We have developed an efficient strategy for the non-covalent functionalization of multi-walled carbon nanotubes(MWCNTs)which allows a biomimetic presentation of carbohydrates on their surface byπ-πstacking interacti...We have developed an efficient strategy for the non-covalent functionalization of multi-walled carbon nanotubes(MWCNTs)which allows a biomimetic presentation of carbohydrates on their surface byπ-πstacking interactions.The strategy is based on the use of sugar-based amphiphiles functionalized with tetrabenzo[a,c,g,i]fluorene(Tbf),a polyaromatic compound with a topology that resembles a butterfly with open wings.The new carbohydrate-tethered Tbf amphiphiles have been synthesized in a straightforward manner using click chemistry.The reported method has been developed in order to improve the rather low ability of pyrene-based systems to exfoliate MWCNTs in water.By means of thermogravimetric analysis(TGA),ultraviolet(UV),infrared(IR),and fluorescence spectroscopies the interaction between MWCNTs and the Tbf group has been found to be stronger than those involving pyrene-based amphiphilic carbohydrates.The resulting aggregates with a multivalent sugar exposition on their surface are able to engage in specific ligand-lectin interactions similar to glycoconjugates on a cell membrane.展开更多
Extracting the light trapped in a waveguide,or the opposite effect of trapping light in a thin region and guiding it perpendicular to its incident propagation direction,is essential for optimal energetic performance i...Extracting the light trapped in a waveguide,or the opposite effect of trapping light in a thin region and guiding it perpendicular to its incident propagation direction,is essential for optimal energetic performance in illumination,display or light harvesting devices.Here we demonstrate that the paradoxical goal of letting as much light in or out while maintaining the wave effectively trapped can be achieved with a periodic array of interpenetrated fibers forming a photonic fiber plate.Photons entering perpendicular to that plate may be trapped in an intermittent chaotic trajectory,leading to an optically ergodic system.We fabricated such a photonic fiber plate and showed that for a solar cell incorporated on one of the plate surfaces,light absorption is greatly enhanced.Confirming this,we found the unexpected result that a more chaotic photon trajectory reduces the production of photon scattering entropy.展开更多
基金This work was supported by the Ministerio de Ciencia e Innovación(grant No.CTQ2010-21755-CO2-00)the Junta de Andalucía(grant Nos.P06-FQM-01852 and P07-FQM-2774)the Centre National de la Recherche Scientifique(France)and the Consejo Superior de Investigaciones Científicas(Egide Picasso 09543XA and Projets Internationaux de Cooperation Scientifiques Program 2008-2010).
文摘We have developed an efficient strategy for the non-covalent functionalization of multi-walled carbon nanotubes(MWCNTs)which allows a biomimetic presentation of carbohydrates on their surface byπ-πstacking interactions.The strategy is based on the use of sugar-based amphiphiles functionalized with tetrabenzo[a,c,g,i]fluorene(Tbf),a polyaromatic compound with a topology that resembles a butterfly with open wings.The new carbohydrate-tethered Tbf amphiphiles have been synthesized in a straightforward manner using click chemistry.The reported method has been developed in order to improve the rather low ability of pyrene-based systems to exfoliate MWCNTs in water.By means of thermogravimetric analysis(TGA),ultraviolet(UV),infrared(IR),and fluorescence spectroscopies the interaction between MWCNTs and the Tbf group has been found to be stronger than those involving pyrene-based amphiphilic carbohydrates.The resulting aggregates with a multivalent sugar exposition on their surface are able to engage in specific ligand-lectin interactions similar to glycoconjugates on a cell membrane.
基金support from the Spanish MINECO(Severo Ochoa Program,grant no.SEV-2015-0522)the MINECO and the Fondo Europeo de Desarrollo Regional FEDER(grant no.MAT2014-52985-R)+3 种基金the Fundacio Privada Cellex,and from the EC FP7 Program(ICT-2011.35)under grant no.NMP3-SL-2013-604506support from the Spanish MINECO/FEDER(grant no.MAT2015-66128-R)support from the Spanish MINECO(grant no.ENE2014-56237-C4)Mexico’s grant program CONACyT.
文摘Extracting the light trapped in a waveguide,or the opposite effect of trapping light in a thin region and guiding it perpendicular to its incident propagation direction,is essential for optimal energetic performance in illumination,display or light harvesting devices.Here we demonstrate that the paradoxical goal of letting as much light in or out while maintaining the wave effectively trapped can be achieved with a periodic array of interpenetrated fibers forming a photonic fiber plate.Photons entering perpendicular to that plate may be trapped in an intermittent chaotic trajectory,leading to an optically ergodic system.We fabricated such a photonic fiber plate and showed that for a solar cell incorporated on one of the plate surfaces,light absorption is greatly enhanced.Confirming this,we found the unexpected result that a more chaotic photon trajectory reduces the production of photon scattering entropy.
