Dry spreading of liquids on solids

In Chapter 3 entitled Dry spreading of liquids on solids (originally the last lecture) the general phenomenon of surface wetting by liquids with different spreading coefficients is examined in its most basic aspects. The specific case of polymer melts is also taken into consideration here we are confronted with many new possibilities either an anomalous slippage of the melt at the wall surface or in some other cases an anomalous sticking of the chains to the wall. 

The dry spreading of polymer solution(66) more complex than that of either the pure liquid or a polymer melt. Assuming the polymer does not adsorb on the surface, the dry spreading of a semidilute solution (from a good solvent) of neutral, flexible chains on a solid surface can be summarized as follows. 

L. Leger, A. M. Guinet-Picard, H. Hervet, D. Ausserre, and M. Erman, Dry spreading of polymer liquids on solid surfaces Role of long-range forces, precursor film profiles, and specific polymeric effects, in New Trends in Physics and Physical Chemistry of Polymers (L. H. Lee, ed.). Plenum Press, New York (1989). 

Dry Spreading of Polymer Liquids on Solid Surfaces Role of Long Range Forces, Precursor Film Profiles and... 

DRY SPREADING OF POLYMER LIQUIDS ON SOLID SURFACES ROLE OF LONG RANGE FORCES, PRECURSOR FILM PROFILES AND SPECIFIC POLYMERIC EFFECTS... 

Method 2. Mix 1 0 g. of 3 5-dinitrobenzoic acid with 1 5 g. of phosphorus pentachloride in a small, dry test-tube. Warm the mixture gently over a small smoky fiame to start the reaction when the reaction has subsided (but not before), boil for 1-2 minutes or until the solid matter has dissolved. Pour the mixture while still liquid on a dry watch glass (CAUTION the fumes are irritating to the eyes). When the product has solidified, remove the liquid by-product (phosphorus oxychloride) by transferring the pasty mixture to a pad of several thicknesses of filter paper or to a small piece of porous tile. Spread the material until the liquid has been absorbed and the residual solid is dry. Transfer the 3 5 dinitrobenzoyl chloride to a test-tube, add 0-5-1 ml. of the alcohol, and continue as in Method 1. 

The liquid food is first foamed and then spread in mats on a perforated or solid support to be dried in hot airstreams. Foaming is accomplished by agitating the fluid product with the airstream. The foam structure is required to last during drying so that the dried prodnct is easily ground to powder. The thickness of the foam layer is maintained at about... 

The product contains moisture (usually water) mainly in the form of adsorbed liquid, capillary liquid, liquid causing the solid to swell or as bound liquid. Adsorbed liquid is a thin liquid film spread on the outer product surface. The vapor pressure above the liquid film corresponds to its saturation pressure at every temperature. Capillary liquid wets the inner pore surface of a porous solid. During the drying process, the liquid has to be transferred to the product surface by capillary forces. With products having macro capillaries of size >10 m, the vapor pressure still approximately cor-... 

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