Layer-by-layer (LBL) self-assembly method was used to fabricate siliceous ultrathin films by using polyhedral oligomeric silsesquioxanes as building blocks. Ammonium salt of octasilsesquioxane acid (OSi8) and poly(dia...Layer-by-layer (LBL) self-assembly method was used to fabricate siliceous ultrathin films by using polyhedral oligomeric silsesquioxanes as building blocks. Ammonium salt of octasilsesquioxane acid (OSi8) and poly(diallyldimethylammonium chloride) (PDDA) were alternately assembled onto CaF2 slide to form nanocomposite multilayers. Linear build-up of the LBL films was confirmed by UV-Vis spectroscopy. IR spectrum suggests existence of OSi8 and PDDA in the LBL films. Atomic force microscopic surface topography of the LBL films indicates the OSi8 covers the entire surface of the topmost layer and shows a granular morphology.展开更多
Polyvinylcarbazole（PVK） composites containing organic-inorganic hybrid polyhedral oligomeric silse-squioxane（POSS） PVK-POSS were prepared by free radical polymerization. POSS monomers reacted with vinylcarbazole a...Polyvinylcarbazole（PVK） composites containing organic-inorganic hybrid polyhedral oligomeric silse-squioxane（POSS） PVK-POSS were prepared by free radical polymerization. POSS monomers reacted with vinylcarbazole and were completely dispersed at molecular level in PVK matrix and PVK-POSS nanocomposites display higher glass transition temperature（Tg） in comparison with neat PVK. Optical properties of PVK/POSS nanocomposites were investigated by UV-spectrum and PL-spectrum and the results show that the PVK-POSS nanoparticles have a good interface effect and improve color purity effectively. The maximum absorption wavelength bathochromically shifts gradually with the increasing of the content of POSS. The luminescent intensity becomes higher and higher with the increase of POSS content, and reaches its maximum luminescent intensity when the POSS content is 3% （mass fraction）, while some POSS-rich nanoparticles are present in matrix when contents of POSS are beyond 5%.展开更多
The flame-retarded polycarbonate（PC） has been made with octaphenyl polyhedral silsesquioxane（OPS） and/or caged bicyclic phosphate（Trimer）.Thermal gravimetric analysis（TGA）,Fourier-transform infrared（FTIR）,TG...The flame-retarded polycarbonate（PC） has been made with octaphenyl polyhedral silsesquioxane（OPS） and/or caged bicyclic phosphate（Trimer）.Thermal gravimetric analysis（TGA）,Fourier-transform infrared（FTIR）,TGA-FTIR,limiting oxygen index（LOI）,and mechanical tests have been employed to characterize the modified PC.The additives of OPS and Trimer in PC have been proved to be effective flame-retardants because of the synergistic interaction between the elements of P and Si.The role of OPS and Trimer in PC degradation are different：OPS participates in the charring of PC,while Trimer makes PC degrade in advance.In addition,OPS and Trimer induced obvious differences in the mechanical properties of PC.展开更多
Two novel and well-defined polyhedral oligomeric silsesquioxanes（POSS） with two same Si_8O_（12） cores and a reactive NH group, namely bridged-POSS（2a and 2b）,have been prepared by the traditional ＇corner-cappin...Two novel and well-defined polyhedral oligomeric silsesquioxanes（POSS） with two same Si_8O_（12） cores and a reactive NH group, namely bridged-POSS（2a and 2b）,have been prepared by the traditional ＇corner-capping＇ reaction.X-ray diffraction demonstrates that those two POSS have the similar T_8 structure.From the thermo-gravimetric analysis,bridged-POSS shows the belter thermal degradation stability than the contrastive POSS.展开更多
