热分解活化能为134.80 k J/mol,70℃下水中的半衰期约为4 h;AIBL在水溶液中具有表面活性,其临界胶束浓度为0.13 g/L,对应的表面张力为33.57 m N/m.以丙烯酰胺为单体、AIBL为引发剂制备了水溶性端基疏水聚合物SPAM.采用溴化法研究其转化率,应用乌氏黏度法、零切黏度法以及荧光探针对其缔合作用进行了研究.结果表明,AIBL具有良好的引发丙烯酰胺聚合的能力;相对于不带疏水长链的引发剂所合成的聚合物PAM,SPAM具有明显的疏水缔合效应,这说明AIBL成功地将疏水长链引入到聚合物的端基中,从而形成端基疏水聚合物.
