|Budget Amount *help
¥1,900,000 (Direct Cost : ¥1,900,000)
Fiscal Year 1992 : ¥500,000 (Direct Cost : ¥500,000)
Fiscal Year 1991 : ¥1,400,000 (Direct Cost : ¥1,400,000)
Transient phenomena of vertical penetration of aqueous surfactant solutions into polyester fabric have been studied with the aim of demonstrations to rate- determining factors in such phenomena, by a new method based on measuring of electric capacitance. When an aqueous solution of sodium lauryl sulfate(SDS), sodium dioctylsulfosuccinate (AOT) lauryl trimethylammonium bromid (DTAB) and polyoxyethylene laurylethers (AE, average addition moles of ethylene oxide n = 4.3 - 17.9) is in contact with a condenser consisting of two parallel plate electrodes with polyester fabric between them, its electric capacitance sensitively changes with the rise of the solution in the fabric. Recording of this change can make possible an accurate tracing from the initial stage of the process. Measurements made with polyester-SDS, AOT, or DTAB solution systems indicate an increase followed by a decrease in the rate of penetration as the concentration is increased. Analysis of the transient characteristics for the experimental results within 1 sec was attempted by application of the theoretical approaches to the dynamics of capillary flow, known from literature, setting essential parameters governing the rate of capillary penetration. It is shown that the increase or decrease in the rate of penetration can be attributed to forming of oriented monolayers or bilayers at the fiber surface during the wetting of the fabric.