Dynamics of Spinodal Decomposition in Critical Polymer Mixtures

• Project/Area Number: 60470100
• Research Category: Grant-in-Aid for General Scientific Research (B)
• Allocation Type: Single-year Grants
• Research Field: 高分子物性
• Research Institution: Gunma University
• Principal Investigator: KUWAHARA Nobuhiro Faculty of Technology, Gunma University, 工学部, 教授 (50000782)
• Co-Investigator(Kenkyū-buntansha): KOYAMA Toshio Faculty of Technology, Gunma University, 工学部, 教務員 (60170403)
• Project Period (FY): 1985 – 1986
• Project Status: Completed (Fiscal Year 1986)
• Budget Amount: ¥3,600,000 (Direct Cost: ¥3,600,000); Fiscal Year 1986: ¥400,000 (Direct Cost: ¥400,000); Fiscal Year 1985: ¥3,200,000 (Direct Cost: ¥3,200,000)
• Keywords: Phase Separation / Spinodal Decomposition / Critical-Point Universality / Polymer Solution / Colloidal Solution / 臨界共溶点

Research Abstract

Dynamics of phase separation has been studied near the upper critical mixing point ( <T_c> =34.42゜C, <W_c> =12.1 wt.%) of the system polydimethylsiloxane (PDMS, <M_n> <-![> <M_w> =80 x <10^3> )-diethyl carbonate (DEC) and the lower critical mixing point ( <T_c> =31.89゜C, <W_c> =1.20 wt.%) of the system pentaethylene glycol dodecyl ether ( <C_(12)> <E_5> )-water (W). The gist obtained is as follows.
1. The system <C_(12)> <E_5> -W near its critical mixing point deviates from the universality class of fluids, binary mixtures, and alloys near their critical points.
2. When the critical mixture of PDMS-DEC and of <C_(12)> <E_5> -W are suddenly brought into the inside of their spinodal curves, clusters in the minority phase grow gradually and the forward scattered-light intensity I forms the maximum peak <I_m> at momentum transfer k= <k_m> .
1) For PDMS-DEC at <T_c> -T <-![> 5 mK the light intensity I(k,t) increases in accordance with I(k,t)[ <t^(1.5)> at momentum transfer k=2.5 x <10^3> <cm^(-1)> for a time of t <<![> 60 sec, I(k,t)[ <t^(2.5)> at k=1.6 x <10^3> <cm^(-1)> over 60 sec <<![> t <<![> 130 sec, and then the peak of scattered light at k= <k_m> increases sharpness and shifts to smaller k with time in the range of t <>![> 190 sec.
2) For <C_(12)> <E_5> -W at T- <T_c> <-![> 1 mK, I(k,t) increases in accordance with I(k,t)[ <t^(2.3)> at k=2.1 x <10^3> <cm^(-1)> for a time of t <<![> 50 sec, I(k,t)[ <t^(3.4)> at k=1.5 x <10^3> <cm^(-1)> over 50 sec <<![> t <<![> 100 sec, and then the peak of scattered light at <k_m> increases sharpness and shifts to smaller k with time in the range of t <>![> 130 sec.
3. The wave length <RAMbda> (=2 <pi> /k) of concentration fluctuations in the early stage of spinodal decomposition is 26 <mu> m for PDMS-DEC at <T_c> -T <[!-> 5 mK and 29 <mu> m for <C_(12)> <E_5> -W at T- <T_c> <-![> 1 mK.

Research Products

• [Publications] 桑原信弘: Physical Review A. 32. 1279-1281 (1985)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] 浜野賢治: Physical Review Letters. 55. 1472-1475 (1985)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] 浜野賢治: Physical Review A. 32. 3168-3171 (1985)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] 浜野賢治: Physical Review A. 33. 485-489 (1986)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] 佐伯進: Macromolecules. 19. 2353-2356 (1986)
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Nobuhiro Kuwahara: "Dynamics of Phase Separation for a Micellar Solution" Physical Review A. 32. 1279-1281 (1985)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Kenji Hamano: "Dynamics of Concentration Fluctuations for a Micellar Solution" Physical Review Letters. 55. 1472-1475 (1985)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Kenji Hamano: "Critical Behaviors in the Two-Phase Region of a Micellar Solution" Physical Review A. 32. 3168-3171 (1985)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Kenji Hamano: "Dynamics of Concentration Fluctuations along the Coexistence Curve of a Binary Mixture" Physical Review A. 33. 485-489 (1986)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Susumu Saeki: "Pressure Dependence of Upper Critical Solution Temperatures in Polymer Solutions" Macromolecules. 19. 2353-2356 (1986)
  • Description: 「研究成果報告書概要(欧文)」より