Discrete nano-aggregates of a poly(ethylene oxide)-b-polybutadiene diblock copolymer (PEO-b-PB) were obtained by self-assembling of the copolymer in a selective solvent of PB followed by the shell cross-linking.The av...Discrete nano-aggregates of a poly(ethylene oxide)-b-polybutadiene diblock copolymer (PEO-b-PB) were obtained by self-assembling of the copolymer in a selective solvent of PB followed by the shell cross-linking.The average behaviors of the PEO crystallization and melting confined within the nano-structured aggregates were studied by differential scanning calorimetry experiments.The experiments demonstrated that the confinement effect arisen from the shells could be tuned by adjusting the degree of PB cross-linking.For the deeply cross-linked sample,the individual particles only crystallized at very low crystallization temperature (T c),wherein the homogenous primary nucleation determined the crystallization rate.For the lightly cross-linked sample,the confinement effect is T c dependent.When T c exceeded 42℃,the lightly cross-linked sample possessed a higher melting temperature and a lower crystallinity compared with the pure PEO-b-PB.展开更多
Photofunctional materials with room-temperature phosphorescence（RTP）commonly appeared in expensive metal-coordination complexes and rare-earth-based compounds.Recently,the metal-free organic RTP materials have been ...Photofunctional materials with room-temperature phosphorescence（RTP）commonly appeared in expensive metal-coordination complexes and rare-earth-based compounds.Recently,the metal-free organic RTP materials have been paid growing attention from scientific community because of the ease of molecular design,low cost as well as potential applications in molecular switches,chemical sensors and biological imaging.To date,efficient RTP materials with high quantum yield are still very limited due to the T_1-S_0 spinforbidden process and weak spin-orbital coupling.Current mechanism based on crystallization-induced or aggregationinduced phosphorescence may serve as an effective way to enhance the RTP[1,2];展开更多
文摘Discrete nano-aggregates of a poly(ethylene oxide)-b-polybutadiene diblock copolymer (PEO-b-PB) were obtained by self-assembling of the copolymer in a selective solvent of PB followed by the shell cross-linking.The average behaviors of the PEO crystallization and melting confined within the nano-structured aggregates were studied by differential scanning calorimetry experiments.The experiments demonstrated that the confinement effect arisen from the shells could be tuned by adjusting the degree of PB cross-linking.For the deeply cross-linked sample,the individual particles only crystallized at very low crystallization temperature (T c),wherein the homogenous primary nucleation determined the crystallization rate.For the lightly cross-linked sample,the confinement effect is T c dependent.When T c exceeded 42℃,the lightly cross-linked sample possessed a higher melting temperature and a lower crystallinity compared with the pure PEO-b-PB.
文摘Photofunctional materials with room-temperature phosphorescence（RTP）commonly appeared in expensive metal-coordination complexes and rare-earth-based compounds.Recently,the metal-free organic RTP materials have been paid growing attention from scientific community because of the ease of molecular design,low cost as well as potential applications in molecular switches,chemical sensors and biological imaging.To date,efficient RTP materials with high quantum yield are still very limited due to the T_1-S_0 spinforbidden process and weak spin-orbital coupling.Current mechanism based on crystallization-induced or aggregationinduced phosphorescence may serve as an effective way to enhance the RTP[1,2];
