Revisiting of dimensional scaling of linear chains in dilute solutions

✍ Scribed by Fei Hong; Yijie Lu; Junfang Li; Wenjing Shi; Guangzhao Zhang; Chi Wu

• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 369 KB
• Volume: 51
• Category: Article
• ISSN: 0032-3861
• DOI: 10.1016/j.polymer.2010.01.034

✦ Synopsis

The dimensions of linear polymer chains are scaled to their molar mass (M) as R ¼ kM a with a ¼ 1/2 and 3/5 in a theta and an athermal solvent, respectively. In a good solvent, both k and a are a function of the solvent quality and chain length range. A high-temperature laser light-scattering spectrometer was used to measure the average radius of gyration (CR g D) and hydrodynamic radius (CR h D) of a set of narrowly distributed linear polystyrene chains in decalin over a wide temperature range. k and a in the scaling experimentally varying with T over a chain length range was analyzed. The results reveal that for CR g D, a ¼ 0.59 À 0.09exp(Às/0.066) and k ¼ 0.60s 2aÀ1 , reasonably agreeing with the thermal blob theory. For CR h D, a ¼ 0.59 À 0.09exp(Às/0.106), but k deviates from the relationship of k f s 2aÀ1 , reflecting that the hydrodynamic interaction and chain draining are not considered in the thermal blob theory.