Gelled solution

It is a typical feature of the diffusion processes at electrodes of small size, which are reached by converging diffusion fluxes, that a steady state can be attained even without convection (e.g., in gelled solutions). Such electrodes, which have dimensions comparable to typical values of 8, are called microelectrodes. 

Glass Fibers and Cellulosic Fibers. Glass fibers and cellulosic fibers are specifically disclosed as preferable reinforcing fibers for a gelling solution... 

Timoptic-XE Gelling solution 0.25, 0.5 1 drop every daya ... 

All these results support our kinetic interpretations of these supersaturated gelling solutions. We assume that the network growth is described by the growth of individual domains, each one ruled by the autocatalytic model (S). This system behaves like an assembly of microdomains. Sach steroid in a supersaturation state is a potential germ of microdo.main. According to distribution curves of induction times for each microdomain, the typical kinetic curves for each part A and B of the phase diagram are obtained. 

Povidone-Iodine (+ Lidocain) Thermo-Gelling Solution (10%)... 

Hermans, J. 1965. Investigation of the elastic properties of the particle network in gelled solutions of hydrocolloids. I. Carboxymethyl cellulose. J. Polym. Sci. A 3 1859-1868. 

Most solutions produced zeolites all were known structures (Table III). The products for each cation system are shown in Figure 10. The relationship between the gelation behaviour and the zeolite produced is that the quickest gelling solutions produce the most open frameworks. 

Figure 10 Zeolite products from thermal treatment of gelled solutions. Zeolites are identified by the structures codes given in ref 21. Am is amorphous, Soln indicates no solid product was obtained and zeolites W and Rb-M are described in refs 22 and 23.

The effect of the concentration of Ca " cations in the gelling solution on the surface area of the aerogel is reported in Fig. 8 for another mannuronate-rich (20% guluronate) alginate after 6 h ripening. The surface area increases with the Ca " concentration and reaches a shallow maximum at the concentration... 

Fig. 8 Influence of the concentration of the gelling solution on the surface area of an alginate...

Scattering signals in a gelling solution are dominated by interference between different clusters evolving by gelation. This interference conceals structural information on individual clusters. Hence, in order to investigate the spatial correlation of concentration fluctuations, a scattering experiment was carried out on a diluted system. 

Fe(N03)3.9H20 or Ni(N03)2.6H20 with a molar ratio of 10% nitrate per alkoxide was added to the gelling solution. Some films, with a thickness of 500 nm, were irradiated with lO Au ions/cm of energy 3 MeV stopping into the substrate. This fluence was chosen because the irradiation effects on the gel densification and on the growth of other metallic clusters (Ag, Cu) in both matrices [4], Other films and monoliths were annealed for Ih at 600 or 1000°C in a vacuum of 10 Torr. 

It is clear that the viscosity of a gelling solution increases and reaches a very high value after the gel has set. If the initial solution shows anomalous (e.i., non NEWTONian viscosity, fluidity dependent on shearing force) the degree of departure from NEWTONian flow increases too. If the solution showed NEWTONian flow, its viscosity will become anomalous Moreover a yield value appears, the liquid becomes elastic. ... 

The method also allows generation of the metal nanoparticles on a solid support (e.g., silica). In this case the support is impregnated with the gelling solution, and the subsequent steps (calcination... 

The exact chemical mechanism of the third basic step in gelation, metal ion crosslinking of two water-soluble polymer molecules, is not well known. However, the finding that shearing a gelling solution increased the gelation rate implied that some step of the process was diffusion controlled . It is sensible to assume that as shear increases the number of polymer/polymer collisions, the number of collisions resulting in crosslinks is also increased. 

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