物理化学学报 >> 1995, Vol. 11 >> Issue (10): 945-949.doi: 10.3866/PKU.WHXB19951019

研究简报 上一篇    下一篇

PEO-PS共聚微粒在MgSO4溶液中聚集的分形

姚松年   

  1. 武汉大学分析测试中心,武汉 430072
  • 收稿日期:1994-10-30 修回日期:1995-02-06 发布日期:1995-10-15
  • 通讯作者: 姚松年

Studies of the Fractal Dimension of Aggregation of Polystyrene Labices Sterically Stabilized by Poly(ethyleneoxide) in the Solution of MgSO4

Yao Song-Nian   

  1. The Centre for Analysis and Measurement,Wuhan University,Wuhan 430072
  • Received:1994-10-30 Revised:1995-02-06 Published:1995-10-15
  • Contact: Yao Song-Nian

关键词: 分形, 聚氧乙烯, 聚苯乙烯

Abstract:

The fractal dimensions (df) of aggregates of latex paticles coated by poly(ethylene oxide)(PEO) have been measured in worse than θ-solvents for different concentrations MgSO4 and temperatures by means of dynamic light scattering. For the lowest molar mass PEO studied (20kg•mol-1) the measurement df of about 2.1 was almost independent of temperature over the range studied. The value corresponds to partially reversible cluster aggregation, which leads to relatively compact aggregates. For the highest molar mass PEO studied (600kg•mol-1), the df decreased significantly ( from 2.4 to 1.7) with temperature, singnifying the generation of more ramified aggregates. The results obtained for this hydrophilic the generation of more ramified aggregates. The results obtained for this hydrophilic polymer contrast makedly with the aggregation of latexes stabilized by the hydrophobic polymer poly(N-isopropylacrylamide)(PNIPAM) which undergoes a coil-to-globule transition.

Key words: Fractal dimension, Poly(ethylene oxide)-polystyrene