Although tremendous efforts have been devoted to the structural and functional tailoring of natural polyphenol-functionalized nan oparticles,preparing ultrasmall sized(<6 nm)particles with precisely-defined structu...Although tremendous efforts have been devoted to the structural and functional tailoring of natural polyphenol-functionalized nan oparticles,preparing ultrasmall sized(<6 nm)particles with precisely-defined structures has remained a grand challenge.In this work,we reported the preparation of ultra-small and precisely structured polyhedral oligomeric silsesquioxanes(POSS)-based polyphenol nanopartides(T8^-,T10^-,and T12^-GAPOSS)by accurately functionalizing the POSS surface with plant polyphenol gallic acid units via thiol-Michael"click"reactions.Those polyphenol nanoparticles exhibited strong free radical scavenging capacity,good biocompatibility and ability to resist cell oxidative damage,which dem on strated great potentials in inhibiting oxidative stress in duced pathologies.展开更多
A polyhedral oligomeric silsesquioxane-[60]fullerene (POSS-C60) dyad was designed and used as a novel electron acceptor for bulk heterojunction (BHJ) polymer solar cells (PSCs) with an inverted device configuration. T...A polyhedral oligomeric silsesquioxane-[60]fullerene (POSS-C60) dyad was designed and used as a novel electron acceptor for bulk heterojunction (BHJ) polymer solar cells (PSCs) with an inverted device configuration. The studies of time-resolved photoinduced absorption of the pristine thin film of poly[(4,4'-bis(2-ethylhexyl)dithieno[3,2-b:2',3'-d]silole)-2,6-diyl-alt-(4,7-bis (2-thienyl)-2,1,3-benzothiadiazole)-5,5'-diyl] (SiPCPDTBT) and the composite thin film of SiPCPDTBT:POSS-C60 indicated efficient electron transfer from SiPCPDTBT to POSS-C60 with inhibited back-transfer. BHJ PSCs made by SiPCPDTBT mixed with POSS-C60 yielded the power conversion efficiencies (PCEs) of 1.50%. Under the same operational conditions, PCEs observed from BHJ PSCs made by SiPCPDTBT mixed with [6,6]-phenyl-C61-butyric acid methyl ester were 0.92%. These results demonstrated that POSS-C60 is a potentially good electron acceptor for inverted BHJ PSCs.展开更多
Dry eye is a common ocular disease that results in discomfort and impaired vision,impacting an individual’s quality of life.A great number of drugs administered in eye drops to treat dry eye are poorly soluble in wat...Dry eye is a common ocular disease that results in discomfort and impaired vision,impacting an individual’s quality of life.A great number of drugs administered in eye drops to treat dry eye are poorly soluble in water and are rapidly eliminated from the ocular surface,which limits their therapeutic effects.Therefore,it is imperative to design a novel drug delivery system that not only improves the water solubility of the drug but also prolongs its retention time on the ocular surface.Herein,we develop a copolymer from mono-functional POSS,PEG,and PPG(MPOSS-PEG-PPG,MPEP)that exhibits temperature-sensitive sol-gel transition behavior.This thermo-responsive hydrogel improves the water solubility of FK506 and simultaneously provides a mucoadhesive,long-acting ocular delivery system.In addition,the FK506-loaded POSS hydrogel possesses good biocompatibility and significantly improves adhesion to the ocular surface.In comparison with other FK506 formulations and the PEG-PPG-FK506(F127-FK506)hydrogel,this novel MPOSS-PEG-PPG-FK506(MPEP-FK506)hydrogel is a more effective treatment of dry eye in the murine dry eye model.Therefore,delivery of FK506 in this POSS hydrogel has the potential to prolong drug retention time on the ocular surface,which will improve its therapeutic efficacy in the management of dry eye.展开更多
Inorganic polyhedral oligomeric silsesquioxane （POSS） was used as the core for the synthesis of poly（t- lysine） peptide dendrimer via copper-catalyzed azide-alkyne click chemistry. The inorganic/organic composite ...Inorganic polyhedral oligomeric silsesquioxane （POSS） was used as the core for the synthesis of poly（t- lysine） peptide dendrimer via copper-catalyzed azide-alkyne click chemistry. The inorganic/organic composite dendrimer was characterized by MS, 1H NMR, FTIR, GPC and DLS.展开更多
