The spontaneous self-assembly of chromophores into light-harvesting antennae provides a potentially low-cost approach to building solar-to-fuel conversion materials. However, designing such supramolecular architectures requires a better understanding of the balance between noncovalent forces among the molecular components. We investigated here the aqueous assembly of perylene monoimide chromophore amphiphiles synthesized with different substituents in the 9-position. The molecular dipole strength decreases as the nature of the substituent is altered from electron donating to electron withdrawing. Compounds with stronger molecular dipoles, in which dipolar interactions stabilize assemblies by 10-15 kJ·mol, were found to form crystalline nanoribbons in solution. In contrast, when the molecular dipole moment is small, nanofibers were obtained. Highly blue-shifted absorption maxima were observed in assemblies with large dipoles, indicating strong electronic coupling is present. However, only the moderate dipole compound had the appropriate molecular packing to access charge-transfer excitons leading to enhanced photocatalytic H production.

Incorporating supramolecular assemblies of chromophore amphiphiles into covalent hydrogels creates a reusable, robust host for photocatalysis.

A switchable perylene monoimide which undergoes reversible morphological and electronic changes controlled by the ionization state of the phenolic oxygen.

The power conversion efficiency of organic solar cells (OSCs) could benefit from systematic studies to improve bulk heterojunction (BHJ) morphology by modifying donor compounds. Supramolecular self-assembly is an attractive strategy to combine the beneficial properties of polymeric donors, such as a well-controlled morphology, with the homogeneous composition of small molecule donors for OSCs. We report here on two tripodal "star-shaped" small-molecule donor compounds based on diketopyrrolopyrrole (DPP) side chains for solution-processed BHJ OSCs. The tripod molecules were found not to aggregate in solution or form crystalline domains in thin films when a branched alkyl chain (2-ethylhexyl) substituent was used, whereas linear (docedecyl) alkyl chains promote the formation of one-dimensional (1D) nanowires and more crystalline domains in the solid state. We demonstrate that the 1D self-assembly of these tripods enhances the performance of the corresponding solution-processed OSCs by 50%, which is attributed to the significant increase in the fill factor of devices resulting from a reduction of trap states.

Background: Rotavirus (RV) is one of the major causes of acute gastroenteritis in infants. It is indispensable to demonstrate the relationship between the diversity and richness of gut microbiota and RV infection using more accurate and effective technology. Objectives: To investigate the differences in fecal microbiota, lactic acid, and short-chain fatty acids (SCFAs) levels between rotaviralinduced diarrhea (RD) infants and healthy (H) infants. Methods: The infants comprised of 25 infants aged few days to six months, who were in good health (n = 12) or diagnosed with rotavirus (n = 13). Fecal matter was analyzed with Illumina Miseq high-throughput sequencing technique targeting the 16s rRNA gene V3-V4 region. Lactic acids and SCFAs were measured by the high-performance liquid chromatography (HPLC) technique. Results: Compared to H infants, the fecal samples in RD infants had lower Shannon diversity index and the bacteria richness (P < 0.05). A higher proportion of Proteobacteria, Enterobacteriaceae and Klebsiella, and lower abundances of Actinobacteria and Knoellia (P < 0.05) were detected in fecal samples of RD infants. The total SCFAs content of fecal samples showed no distinction between RD and H infants, yet lower levels of lactic acid were observed in fecal samples of RD infants. Conclusions: Rotaviral infection in infants led to an alteration of fecal microbiota and lactic acid concentration compared with healthy infants. Fecal microbiota and metabolite may advance the understanding and treatment of RD.

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We report the solution kinetics for the photo-excited, intramolecular electron transfer of malachite green leucocyanide (MGCN) to form the malachite green dye cation (MG +) and a cyanide anion (CN-).By analyzing picosecond resolved fluorescence emission and transient absorbance we have identified the ionizing state as the MGCN excited singlet.The solvent dielectric constant dramatically affected the kinetics of ion formation and the ultimate yield of ionization. The MG+ rise kinetics are not simple first order in the first 300 ps. The kinetics show a very fast rise that is almost independent of solvent dielectric constant (s) which is then followed by a slower rise that is very dependent on dielectric constant. More experiments to refine the solvent dependence are in progress.The apparatus included a synch pumped dye laser for fluorescence lifetime analysis and an amplified, synch pumped dye laser for transient absorption analysis.