TWO EFFECTIVE BUT INEXPENSIVE ANTIWETTING AGENTS JAY E. TAYLOR Ohio State University, Columbus, Ohio
This preparation has been used in this laboratory and anticreeping properties upon glass is well known. with excellent success on a variety of articles. These Certain rather costly preparations of selected silicone have included beakers to contain solutions for pH derivatives are on the market for these uses. An in- measurement, special reaction flasks designed to hold expensive and yet excellent antiwetting agent may be two separate solutions, stirring rods which may be removed from, a solution with a negligible loss of easily prepared from ordinary silicone grease. Approximately one gram of either regular or vacuum liquid, pipets which give complete delivery of a meassilicone grease is dissolved completely in 50 ml. of low- ured liquid, pipets which mill hold two different soluboiling petroleum ether or similar solvent. Vigorous tions separated by an air column, etc. Owing t o the creeping tendencies of the silicone shaking is necessary. If regular silicone grease is used the resulting cloudy solution may be filtered and the grease itself it is definitely not recommended when a clear filtrate used immediately. If the vacuum grease limited area on a piece of apparatus is to receive antiis used it will be necessary to allow the mixture to wetting treatment. (It is this same tendency to creep stand for about one week and then decant the clear which often makes the silicones highly undesirable solution from the settled precipitate. The glass surface as stopcock or sealing lubricants.) However, marking to be treated is first carefully cleaned and dried. Fol- with a wax pencil works admirably. For example, if lowing this, it is rinsed with clear silicone solution, one desires to prevent dribbling while pouring from a allowed t o drain, thoroughly dried either in an oven or beaker or volumetric flask, about one-fourth inch or by long standing, and finally treated with cleaning more of the area on the outside edge of the pouring solution and rinsed to smooth the surface. A surface lip may be marked with a glass-marking pencil and coated in this manner will withstand several subse- then warmed to melt or sinter the wax. This gives quent treatments by cleaning solution with only a a highly effective antiwetting surface which will not spread beyond the area of application. moderate loss in antiwetting efficiency.
THEcapacity of the silicones to confer antiwetting
