Influence of surface silanol structure and hydration forces on alkoxide-derived silica gel structure

1997 ◽  
Vol 501 ◽  
Author(s):  
H. Kamiya ◽  
M. Yoshida ◽  
M. Mitsui
Keyword(s):  
Solid Surface ◽  
Mercury Porosimetry ◽  
Water Layer ◽  
Interaction Force ◽  
Repulsive Force ◽  
Solid Surfaces ◽  
Silica Gels ◽  
Gel Structure ◽  
Hydration Force ◽  
Hydrogen Bonded

ABSTRACTThe effects of the surface silanol structure and interaction force between solid surfaces in water on the gel structure using acid catalyzed hydrolysis alkoxide-derived silica gels with various preparation conditions. The present study focused on the amount of catalysts and H2O/TEOS mole ratios. Surface silanol structure, interaction between solid surfaces and the structure in dried-gels were determined by a FT-nIR, FT-IR, Atomic Force Microscope (AFM) and a mercury porosimetry, respectively. As results, when a relatively low H2O/TEOS mole ratio ( from 4 to 40) was used, surface silanol was almost hydrogen bonded silanol, and isolated silanol disappeared. Since this hydrogen-bonded silanol formed a hydrogen bonded water layer on silica surface, short-range additional hydration force (less than 2 nm) appeared between solid surface and the tip of AFM. When H2O/TEOS mole ratio increase in the range from 20 to 40, the surface density of isolated silanol increased and that of residual Si-OC2H5 decreased. Relatively long-range additional repulsive force on these silica gels reached 20 nm from solid surface. The pore diameter in each dried gel almost corresponded to the surface distance, which acted the additional repulsive force.

scholarly journals Hydrogen-bonded silica gels dispersed in a smectic liquid crystal: A random fieldXYsystem

2002 ◽  
Vol 65 (5) ◽  
Author(s):  
S. Park ◽  
R. L. Leheny ◽  
R. J. Birgeneau ◽  
J.-L. Gallani ◽  
C. W. Garland ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Silica Gels ◽  
Smectic Liquid Crystal ◽  
Hydrogen Bonded

Investigation of the Interaction Force betweenCryptosporidiumparvumOocysts and Solid Surfaces

Langmuir ◽  
2007 ◽  
Vol 23 (14) ◽  
pp. 7475-7483 ◽  
Author(s):  
T. L. Byrd ◽  
J. Y. Walz
Keyword(s):  
Interaction Force ◽  
Solid Surfaces

On the Hysteresis of Adsorption on Solid Surfaces

1952 ◽  
Vol 5 (2) ◽  
pp. 288
Author(s):  
RG Wylie
Keyword(s):  
Phase Transitions ◽  
Solid Surface ◽  
Three Dimensional ◽  
Solid Surfaces ◽  
Two Dimensional ◽  
Capillary Effects ◽  
First Order ◽  
Adsorption Of Gases ◽  
First Order Phase ◽  
Hysteresis Phenomena

Hysteresis phenomena associated with the adsorption of gases on solid surfaces are usually explained in terms of three-dimensional capillary effects or with more or less unspecific reference to phase transitions. It is shown that hysteresis effects are to be expected when two dimensional phase transitions occur on solids. In the connection, the thermodynamic equation governing the equilibrium of small, incompressible two-dimensional phases is derived. Such phases can form on an imperfect solid surface in an irreversible manner and, as calculation shows, can contribute significantly to the hysteresis of adsorption. In some cases the phase change may be responsible for the whole effect. The diffuseness of first-order phase transitions may be due to the same mechanism.

A two-dimensional hydrogen-bonded water layer in the structure of a cobalt(III) cubane complex

2014 ◽  
Vol 70 (2) ◽  
pp. 198-201 ◽  
Author(s):  
Ji Qi ◽  
Xiang-Sheng Zhai ◽  
Hong-Lin Zhu ◽  
Jian-Li Lin
Keyword(s):  
Water Clusters ◽  
Three Dimensional ◽  
Water Layer ◽  
Water Molecules ◽  
Supramolecular Network ◽  
Two Dimensional ◽  
Solvent Water ◽  
Water Layers ◽  
Hydrogen Bonded

A tetranuclear CoIIIoxide complex with cubane topology, tetrakis(2,2′-bipyridine-κ2N,N′)di-μ2-carbonato-κ4O:O′-tetra-μ3-oxido-tetracobalt(III) pentadecahydrate, [Co4(CO3)2O4(C10H8N2)4]·15H2O, with an unbounded hydrogen-bonded water layer, has been synthesized by reaction of CoCO3and 2,2′-bipyridine. The solvent water molecules form a hydrogen-bonded net with tetrameric and pentameric water clusters as subunits. The Co4O4cubane-like cores are sandwiched between the water layers, which are further stacked into a three-dimensional metallo-supramolecular network.

