Aggregation-induced emission(AIE)luminogens are attractive dyes to probe poly-mer properties that depend on changes in chain mobility and free *** embedded in polymers the restriction of intramolecular motion(RIM)can ...
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Aggregation-induced emission(AIE)luminogens are attractive dyes to probe poly-mer properties that depend on changes in chain mobility and free *** embedded in polymers the restriction of intramolecular motion(RIM)can lead to their photoluminescence quantum yield(PLQY)strong enhancement if local microviscosity increases(lowering of chain mobility and free volume).Nonethe-less,measuring PLQY during stimuli,*** or mechanical stress,is technically challenging;thus,emission intensity is commonly used instead,assuming its direct correlation with the ***,by usingfluorescence lifetime as an absolutefluorescence parameter,it is demonstrated that this assumption can be invalid in many commonly encountered *** this aim,different poly-mers are loaded with tetraphenylenethylene(TPE)and characterized during the application of thermal and mechanical stress and physical *** these con-ditions,polymer matrix transparency variation is observed,possibly due to local changes in refractive index and to the formation of *** combin-ing different characterization techniques,it is proved that scattering can affect the apparent emission intensity,while lifetime measurements can be used to ascertain whether the observed phenomenon is due to modifications of the photophysi-cal properties of AIE dyes(RIM effect)or to alterations in the matrix optical properties.
Electrospun fibers of shape memory triethoxysilane-terminated poly(epsilon-caprolactone)(PCL-TES)loaded with bioactive glasses(BG)are here *** PCL-TES,as well as PCL/BG nanocomposite fibers,are also considered for ***...
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Electrospun fibers of shape memory triethoxysilane-terminated poly(epsilon-caprolactone)(PCL-TES)loaded with bioactive glasses(BG)are here *** PCL-TES,as well as PCL/BG nanocomposite fibers,are also considered for *** is proposed that hydrolysis and condensation reactions take place between triethoxysilane groups of the polymer and the silanol groups at the BG particle surface,thus generating additional crosslinking points with respect to those present in the PCL-TES *** as-spun PCL-TES/BG fibers display excellent shape memory properties,in terms of shape fixity and shape recovery ratios,without the need of a thermal crosslinking *** particles confer in vitro bioactivity to PCL-based nanocomposite fibers and favor the precipitation of hydroxycarbonate apatite on the fiber *** cytocompatibility tests demonstrate that the addition of BG particles to PCL-based polymer does not inhibit ST-2 cell *** novel approach of using bioactive glasses not only for their biological properties,but also for the enhancement of shape memory properties of PCL-based polymers,widens the versatility and suitability of the obtained composite fibers for a huge portfolio of biomedical applications.
The chemodivergent ring-opening of cyclobutanols is described under the carbocatalytic assistance of graphene oxide(GO).The protocol enables the synthesis of diversely functionalized dienes or indenes(26 examples)base...
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The chemodivergent ring-opening of cyclobutanols is described under the carbocatalytic assistance of graphene oxide(GO).The protocol enables the synthesis of diversely functionalized dienes or indenes(26 examples)based on the amount of GO ***(XPS and ssNMR)as well as experimental investigations revealed a direct involvement of theπ-domains of GO in tuning the stability of carbocationic intermediates during the reaction.
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