Sponge-like phase

For hard biomass made from crystalline cellulose, an inversed structure was found, with the carbon being the continuous phase, penetrated by a sponge-like continuous system of nanopores (representing the majority volume). These products are also... 

The oilseed reaches typically 112.8°C (235°F), as read by a thermometer near the die plate, and approximately 10-13% moisture. Internal pressure is 13 0 times greater than atmospheric pressure. At this pressure and temperature, all moisture, even injected steam, is compressed into the liquid phase. On release into atmospheric pressure, some of the moisture flashes to reach equilibria. This vaporizing moisture inflates the collets with internal pores and surface cracks, imparting a porous, sponge-like structure to the collet. 

The oilseed reaches 235°E at 10-13% moisture at the die plate under a pressure of 30 0 atmospheres. All the water (natural moisture, injected steam, and liquid water) is compressed into the liquid phase. When the product leaves the high-pressure interior of the expander, some of the moisture flashes to reach equilibrium at atmospheric pressure. The flashing inflates the collets with internal pores and surface cracks, giving the collets a sponge-like structure. Eigure 17 shows typical soybean collets made with expander for solvent extraction. 

Phase-inversion membranes frequently show a sponge-like structure. The volume flux through these membranes is described by the Hagen-Poiseulle or the Kozeny-Carman relation, although the morphology is completely different. 

Stucky11751 developed a procedure for the synthesis of sponge-like silica membranes with 3-D meso-macrostructures. The process utilizes multiphase media composed of a mesoscopically ordered block copolymer-silica phase that macroscopically separates from an electrolyte phase. The different characteristic lengthscales in hierarchically organized composite structures can be independently adjusted. 

While MCM-41- and 48-based materials dominate as the primary mesoporous materials explored for gas-phase propylene epoxidation, a recent article examines the reactivity of Au deposited on Ti-TUD containing 3 mol% Ti [57]. Ti-TUD consists of a sponge-like structure with an average pore size of about 13 run. Although the specific surface area of this material is less than that of MCM-41 or MCM-48, the larger pore system allowed for essentially all of the deposited Au to have access to the pore system. A maximum rate of 53.7 gpo kgcat 470 °C... 

Controlled pore glass is prepared by heating certain types of borosilicate glass to 500-800 C until it separates into silicate-rich and boron-rich phases. (Figure 16-2). The borate phase is then dissolved with acid, producing a sponge like arrangement with pores from 2.5-7.0 nm. 

Fig. 12 shows micro-gel particles cross-linked by irradiation of a phase- separated solution in the two differently swollen states, at 25°C in a highly-swollen state and at 40°C at low degree of swelling. For details see (Amdt et al. 2001a). Irradiation of a high concentrated solution results in a bulky hydrogel with typical dimension in the cm-range. The sponge-like stmcture of the formed PVME hydrogel (irradiation of a PVME-solution in the phase-separated state) at different temperatures (swollen above and below the volume phase transition temperature) is shown in Fig. 13. The irradiation dose was 50 kGy.

Fig. 29 Distribution of water inside a collapsed PNIPAAm gel. The volume phase transition was induced by per-deuterated methanol. The figures show Fourier images (slice selection, T2-weight-ed) of a vertical plane of PNIPAAm swollen in D2O. Distribution of water inside (a) a homogeneous gel and (b) a sponge-like gel. (c) Structure of the sponge-like gel (FESEM micrograph), scale bar 250 nm. 1 D2O/CH3OD environment 2 collapsed skin 3 shrunken gel (shrinkage barrier) 4 swollen gel. Reproduced from (Arndt et al. 2006), Fig. 7, p.l88, with kind permission of Springer Science and Business Media...

Compressed CO2 dissolves in melts of fats. Solubility measurements show at higher pressures, a minimum in the liquid-vapour isopleth, which is an indication of type III phase behaviour. Batch particle formation experiments show an influence of C02/melt-ratio, feed rate, temperature and pressure on the particle size and structure. This information is crucial for the development of applications and for optimization of the process. Three main shapes can be distinguished, spherical (solid or hollow), distorted and sponge-like particles. The particle sizes are in the range of 5-200pm... 

The study of oil uptake during the frying of foods is rather complex and significantly depends on the substrate to be fried. For example, immersion in hot oil causes several transformations within a tortilla chip (McDonough et al., 1993). The oil coats and adheres to the surface of the chip, and free moisture in the chip turns to steam and exits, leaving behind a uniform sponge-like tunnel network. As the steam exits the chip, the oil is drawn inside the tunnels. Starch chains, protein, and lipids interact to form a continuous phase that becomes firm upon dehydration. 

Furthermore, the results of a study on the distribution of 18-crown-6 between the toluene phase and the omega phase indicated that the amount of crown ether in the toluene phase remained low and relatively constant even though 3.50-11.45 mmol of crown ether were added [146], It appeared that the omega phase acted like a sponge that was capable of adsorbing the added crown ether. For the 18-crown-6-catalyzed displacement of benzyl bromide with KCN salt in toluene [146], it was found that the observed first-order rate constant was quite independent of the amounts (5.0 12.0 mmol) of 18-crown-6, which implied that the displacement reaction probably took place mainly in the organic phase. Mechanistic rationalization of this crown ether-catalyzed two-phase reaction is described as follows ... 

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