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Chemical luminescence

Zhifang Li, Tianye Yang, Qi Zhao, Mingzhe Zhang
Trivalent lanthanide-doped luminescent nanomaterials have unique spectral and magnetic properties, which have been extensively investigated due to their potential application prospects in a number of new technologies. The rare earth Dy(3+) and Tb(3+) ions co-doped β-In2S3 dilute nanoparticles with different doping concentrations were successfully synthesized by a gas-liquid phase chemical deposition method. The band gap energy could be tuned by varying the doping concentration from 3.17 to 3.51 eV. The In2S3:Dy(3+),Tb(3+) nanoparticles exhibited strong photoluminescence emission peaks and room temperature ferromagnetism...
June 19, 2017: Physical Chemistry Chemical Physics: PCCP
Wei Liu, Kun Zhu, Simon J Teat, Gangotri Dey, Zeqing Shen, Lu Wang, Deirdre M O'Carroll, Jing Li
Extensive research has been pursued to develop low-cost and high-performance functional inorganic-organic hybrid materials for clean/renewable energy related applications. While great progress has been made in the recent years some key challenges remain to be tack-led. One major issue is the generally poor stability of these materials which originates from relatively fragile/weak bonds between inorganic and organic constituents. Herein, we report a unique "all-in-one" (AIO) approach in constructing robust structures with desired properties...
June 17, 2017: Journal of the American Chemical Society
P Gąsiorski, M Matusiewicz, E Gondek, T Uchacz, K Wojtasik, A Danel, Ya Shchur, A V Kityk
Paper reports the synthesis and spectroscopic studies of two novel 1,3-diphenyl pyrazoloquinoxaline (PQX) derivatives with 6-substituted methyl (MePQX) or methoxy (MeOPQX) side groups. The optical absorption and fluorescence emission spectra are recorded in solvents of different polarity. Other photophysical constants, such as the fluorescence lifetime and quantum yield, radiationless and radiative rate constants, electronic transition dipole moments, give complete characterization of MePQX and MeOPQX dyes as materials for potential luminescence or electroluminescence applications...
June 6, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Pei Yang, Bo Tai, Weikang Wu, Jian-Min Zhang, Feng Wang, Shan Guan, Wei Guo, Yunhao Lu, Shengyuan A Yang
Perovskite oxide materials have been attracting significant attention due to their rich physical and chemical properties. With its proven stability and bio-compatibility, we suggest the lanthanide-doped perovskite to be a promising material for biological luminescence applications. Here, taking CaTiO3 as a concrete example, we systematically investigate its doping properties using first-principles computational methods. We determine the conditions allowing the growth of CaTiO3 against various competing phases...
June 21, 2017: Physical Chemistry Chemical Physics: PCCP
Sabine E Apitz, Suzanne Agius
The effects of possible changes to the Canadian two tiered assessment framework for dredged material based on outcomes of the 2006 Contaminated Dredged Material Management Decisions Workshop (CDMMD) are evaluated. Expanding on the "data mining" approach described in Apitz and Agius, 2013, which focused solely on chemical lines of evidence, the efficacy of Tier 1 approaches (increases to the number of chemical analytes, use of mean hazard quotients and the use of a screening bioassay) in predicting toxicity are evaluated...
June 10, 2017: Integrated Environmental Assessment and Management
Murielle F Delley, Giuseppe Lapadula, Francisco Núñez-Zarur, Aleix Comas-Vives, Vidmantas Kalendra, Gunnar Jeschke, Dirk Baabe, Marc D Walter, Aaron J Rossini, Anne Lesage, Lyndon Emsley, Olivier Maury, Christophe Copéret
Grafting molecular precursors on partially dehydroxylated silica followed by a thermal treatment yields silica-supported M(III) sites for a broad range of metals. They display unique properties such as high activity in olefin polymerization and alkane dehydrogenation (M = Cr) or efficient luminescence properties (M = Yb and Eu) essential for bioimaging. Here, we interrogate the local structure of the M(III) surface sites obtained from two molecular precursors, amides M(N(SiMe3)2)3 vs siloxides (M(OSi(O(t)Bu)3)3·L with L = (THF)2 or HOSi(O(t)Bu)3 for M = Cr, Yb, Eu, and Y, by a combination of advanced spectroscopic techniques (EPR, IR, XAS, UV-vis, NMR, luminescence spectroscopies)...
June 21, 2017: Journal of the American Chemical Society
Alex D Johnson, Fei Cheng, Yutsung Tsai, Chih-Kang Shih
We have investigated how the photoluminescence (PL) of WSe2 is modified when coupled to Ag plasmonic structures at low temperature. Chemical vapor deposition (CVD) grown monolayer WSe2 flakes were transferred onto a Ag film and a Ag nanotriangle array that had a 1.5 nm Al2O3 capping layer. Using low-temperature (7.5 K) micro-PL mapping, we simultaneously observed enhancement of the defect-bound exciton emission and quenching of the band edge exciton emission when the WSe2 was on a plasmonic structure. The enhancement of the defect-bound exciton emission was significant with enhancement factors of up to ∼200 for WSe2 on the nanotriangle array when compared to WSe2 on a 1...
