Thermodynamics and the effect of guanidine hydrochloride and potassium chloride on the hydrophobic hydration of tetrabutylammonium bromide and tetra-n-pentylammonium bromide in water

1973 ◽  
Vol 77 (19) ◽  
pp. 2335-2338 ◽  
Author(s):  
B. Chawla ◽  
S. Sunder ◽  
J. C. Ahluwalia
Keyword(s):  
Potassium Chloride ◽  
Guanidine Hydrochloride ◽  
Tetrabutylammonium Bromide ◽  
Hydrophobic Hydration

Comparison of the Inhibitory Action of KCl and Guanidine Hydrochloride Solutions on Montmorillonite Swelling

1982 ◽  
Vol 22 (04) ◽  
pp. 514-522 ◽  
Author(s):  
M. Iltis ◽  
G. Didier ◽  
P. Lareal
Keyword(s):  
Potassium Chloride ◽  
Inhibitory Action ◽  
Guanidine Hydrochloride ◽  
Research Work ◽  
Cylindrical Sample ◽  
Degree Of Saturation ◽  
Composition Analysis ◽  
Drilling Mud ◽  
Swelling Clays ◽  
Before And After

Abstract This study compares the effectiveness of potassium chloride with guanidine chlorhydrate in the prevention of-clay swelling. The results given on various swelling tests on calcic montmorillonite led to the conclusions thatguanidine chlorhydrate is more effective than potassium chloride, especially in low concentrations, andwater immersion of samples treated by both solutions shows the permanent feature of the inhibitive action of guanidine chlorhydrate in swelling on one hand and the important increase in swelling of immersed samples treated by potassium chloride on the other. The viscosity measure of montmorillonite suspensions, before and after solution ion elimination by dialysis. confirms these observations. Introduction Among the grounds encountered in drilling, swelling clays are those that raise major problems for wall firmness. These clays, commonly called "gumbos," raise many problems related to swelling, dispersion, and a strong tendency of the cuttings to aggregation. These problems result from the interaction of the drilling mud with the terrain traversed. An analysis of the effectiveness of various materials used in drilling muds to stabilize clayed zones led us to focus on the action of two solutions capable of inhibiting swelling:potassium chloride. which is normally used in drilling wells, andguanidine hydrochloride, which displays a strong fixation tendency on montmorillonite. The purpose of this study is to compare the inhibitory action of these two salts and the influence of their concentration in the solutions by means of relatively simple tests. This research work is limited to treatment of a montmorillonite clay. The Material Investigated To examine the behavior of swelling clays in the presence of the two solutions selected, it would be ideal to carry out tests on samples representative of the horizons that raised problems during drilling operations. However, it is difficult to extract enough clay of stable composition from the cuttings; moreover, the clay is polluted by the drilling mud. Composition analyses of clays that are difficult to drill because of swelling showed that montmorillonite was present in all the samples investigated. Hence this study is limited to an examination of the action of KCl and guanidine hydrochloride on a previously investigated montmorillonite. The montmorillonite used was an Italian natural calcium montmorillonite, supplied untreated and finely ground. The composition analysis carried out in the Compagnie Francaise des Petroles (CFP) laboratory at Bordeaux yielded the results given in Table 1. Table 2 gives the geotechnical properties of the clay investigated. Swelling Tests of Compacted Samples Unidirectional Swelling This test was performed in the measurement cell shown in Fig. 1. The cylindrical sample was hooped laterally and its swelling measured in a single direction. The procedure was as follows.Five grams of clay dried in an oven at 100 deg. C were placed in a measurement cell.The clay was saturated by it KCl or guanidine hydrochloride solution for 24 hours (by filtration) (the degree of saturation measured on some samples after compacting was found to exceed 95%). SPEJ P. 514^

Size and temperature dependence of hydrocarbon solubility in concentrated aqueous solutions of urea and guanidine hydrochloride

2002 ◽  
Vol 80 (4) ◽  
pp. 388-400 ◽  
Author(s):  
Giuseppe Graziano
Keyword(s):  
Temperature Dependence ◽  
Interaction Energy ◽  
Guanidine Hydrochloride ◽  
Van Der Waals ◽  
Hydrophobic Hydration ◽  
Van Der Waals Interaction ◽  
Threshold Size ◽  
Aqueous Urea ◽  
Work Of Cavity Creation ◽  
The Difference

