Light-up the white light emission in microscale with a superior deep-blue AIE fiber as wave-guiding source

The development of high-performance organic blue light-emitting emitters is in urgent to act as an excitation source to contribute the white light generation.On the other hand,the investigation on optical waveguides have been received increasing attentions because they can manipulate the light propagation accurately in the microscale to boost the optoelectronic and energy conversion applications.In this work,we facilely prepared a deep-blue aggregation-induced emission(AIE)dye,namely TPP-4OMe,which shows high luminescent efficiency,narrow emission band and good stability in the aggregate state.TPP-4OMe can be fabricated as deep-blue AIE microfibers readily with definite morphology and composition.Based on the AIE microfibers,the active waveguide to transmit deep-blue emission signals can be achieved with a very low optical loss coefficient(α)of 6.7×10^(−3)dBμm^(−1).Meanwhile,the full-visible broadband low-loss passive waveguide can be well performed with these AIE microfibers,which has never been observed in the pure organic crystals.More interestingly,the excellent properties of AIE microfibers enable them to act as a wave-guiding excitation source,resulting in a distinct and pure white light emission.The present work not only provides excellent blue light-emitting materials but also bridges the waveguide to realize the efficient white light emission to accelerate the practical applications.

Photocatalytic Transition-Metal-Free Direct 3-Acetalation of Quinoxaline-2(1H)-ones

A general transition-metal-free visible-light-promoted 3-acetalation reaction of quinoxaline-2(1H)-ones was developed under mild conditions.By employing 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene(4CzIPN)as an inexpensive photocatalyst,and glyoxylic acid acetal as a radical source,various acetalated quinoxaline-2(1H)-ones were constructed in moderate to good yields.Moreover,the versatility of this protocol is highlighted by the successful application in the late-stage modification of drug molecules and the various functionality transformations.The excellent antitumor activity of the acetalated product demonstrated that this streamlined and sustainable approach could have emerged as a powerful strategy for structural modification in medicinal chemistry.

Light-induced thermal convection for collection and removal of carbon nanotubes

Carbon nanotubes(CNTs)have exhibited immense potential for applications in biology and medicine,and once their intended purpose is fulfilled,the elimination of residual CNTs is essential to avoid negative effects.In this study,we demonstrated the effective collection and simple removal of CNTs dispersed in a suspension via thermal convection.First,a tapered fiber tip with a cone angle and end diameter of 10°and 3μm,respectively,was fabricated via a heating and pulling method.Further,a laser beam with a power and wavelength of 100 mW and 1.55^m,respectively,was launched into the tapered fiber tip,which was placed in a CNT suspension,resulting in the formation of a microbubble on the fiber tip.The temperature gradient on the microbubble and suspension surface induced thermal convection in the suspension,which resulted in the accumulation of CNTs on the fiber tip.The experimentally formed CNT cluster possessed a circular top surface with a diameter of 87 nm and an arched cross-section with a height of 19μm.Furthermore,this CNT cluster was firmly attached to the fiber tip.Therefore,the removal of CNT clusters can be realized by simply removing the fiber tip from the suspension.Moreover,we simulated the thermal convection that caused CNT aggregation.The obtained results indicate that convection near the fiber tip flows toward it,which pushes the CNTs toward the fiber tip and enables their attachment to it.Further,the flow velocity is symmetrically distributed as a Gaussian function,which results in the formation of a circular top surface and arched cross-sectional profile for the CNT cluster.Our method may be applied in biomedicine for the collection and removal of nano-drug residues.