Acta Phys. -Chim. Sin. ›› 1995, Vol. 11 ›› Issue (06): 541-546.doi: 10.3866/PKU.WHXB19950613

• ARTICLE • Previous Articles     Next Articles

Study of Temperature Effect of Micellar Solutions of PSDMS Block Copolymer in n-Heptane by Positron Annihilation

Xiong Xing-Min,Yang Ju-Hua,Ye Mei-Ling,Zhang Ying-Jiu,Shi Liang-He   

  1. Institute of High Energy Physics,Academic Sinica,Beijing 100080|Institute of Chemistry,Academic Sinica,Beijing 100080
  • Received:1994-08-17 Revised:1995-01-26 Published:1995-06-15
  • Contact: Xiong Xing-Min


The positron lifetime technique has been used to study the temperature behavior of micelle in solution of polystyrene-polydimethylsiloxane diblock copolymer in n-heptane. The results indicate that positron annihilation parameters are found to be sensitive to structural and microphase changes taking place in the micellar solutions. The abrupt changes in the o-Ps lifetime and intensity observed at certain temperature appear to be associated with variations in the aggregation state of the copolymer molecules in solutions. Above the critical micelle temperature the o-Ps lifetime increases sharply with increasing temperature. This behavior indicates the process of disintegration of molecular aggregates to free copolymer molecules.

Key words: Positron annihilation;Blok copolymer;Micellar solution;Temperature effect