Effect of surface hydrophilicity and water vapor pressure on the interfacial shear strength of adsorbed water layer

2004 ◽  
Vol 84 (11) ◽  
pp. 1919-1921 ◽  
Author(s):  
Doo-In Kim ◽  
Hyo-Sok Ahn ◽  
Dong-Hoon Choi
Keyword(s):  
Shear Strength ◽  
Water Vapor ◽  
Vapor Pressure ◽  
Interfacial Shear Strength ◽  
Water Vapor Pressure ◽  
Water Layer ◽  
Adsorbed Water ◽  
Interfacial Shear ◽  
Surface Hydrophilicity ◽  
Effect Of Surface

scholarly journals Comparative study of the effect of water on the heterogeneous reactions of carbonyl sulfide on the surface of α-Al<sub>2</sub>O<sub>3</sub> and MgO

2009 ◽  
Vol 9 (16) ◽  
pp. 6273-6286 ◽  
Author(s):  
Y. Liu ◽  
Q. Ma ◽  
H. He
Keyword(s):  
Water Vapor ◽  
Vapor Pressure ◽  
Heterogeneous Reaction ◽  
Water Vapor Pressure ◽  
Carbonyl Sulfide ◽  
Water Layer ◽  
Heterogeneous Reactions ◽  
Effect Of Water ◽  
Mineral Dusts ◽  
Α Al2o3

Abstract. Here we compared the heterogeneous reactions of carbonyl sulfide (OCS) on the surface of α-Al2O3 and MgO and the effect of water on the reactions at 300 K using Knudsen cell–mass spectrometry, diffuse reflectance infrared Fourier transform spectroscopy, and temperature programmed reactions. H2S and CO2 were found to be hydrolysis products of OCS on both α–Al2O3 and MgO at ambient temperature. At low water vapor pressure (<6.8×10−6 Torr), when water vapor pressure in the Knudsen cell reactor increased from 2.3×10−6 to 6.8×10−6 Torr, the initial true uptake coefficient of OCS on α-Al2O3 decreased from 4.70±0.45×10−7 to 3.59±0.34×10−7; while it increased from 5.19±0.49×10−7 to 6.48±0.62×10−7 on MgO under the same conditions. At high relative humidity (0.07–0.67), the observed uptake coefficients of OCS on α-Al2O3 and MgO, which were measured using an in situ DRIFTS, decreased from 4.63±0.22×10−6 to 1.00±0.47×10−6 and from 9.72±0.46×10−5 to 7.68±0.36×10−5, respectively, when RH increased from 0.07 to 0.67 corresponding to 1.7–15.9 Torr of water vapor pressure. In the RH region of 0.17–0.67, the average observed uptake coefficient of OCS on α-Al2O3 and MgO was equal to 8.34±2.19×10−7 and 8.19±0.48×10−5, respectively. The restrictive effect of water on the heterogeneous reaction of OCS on the surface of α-Al2O3 and MgO was found to be related to competitive adsorption between water and OCS molecules; while the promotive effect of water on the heterogeneous reaction of OCS on the surface of MgO at low coverage was ascribed to the formation of surface hydroxyl groups. When the environmental RH was greater than the RH of the monolayer, which occurred readily at the atmospherically relevant humidity in the troposphere, thick water layer formed on the mineral dusts, especially, the basic thick water layer formed on the basic component of mineral dusts may be the primary contributor to the heterogeneous hydrolysis of OCS in the troposphere.

THE LOW PRESSURE DEHYDRATION OF MAGNESIUM SULPHATE HEPTAHYDRATE AND COBALTOUS CHLORIDE HEXAHYDRATE

1956 ◽  
Vol 34 (5) ◽  
pp. 591-599 ◽  
Author(s):  
R. W. Ford ◽  
G. B. Frost
Keyword(s):  
Water Vapor ◽  
Vapor Pressure ◽  
Magnesium Sulphate ◽  
Copper Sulphate ◽  
Water Vapor Pressure ◽  
Adsorbed Water ◽  
Vapor Pressures ◽  
Cobaltous Chloride ◽  
Chloride Hexahydrate ◽  
Initial Drop

Rates of dehydration under vacuum, and at a series of controlled water vapor pressures, have been carried out for powdered samples of magnesium sulphate heptahydrate and of cobaltous chloride hexahydrate. It has been found for the magnesium salt that as the pressures are increased, the rate at first drops rapidly, this decrease being followed by a period of acceleration which is followed in turn by a decline. The curves are similar to those previously reported for copper sulphate pentahydrate, but the changes occur over a much wider range of water vapor pressures. In the dehydration of cobaltous chloride hexahydrate the initial drop in rate with increase in water vapor pressure is not observed. The results are interpreted in terms of the crystallization of intermediate products in the presence of adsorbed water.

Effect of Surface Treatment on the Properties of PPTA Fiber

2013 ◽  
Vol 798-799 ◽  
pp. 215-218
Author(s):  
Zhao Jia
Keyword(s):  
Shear Strength ◽  
Experimental Design ◽  
Surface Treatment ◽  
Interfacial Shear Strength ◽  
Interfacial Shear ◽  
Epoxy Composites ◽  
Orthogonal Experimental Design ◽  
Optimum Conditions ◽  
Pull Out ◽  
Effect Of Surface

In this article, the potassium permanganate solutions (KMnO4) was used to treat the PPTA fiber based on an orthogonal experimental design. The optimum conditions of KMnO4treatment were concentration of 20%, temperature of 30°C and treating time of 20min. The interfacial properties of aramid fiber/epoxy composites were investigated by the single fiber pull-out test (SFP), and the results showed that the interfacial shear strength (IFSS) of aramid/epoxy composites was remarkbly improved.

scholarly journals Enhanced Interfacial Shear Strength and Critical Energy Release Rate in Single Glass Fiber-Crosslinked Polypropylene Model Microcomposites

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2552 ◽  
Author(s):  
Uwe Gohs ◽  
Michael Mueller ◽  
Carsten Zschech ◽  
Serge Zhandarov
Keyword(s):  
Shear Strength ◽  
Electron Beam ◽  
Energy Release Rate ◽  
Glass Fiber ◽  
Release Rate ◽  
Interfacial Shear Strength ◽  
Glass Fibers ◽  
Critical Energy ◽  
Interfacial Shear ◽  
Critical Energy Release Rate

Continuous glass fiber-reinforced polypropylene composites produced by using hybrid yarns show reduced fiber-to-matrix adhesion in comparison to their thermosetting counterparts. Their consolidation involves no curing, and the chemical reactions are limited to the glass fiber surface, the silane coupling agent, and the maleic anhydride-grafted polypropylene. This paper investigates the impact of electron beam crosslinkable toughened polypropylene, alkylene-functionalized single glass fibers, and electron-induced grafting and crosslinking on the local interfacial shear strength and critical energy release rate in single glass fiber polypropylene model microcomposites. A systematic comparison of non-, amino-, alkyl-, and alkylene-functionalized single fibers in virgin, crosslinkable toughened and electron beam crosslinked toughened polypropylene was done in order to study their influence on the local interfacial strength parameters. In comparison to amino-functionalized single glass fibers in polypropylene/maleic anhydride-grafted polypropylene, an enhanced local interfacial shear strength (+20%) and critical energy release rate (+80%) were observed for alkylene-functionalized single glass fibers in electron beam crosslinked toughened polypropylene.

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