Abstract: Method for making a water insoluble hydrophilic polymeric substrate having incorporated therein a dispersion of a finely precipitated metal sulfide for sorbing by ion exchange heavy metals from aqueous solutions such as photographic solutions, seawater, mine tailings, electroplating baths and the like, the substrate being formed from such polymers as cellulose esters, cellulose ethers, starches cross-linked to render them water insoluble, natural polymers, or regenerated cellulose; and the product of the method.

Abstract: A transparent hydrophilic film for detecting the presence of heavy metals in aqueous solutions; the method of making same and the film as made by the method; and the use of a transparent hydrophilic film having therein a dispersion of finely precipitated zinc sulfide which becomes discolored by ion exchange when indicating the presence of heavy metals, the degree of discoloration being also a measurement of the concentration of such heavy metals.

Abstract: A hydrophilic, cellulose ester material that may be used as a filter or ion exchanger to sorb heavy metal ions, such as silver, mercury, lead, copper and cadmium, from aqueous solutions, the material having incorporated therein a high surface area zinc sulfide of at least 15 square meters per gram, and preferably at least 24 square meters per gram; and method for incorporating high surface area zinc oxide into a cellulose ester material by slurry process or solution process and converting the zinc oxide so incorporated into high surface area zinc sulfide; and product of the method.

Abstract: A hot melt adhesive having low viscosity and very low tackiness at application temperatures for bonding crystalline and amorphous fibers at their contact points in a cigarette tobacco smoke filter element, the hot melt adhesive being a blend of about 25 to about 75 weight percent wax and about 75 to about 25 weight percent of a tackifying hydrocarbon resin; and tobacco smoke filter elements bonded by the hot melt adhesive.