Particle Adhesion to Solid Surfaces

1990 ◽  
Vol 33 (2) ◽  
pp. 33-37
Author(s):  
Lewis Hecht
Keyword(s):  
Particle Size ◽  
Physical Properties ◽  
Solid Surface ◽  
Review Paper ◽  
Solid Surfaces ◽  
Particle Adhesion ◽  
Sources Of Information ◽  
Technical Literature ◽  
The Subject ◽  
Adhesive Forces

This review paper provides cleanroom technologists with an up-to-date overview on the subject of particle adhesion to solid surfaces. The discussion consists of four sections: (1) fundamental concepts of adhesion, (2) the nature of a solid surface, (3) the physical properties of particles, and (4) comments on the various theories of particle adhesion to solid surfaces. Some practical examples are also cited. A numeric example of adhesive forces as a function of particle size is presented in detail. The appendix contains references to other useful sources of information in the technical literature.

Adsorption Processes at Solid Surfaces-Studied by Electrokinetic Investigations

2006 ◽  
Vol 314 ◽  
pp. 19-24 ◽  
Author(s):  
Cornelia Bellmann ◽  
Anja Caspari
Keyword(s):  
Zeta Potential ◽  
Surface Chemistry ◽  
Solid Surface ◽  
Adsorption Process ◽  
Ph Value ◽  
Streaming Potential ◽  
Solid Surfaces ◽  
Multicomponent Mixtures ◽  
Adsorption Processes ◽  
Different Shapes

The process of electrophoretic deposition depends strongly on the electrokinetic properties and with it the surface properties of the material that will be processed. Different additives, conditioners but also the suspending liquid influence the surface of the applied material by adsorption. Electrokinetic investigations reflect changes in properties at the outermost solid surface very sensitive. Streaming potential measurements are especially suited for studying such changes of surface chemistry at solids with different shapes. Two approaches are applicable: 1. The adsorption process was done before measuring. The result of this process should be shown. In this case it will be interesting to see differences in the functionality of the solid surface. The zeta potential will be measured versus different pH value. 2. The adsorption process will be studied directly. The zeta potential will be determined versus the concentration of the adsorptive. The second approach can be used for investigation of adsorption of multicomponent mixtures. Competing adsorption processes are detectable.

scholarly journals Interaction Force between Solid Surfaces (lst Report)

1986 ◽  
Vol 52 (10) ◽  
pp. 1795-1801
Author(s):  
Yuzo MORI ◽  
Kazuhisa SUGIYAMA ◽  
Katsuyoshi ENDOH ◽  
Hidekazu GOTOH
Keyword(s):  
Interaction Force ◽  
Solid Surfaces

scholarly journals Hybrid Atomistic-Continuum Simulation of Nanostructure Defect-Induced Bubble Growth

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Yijin Mao ◽  
Bo Zhang ◽  
Chung-Lung Chen ◽  
Yuwen Zhang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Phase Change ◽  
Molecular Dynamic ◽  
Solid Surface ◽  
Bubble Growth ◽  
Molecular Level ◽  
Liquid Argon ◽  
Solid Surfaces ◽  
Solid Copper

Effects of nanostructured defects of a copper solid surface on bubble growth in liquid argon have been investigated through a hybrid atomistic-continuum (HAC) method. The same solid surfaces with five different nanostructures, namely, wedge defect, deep rectangular defect (R-I), shallow rectangular defect (R-II), small rectangular defect (R-III), and no defect were modeled at the molecular level. Liquid argon was placed on top of hot solid copper with a superheat of 30 K after equilibration was achieved with computational fluid dynamics–molecular dynamic (CFD–MD) coupled simulation. Phase change of argon on five nanostructures has been observed and analyzed accordingly. The results showed that the solid surface with wedge defect tends to induce a nanobubble more easily than the others, and the larger the size of the defect, the easier it is for the bubble to generate.

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