engleski

ESR spectroscopy for the study of polymer heterogeneity

In recent years the motional and structural heterogeneity of polymers and their phase separation on a nanoscale length have been approached by many experimental techniques. This review compiles the literature on the application of electron spin resonance (ESR) spectroscopy - spin label/probe methods in heterogeneous polymer systems over the past decade. The achievements and limitations of the ESR method in the study of homopolymer heterogeneity, crosslinked polymer networks, polymer blends, interpenetrating network, copolymers and block copolymers are overviewed and compared with the some other allied methods. Recent analysis of complex ESR spectra and their corresponding types of motion are presented in the article. Information on molecular dynamics in a wide range of spin label/probe motion, free volume and free-volume distribution, phase separation, phase morphology and small molecule penetration are the main issues of the remaining sections. The last section covers some other ESR techniques such as continuous wave, linear and nonlinear methods and pulse ESR supported by their possible features or those already achieved in the field of polymer research. ESR advanced methods offer new possibilities to expand the limits as well as a sensitivity of molecular dynamics detection in gaining information on realistic molecular behavior in complex polymer materials.

electron spin resonance (ESR); spin probe/spin label; heterogeneity; polymers; copolymers; polymer blends; interpenetrating networks

nije evidentirano