Liquid bonding

Unlike the solid state, the liquid state cannot be characterized by a static description. In a liquid, bonds break and refomi continuously as a fiinction of time. The quantum states in the liquid are similar to those in amorphous solids in the sense that the system is also disordered. The liquid state can be quantified only by considering some ensemble averaging and using statistical measures. For example, consider an elemental liquid. Just as for amorphous solids, one can ask what is the distribution of atoms at a given distance from a reference atom on average, i.e. the radial distribution function or the pair correlation function can also be defined for a liquid. In scattering experiments on liquids, a structure factor is measured. The radial distribution fiinction, g r), is related to the stnicture factor, S q), by... 

Stationary phase Liquid, solid Ionic gel, cross-linked liquid Bonded phase Polar vs. nonpolar... 

Ritala, M., Holm, P., Schaefer, T., and Kristensen, H. G., Influence of Liquid Bonding Strength on Power Consumption during Granulation in a High Shear Mixer, Drug Development and Industrial Pharmacy, 14(8) 1041— 1060(1988)... 

Adsorption/desorption-molecules or fragments from gas or liquid bond to solid surface. 

Diffusion rates in liquids (LC) are typically three to four orders of magnitude less than in gases (GC). The lower mobile-phase diffusivity Dm affects two of the plate-height terms in liquid chromatography given in Table 19.1. First, the B/u term is small. Secondly, the Cmu term is large. The Csu term is small in many LC applications where the stationary phase is only a monolayer of liquid bonded to the surface of a solid... 

Figure 5.3 Mobile liquid bonds (a) pendular (b) funicular (c) capillary. From Sherrington, P.J. and Oliver, R., Granulation, Heyden, 1981. Copyright John Wiley Sons Limited. Reproduced with permission.

In gas chromatography,1 2 gaseous analyte is transported through the column by a gaseous mobile phase, called the carrier gas. In gas-liquid partition chromatography, the stationary phase is a nonvolatile liquid bonded to the inside of the column or to a fine solid support... 

Fig. 2.3. Mobile liquid bonding states of liquid content in an agglomerate. (A) pendular state (B) funicular state (C) capillary state (D) particles in liquid droplet.

The kinetics of a granulation process can be dramatically improved by the addition of recycled seed agglomerates. These nuclei readily pick up the fine feed material in layer growth since the pendular liquid bond between two particles increases in strength as the size difference between the particles becomes larger [15]. It has been suggested [16] that the coalescence proba-... 

In these methods of size enlargement, powders are densified and compacted by application of external force in a confined space. Forces involved to produce a stable agglomerate include solid bridges, immobile liquid bonds, surface forces and mechanical interlocking. The success of the operation depends in part on the effective utilization and transmission of the applied external force and in part on the physical properties of the particulate material. 

There is a lot of art in this technique, too, but there are also several publications in the open literature about the principles of this shaping process. The basic mechanisms which play a role are described in the classic review by Rumpf [18]. Newitt and Conway-Jones [19] identified four types of liquid bonding mechanisms which depend on the relative amount of liquid present in the wetted powder. Rumpf calculated the strength of the bond between the particles in the wetted powder. 

Assuming that, for a pure metal on its own solid, the solid-liquid and liquid-liquid bond energies, eSl and Ll> are equal, which is the approximation used in the classical work of Skapski (1956), and knowing that the molar heat of melting of the pure metal Lm is related to pair energies by... 

Ritala, M. Holm, P. Schaefer, T. Kristensen, H.G. Influence of liquid bonding strength on power consumption during granulation in a high shear mixer. Drug Dev. Ind. Pharm. 1988, 14, 1041. 

Affinity Group-specific liquid bonded to a solid surface Partition between surface liquid and mobile liquid... 

In liquid-bonded-phase partition chromatography, the stationary phase is an organic species that is attached to the surface of the packing particles by chemical bonds. 

Liquid bonded-phase chromatography Partition chromatography that makes use of a stationary phase that is chemically bonded to the column packing. 

In GLC, separation occurs based on differences in partitioning of the sample components between the carrier gas and the liquid phase. A wide selection of liquid phases makes GLC a versatile separation technique. Further, the liquid phase can be a polymer or a chemically bonded phase. In all cases, the liquid phase is film coated or chemically bonded onto a solid support surface or a column wall. Liquid-bonded phases overcome the problem of leakage of the stationary phase material into the carrier. They are used commonly in LC also, and the process to fabricate... 

NP liquid bonded Poly(dimethylsiloxane) 400 General purpose... 

NP liquid bonded Poly(phenylmethylsiloxane) 320 Pesticides, herbicides, PCBs, and PAHs... 

P liquid bonded Poly(alkylene glycol) 240 Fatty acid methyl esters, phenols, fragrance oils, and aldehydes/ketones... 

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