June 6, 2017: Nano Letters
Kazuto Takaishi, Tadashi Ema, Takahiro Yamamoto, Sakiko Hinoide
A series of oligonaphthodioxepins was synthesized, revealing a helically arranged octamer, (R,R,R,R,R,R,R)-3, which showed intense circularly polarized luminescence (CPL) both in solution and in the solid state. The fluorescence quantum yields (ΦFL) in solution and in the solid state were 0.90 and 0.22, respectively, and the glum values in solution and in the solid state were +2.2 × 10-3 and +7.0 × 10-3, respectively. This is one of the highest solid-state CPL glum values yet reported. The high ΦFL and glum values were due to the rigidity as well as to the fact that (R,R,R,R,R,R,R)-3 was a non-planar molecule...
May 30, 2017: Chemistry: a European Journal
Ishwar Prasad Sahu, D P Bisen, K V R Murthy, R K Tamrakar
Ca2 MgSi2 O7 :Ce(3+) , Ca2 MgSi2 O7 :Eu(2+) and Ca2 MgSi2 O7 :Eu(2+) ,Ce(3+) phosphors were prepared using the solid-state reaction method. The crystal structures of the sintered phosphors were of melilite type, which has a tetragonal crystallography. The chemical compositions of the sintered phosphors was confirmed by energy dispersive X-ray spectroscopy. The different thermoluminescence kinetic parameters [activation energy (E), frequency factor (s) and order of the kinetics (b)] of these phosphors were evaluated and compared using the peak shape method...
May 29, 2017: Luminescence: the Journal of Biological and Chemical Luminescence
Masato Okazaki, Youhei Takeda, Przemyslaw Data, Piotr Pander, Heather Higginbotham, Andrew P Monkman, Satoshi Minakata
Novel U-shaped donor-acceptor-donor (D-A-D) π-conjugated multi-functional molecules comprising dibenzo[a,j]phenazine (DBPHZ) as an acceptor and phenothiazines (PTZ) as donors have been developed. Most importantly, the D-A-D compounds exhibit not only distinct tricolor-changeable mechanochromic luminescence (MCL) properties but also efficient thermally activated delayed fluorescence (TADF). Quantum chemical calculations, X-ray diffraction analysis, and systematic studies on the photophysical properties indicated that the "two-conformation-switchable" PTZ units play a highly important role in achieving multi-color-changing MCL...
April 1, 2017: Chemical Science
Lanhua Chen, Juan Diwu, Daxiang Gui, Yaxing Wang, Zhehui Weng, Zhifang Chai, Thomas E Albrecht-Schmitt, Shuao Wang
The oxidation state greatly affects the chemical behavior of uranium in the nuclear fuel cycle and in the environment. Phosphonate ligands, on the other hand, show strong complexation toward uranium at different oxidation states and are widely used in nuclear fuel reprocessing. Therefore, in this work, the reduction behavior of U(VI) with the presence of a phosphonate ligand is investigated under mild solvothermal conditions. By adjusting the reaction time, temperature, and counterion species, a series of uranium diphosphonates including two U(VI), seven U(IV), two mixed-valent U(IV/VI), and one distinct U(IV/V/VI) compounds were obtained...
May 26, 2017: Inorganic Chemistry
Emille M Rodrigues, Diogo A Gálico, Italo O Mazali, Fernando A Sigoli
The chemical composition, shape and size of upconverting nanoparticles are known to have a great influence on their spectroscopic properties, such as the emission color and the emission intensity variation as a function of temperature. This work shows the color tuning and the thermal sensitivity of NaYb0.67Gd0.30F4:Tm0.015:Ho0.015 nanoparticles synthesized by two different approaches of the same synthetic method showing the influence of size and morphology, 250 nm hexagonal-plated and 30 nm spheroidal nanoparticles, on the visible upconversion color under NIR irradiation...
May 25, 2017: Methods and Applications in Fluorescence
Chen Wang, Li Tian, Wei Zhu, Shiqiang Wang, Peng Wang, Yun Liang, Wanlin Zhang, Hongwei Zhao, Guangtao Li
By incorporating a cationic dye within a metal-organic framework (MOF) through an ion-exchange process, a responsive dye@bio-MOF-1 composite has been synthesized, serving as a dual-emitting platform for enhanced detection of different kinds of nitro-explosives, especially nitroalkanes, nitramines, and nitrate esters. The dye@bio-MOF-1 composite was constructed with free amines on their well-defined cavities, which is essential for the capture of explosives into their confined nanospace. It was observed that the encapsulation of explosives into the constructed dye@bio-MOF-1 composite could dramatically alter the luminescent properties of the dyes as well as the MOF skeletons owing to the size exclusivity and confinement-induced effect...
