Colloidal solutions of niobium trisulfide and niobium triselenide

2014 ◽  
Vol 2 (28) ◽  
pp. 5479-5486 ◽  
Author(s):  
Vladimir E. Fedorov ◽  
Sofya B. Artemkina ◽  
Ekaterina D. Grayfer ◽  
Nikolay G. Naumov ◽  
Yuri V. Mironov ◽  
...  
Keyword(s):  
Organic Solvents ◽  
Colloidal Solutions ◽  
Niobium Triselenide

Bulk NbS3and NbSe3were stably dispersed in a number of organic solvents to yield colloids containing thin well-crystallized nanoribbons of NbS3and NbSe3.

scholarly journals Modification of copper(I) – based activation solution with organic solvents and surfactants in the process of chemical copperplating

2019 ◽  
Vol 59 (8) ◽  
pp. 86-91
Author(s):  
Ludmila A. Brusnitsina ◽  
◽  
Elena I. Stepanovskih ◽  
Tatiana A. Aleхeeva ◽  
◽  
...  
Keyword(s):  
Organic Solvents ◽  
Printed Circuit Boards ◽  
Adhesive Layer ◽  
Dielectric Materials ◽  
Dielectric Surface ◽  
Colloidal Solutions ◽  
High Concentration ◽  
Active Centers ◽  
Catalytically Active ◽  
Activating Solution

In the processes of chemical and galvanic metallization of dielectric materials, in particular in the production of printed circuit boards, surface activation mainly uses compounds of precious metals and colloidal solutions characterized by limited stability during storage due to the coagulation process. To activate dielectric materials it is advisable to use true solutions based on monovalent copper compounds. For continuous metallization of the dielectric, it is necessary to obtain a sufficiently large number of catalytic active centers on the surface. This can be achieved in two ways: to create a high concentration of Cu(I) in the activation solution or to increase the thickness of the activating layer. The aim of this work is to modify the activating solution by introducing organic solvents and surfactants into its composition, contributing to an increase in the concentration of catalytically active centers on the dielectric surface. In order to better distribute the activating solution on the dielectric surface and in the holes, as well as to increase the sorption of copper(I) by the adhesive layer, the modifying effect of organic solvents on the activating composition was studied. As such solvents, dimethylformamide (DMFA) and dimethyl sulfoxide (DMSO) used in the preparation of the surface of the adhesive layer were studied. In the process of swelling, the solvent penetrates into the thickness of the adhesive layer. Due to this, the activator containing an organic solvent has the ability to be fixed on the surface not only due to the micro-roughness created in the etching process, but also able to penetrate deep into the swollen layer. It is established that the maximum thickness of the swollen layer for 10% solution is reached by the time of swelling 30-40 minutes, for 20% ‒ 20 minutes, for 50% ‒ more than 45 minutes. By the time of swelling, equal to 5 minutes, for 10, 20 and 50% solutions, the thickness of the swollen layer, respectively, is 1.00; 1.14; 1.55 microns. It is shown that the presence of organic solvents in the activator increases the adhesion of the metal coating by an average of 1.3 times. In order to better distribute the activator on the dielectric surface and in the holes, as well as to increase the adsorption of copper(I), it is advisable to introduce surfactants into the activator, which reduce the surface tension at the interface. Introduction to the composition of the surfactant activating solution affect the adhesion of the metal to the dielectric. It was found that the introduction of surfactant into the activating solution leads to an increase in the concentration of copper on the dielectric surface. Nonionic surfactant brand OP-10 in the activator provides a high concentration of catalytically active centers and get the highest adhesion of metal to the dielectric.

UNTERSUCHUNGEN ÜBER DIE EXTRAKTION DES ROTEN KOBER-FARBSTOFFS DURCH ORGANISCHE LÖSUNGSMITTEL ZUR ÖSTROGENBESTIMMUNG IM HARN

1960 ◽  
Vol XXXV (I) ◽  
pp. 34-48 ◽  
Author(s):  
Gerd Ittrich
Keyword(s):  
Menstrual Cycle ◽  
Organic Solvents ◽  
Urine Sample ◽  
Phenol Derivatives ◽  
Organische Lösungsmittel ◽  
Colour Complex

ABSTRACT A series of organic solvents and phenol derivatives have been examined for the extraction of the pink Kober-colour complex. Optimal results could be achieved for fluorimetry by a solution of 2 % (w/v) p-nitrophenol and 1 % (v/v) ethanol in acetylenetetrabromide, when the green mercury line (546 mμ was used as primary light. The sensitivity, stability and specificity have been improved, compared with the previously described reaction. By changing the sequence of purification steps and by reducing the volume of the urine sample (5 ml) the method for the determination of total oestrogens has been simplified. Approximately 10 determinations can be done within 3–4 hours by one person. Recovery experiments and comparative determinations with a previously described method have been carried out. The excretion of total oestrogens in a complete menstrual cycle is determined with the described method.

Imidazole Promoted Efficient Anomerization of β-D-Glucose Pentaacetate in Organic Solutions and Solid State

2019 ◽  
Author(s):  
Meifeng Wang ◽  
Liyin Zhang ◽  
Yiqun Li ◽  
Liuqun Gu
Keyword(s):  
Solid State ◽  
Organic Solvents ◽  
Room Temperature ◽  
Materials Design ◽  
The Future ◽  
Organic Solutions ◽  
Glucose Pentaacetate

<p></p>Anomerization of glycosides were rarely performed under basic condition due to lack of efficiency. Here an imidazole promoted anomerization of β-D-glucose pentaacetate was developed; and reaction could proceed in both organic solvents and solid state at room temperature. Although mechanism is not yet clear, this unprecedent mild anomerization in solid state may open a new promising way for stereoseletive anomerization of broad glucosides and materials design in the future..

Evaluation of exposure by organic and inorganic substances for identifying growing risk groups

2020 ◽  
pp. 685-686
Author(s):  
L. V. Lukovnikova ◽  
K. I. Stosman ◽  
E. E. Lesiovskaya
Keyword(s):  
Organic Solvents ◽  
Risk Groups ◽  
Blood Levels ◽  
Inorganic Substances ◽  
Cortisol Levels

Working in contact with nitroglycerine, TNT, RDX, oxygenatom, organic solvents, recorded elevated levels of cortisol in the blood. In contact with metals, their blood levels and cortisol levels did not differ from the average values of the professionally employed population.

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