Morphology and Wetting Stability of Nanofilms of ABC Miktoarm Star Terpolymers

• Published in: Macromolecules Vol. 53; no. 2; pp. 594 - 601
• Main Authors: Yang, Yan-Ling, Tsao, Heng-Kwong, Sheng, Yu-Jane
• Format: Journal Article
• Language: English
• Published: American Chemical Society 28.01.2020
• Subjects: films (materials); molecular dynamics; nanosheets
• ISSN: 0024-9297; 1520-5835; 1520-5835
• DOI: 10.1021/acs.macromol.9b02621

The morphology and wetting stability of nanofilms formed by A y B y C z miktoarm star terpolymers were explored by many-body dissipative particle dynamics. The length ratio of C- to A-arm (w = z/y) ranges from 0.25 to 5. On nonselective substrates, the nanofilm displays morphology as the lamella at w < 0.5, various Archimedean tilings at 0.5 ≤ w < 3, and the alternating lamella at w = 3. The nanofilm becomes unstable at w = 5. While our findings of Archimedean tiling patterns [6.6.6], [8.8.4], and [12.6.4] are consistent with thin film experiments, [8.6.4; 8.6.6] and [10.6.4; 8.6.4] have not been reported. The wetting stability was determined by the final fates of thin films subject to disturbances, including (i) nucleation and growth, (ii) self-healing, and (iii) stable hole. The stability follows descending order: [6.6.6] > [8.6.4; 8.6.6] > [10.6.4; 8.6.4] > [8.8.4] > [12.6.4] > alternating lamella > lamella > alternating cylinder. On selective substrates with weaker or stronger attraction with C-arms, the defects formed by C-arms prevail for the former but the lamella morphology dominates for the latter.