Isotactic polypropylene（iPP） was modified by the introduction of polyhedral oligomeric silsesquioxanes（POSS） and 1,3：2,4-bis（3,4-dimethylbenzylidene）sorbitol（DMDBS）. Chemical combination of （3-mercapto）- pr...Isotactic polypropylene（iPP） was modified by the introduction of polyhedral oligomeric silsesquioxanes（POSS） and 1,3：2,4-bis（3,4-dimethylbenzylidene）sorbitol（DMDBS）. Chemical combination of （3-mercapto）- propyl-heptaisobutyl POSS with DMDBS（POSS-DMDBS）, and physical mixing of DMDBS with octaisobutyl POSS （iso-POSS/DMDBS） or trisilanolisobutyl POSS（tri-POSS/DMDBS） were applied respectively to modifying iPP, and the effects of POSS and DMDBS on crystallization, rheological and mechanical properties of iPP were systematically investigated. The results indicate that iso-POSS/DMDBS and tri-POSS/DMDBS were more effective than POSS-DMDBS on the improvement of the crystallization behavior of iPP due to the higher crystallization temperature, while the crystal!inity of iPP containing POSS-DMDBS was enhanced, approximately approached to that of iPP containing tri-POSS/DMDBS. The tensile strength of iPP with POSS-DMDBS was significantly increased from 34 MPa to 40 MPa, as high as that of iPP with iso-POSS/DMDBS. The different effects caused by the specific interaction between POSS and DMDBS could possibly be applied in the modification of iPP.展开更多
There are numerous numbers of hypoxia-selective luminescent probes based on oxygen quenching of phosphorescence.We show a unique design for luminescent probes to detect hyperoxia utilizing hybrid networks consisting o...There are numerous numbers of hypoxia-selective luminescent probes based on oxygen quenching of phosphorescence.We show a unique design for luminescent probes to detect hyperoxia utilizing hybrid networks consisting of aggregation-induced emission(AIE)-active dyes and disulfide linkers.At the initial state,emission from the AIE-active dyes is inducible by suppressing energy-consumable intramolecular motions in the hybrid matrices,while the decrease in intensity was detected by releasing molecular motions corresponded to bond scission at the disulfide linkers.Particularly,it was shown that this process selectively proceeds in hypoxia.As a result,positive luminescent signals were obtained in hyperoxia.展开更多
文摘Layer-by-layer (LBL) self-assembly method was used to fabricate siliceous ultrathin films by using polyhedral oligomeric silsesquioxanes as building blocks. Ammonium salt of octasilsesquioxane acid (OSi8) and poly(diallyldimethylammonium chloride) (PDDA) were alternately assembled onto CaF2 slide to form nanocomposite multilayers. Linear build-up of the LBL films was confirmed by UV-Vis spectroscopy. IR spectrum suggests existence of OSi8 and PDDA in the LBL films. Atomic force microscopic surface topography of the LBL films indicates the OSi8 covers the entire surface of the topmost layer and shows a granular morphology.
基金Beijing Natural Science Foundation(No.2072015)the National High Technology Research and Development Program of China(No.2006AA032563).
文摘Polyvinylcarbazole（PVK） composites containing organic-inorganic hybrid polyhedral oligomeric silse-squioxane（POSS） PVK-POSS were prepared by free radical polymerization. POSS monomers reacted with vinylcarbazole and were completely dispersed at molecular level in PVK matrix and PVK-POSS nanocomposites display higher glass transition temperature（Tg） in comparison with neat PVK. Optical properties of PVK/POSS nanocomposites were investigated by UV-spectrum and PL-spectrum and the results show that the PVK-POSS nanoparticles have a good interface effect and improve color purity effectively. The maximum absorption wavelength bathochromically shifts gradually with the increasing of the content of POSS. The luminescent intensity becomes higher and higher with the increase of POSS content, and reaches its maximum luminescent intensity when the POSS content is 3% （mass fraction）, while some POSS-rich nanoparticles are present in matrix when contents of POSS are beyond 5%.
