Phase Swelling

Starch acrylonitrile in 10% emulsion Freezing cycles, number Block copolymerization % 

The emulsion was stabilized with 0.25% block copolymer of starch and methyl methacrylate synthesized by mastication. 

Swelling min Monomer % Polymerization Product composition % Cellulose acetate Block copolymer % %  

Ceresa synthetized also block copolymers of poly(methyl methacrylate) with acrylonitrile and styrene and of polyethylene with methyl methacrylate, styrene using this method (104). 

---

The dDAVP preparations used in this study were prepared in low water contents so that the lamellar phase was formed, which in turn was injected into the rabbits. The reason for this was the fact that the lamellar phase with its mucous-like rheology is easier to inject than the stiff cubic phase. Since the lamellar phase swells into the cubic phase in excess water according to the phase diagram in Figure 1, a phase transition was expected also in the in vivo situation. The transition was found to be very fast as judged by inspection of the injection site immediately after administration. 

There are apparently two sources of this effect. The molar volume of water changes relatively little as a result of the presence of a small quantity of dissolved octanol, however the quantity of dissolved water in the octanol is considerable, causing a reduction in molar volume of the octanol phase. The result is that even if activity coefficients are unaffected, log S0/Sw will be about 0.1 units less than that of log KoW. Effectively, the octanol phase swells as a result of the presence of water, and the concentration is reduced. In addition, when log KqW exceeds 4.0 there is an apparent effect on the activity coefficients which causes log (SQ/SW) to increase. This increase can amount to about one log unit when log Kow is about 8. A relatively simple correlation based on the analysis by Beyer et al. (2002) (but differing from their correlation) is that... 

Mobile fluid interaction with the stationary phase in SFC was investigated with mass spectrometric tracer pulse chromatography (96). Using capillary supercritical fluid chromatography, the effect of methanol as an additive was studied on the partition behavior of n-pentane into 5 % phenylmethylsilicone stationary phase. The results showed that the mobile fluid uptake by the stationary phase decreased with increasing temperature and pressure. Thus suggests that stationary phase swelling, may occur in SFC. 

Figure 12.12. Dependence of rubber phase swelling of NR / MWNTs composites on the amount of carbon nanotubes.

The Nernst-Planck model is based on limiting laws for ideal systems. It accounts only for diffusion and electric transference of ions, not for electroosmotic solvent transfer in the ion-exchanger phase, swelling or shrinking of the ion-exchange material, variations of activity coefficients and diffu-sivities, and possible slow structural relaxation of the exchanger matrix. It also postulates the existence of individual diffusion coefficients for ions. 

The nonaqueous systems also form liquid crystals analogous to aqueous systems in ternary systems with an added weakly hydrophilic component. SDS has been extensively employed in studies of ternary and quaternary systems with glycerol or formamide, a long-chain alcohol, and, sometimes, hydrocarbon [97-101], In the SDS-glycerol-decanol system the lamellar phase swells extensively, even more so than in water [97], While no liquid crystals form at room temperature in the binary systems, a D-phase occurs when decanol is added. 

As the La-Hu transition proceeds, the mean interfacial molecular area drops and the mean area at the chain end of the molecule increases (2, 23). Effectively, the molecular volume has been subjected to a torque due to an expansive chain pressure relative to a net cohesive interaction near the head groups (4). This torque is conveniently described as a spontaneous curvature, C0 (4, 17), to a specific radius of curvature, R0 = 1/C0, at which point the net torque is almost zero. All Hu phases swell only to a limited degree. In a transition in coexistence with excess water, there is generally a change in the... 

During the rehumidification phase, swelling is observed. However, the strain amplitude is four to five times less than the strain associated with shrinkage. That means that the desiccation-rehumidification cycle generates irreversible strain. 

The phenomenon of bonded phase swelling or solvation has been reported for pure supercritical fluids by Sie et al. (Z ) and Springston et al. (22) ... 

Hessel [79] has proposed a mechanism of spontaneous emulsification which involves a two-step process (1) the monomer phase swells the bilayers of the unilamellar vesicl which results in microemulsion droplets budding off the bilayer, and (2) the microemulsion droplets swell to miniemulsion droplet dimensions (50-400 nm). Diffusion of the monomer through the aqueous phase is... 

If more and more surfactant is added to a Winsor III system, the surfactant-rich phase swells at the expense of the excess oil and water phases. From a certain point, a single surfactant-rich phase is found. Upon increasing the amount of surfactant even further, a first-order transition to a lamellar phase may be observed. In a special case, it has been shown that the coexistence region between the (bicontinuous) microemulsion phase and a lamellar phase was extended into the region where the surfactant-rich phase coexists with excess oil and water, leading to a four-phase equilibrium water-lamellar phase-microemulsion phase-oil [58]. In Ref. 46, even a three-phase equilibrium, water-lamellar phase-oil, was observed, the bicontinuous microemulsion phase apparently being absent. 

The reactions between the alkaline solution and reservoir oil generate the complex oil recovery mechanisms of AF postulated to date (1) in-situ surfactant generation by neutralization (saponification), (2) reduction of the interfacial tension (IFT) at the oil-water interface, (3) temporary wettability alteration, (4) emulsification with entrainment, (5) emulsification with entrapment, (6) emulsification with coalescence, (7) oil phase swelling, and (8) breaking out the rigid films. Thus, the consumption of alkalinity through the reactions of alkaline solution with reservoir waters and rock constituents has been accepted as the most important disadvantage of the AF process. ... 

Possible reasons for the final rapid failure of the vessel may be structural instability of the vessel, rapid overpressurization due to a dynamic head space impact of the two-phase swell initiated upon a depressurization (initiated by the formation of a thermal crack or tear which arrests), or the rapid quenching of its crack tip, due to the two-phase discharge, that results in large local thermal stresses that cause the uncontrolled vessel failure. 

Sumathipala, K., J. E. S. Venart, and E. R. Steward. 1990. Two-Phase Swelling and Entrainment during Pressure Relief Valve Discharge, Journal of Hazardous Materials, vol. 25, pp. 219-236. 

B6 next rapidly expands and B4 compresses due to this unequal pressure distribution (Fig. 42M). and the now superheated and supersaturated cyclohexane rapidly (—50 ms) boils up. The impact of this two-phase swell results in a head-space impact and dynamic re/ overpressurization (Gromles, 1984 Venart and Ramier, 2000). This immediately causes both the compression of the downstream, B6, bellows and the initiation of upwards squirm of the B4 bellows (Fig. 42.8c-e). First there is a thud as B4 is compressed, and then a minor mmbling of the boiling process in the B4 region of the pipe bridge, and then a further thud as B6 is compressed by the repressurization occurring near B4 (Table 42.1). 

---