Behavior of Polyethylene Oxide Based Nonionic Surfactants in Silicon Processing Using Alkaline Solutions

1995 ◽  
Vol 142 (2) ◽  
pp. 621-627 ◽  
Author(s):  
Joong S. Jeon ◽  
Srini Raghavan ◽  
Roger P. Sperline
2021 ◽  
pp. 47-50
Author(s):  
Жанна Ивановна Кузина ◽  
Борис Владиленович Маневич

В статье представлены результаты экспериментов, согласно которым общепринятые концентрации 0,5; 1,0; 1,5 % рабочих щелочных растворов характеризуются более высоким поверхностным натяжением, чем вода. Введение комплексоната в растворы щелочных электролитов практически не влияет на эти показатели. При этом достигается степень удаления отложений с контактной поверхности на 14-17 % в зависимости от концентрации гидроксида щелочного металла. По результатам определения поверхностного натяжения и эмульгирующей способности различных видов поверхностно-активных веществ (ПАВ) выявлены наиболее рациональные из них. Для удаления отложений с преимущественным содержанием белковой фракции и функциональных добавок акцент следует направить на применение неионогенных ПАВ с наименьшим показателем поверхностного натяжения при концентрациях щелочной основы 1,7-2,5 %. При наличии значительных отложений жировой фракции и функциональных добавок необходимо использовать анионные ПАВ в смеси с диспергаторами, снижающими пенообразующую способность моющих растворов. Концентрация щелочных компонентов в процессе мойки может варьировать в пределах 0,5-1,2 %. The article presents the results of experiments, according to which the generally accepted concentrations 0.5; 1.0; 1.5 % of working alkaline solutions are characterized by a higher surface tension than water. The introduction of a complexonate into solutions of alkaline electrolytes has practically no effect on these indicators. In this case, the degree of removal of deposits from the contact surface is achieved by 14-17 %, depending on the concentration of alkali metal hydroxide. Based on the results of determining the surface tension and emulsifying abilities of various types of surfactants, the most rational of them were identified. To remove deposits with a predominant content of the protein fraction and functional additives, the emphasis should be on the use of nonionic surfactants with the lowest surface tension at alkaline base concentrations 1.7-2.5 %. In the presence of significant deposits of the fat fraction and functional additives, it is necessary to use anionic surfactants in a mixture with special dispersants that reduce the foaming ability of washing solutions. The concentration of alkaline components in the washing process can vary within 0.5-1.2 %.


Author(s):  
G. G. Cocks ◽  
C. E. Cluthe

The freeze etching technique is potentially useful for examining dilute solutions or suspensions of macromolecular materials. Quick freezing of aqueous solutions in Freon or propane at or near liquid nitrogen temperature produces relatively large ice crystals and these crystals may damage the structures to be examined. Cryoprotective agents may reduce damage to the specimem, hut their use often results in the formation of a different set of specimem artifacts.In a study of the structure of polyethylene oxide gels glycerol and sucrose were used as cryoprotective agents. The experiments reported here show some of the structures which can appear when these cryoprotective agents are used.Figure 1 shows a fractured surface of a frozen 25% aqueous solution of sucrose. The branches of dendritic ice crystals surrounded hy ice-sucrose eutectic can be seen. When this fractured surface is etched the ice in the dendrites sublimes giving the type of structure shown in Figure 2. The ice-sucrose eutectic etches much more slowly. It is the smooth continuous structural constituent surrounding the branches of the dendrites.


1994 ◽  
Vol 91 ◽  
pp. 901-908 ◽  
Author(s):  
H Zanni ◽  
P Nieto ◽  
L Fernandez ◽  
R Couty ◽  
P Barret ◽  
...  

TAPPI Journal ◽  
2010 ◽  
Vol 9 (7) ◽  
pp. 35-41
Author(s):  
OUTI A. HYÖKYVIRTA ◽  
TOM E. GUSTAFSSON

This investigation evaluated the applicability of a molybdenum sulfide reference electrode (MSRE) as an internal reference electrode for use in alkaline sulfide solutions over a range of pulp digester liquors at 170°C. The electrode remained stable during the exposure period of two weeks. The experimentally determined half cell potential of the MSRE is E = -0.91 VSHE. The surface of the MSRE was examined by scanning electron microscope (SEM) and electron spectroscopy for chemical analysis (ESCA) to verify the chemical composition of the thin surface film. Based on ESCA studies, the surface film contained molybdenum disulfide and sodium disulfide. During storage of the specimens, sulfide was partly oxidized to sodium sulfite in air. Next to the metallic molybdenum, a mixed molybdenum disulfide and molybdenum hydroxide layer was detected.


1990 ◽  
Vol 45 (2) ◽  
pp. 231-244 ◽  
Author(s):  
H. A. Nasr-El-Din ◽  
K. C. Khulbe ◽  
V. Hornof ◽  
G. H. Neale

2009 ◽  
Vol 46 (5) ◽  
pp. 272-278 ◽  
Author(s):  
E. A. M. Gad ◽  
E. M. S. Azzam ◽  
I. Aiad ◽  
W. I. M. El-azab

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