scholarly journals INFLUENCE OF ACID-BASE PROPERTIES OF OXIDE FILLERS ON THE FREE SURFACE ENERGY OF EPOXY-POLYMER MATERIALS

Author(s):  
Yuliya Danchenko ◽  
Tatiana Obigenko ◽  
Maria Kachomanova ◽  
Mykhailo Teslenko
1948 ◽  
Vol 158 (1) ◽  
pp. 297-316
Author(s):  
W. T. Bottomley

Van Iterson's experiments show that cavitation erosion is produced by the collapse of minute air bubbles in water in a state of air supersaturation. This is contrary to the usual conception that cavitation erosion is due to the collapse of vapour bubbles. The author gives results of experiments which indicate that the bubbles which form and collapse at the stage of incipient cavitation in aerated water are air bubbles in a supersaturated state. The experiments also show that vapour bubbles which collapse in de-aerated water are in thermal equilibrium. It is shown that the collapse of bubbles in thermal equilibrium cannot cause erosion because the vapour pressure inside and the hydrostatic pressure surrounding the bubbles are balanced during collapse. The energy producing cavitation erosion is the free surface energy liberated by the collapse of the air bubbles. The final collapse velocity is the velocity of sound in water and the magnitude of the blow produced is of the order of 120 tons per sq. in. or more. The effect of these views on the interpretation of the model tests in cavitation tunnels and on the cavitation number is discussed.


2009 ◽  
Vol 50 (6) ◽  
pp. 1171-1176
Author(s):  
N. Yu. Sdobnyakov ◽  
A. N. Bazulev ◽  
V. M. Samsonov ◽  
D. A. Kul’pin ◽  
D. N. Sokolov

2006 ◽  
Vol 252 (15) ◽  
pp. 5384-5386 ◽  
Author(s):  
S. Garruchet ◽  
O. Politano ◽  
J.M. Salazar ◽  
A. Hasnaoui ◽  
T. Montesin

2013 ◽  
Vol 6 (2) ◽  
pp. 157-159 ◽  
Author(s):  
I. A. Starostina ◽  
O. V. Stoyanov ◽  
N. V. Sokorova

RSC Advances ◽  
2015 ◽  
Vol 5 (60) ◽  
pp. 48712-48719 ◽  
Author(s):  
S. Ramanaiah ◽  
Vikram Karde ◽  
P. Venkateswarlu ◽  
Chinmay Ghoroi

Temperature dependent surface energy variations observed in Gabapentin and Pregabalin drugs.


Vestnik MGSU ◽  
2019 ◽  
pp. 94-101
Author(s):  
Valentina I. Loganina ◽  
Erkebulan B. Mazhitov

Introduction. The use as a binder in the manufacture of silicate paints polysilicate solutions obtained by mixing liquid glass and silica sol is considered. To regulate the rheological properties of the paint, improve the filling and prevent the pigment part from sagging, it has been proposed to introduce glycerin into the binder composition. The results of studying the interfacial interaction between the paint and the substrate are given. Materials and methods. In developing the formulation of silicate paints based on polysilicate solutions, MK-2 microcalcite, marshalite, diatomite and talc of MT-GSM grade were used as a filler, and titanium dioxide as a pigment. Polysilicate solutions were obtained by reacting stabilized solutions of colloidal silica (sols) with aqueous solutions of alkali silicates (liquid glasses). Nanosil 20 and Nanosil 30 silicic acid sol were used, produced by the Promsteklocentr PC. Used potassium liquid glass with module M = 3.29. A thermodynamic method was used to assess the interfacial interaction. Results. Shown that the introduction of glycerol into the formulation of a sol of silicate paint promotes a decrease in the interfacial surface tension and a better wetting of the surface of the mortar substrate. An increase in wetting coefficient is observed. Coatings based on sol silicate paints with the addition of glycerin are characterized by increased crack resistance. An increase in tensile strength, maximum tensile properties, and decrease in the elastic modulus of paint membranes based on the composition with glycerol has been established. The values of the free surface energy of the coating based on the sol of silicate paint and the ratio of the polar to the dispersion component of the free energy of the surface are given. Coatings based on sol of silicate paint with the addition of glycerin are characterized by a large value of the free energy of the surface. In the process of moistening a decrease in the free surface energy is observed due to a decrease in the dispersion component. Conclusions. Studies have shown that the introduction of an additive of glycerin in the formulation of a silicate paint sol contributes to an increase in the performance properties of coatings based on it.


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