Enhance understanding of rhythmic crystallization in confined evaporating polymer solution films: from environment to solution film and then to one period. Issue 51 (9th May 2016)

• Record Type: Journal Article
• Authors: Li, Yiguo; Wang, Zongbao; Gu, Qun; Wu, Xuedong
• Is Part Of: RSC advances. Volume 6:Issue 51(2016)
• Page Start: 45241
• Page End: 45249
• Publication Date: 2016-05-09
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra02803a
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : An enhanced understanding of rhythmic crystallization in an evaporating polymer solution is explored from the environment to the film and to within one period. Abstract : It has been shown that rhythmic-crystallization-caused concentric ringed spherulites in polymer solution films can only be observed upon a confined slow evaporation. Here, by analysing the physical principle of evaporative crystallization, the special effects of experimental conditions on such rhythmic crystallization in a confined environment are explored via optical microscopy and atomic force microscopy observations. It is unveiled that the coupling of the confined conditions and extra solvent provides a suitable and stable solvent partial pressure that ensures the generation and continuation of rhythmic crystal growth. By slanting the substrate, the unusual dependences of radial growth rate and ring periodicity upon the film thickness are also illustrated. Finally, the growing front evolution and the melt-like growth in the induction time before the next period are demonstrated. These present findings significantly enhance our understanding of the rhythmic crystallization in evaporating polymer solution films.