Water surface tension, isopropanol

Another INDA repellency test especially useful for nonwovens intended for medical use is 1ST 80.8(01). This test is similar to AATCC 118 in that a series of liquids with varying surface tensions are placed dropwise on the sample to determine at what point the nonwoven is wetted. The difference in this test is that the liquids used are composed of varying concentrations of alcohol and water from 100% water (rating 0) to 100% alcohol (rating 10). Methanol, ethanol and isopropanol may be used as the alcohol component. The higher the rating, the higher the level of repellency of the nonwoven. 

Improved control of and/or improved latitude in ink/water balance at the printing plate by this mechanism is accomplished best with isopropanol because of its bulk-reinforced surface activity. Limited-solubility additives, such as 2-ethyl-l, 3-hexanediol, function similarly but are slightly less effective. Commercial fountain concentrates using soluble, low-surface- tension additives provide some of this improved control but remain more dependent on printing format, ink and additive variables. Commercial concentrates having high surface tension provide none of this enhanced control and with no fountain solution additives the system is virtually inoperable. 

Can these results for water sorption be related to the application of fountain solution to paper during lithographic printing In Figure 16 the addition of a surfactant is seen to have little effect on the dynamic surface tension of water at a surface age of 3 ms. Thus, on the time scale of the wetting of newsprint, fountain solutions which consist principally of an aqueous solution of gum arable may behave similarly to the case of water alone. Conversely, as shown in Figure 17 fountain solutions containing isopropanol exhibit lower dynamic surface tensions and should wet paper more readily than water alone. 

Example Erhomid RO/6G d 1,143 (9.52 Ibs/gnO surface tension of 0,1% aq soln 47 dynes/cm, of 1.0% aq soln 46 dynes/cm Sol in water (1% soln still clear at bp), benzene, ligroin CCl4 dioxane acetone isopropanol. use Detergents manuf feed supplements. 

The composition and flow rate of the solvent are two variables that are paramount for optimum operation of the ESI system. The flow rate determines the size as well as the size distribution of the droplets formed during ESI. A conventional ESI source operates at a flow rate of I toIO p,L/min. At higher flow rates, the spray is not stable because of the formation of larger droplets, which lead to electrical breakdown. Similarly, a fluid with high surface tension, such as pure water, is difficult to electrospray, but many polar solvents commonly used in RP-HPLC (e.g., methanol, ethanol, isopropanol, and acetonitrile) are suitable for the electrospray operation. Nonpolar solvents are difficult to disperse therefore, normal-phase HPLC is not easy to implement with the ESI process unless a polar solvent is admixed with the nonpolar mobile phase. 

The role of the dispersant can be explained as follows since the surface tension of ethanol, propanol and isopropanol are much smaller than that of water[6], it is expected to reduce the attraction between colloid particles and prevent the aggregation of the particles by adding such agent to the system. However, too much dispersant would lead to the particles growth, it is important to control the amount of dispersant for keeping the smallest particle size. 

Uses Foaming agent and paraffin solubilizer controls surface tension in organic systems, solv.-based urethane coating, specially inks, adhesive lems Properties Cl. to si. hazy bluish Iiq. sol. in kerosene, heptane (> 80%) sol. in water, isopropanol (< 1%) sp.gr. 0.71-0.79 fp. -13C b.p. 160C evaporation rate 0.1 11% act. VOC 89%... 

Properties Cl. Iiq. Hazen color 30 max. si. to no odor sol. in ethyl, butyl acetate, isopropyl palmitate, isopropyl myrisate insol. in water, veg. oils, fatty acids, glycerine, ethanol, isopropanol sp.gr. 0.965 pour pt. = -55 C flash pt. > 300 C surface tension = 20.9 mN/m ref. index 1.402 UseLevei 0.5-10%... 

In the presence of salt it was assumed that electrical double layer repulsion is suppressed and the action of the SDS/NaCl solutions was simply to enhance wetting. In a parallel study with isopropanol /water mixtures 5 we found that there exists a linear relationship between wjj and yl where Wq = 0 when the liquid surface tension is equal to the critical wetting tension yc. The value of Yc in these alcohol/water mixtures was ca 22 mNm i which is lower than Ys PET because of the well known adsorption effect 20 and hence the complete inhibition of adhesion due to wetting occurs when yc YS Similar adsorption effects have been observed for SDS solutions 2 and this is reflected by the value of yc oi ca lOmNm determined in this work from contact angle measurements on Mylar film. The measured Wq (= 0.95 yN) in water gives the fallowing expression for as a function of yl assuming that a linear interpolation can be made between YL YC 10 Nm l and yl Ywater 72.2 mNm"l. 

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