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5440538 
Journal Article 
From a dissolved polystyrene coil to an intramolecularly-hyper-cross-linked ''nanosponge'' 
Davankov, VA; Ilyin, MM; Tsyurupa, MP; Timofeeva, GI; Dubrovina, LV 
1996 
Macromolecules
ISSN: 0024-9297
EISSN: 1520-5835 
AMER CHEMICAL SOC 
WASHINGTON 
29 
26 
8398-8403 
English 
Linear polystyrene of Mw = 330 000 and Mw/Mn = 1.04 in which 50% and 100% of the phenyl residues were chloromethylated were heated in a 0.5 g/L ethylene dichloride solution in the presence of SnCl4 to convert them into an intramolecularly hyper-cross-linked soluble material. The spherical macromolecular species obtained exhibit low density and high surface area (up to 1000 m2/g) and swell strongly in all nonsolvents for linear polystyrene. Solutions in good polystyrene solvents exhibit low viscosity and reduced partial specific volume, but exceedingly high diffusion and sedimentation constants. According to size exclusion chromatography, dynamic light scattering, low angle X-ray scattering and electron microscopy, the diameter of the hyper-cross-linked species is estimated as about 12 nm in the dry state and about 17 nm in solution. In tetrahydrofuran, they associate reversibly, probably forming clusters consisting of 13 regularly packed particles. Because of the partial association, molecular weight measurements (using elastic light scattering and ultracentrifugation techniques) produce values slightly exceeding the 350 000-370 000 expected for the isolated particle.