Estimate of the Fluid Force Related to Washing Mechanism -Analysis of Viscoelasticity for Aqueous Solutions of Surfactant and Mechanism for Soil Removing -

2002 Fiscal Year Final Research Report Summary

• Project/Area Number: 13680110
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 家政学一般(含衣・住環境)
• Research Institution: IWATE University
• Principal Investigator: AMAKI Keiko IWATE UNIV., EDICATION, ASOCIATE PROFESSOR, 教育学部, 助教授 (80193019)
• Project Period (FY): 2001 – 2002
• Keywords: Aqueous Solution of Surfactant / Washing / Fluid Force / Emulsion / Analysis of Pictures

Research Abstract

The purpose of this research is to investigate the effect of fluid force on detergency. That is to measure the deformation of surfactant micelles when aqueous solutions of surfactant is flowing. But micelles are too small to see, so I used some oil-in-water type (O/W) and water-in-oil type (W/O) emulsions made of oleic acid and pure water (these are as a bigger model of surfactant micelles). The ratio of height to width was calculated using by the observation system of heating, shear flowing.
The following results are obtained. The ratio of height to width was increased (>1), it means the shape of drops deformed to elliptic sphere, when every emulsions were flowing. And the flow stopped, it was decreased immediately (almost=1), the shape returned to sphere. For all emulsions used, the ratio of height to width increases with an increase in low shear rate. But the ratio decreases at some high shear rate, and it increases again with higher shear rate. There is room for further investigation on this point.