title: Quantitative description of aggregation and dissociation of polystyrene chains in cyclohexane solutions by resonance light scattering technique.
abstract: The resonance light scattering (RLS) technique based on a conventional fluorescence spectrophotometer was used to quantitatively describe the aggregation and dissociation of polystyrene (PS) in cyclohexane solution during cyclic heating and cooling. Transitions in conformation of PS molecules and aggregation of PS chains in the course of phase separation were revealed. The results indicated that PS chains changed from random coils to collapsed globules and then aggregated when temperature decreased. In contrast, when the system is heated, the chain aggregates were initially swelled and followed by gradual dissociation. Subsequently, the conformation of PS chains returned to the original state. Kinetics of phase separation of the PS solution was analyzed, which allowed estimation of the apparent activation energy.
authors.affiliation: Key Laboratory for Polymer Composite and Functional Materials of the Ministry of Education, DSAPM Lab, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, China.
authors.forename: Wen Zhi
authors.initials: WZ
authors.lastname: Zhang
authors.forename: Xu Dong
authors.initials: XD
authors.lastname: Chen
authors.forename: Jin
authors.initials: J
authors.lastname: Yang
authors.forename: Wei-ang
authors.initials: WA
authors.lastname: Luo
authors.forename: Ming Qiu
authors.initials: MQ
authors.lastname: Zhang