Solid/liquid interactions

Liquid-solid interactions due to long-range intermolecular forces are much larger than are gas-solid interactions. This means that it is easier to collect fine particles at a liquid-liquid interface than at a gas-liquid interface. 

Precipitation of niobium and tantalum compounds in forms that are suitable for separation from the aqueous media (liquid-solid interaction) ... 

Rubber swelling modifies the liquid/solid work of adhesion. Wo, because in addition to the initial liquid/solid interactions, liquid diffusion into the solid produces supplementary liquid/liquid interactions, hquid molecules having passed through the liquid/solid interface. Therefore, to the initial work of adhesion in the absence of swelling, Wq, an additional term corresponding to a fraction of the cohesion energy of the liquid, 2y, should be added. If / is the time of diffusion, the work of adhesion at /, Wo(t), can then be expressed as... 

Principles and Characteristics In this most simple liquid-solid interaction a resin is washed with a solvent to (selectively) remove external components. This additive isolation procedure can be used to show that a component is applied on the surface of a polymer pellet, as opposed to blending throughout the polymer. Other LSE procedures consist in soaking the polymer in boiling solvent and cold liquids. 

Isolation may occur by liquid-solid interaction (extraction, dissolution) or heat (thermal, pyrolytic, laser). Extraction methods easily handle qualitative screening for low- to medium-MW compounds fail for high-MW components or polymer-bound functionalities and are less reliable quantitatively (analyte dependent). When applicable, dissolution methods suffer from sensitivity, because of the dilution effect on account of the polymer. In-polymer analysis performs well for qualitative screening, but is as yet not strongly performing for quantitative analysis, except for some specific questions. 

Although this concept was originally derived for gas-solid adsorption, it can also be successfully applied to describe a liquid-solid interaction process when using the equations... 

The above exceptions leave relatively few sensors based on integrated separation and detection, particularly of the types involving gas-liquid and liquid-liquid interfaces, which require the detector to be responsive to the gas or ion (molecule) transferred across the membrane. The scope of liquid-solid interactions is somewhat broader as it enables not only retention of the analyte and monitoring of some intrinsic property, but also to retain a product of a previous reaction, thereby substantially expanding the possibilities. 

The bed scale corresponds to the whole bed or to a volume containing a large number of particles. That is the level at which we want to derive models for the investigated transport processes. However these processes are generally ruled by gas-liquid-solid interactions occurring at the particle scale. That is the reason why it is necessary to model these processes at the particle scale. The change of scale or volume averaging between both levels is ruled by the percolation process, i.e., by the velocity distribu-... 

Some unexpectedly complex liquid solid interactions have been detected and studied by ultrasonic impedance measurements (ultrasonic impedometry). Small amounts of water and alcohols have pronounced effects on the physical state of hydrophilic polymers specifically, the high frequency shear modulus and crystallinity index of a poly (vinyl alcohol) film increases with water content to a maximum before normal solution phenomena occur. These effects are attributed to the increased molecular order owing to water hydrogen bonded between polymer chains. The unusual effects of moisture on a novel poly(vinyl chloride)/plasticizer system and on hydrophilic polymers other than poly (vinyl alcohol) are also described. 

The comparison with adsorption at the gas-solid interface is further complicated by the fact that some adsorbents cannot be outgassed without an irreversible change in their texture. Also, changes in texture may occur when the adsorbent is immersed in a pure liquid or a solution. For these reasons, it is necessary to utilize special methods which provide direct information on the particular liquid-solid interactions. 

In connection with quantifying possible changes in the structure of liquids due to confinement in pores, an old rule, known as Gurvitsch s rule ) may be mentioned. It states that for a variety of different liquids the total pore volume is within narrow limits identical, if computed on the basis of their bulk densities. For Instance, McKee l finds a maximum variation of 4% for a number of organic adsorptives on silica gel with a (Kelvin) radius of 1.7 nm. suggesting that only minor structural deviations take place. However, for more strongly associated liquids like water, and for narrower pores, the deviations may be larger. Then the liquid-solid interaction also starts to play its role. 

Porous Texture and Surface Characterization from Liquid-Solid Interactions Immersion Calorimetry AND Adsorption from Solution... 

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