1995 Fiscal Year Final Research Report Summary
STUDY OF THE REORIENTATIONAL MOTION OF RODLIKE MICELLES BY ULTRASONICALLY INDUCED BIREFRINGENCE
Project/Area Number |
06640743
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Research Category |
Grant-in-Aid for General Scientific Research (C)
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Allocation Type | Single-year Grants |
Research Field |
機能・物性・材料
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Research Institution | NAGOYA UNIVERSITY |
Principal Investigator |
KODA Shinobu NAGOYA UNIVERSITY,SCHOOL OF ENGINEERING,ASSOCIATE PROFESSOR, 工学部, 助教授 (10126857)
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Project Period (FY) |
1994 – 1995
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Keywords | ULTRASONICS / BIREFRINGENCE / RODLIKE MICELLES / REORIENTATIONAL MOTION / ENTANGLEMENT |
Research Abstract |
The purpose of this work is to directly measure the orientational relaxation times of rodlike micelles and to get new information about the stability of rodlike micelles by ultrasonically induced birefringence method. The light detector and optical system were improved to measure the frequency dependence of ultrasonically induced birefringence (ultrasonically induced birefringence spectroscopy). In order to clarify ultrasonically induced birefringence of rodlike colloidal particle, the frequency dependence of ultrasonically induced birefringence was measured for hematite sol and poly (tetrafluoroehylene) (PTFE) latex. The birefringence was observed in the wide frequencyrange from 5 to 225 MHz. A new theory of ultrasonically induced birefringence should be required for the case of rodlike colloidal particle combining the Oka theory with the turning torque in viscous fluids. The hexadecyldimethylame oxides (C16DMAO) were synthesized and ultrasonically induced birefringence was measured for aqueous C16DMAO solutions of 20 and 50 mM.The intensity of the birefringence was in the range 10^<-10>-10^<-9> and increased with approaching to isotropic-nematic phase transition point. The birefringence was proportional to the square root of ultrasonic intensity, while the those of hematite soland PTFE latex were proportional to the ultrasonic intensity. The change of shape of rod like micelles was not observed within our experimental condition. The three different processes of orientational relaxation motions of solutions of 50mM were observed from the trace of the transient birefringence and the orientational relaxation times lied from 0.03 to 0.04 sec. The processes are as cribed to the motion of the complicated entanglement of the rod like micelles. In the range of the low concentration of micelle, the single relaxation was observed and the orientational relaxation times for 20 mM solution at 35 and 50 ゚C were 0.31 and 0.24 sec, respectively.
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Research Products
(13 results)