Room temperature diazotization and coupling reaction using a DES–ethanol system: a green approach towards the synthesis of monoazo pigments

2019 ◽  
Vol 55 (42) ◽  
pp. 5970-5973
Author(s):  
Sujit Suresh Kamble ◽  
Ganapati Subray Shankarling

Synthesis of a stable diazonium salt at room temperature followed by the synthesis of monoazo pigments using DES–ethanol system.

BioResources ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 89-104
Author(s):  
Liangliang An ◽  
Chuanling Si ◽  
Guanhua Wang ◽  
Cheol Soon Choi ◽  
Yong Ho Yu ◽  
...  

A green, effective, and feasible reaction for esterification of lignin with oleic acid in water at room temperature was investigated. A surfactant-combined system (p-toluenesulfonic acid/4-dodecylbenzenesulfonic acid) was designed to simultaneously solubilize kraft lignin and disperse the oleic acid, producing microreactors for esterification. Esterification using a higher 4-dodecylbenzenesulfonic acid dosage at room temperature was found to be a good option, and an increasing oleic acid dosage had no effect on improving the degree of esterification. Structural characterization analyses confirmed the successful esterification of lignin with oleic acid, indicating the effectiveness and feasibility of esterification of macromolecules in water. Due to the introduction of a long flexible aliphatic chain, the lignin ester showed a noticeable decrease in glass transition temperature, an obvious increase in contact angle, and exhibited excellent thermoplasticity, processability, and hydrophobicity. Additionally, lignin-ester nanoparticles were prepared through the micellization of p-toluenesulfonic acid. Therefore, the method of esterification using surfactant-combined microreactors in water is promising for high value-added utilization of lignin.


Author(s):  
Xiaoqing Liu ◽  
Wenbo Dai ◽  
Qian Junjie ◽  
Yunxiang Lei ◽  
Miaochang Liu ◽  
...  

A new doped system with pure phosphorescent emission is constructed using four 1-(4-(diphenylamino)phenyl)-2-phenylethan-1-one derivatives containing halogen atoms as the guests and benzophenone as the host. That is, the doped system...


2021 ◽  
Vol 45 (12) ◽  
pp. 5526-5539
Author(s):  
Zhi Zhang ◽  
Zhihang Huang ◽  
Hong Yuan

A KCC-1/Al–SO3H catalyst with Si/Al = 5 was prepared to directly catalyse the synthesis of ethyl levulinate from cellulose in an ethanol/toluene co-solvent system. A reaction yield of 28.8 mol% was achieved after 6 h at 200 °C.


2012 ◽  
Vol 576 ◽  
pp. 314-317
Author(s):  
Sinin Hamdan ◽  
M. Saiful Islam

Five types of selected tropical light hardwoods were chemically modified with benzene diazonium salt to improve their physical and mechanical properties. Benzene diazonium salt underwent a coupling reaction with wood which was confirmed through FT-IR analysis. The compressive modulus of the treated wood increased, whereas modulus of rupture was shown to decrease on treatment. The modified wood samples had higher hardness (Shore D) values compared to that of the control ones.


ChemInform ◽  
2005 ◽  
Vol 36 (38) ◽  
Author(s):  
Jun-xiao Yang ◽  
Kuo-yan Ma ◽  
Fang-hua Zhu ◽  
Wen Chen ◽  
Bo Li ◽  
...  

1992 ◽  
Vol 287 ◽  
Author(s):  
T.S. Yen ◽  
W.Y. Sun

ABSTRACTAdditions and revisions to several of the most important phase diagrams and phase behavior diagrams in the silicon nitride field are reviewed in this work, with emphasis on the Y-Si-A1-O-N system. This information is further used to make observations on the promising silicon nitride systems containing either highly refractory grain boundary phases or compatible matrix phases of desirable properties. Examples are provided to illustrate the advantage of such a basic approach to materials design. Hardness, toughness, strength at room temperature and elevated temperature and even sinterability can all be improved by adopting such an approach.


