Bubble self-supporting

Systematic diffusion experiments were also conducted with self-supported zeolite wafers (7-14 mg cm ) which were activated at 10 Pa and 675 K for 1.5 h. Prior to contact with the sorbate, the IR cell was filled with dried helium as a carrier gas. Subsequently, one or two components (benzene or ethylbenzene), carried by helium bubbling through thermostatted saturators, could be admitted. A system of mass-flow controllers allowed for an independent change of the partial pressures while the total pressure could be kept constant [22]. The time required to pass the sorbate from the inlet valve to the place of the zeolite wafer was about 4 s. IR spectra were obtained in intervals as short as 0.37 s. 

Films of semiconductors up to a few hundred nanometers in thickness have been formed by the simple reaction between H2S or H2Se and the surface of an aqueous solution of the metal ion. This technique was described long ago for PbS and PbSe [201], A more comprehensive description of the method, extended to a number of different metal sulphides, has been given [202]. It is stressed that the gas phase is passed over the solution surface and not bubbled through the solution, which would break up the film. In fact, if the gas flow continues for too long (typically more than a few minutes), the film tends to break up and precipitate. Since the substrate for these films is a liquid surface, the films can be (carefully) picked up and transferred to another surface or possibly even be self-supporting in small areas. 

Vesicles (latin vesicula = small bubble) are self-supported closed bilayer assemblies of several thousand amphiphiles that enclose an aqueous interior volume. The bilayer is a two-dimensional fluid composed of amphiphiles with their hydrophilic head groups exposed to the aqueous solutions and their hydrophobic tails aggregated to exclude water (Fig. 1). The hilayer structure is highly ordered yet dynamic because of the rapid lateral motion of the amphiphiles within the plane of each half of the bilayer. 

When smectic membranes are exposed to external pressure from one side, they bend imtil a balance between pressure difference and surface tension is established. In this way, self-supporting spherical bubbles can be produced. ... 

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