Diffusivities of acetone

A similar technique, the so-called spontaneous emulsification solvent diffusion method, is derived from the solvent injection method to prepare liposomes [161]. Kawashima et al. [162] used a mixed-solvent system of methylene chloride and acetone to prepare PLGA nanoparticles. The addition of the water-miscible solvent acetone results in nanoparticles in the submicrometer range this is not possible with only the water-immiscible organic solvent. The addition of acetone decreases the interfacial tension between the organic and the aqueous phase and, in addition, results in the perturbation of the droplet interface because of the rapid diffusion of acetone into the aqueous phase. 

Calculate the time taken for the liquid level to fall to 5 cm below the top of the tube, neglecting the effects of bulk flow in the vapour. 1 kmol occupies 22.4 m3. Molecular weights of acetone, dibutyl phthalate = 58 and 279 kg/kmol respectively. Liquid densities of acetone, dibutyl phthalate = 764 and 1048 kg/m3 respectively. Vapour pressure of acetone at 315 K = 60.5 kN/m2. Diffusivity of acetone vapour in air at 315 K = 0.123 cm2/s. 

Drechsel, P., J. L. Hoard and F. A. Long Diffusion of acetone into cellulose nitrate films and study of the accompanying orientation. J. Polymer Sci. 10, 241 (1953). 

Kokes, R. J., F. A. Long and J. L. Hoard Diffusion of acetone into polyvinyl acetate above and below the second-order transition. J. Chem. Phys. 20, 1711 (1952). 

E. Bagley and J. B. Wilkens Anomalous diffusion of acetone into cellulose acetate. J. Chem. Phys. 21, 1412 (1953). 

We assume that helium is insoluble in the liquid phase. The interfacial rates of diffusion of acetone and benzene can be calculated at the top of the column in an iterative manner using the following steps ... 

A brass (Cu-Zn) bar, wound with molybdenum wire, was plated with copper metal. The specimen was annealed in a series of steps, in which the movements of the molybdenum wires were recorded. The inert markers had moved from the interface towards the brass end of the specimen, which contained the fastest diffuser - zinc. This is now called the Kirkendall effect. A similar marker experiment had actually been performed by Hartley a year earlier while studying the diffusion of acetone in cellulose acetate (Hartley, 1946), but most metallurgists were not familiar with this work (Darken and Gurry, 1953). 

Figure 1. Results of PFG NMR measurements of the self-diffusivities of acetone, isopropanol, propene, and water in NaX...

FIG. 3—Schematic of the side-view of the bonded PSA tape illustrating the path of diffusion of acetone. 

This process is based on the separation of a water-soluble solvent from aqueous solution through the salting-out effect. Initially, polymer and drug are dissolved in a solvent such as acetone and then the polymer solution is emulsified into an aqueous solution containing electrolytes (such as magnesium chloride, calcium chloride and magnesium acetate), non-electrolytes (such as sucrose), and a colloidal stabilizer such as poly(vinyl pyrrolidone) or hydroxyethylcellulose. Finally, the oil/water emulsion is diluted with a sufficient volume of water to enhance the diffusion of acetone into the aqueous phase by inducing the formation of nanospheres. Both the... 

Two milliliters of acetone (mol. wt. of 58) and 2 ml of dibutyl phthalate are combined and placed in a 6-mm-diameter vertical glass tube placed in a 315 K bath. Air at 315°K and atmospheric pressure flows across the top of the tube. The liquid mixture is initially at 1.15 cm below the tube top. What is the amount of time needed for the liquid level to fall to 5 cm below the tube top Vapor pressure and diffusivity of acetone are 60.5 kN/m and 0.123 cm /sec. Acetone and dibutyl phthalate liquid densities are 764 and 1048 kg/m. ... 

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