Colloidal layer

Advantage has also been taken of dispersed clays to host small particles [478]. Montmorillonite clays are colloidal, layered aluminosilicates with ex-... 

Table 1) Is due, at least in part, to a tighter colloid layer structure. Membranes formed at the same pressure but different crossflow velocities show similar values of Hint (Trials 5-8 in Table 1), although at the higher velocities there is some decrease, which may be due to imperfections in the thinner dynamically formed layer.

If. in place of bringing two solutions in contact with each other, they be separated by a solid or semi-solid, moist, colloid layer, diffusion takes place in the same way through the interposed layer. Advantage is taken of this hurt to separate cryst oids from colloids the process of dialyeis. The mixed solutions of crystalloid and coUoid are brought into the inner vessel of a dialyser. Fig. 13, whose bottom consists of a layer of moist parchment paper, while tiae outer vessel is filled with pure water. Water... 

A suspension of droplets of vinyl chloride monomer (VCM) in water, of size 30-150 iJim, is formed by agitation with a stirrer. It is stabilised by a colloidal layer of partially hydrolysed polyvinyl acetate or other water-soluble polymer. When the suspension is polymerised at a temperature in the range 50-70 °C, PVC molecules form in the VCM droplets. As PVC is insoluble in VCM, it precipitates in the form of primary particles, initially... 

Clays are colloidal layered hydrous aluminosilicates. There are relatively few examples of porphyrin intercalation into clays reported, mostly with either smectite clays or layered double hydroxides (LDH). Smectite clays consist of negatively charged layered aluminosilicate sheets. These sheets are separated by cations and water molecules. The... 

AFM has been proven to be useful when studying the structure of the colloidal fouling layer formed on the membrane surface. Compact packing of the colloidal layer reduces the membrane flux. 

Incorporation of metal particles, inorganic oxides and other types of colloidal materials into these layered assemblies has also been pursued [44,45,48,68-73]. Colloidal layers have provided photochemical, structural, catalytic, conductive or semi-conducting functions in these composite type structures. 

Nanoparticle passivation should be accomplished to allow time for the preservation of their energy-rich state. A highly significant theoretical and practical problem is to control the surface processes or processes in thin subsuperficial layers of polymer granules, films, or fibers. The preparation of self-assembling colloidal layers of Au, Ag, and Ag-Au on the siuface of plasma-purified PTFE is of interest. The PTFE surface and those of other polymers had been premodified by hydrolyzed alkoxysilanes containing functional groups. When such surfaces are contacted with dilute solutions of monodisperse colloids, the assembly of nanoparticles takes place. They form as a monomolecular layer, which is 5-70 nm thick in the case of Ag and 5-20 nm thick in the case of Au and Au-Ag. 

The ability of exogenous proteins to reduce the skin and eye irritation potential of detergents was highlighted many decades ago in the cosmetic chemistry community. First extensive insights were probably those of Meinecke (4), who reported that addition of a protein hydrolysate or a protein-fatty acid condensate to a solution of a highly irritant surfactant (sodium alkylbenzene sulfonate) caused a remarkable increase in the skin tolerability of the product and postulated a protective effect based on the formation of a protein colloidal layer on the skin, which could prevent or minimize the direct interaction of tenside molecules with skin keratin. The same interpretation has been advanced more recently by other authors (116-118). 

Fig. 2 Laser scanning microscope pictures recorded in reflection from the diazosulfonate terpolymerfilm after UV irradiation through a TEM grid mask and subsequent adsorption of gold nanocolloids brighter areas indicate the gold colloid layer.

The basis of surface enhanced optical absorption is the so-called "anomalous absorption". To observe anomalous absorption an absorbing colloid or colloid layer is positioned in a defined distance to a metal mirror and illuminated from the colloid side. At a certain distance of the colloid or absorbing layer to the mirror the incident fields has the same phase as the electromagnetic field that is reflected by the mirror at the position of the absorbing colloid particle (or colloid particle layer). The set-up is described as a reflection interference system, which feedback mechanism strongly enhances the absorption coefficient of the absorbing colloid (layer). 

Cluster layers can be applied via sputtering or precipitation processes directly onto a surface, but in most cases they will bind via the above described linker application. Neither way do these colloid layers or cluster films form a barrier of diffusion for fluids or gases. ITie reason for this is the particle structure of these cluster films enabling an "easy passage for fluids and gases. This allows measurement of analyte concentrations... 

Suzuki, K. Wariishi, K. Silver halide photographic material containing (poly)methineoxonol solid dispersed dye in colloidal layer. Jpn. Kokai Tokkyo Koho JP 06332112, 1994 Chem. Abstr. 1995, 122, 201116. 

Vignati, E., Piazza, R. and Lockhart, T.P. (2003) Pickering emulsions interfitcial tension, colloidal layer morphology, and ti apped-particle motion. Langmuir, 19, 6650-6656. 

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