June 5, 2017: ACS Applied Materials & Interfaces
Daniela S Gomes, Licínio M Gando-Ferreira, Rosa M Quinta-Ferreira, Rui C Martins
Diclofenac (DCF) and Sulfamethoxazole (SMX) are two of the most frequently detected pharmaceutical compounds in water and are hardly removed by biological treatment systems. The presence of H2O2 was investigated in the ozonation of these two compounds. Experiments were carried out with both using distilled water and secondary effluent from a municipal wastewater treatment plant spiked with pharmaceuticals. Chemical oxygen demand (COD) abatement rate improved when H2O2 was added at the beginning of the ozonation process and when the ozone inlet concentration increased, attaining a maximum value of 91% and simultaneously a lower ozone waste for a H2O2 initial concentration of 5 mM and an ozone inlet concentration of 20 g Nm(-3)...
June 8, 2017: Environmental Technology
Mo Li, Yifan Jia, Yan Ling, Yilu Chen, Lu Zhang, Dan Luo, Lidan Lai, Meijun Guo, Dalei Zhang, Min Ren, Hong Xu, Haibin Kuang
Expression and function of the follicle‑stimulating hormone receptor (FSHR) are traditionally thought to be limited to the ovary in females. However, recent studies have indicated that the FSHR is also expressed in endothelial cells of the placental vasculature, and that the haploinsufficiency of the feto‑placental FSHR impaired the growth of the mouse placenta. The aim of the current study was to investigate the placental expression of FSH and FSHR in pregnancies complicated by pre‑eclampsia. Placental tissue samples were collected from 20 pregnancies with pre‑eclampsia and 25 normal pregnancies...
July 2017: Molecular Medicine Reports
Jing-Xing Wu, Bing Yan
Using p-phenylenediamine as a precursor, p-carbon dots (p-CDs) with strong red-light emission were encapsulated into a metal-organic framework (MOF) followed by introduction of green light-emitting Tb(3+) to form a two-color light-emitting hybrid (Tb(3+)@p-CDs/MOF). The as-prepared fluorescent-functionalized MOF not only maintained the excellent optical properties of p-CDs and Tb(3+) to give strong emission, but also had good chemical and physical properties. The chosen p-CDs were aggregated readily in water, which led to only very weak photoluminescence, whereas the opposite effect was noted in the organic solvents ethanol, dimethylformamide and cyclopropane...
May 30, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
David Wiedmer, Fernanda Cristina Petersen, Jessica Lönn-Stensrud, Hanna Tiainen
The chemical decontamination of infected dental implants is essential for the successful treatment of peri-implantitis. The aim of this study was to assess the antibacterial effect of a hydrogen peroxide-titanium dioxide (H2O2-TiO2) suspension against Staphylococcus epidermidis biofilms. Titanium (Ti) coins were inoculated with a bioluminescent S. epidermidis strain for 8 h and subsequently exposed to H2O2 with and without TiO2 nanoparticles or chlorhexidine (CHX). Bacterial regrowth, bacterial load and viability after decontamination were analyzed by continuous luminescence monitoring, live/dead staining and scanning electron microscopy...
May 19, 2017: Biofouling
Na Niu, Zhuoming Ma, Fei He, Shujun Li, Jian Li, Shouxin Liu, Piaoping Yang
Carbon dots, which are less than 10 nm in diameter, have been widely investigated because of their unique luminescence properties and potential for use in bioimaging. In the present work, natural carbon dots (L-CDs) were obtained by molecular aggregation, using ethanol-extracted cellulolytic enzyme lignin. The whole process for the preparation of L-CDs was green and simple to operate and did not use toxic chemical reagents or harsh conditions. The newly prepared L-CDs emitted multicolor photoluminescence following one- and two-photon excitation...
May 30, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Chris S Hawes, Amy D Lynes, Kevin Byrne, Wolfgang Schmitt, Gavin Ryan, Matthias E Möbius, Thorfinnur Gunnlaugsson
A heterotopic naphthalimide ligand N-(4-picolyl)-4-(4'-carboxyphenoxy)-1,8-naphthalimide HL is utilised for the formation of self-assembled soft materials. In the presence of K(+) ions, L(-) forms a robust photoluminescent hydrogel 1 which is reversible under thermal, mechanical or chemical stimuli.
May 17, 2017: Chemical Communications: Chem Comm
R Viswanath, H S Bhojya Naik, G Arun Kumar, I K Suresh Gowda, S Yallappa
Luminescence technology has been improved with the help of semiconductor nanoparticles that possess novel optical and electrical properties compared with their bulk counterpart. The aim of this study was to design semiconductor nanocrystals in their pure (ZnS) or doped form (ZnS:Mn) with different concentrations of Mn(2+) ions by a wet chemical route stabilized by ethylenediamine tetra-acetic acid (EDTA) and to evaluate their luminescence properties. The nanocrystals were characterized by physicochemical techniques such as X-ray diffraction (XRD), High-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SEAD), EDS, and ultraviolet (UV)-visible light and photoluminescence (PL) studies...
May 16, 2017: Luminescence: the Journal of Biological and Chemical Luminescence
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