Placement and characterization of pairs of luminescent molecules in spatially separated regions of nanostructured thin films

Methods of making mesostructured sol-gel silicate thin films containing two different molecules deliberately placed in two different spatially separated regions in a one-step, one-pot preparation are developed and demonstrated. When the structure-directing agent is the surfactant cetyltrimethylammonium bromide, the structure is 2-D hexagonal with lattice spacings between 31.6 and 42.1 angstroms depending on the dopant molecules and their concentrations. The three general strategies that are used to place the molecules are philicity (like dissolves like), bonding, and bifunctionality. These strategies take advantage of the different chemical and physical properties of the regions of the films. These regions are the inorganic silicate framework, the hydrophobic organic interior of the micelles, and the ionic interface between them. Luminescent molecules that possess the physical and chemical properties appropriate for the desired strategies are chosen. Lanthanide and ruthenium complexes with condensable trialkoxysilane groups are incorporated into the silicate framework. 1,4-Naphthoquinone, pyrene, rhodamine 6G and coumarin 540A, and lanthanides with no condensable trialkoxysilanes occupy the hydrophobic core of micelles by virtue of their hydrophobicity. The locations of the molecules are determined by luminescence spectroscopy and by luminescence lifetime measurements. In all cases, the long-range order templated into the thin film is verified by X-ray diffraction. The simultaneous placement of two molecules in the structured film and the maintenance of long-range order require a delicate balance among film preparation methodology, design of the molecules to be incorporated in specific regions, and concentrations of all of the species.     

Enantioseparation of novel chiral heterometal tetrahedral clusters by high-performance liquid chromatography

A series of novel chiral heterometal tetrahedral clusters have firstly been separated on cellulose tris-(3,5-dimethylphenylcarbamate) stationary phase by high-performance liquid chromatography using n-hexane as the mobile phase containing different alcohols as modifiers. The effects of concentration and structures of alcohols in the mobile phases and structures of chiral heterometal tetrahedral clusters on enantioseparation were investigated. The results showed that the concentration and structures of alcohols had large effects on enantioseparation. It also was found that both the metal in the tetrahedral core and the ligand coordinated to the atom in tetrahedral core had significant effects on their chromatographic behavior.     

New carbazole‐based conjugated polymers containing pyridylvinyl thiophene units for polymer solar cell applications: Morphological stabilization through hydrogen bonding

We have synthesized two conjugated polymers ( P1 , P2 ) containing alternating electron‐donating and ‐accepting units, based on N‐alkyl‐2,7‐carbazole, 4,7‐di(thiophen‐5‐yl)‐2,1,3‐benzothiadiazole and 3‐[2‐(4‐pyridyl)vinyl]thiophene units. These conjugated polymers contained different contents of pyridine units, which were incorporated to form hydrogen bonds with [6,6]‐phenyl‐C₆₁‐butyric acid (PCBA). When these hydrogen bonding interactions were present in the polymer thin films, their thermal stability improved; deterioration, which occurred through aggregation of PCBA methyl ester after lengthy annealing times, was also suppressed. The power conversion efficiency of a device incorporating the film featuring hydrogen bonding interactions remained at 75% of the original value after thermal annealing for 5 h at 140 °C. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Computer-generated holograms with a commercial microfilm

We have successfully used a commercial microfilm to produce good quality two-dimensional and three-dimensional computer-generated binary holograms.     

Non‐Alkaloidal Constituents from the Stem of Ficus Septica

Seven triterpenes, two lignans, and twelve other known compounds were isolated from the non‐alkaloidal fractions of the stem of Ficus septica Among these triterpenoids, a rare triterpene skeleton derivative, 13,27‐cycloursan‐3β‐ylacetate was isolated from natural sources for the first time. All the structures of these compounds were elucidated by spectroscopic methods.     

Sol-Gel Distribution of Polycondensation Reaction

A theoretical approach to polycondensation reaction of Aa-Bb type Involving intramolecular cycllzatlon has been proposed by Tang Au-chin et al.. In this paper, the theoretical sol-gel distribution is tested by polycondensation of adipic acid with trimethylol propane in a sto-ichiometric ratio of 0. 8, and the effect of intramolecular cyclization is discussed in detail.     

Efficient gel‐type electrolyte with bismaleimide via in situ low temperature polymerization in dye‐sensitized solar cells

This study reports the characteristics of gel‐type dye‐sensitized solar cells (DSSCs), fabricated with gel‐type electrolyte containing poly‐1,1′‐(methylenedi‐4,1‐phenylene)bismaleimide (PBMI), or poly‐1,1′‐(3,3′‐dimethyl‐1,1′‐biphenyl‐4,4′‐diyl)bismaleimide (PDBBMI), or poly‐N,N′‐(4‐methyl‐1,3‐phenylene)bismaleimide (PMPBMI), prepared by in situ polymerization of the corresponding monomer without an initiator at 30 °C. Incorporating 0.3 wt % content of exfoliated alkyl‐modified nanomica (EAMNM) into PBMI‐gelled electrolyte leads to higher short‐circuit current density (J_sc = 17.14 mA cm^?2) and efficiency (η = 7.02%) than that of neat PBMI‐gel electrolyte (J_sc = 15.32 mA cm^?2, η = 6.41%). Incorporating 0.3 wt % EAMNM into PBMI‐gelled electrolyte results in remarkably stable device performance under continuous light soaking under one sun (100 mW cm^?2) at 55 °C. The efficiency of DSSCs based on PBMI/0.3 wt % EAMNM‐gelled electrolyte drops by only 1.7% (η = 6.93%) after 500 h of continuous light soaking. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010