基金Sponsored by the National High Technology Research and Development Program of China("863"Program)(2007AA03Z538)
文摘The flame-retarded polycarbonate（PC） has been made with octaphenyl polyhedral silsesquioxane（OPS） and/or caged bicyclic phosphate（Trimer）.Thermal gravimetric analysis（TGA）,Fourier-transform infrared（FTIR）,TGA-FTIR,limiting oxygen index（LOI）,and mechanical tests have been employed to characterize the modified PC.The additives of OPS and Trimer in PC have been proved to be effective flame-retardants because of the synergistic interaction between the elements of P and Si.The role of OPS and Trimer in PC degradation are different：OPS participates in the charring of PC,while Trimer makes PC degrade in advance.In addition,OPS and Trimer induced obvious differences in the mechanical properties of PC.
基金the National Natural Science Foundation of China(No20772092)the Hubei Province Natural Science Fund for Distinguished Young Scholars(No2007ABB021) for financial support
文摘Two novel and well-defined polyhedral oligomeric silsesquioxanes（POSS） with two same Si_8O_（12） cores and a reactive NH group, namely bridged-POSS（2a and 2b）,have been prepared by the traditional ＇corner-capping＇ reaction.X-ray diffraction demonstrates that those two POSS have the similar T_8 structure.From the thermo-gravimetric analysis,bridged-POSS shows the belter thermal degradation stability than the contrastive POSS.
基金the National Natural Science Foundation of China(Nos.51603133 and 21774079)National Key R&D Program of China(No.2019YFA0904500)+1 种基金the Program of the Science,Technology Department of Guangzhou,China(No.201803020039)the Fundamental Research Funds for Central Universities.
文摘Although tremendous efforts have been devoted to the structural and functional tailoring of natural polyphenol-functionalized nan oparticles,preparing ultrasmall sized(<6 nm)particles with precisely-defined structures has remained a grand challenge.In this work,we reported the preparation of ultra-small and precisely structured polyhedral oligomeric silsesquioxanes(POSS)-based polyphenol nanopartides(T8^-,T10^-,and T12^-GAPOSS)by accurately functionalizing the POSS surface with plant polyphenol gallic acid units via thiol-Michael"click"reactions.Those polyphenol nanoparticles exhibited strong free radical scavenging capacity,good biocompatibility and ability to resist cell oxidative damage,which dem on strated great potentials in inhibiting oxidative stress in duced pathologies.
基金supported by the US NSF (DMR-0906898)the Joint Research Fund for Overseas Chinese Scholars, the National Natural Science Foundation of China (5082830)
文摘A polyhedral oligomeric silsesquioxane-[60]fullerene (POSS-C60) dyad was designed and used as a novel electron acceptor for bulk heterojunction (BHJ) polymer solar cells (PSCs) with an inverted device configuration. The studies of time-resolved photoinduced absorption of the pristine thin film of poly[(4,4'-bis(2-ethylhexyl)dithieno[3,2-b:2',3'-d]silole)-2,6-diyl-alt-(4,7-bis (2-thienyl)-2,1,3-benzothiadiazole)-5,5'-diyl] (SiPCPDTBT) and the composite thin film of SiPCPDTBT:POSS-C60 indicated efficient electron transfer from SiPCPDTBT to POSS-C60 with inhibited back-transfer. BHJ PSCs made by SiPCPDTBT mixed with POSS-C60 yielded the power conversion efficiencies (PCEs) of 1.50%. Under the same operational conditions, PCEs observed from BHJ PSCs made by SiPCPDTBT mixed with [6,6]-phenyl-C61-butyric acid methyl ester were 0.92%. These results demonstrated that POSS-C60 is a potentially good electron acceptor for inverted BHJ PSCs.
基金Y.Han,L.Jiang,H.Shi and C.Xu contributed equally to this work.This study was supported in part by grants from The National Key R&D Program of China(2020YFA0908100)the National Natural Science Foundation of China(NSFC No.82070931,81770891,81971724,81773661)+1 种基金the Agency for Science,Technology and Research(A*STAR)under its AME IAF-PP Specialty Chemicals Program(Grant No.A1786a0034)and the Huaxia Translational Medicine Fund for Young Scholars(No.2017-A-001).
