서지주요정보
유동장과 전기장의 복합장에서 쌍극자를 갖는 고분자 용액의 해석 = Analysis of solutions of rigid macromolecules with dipoles in hydrodynamic and electric fields
서명 / 저자 유동장과 전기장의 복합장에서 쌍극자를 갖는 고분자 용액의 해석 = Analysis of solutions of rigid macromolecules with dipoles in hydrodynamic and electric fields / 권무현.
저자명 권무현 ; Kwon, Moo-Hyun
발행사항 [대전 : 한국과학기술원, 1992].
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소장정보

등록번호

8002459

소장위치/청구기호

학술문화관(문화관) 보존서고

DCE 92002

SMS전송

도서상태

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초록정보

Rheo-optical state of dilute solution of rigid macromolecules in simultaneous hydrodynamic and electric fields is investigated theoretically and experimentally. Macromolecules are taken to be non-electrolytic rigid Brownian spheroids of arbitrary aspect ratio and a dielectric Newtonian fluid is used as a solvent. Both permanent and induced dipole moments are included. Optical state of a solution was investigated through two optical functions, birefringence and extinction angle, and results obtained from analytical studies were discussed and compared with ones from experiments. First, for clear circumstances, a modeled solution system having above conditions is presented. The governing equation describing the behavior of particles dissolved at the model solution is derived from the torque balance. Final form of that equation is the normalized diffusion equation solved for the orientation distribution function which presumes the probability that the major axis of a spheroid has a particule direction. This equation was expressed in terms of dimensionless field parameters and operators related to respective fields. In addition to optical property of a solution, rheological property can be investigated through the component functions of the stress tensor. Expression of stress tensor pertinent to this model solution were obtained. The converged solutions are used in the prediction of the steady state optical functions such as birefringence and extinction angle over very wide ranges of field strengths. To solve the problem with arbitrary strength of fields, numerical analysis was performed. The Galerkin method based on spherical harmonics was adopted for the steady state problem and a newly desinged numerical scheme was used to manage with inversion of the huge matrix caused by the strong field problem. Transient Problem could be solved by 4th order Runge-Kutta method. Numerical results up to the saturation field strengths were obtained. Optical properties of the model solultion varied according to not only the absolute strengths of respective fields but also the relative strengths. Thus to interpret the results systematically full ranges of the field strengths were divided into 3 regions. 0.1 and 0.03644 w/v % m-cresol solutions of Poly-γ-benzyl-L-glutamate having molecular weights of 4 sizes ranging from 15,000 to 236.000 were experimented under the combined fields over wide field strengths in witch maximum shear rate was 400 sec$^{-1}$ and electric field was loaded up to 33kv/cm. Transient birefringence and extinction angle were simultaneously measured using the phase-modulated birefringence method. Birefringence experiment using a PBLG solution is usually performed on characteristic time unit of a few msec order and experiments at strong fields is basically restricted by performance of apparatus. Especially, electric birefringence experiment is limited by a dielectric breakdown of a solution caused by strong electric fields and experiments under combined fields are accompanied by the piezoelectric effects. Experimental characteristics and problems of the component and the combined fields were discussed through the representitive transient experiments. Analyses of steady state results obtained from the combined field experiments were presented. Hydrodynamic interaction between polymer particles was not occurred within experimented conditions, but electric effects were sensitive to both the applied electric field strength and concentration of a solution. Optical state of a solution could be explained to a certain extent by the dimensionless field parameters established in the theory. However, mainly due to electric hindrance, flow instibility by the strong combined fields. and deterioration of a solution by succesive electric experiments, experimental values deviated from theoretically predicted ones. Finally, through the steady state results from the combined field experiments using m-cresol solution of PBLG of M.W. =236,000 optical constant of the solution, permanent dipole strength of PBLG, and its rotational diffusivity were given.

서지기타정보

서지기타정보
청구기호 {DCE 92002
형태사항 xvi, 187 p. : 삽도 ; 26 cm
언어 한국어
일반주기 부록 : A, 연산자 $Ω_1$. - B, 연산자 $Ω_2$. - C, 연산자 $Ω_3$. - D, 연산자 Λ. - E, (Ⅱ-37) 식의 상수 계수들. - G. 연구에 관련된 Program code
저자명의 영문표기 : Moo-Hyun Kwon
지도교수의 한글표기 : 박오옥
지도교수의 영문표기 : O-Ok Park
학위논문 학위논문(박사) - 한국과학기술원 : 화학공학과,
서지주기 참고문헌 : p. 140-146
주제 Macromolecules.
Numerical analysis.
수치 해석. --과학기술용어시소러스
전기장. --과학기술용어시소러스
고분자. --과학기술용어시소러스
Electric fields.
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