Synlett ◽  
2017 ◽  
Vol 28 (16) ◽  
pp. 2153-2156 ◽  
Author(s):  
Wen-Ting Wei ◽  
Hongze Liang ◽  
Wen-Ming Zhu ◽  
Weida Liang ◽  
Yi Wu ◽  
...  

A radical–radical cross-coupling reaction of phenols with tert-butyl nitrite has been developed with the use of water as an additive. This method allows the construction of C–N bonds under an air atmosphere at room temperature, providing the ortho-nitrated phenol derivative in moderate to good yields.


2021 ◽  
Vol 13 (8) ◽  
pp. 4158
Author(s):  
Marcos A. Bento ◽  
Sara Realista ◽  
Ana S. Viana ◽  
Ana M. Ferraria ◽  
Paulo N. Martinho

Reproducible materials that have detection properties towards a certain molecule are very important for applications in the fabrication of devices. Among all the substrates that are used, highly oriented pyrolytic graphite allows to clearly image a monolayer. On the other hand, cryptand molecules are versatile because they can sense certain analytes with high selectivity. The highly oriented pyrolytic graphite electrode was first functionalized with an aryl bearing a bromine or an alkyne group to further attach cryptand molecules to its surface. The functionalization was performed through the electroreduction of aryl diazonium salts. While functionalization with an aryl-bromine produced a 20 nm-thick dendritic layer, functionalization of the surface with an aryl bearing a terminal alkyne produced a 9.7 nm-thick multilayer. However, if the diazonium salt is prepared in situ, a 0.9 nm monolayer with aryl–alkyne groups is formed. The alkyne functionalized electrode reacted with a bromo-cryptand through a Sonogashira C–C coupling reaction yielding electrodes functionalized with cryptands. These were immersed in a solution of a Co(II) salt resulting in Co(II)-cryptate modified electrodes, highlighting the ability of the cryptands’ modified electrode to sense metal ions. The electrode surface was analyzed by X-ray photoelectron spectroscopy after each modification step, which confirmed the successful functionalization of the substrate with both the cryptand and the cryptate. Cyclic voltammetry studies showed stable current response after approximately six cycles. Different reduction processes were detected for both cryptand (−1.40 V vs. SCE) and cryptate (−1.22 V vs. SCE) modified highly oriented pyrolytic graphite.


2019 ◽  
Vol 109 (03) ◽  
pp. 189-193
Author(s):  
A. Keller ◽  
S. Adler ◽  
N. Zobel

Im Forschungsprojekt „CPPSProcessAssist“ wurde für vier kleine und mittlere Unternehmen (KMU) der Prozessindustrie ein modulares und mobiles Assistenzsystem zur Instandhaltungsunterstützung entwickelt. Neben der technologischen Entwicklung des Systems wurde im Projekt eine Vorgehensweise zur Gestaltung und Einführung des Systems in den Unternehmen erarbeitet. Mitarbeiter der Schicht und Schichtleitung, Projektingenieure, Instandhalter sowie Technologieentwickler wurden als Mitgestalter des Systems und der daraus folgenden Veränderungen im Unternehmen eingebunden. Das resultierende System bildet die unternehmensübergreifenden Anforderungen von Instandhaltungsaufgaben in der Prozessindustrie technisch ab und ist an vorhandene IT-Infrastrukturen anpassbar. Die gewählte Vorgehensweise zur Einbindung der Mitarbeiter in der Gestaltung des Systems trug dazu bei, die unternehmens- und nutzerspezifischen Anforderungen in das System zu integrieren sowie die Mitarbeiter zu Eingabe bedarfsgerechter Assistenzinhalten zu befähigen.   A modular and portable maintenance assistance system was developed for four small and medium-sized process manufacturers in the research project CPPSProcessAssist. Along with the technological development of the system, a procedure for designing and implementing the system in the companies was developed. Shift workers and managers, project engineers, maintenance engineers and technology developers were involved in designing the system and implementing the ensuing changes in their companies. The resulting system technically maps cross-company requirements for maintenance work in process manufacturing and can be modified for existing IT infrastructures. The selected procedure for involving employees in the system design helped integrating specific company and user requirements in the system and enabling employees to enter content in the assistance system based on their needs.


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