Latex dust, removal

Latex molding employs casts made of unglazed porcelain or plaster of paris. The molds are dusted with talc to prevent sticking. The latex compound is then poured into the mold and allowed to develop the required thickness. The mold is emptied of excess rubber and then oven dried. The mold is removed and the product is again dried in an oven. Casting is used to manufacture dolls, prosthetics, printing matrices, and relief maps. 

Sample Preparation. The polystyrene spheres to be used should be monodis-perse with a particle radius i of about 50 nm, although any size in the range i = 30 to 100 nm is suitable. Such nanospheres are available commercially as aqueous latex suspensions with 1% to 10% PS by weight. A small amount of this latex suspension should be diluted 100- to 1000-fold. Using a microsyringe, take 0.1 mL from the PS stock, deliver this into a rinsed dilution bottle, and then add 10 mL of a hltered lO-mM solution of NaCl or other 1 1 electrolyte. The purpose of this electrolyte is to partially suppress coulombic interactions (electrostatic double-layer repulsion) that can influence the diffusion constant and lead to R values that are artificially high by —10%. The electrolyte solution should be prepared from distilled water and stored at room temperature. Before use, it must be hltered through a suitable membrane (0.1-jum pore size) to remove dust particles. Avoidance of dust is cracial, and capped dilution bottles should be used. 

The use of disposable laboratory garments can eliminate the problem of cleaning chemically exposed garments and reduce the spread of chemical aerosols outside the laboratory. In addition to a laboratory coat, head and shoe covers and gloves (latex and neoprene types) should be provided. Each employee should be fitted with a full-face-mask respirator containing cartridges to remove dust and organic vapors. 

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