scholarly journals Chirality induction on non-chiral dye-linked polysilsesquioxane in nanohelical structures

2020 ◽  
Vol 56 (53) ◽  
pp. 7241-7244 ◽  
Author(s):  
Naoya Ryu ◽  
Tsutomu Kawaguchi ◽  
Hiroshi Yanagita ◽  
Yutaka Okazaki ◽  
Thierry Buffeteau ◽  
...  

Chirally arranged organic dye-linked polysilsesquioxane was prepared, through a sol–gel transcription using its non-chiral precursor with a chiral supramolecular template, and its chiroptical properties were investigated.

2014 ◽  
Vol 5 ◽  
pp. 1082-1090 ◽  
Author(s):  
Subia Ambreen ◽  
N D Pandey ◽  
Peter Mayer ◽  
Ashutosh Pandey

Ta8(μ3-O)2(μ-O)8(μ-OEt)6(OEt)14 (1) was obtained by the controlled hydrolysis of tantalum ethoxide Ta(OEt)5 in the presence of ammonia. Compound 1 is considered as the intermediate building block in the sol–gel polymerization of Ta(OEt)5. Further hydrolysis of compound 1 yielded nanoparticles of Ta2O5, which were characterized by various techniques such as TGA-DTA-DSC, UV–vis DRS, XRD, SEM, TEM, particle size analyzer (DLS) and the Brunauer–Emmett–Teller (BET) method. The band gap of the particles was calculated by using the Tauc plot. The photocatalytic activity of Ta2O5 nanoparticles was tested by the degradation of the organic dye rhodamine B.


2014 ◽  
Vol 73 (1) ◽  
pp. 9-13 ◽  
Author(s):  
Mahboube Mohaghegh Motlagh ◽  
S. A. Hassanzadeh-Tabrizi ◽  
Ali Saffar-Teluri

2011 ◽  
Vol 239-242 ◽  
pp. 1006-1009
Author(s):  
Yun Long Deng ◽  
Yun Hui Sun ◽  
Du Xia Cao ◽  
Ying Chen ◽  
Zhi Qiang Liu

A D-π-D type of organic dye 2,7-di[4-(N,N-diphenylamino)styryl]-9-n-pentyl-9H- carbazole (DPSPC) with diphenylamine as donor group and styrene-carbazole-styrene as conjugation bridge has been synthesized. The photophysical properties of the dye in different solvents and poly methyl methacrylate/organic modified sol-gel glasses are researched. The results indicate that the fluorescence properties of the organic dye in composite glass increase relative to that in solvents and there are no fluorescence quenching in high doped concentration in composite glass matrixes. The dye has higher stability in the composite glass than that in solution.


ACS Nano ◽  
2021 ◽  
Author(s):  
Peizhao Liu ◽  
Yann Battie ◽  
Marion Decossas ◽  
Sisareuth Tan ◽  
Emilie Pouget ◽  
...  

2014 ◽  
Vol 937 ◽  
pp. 237-243
Author(s):  
Jie Dong ◽  
Hong Fang Shen ◽  
Yan Min Wang ◽  
You Jun Lu ◽  
Guo Li Fang

Ultrasonic assisted citrate sol-gel is used to synthesis LaCoO3(LCO) ultrafine particles. The influence of ultrasonic time on the properties of the samples was investigated. TG-DSC is applied to determine the phase transition of LCO gel precursor. XRD, FESEM and H2-TPR were applied to characteristic crystalline phase structure, morphology, thermal stability of LCO samples. The results indicated that LCO particles exhibit a well-formed polycrystalline rhombohedral distorted perovskite structure, and their particles are well-decentralized, in a smaller size and better dispersivity as the increasing of ultrasonic time ranged from 0min to 60min. H2-TPR implied that ultrasonic assistance can lower the reduction temperature of the product in the zone of low temperature and raise the temperature in the zone of high temperature. Ultrasonic assistance is not conductive to increase organic dye decolorization efficiency of LCO powders in darkroom when taking methyl orange and gold orange II as targeted dye.


Chemija ◽  
2019 ◽  
Vol 30 (4) ◽  
Author(s):  
D. Kaušpėdienė ◽  
E. Zubrytė ◽  
A. Gefenienė ◽  
M. Jovaišaitė ◽  
V. Gefenas ◽  
...  

In this study, CuO nanoparticles have been synthesized via a simple sol–gel method and green synthesis using flower (Matricaria chamomilla) extract. XRD analysis of the synthesized CuO nanoparticles clearly indicated a crystalline nature with a monoclinic structure regardless of the method of synthesis, while SEM revealed that the used synthesis methods affected the morphology of the CuO nanoparticles. The oxidative degradation kinetics of the organic dye Methyl Orange (MO) in the presence of the synthesized catalyst CuO and H2O2 has been investigated and compared depending on the dye concentration, reaction time and temperature. The catalytic activity of CuO was studied by measuring the UV–visible spectrum of the MO dye solution treated with CuO and H2O2. It was determined that the MO degradation reaction kinetics followed the pseudo-first-order mechanism. Thermodynamic studies indicated an endothermic nature (∆H# = +73.03 kJ mol–1) and a decrease in randomness at the catalyst CuO/solution interface during the reaction (∆S# = –0.021 kJ mol–1 K–1). At the same conditions, the green synthesized CuO nanoparticles exhibit similar activity properties as CuO synthesized using the sol–gel method. Besides, the green synthesis of CuO nanoparticles is simple and uses a small number of chemicals. The obtained CuO may be a promising catalyst for the oxidative degradation of organics, especially used in medical procedures.


1994 ◽  
Vol 351 ◽  
Author(s):  
Eric P. Bescher ◽  
John D. Mackenzie ◽  
Tomoko Ohtsuki ◽  
Nasser Peyghambarian

ABSTRACTThis paper describes the processing of rare-earth/organic dye composites fabricated via three different sol-gel routes. In the first approach, low hydroxyl ormosil matrices were fabricated via reaction of a methyl-modified silicon halide with tertiary alcohol and subsequently doped with erbium iodide and a near-infrared dye. In the second approach, gels were made from tetramethoxysilane and doped with erbium complexes and dyes. In the third approach, a hybrid siloxane method was used. No Er3+ luminescence at 1.55 mm was observed in any of the three cases, mainly due to the strong absorption of the matrices centered around 1.4 mm. Fluorescence of Er3+ in the visible was observed in the first matrice, but no dye luminescence was detected. Dye luminescence was observed in the second type matrix, along with some reabsorption of the dye luminescence by Er3+. In the third approach, neodymium exhibited optical activity in the near infrared, as well as the dye.


2013 ◽  
Vol 650 ◽  
pp. 3-6 ◽  
Author(s):  
Li Ming Jiang

The Ag/TiO2powders with different Ag contents were synthesized with tetrabutyl titanate as a titanium source and silver nitrate as silver source by sol-gel method, and the Ag contents in the Ag/TiO2powders were 0.1%, 0.3%, 0.5 %, 0.8%, 1%, 1.5%, 2%, 2.5%, 3%, and 4% (mole ratio) respectively. Meanwhile, Rhodamine B was used as target degradant to value the photocatalytic activity of Ag/TiO2powders, the effects of Ag contents, the calcination temperature and calcination time on the photocatalytic activity were disscussed The results show that catalytic activity of the Ag/TiO2powders prepared with the Ag content of 2%, calcination temperature of 450 °C and calcination time of 2 hours exhibited the best photocatalytic activity, which was ascribed to the abundant electron traps in favor of the separation of the photoinduced electron-hole pairs.


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