At 25°C, methane and ethane are more soluble in water than in 7 M aqueous urea or 4.9 M aqueous guanidine hydrochloride (GuHCl); the reverse is true for larger hydrocarbons. In addition, the hydrocarbon solubility in 7 M aqueous urea or 4.9 M aqueous GuHCl increases compared with that in water on raising the temperature in the range of 5–45°C. These experimental data have not yet been rationalized. Using a well-founded theory of hydrophobic hydration, the present analysis indicates that the transfer of hydrocarbons from water to 7 M aqueous urea or to 4.9 M aqueous GuHCl is favored by the difference in the solute–solvent van der Waals interaction energy, and contrasted by the difference in the work of cavity creation. At room temperature, on increasing the hydrocarbon size, the first contribution rises in magnitude more rapidly than the second contribution, accounting for the threshold size occurrence. Moreover, the second contribution decreases in magnitude with an increase in temperature, becoming less unfavorable, while the first contribution is practically constant in the range of 5–45°C. The different temperature dependence of the work of cavity creation in such solvent systems is due to the fact that the density of 7 M aqueous urea and 4.9 M aqueous GuHCl decreases more rapidly than that of water when raising the temperature. The relationship between the density of a liquid and the work to create a cavity in it is discussed in detail.Key words: work of cavity creation, solute-solvent van der Waals interaction energy, H-bond reorganization.

Hydrophobic hydration at the level of primitive models

1999 ◽  
Vol 96 (8) ◽  
pp. 1237-1248 ◽  
Author(s):  
MILAN PREDOTA, IVO NEZBEDA
Keyword(s):  
Hydrophobic Hydration

On the Preparation of Bovine α-Thrombin

1978 ◽  
Vol 39 (01) ◽  
pp. 193-200 ◽  
Author(s):  
Erwin F Workman ◽  
Roger L Lundblad
Keyword(s):  
Immobilized Enzyme ◽  
Catalytic Properties ◽  
Specific Activity ◽  
Guanidine Hydrochloride ◽  
Low Molecular Weight ◽  
Reversible Process ◽  
Gel Beads ◽  
Tissue Thromboplastin ◽  
C 50 ◽  
Hydrolysis Of

SummaryAn improved method for the preparation of bovine α-thrombin is described. The procedure involves the activation of partially purified prothrombin with tissue thromboplastin followed by chromatography on Sulfopropyl-Sephadex C-50. The purified enzyme is homogeneous on polyacrylamide discontinuous gel electrophoresis and has a specific activity toward fibrinogen of 2,200–2,700 N.I.H. U/mg. Its stability on storage in liquid media is dependent on both ionic strenght and temperature. Increasing ionic strength and decreasing temperature result in optimal stability. The denaturation of α-thrombin by guanidine hydrochloride was found to be a partially reversible process with the renatured species possessing properties similar to “aged” thrombin. In addition, the catalytic properties of a-thrombin covalently attached to agarose gel beads were also examined. The activity of the immobilized enzyme toward fibrinogen was affected to a much greater extent than was the hydrolysis of low molecular weight, synthetic substrates.

Effects of magnesium on the vasoconstrictor responses to norepinephrine and potassium chloride in the rat mesenteric artery.

1982 ◽  
Vol 23 (5) ◽  
pp. 783-789
Author(s):  
Hiromichi SUZUKI ◽  
Kazuoki KONDO ◽  
Michiko HANDA ◽  
Takao SARUTA
Keyword(s):  
Potassium Chloride ◽  
Mesenteric Artery ◽  
Rat Mesenteric Artery

Influence of mixed aqueous solutions of polyhexamethylene guanidine hydrochloride and OP-10 on vegetable crop seeds

2018 ◽  
Vol 11 (2) ◽  
pp. 164-172
Author(s):  
О.A. Yessimova ◽  
◽  
А.О. Adilbekova ◽  
M.Zh. Kerimkulova ◽  
G.D. Isenova ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Guanidine Hydrochloride ◽  
Vegetable Crop ◽  
Polyhexamethylene Guanidine

Effects of different concentrations of potassium chloride on some growth parameters of Solanum melongena L.

2020 ◽  
Vol 52 (6) ◽  
Author(s):  
Sher Wali ◽  
Siraj Uddin ◽  
Muhammad Junaid ◽  
Gulzad Ahmad ◽  
Fazli Rahim
Keyword(s):  
Potassium Chloride ◽  
Growth Parameters ◽  
Solanum Melongena
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