文摘Dry eye is a common ocular disease that results in discomfort and impaired vision,impacting an individual’s quality of life.A great number of drugs administered in eye drops to treat dry eye are poorly soluble in water and are rapidly eliminated from the ocular surface,which limits their therapeutic effects.Therefore,it is imperative to design a novel drug delivery system that not only improves the water solubility of the drug but also prolongs its retention time on the ocular surface.Herein,we develop a copolymer from mono-functional POSS,PEG,and PPG(MPOSS-PEG-PPG,MPEP)that exhibits temperature-sensitive sol-gel transition behavior.This thermo-responsive hydrogel improves the water solubility of FK506 and simultaneously provides a mucoadhesive,long-acting ocular delivery system.In addition,the FK506-loaded POSS hydrogel possesses good biocompatibility and significantly improves adhesion to the ocular surface.In comparison with other FK506 formulations and the PEG-PPG-FK506(F127-FK506)hydrogel,this novel MPOSS-PEG-PPG-FK506(MPEP-FK506)hydrogel is a more effective treatment of dry eye in the murine dry eye model.Therefore,delivery of FK506 in this POSS hydrogel has the potential to prolong drug retention time on the ocular surface,which will improve its therapeutic efficacy in the management of dry eye.
基金supported by the National Basic Research Program of China(National 973 program,No.2011CB606206)National Science Foundation of China(NSFC,Nos.31170921,51133004)+1 种基金the National Science Foundation for Excellent Young Scholars(No.51222304)Program for Changjiang Scholars and Innovative Research Team in University(No.IRT1163)
文摘Inorganic polyhedral oligomeric silsesquioxane （POSS） was used as the core for the synthesis of poly（t- lysine） peptide dendrimer via copper-catalyzed azide-alkyne click chemistry. The inorganic/organic composite dendrimer was characterized by MS, 1H NMR, FTIR, GPC and DLS.
文摘Isotactic polypropylene（iPP） was modified by the introduction of polyhedral oligomeric silsesquioxanes（POSS） and 1,3：2,4-bis（3,4-dimethylbenzylidene）sorbitol（DMDBS）. Chemical combination of （3-mercapto）- propyl-heptaisobutyl POSS with DMDBS（POSS-DMDBS）, and physical mixing of DMDBS with octaisobutyl POSS （iso-POSS/DMDBS） or trisilanolisobutyl POSS（tri-POSS/DMDBS） were applied respectively to modifying iPP, and the effects of POSS and DMDBS on crystallization, rheological and mechanical properties of iPP were systematically investigated. The results indicate that iso-POSS/DMDBS and tri-POSS/DMDBS were more effective than POSS-DMDBS on the improvement of the crystallization behavior of iPP due to the higher crystallization temperature, while the crystal!inity of iPP containing POSS-DMDBS was enhanced, approximately approached to that of iPP containing tri-POSS/DMDBS. The tensile strength of iPP with POSS-DMDBS was significantly increased from 34 MPa to 40 MPa, as high as that of iPP with iso-POSS/DMDBS. The different effects caused by the specific interaction between POSS and DMDBS could possibly be applied in the modification of iPP.
基金This work was supported by the Grant-in-Aid for Scientific Research(A)(No.JP17H01220)the Grant-in-Aid for Scientific Research on Innovative Areas“New Polymeric Materials Based on Element-Blocks(No.2401)”(No.JP24102013)the Grant-in-Aid for Challenging Research(Pioneering)(No.JP18H05356).
文摘There are numerous numbers of hypoxia-selective luminescent probes based on oxygen quenching of phosphorescence.We show a unique design for luminescent probes to detect hyperoxia utilizing hybrid networks consisting of aggregation-induced emission(AIE)-active dyes and disulfide linkers.At the initial state,emission from the AIE-active dyes is inducible by suppressing energy-consumable intramolecular motions in the hybrid matrices,while the decrease in intensity was detected by releasing molecular motions corresponded to bond scission at the disulfide linkers.Particularly,it was shown that this process selectively proceeds in hypoxia.As a result,positive luminescent signals were obtained in hyperoxia.
