Aggregation states and surface wettability in films of poly(styrene-block- 2-perfluorooctyl ethyl acrylate) diblock copolymers synthesized by atom transfer radical polymerization

Masaya Hikita, Keiji Tanaka, Tetsuya Nakamura, Tisato Kajiyama, Atsushi Takahara

Research output: Contribution to journalArticlepeer-review

55 Citations (Scopus)

Abstract

Well-defined poly(styrene-block-2-perfluorooctyl ethyl acrylate) [P(St-b-PFA)] copolymers with various chemical compositions were synthesized by atom transfer radical polymerization. Films of P(St-b-PFA) were structurally characterized, from bulk to surface, on the basis of transmittance electron microscopic observation and small-angle X-ray scattering, X-ray photoelectron spectroscopic, and contact angle measurements. For a comparison, poly(styrene-random-2-perfluorooctyl ethyl acrylate) [P(St-ran-PFA)] copolymers were also synthesized by conventional free radical polymerization. While P(St-b-PFA) with the 2-perfluorooctyl ethyl acrylate (PFA) content higher than 18.7 mol % formed a typical phase-separated cylinder structure, P(St-b-PFA) with a lower PFA content and P(St-ran-PFA) were in a miscible state. Since the perfluoroalkyl groups possess extremely low surface energy, they were preferentially segregated at the film surface, resulting in the formation of the PFA surface layer. This was the case for all P(St-b-PFA) films examined, although the aggregation state at the surface was strongly dependent on the PFA content. In the case of the P(St-b-PFA) with the PFA content higher than 18.7 mol %, both advancing and receding contact angles for water were 120° and even larger with almost no hysteresis. In addition, extremely excellent oil-repellent surface properties such as advancing and receding contact angles for dodecane of 76° and 75° were also observed. However, these intriguing liquid-repellent properties were not observed for the films of miscible P(St-b-PFA) and P(St-ran-PFA). Therefore, it can be concluded that the internal structure beneath the surface as well as the surface itself should be deeply considered to design excellent and stable liquid-repellent materials.

Original languageEnglish
Pages (from-to)5304-5310
Number of pages7
JournalLangmuir
Volume20
Issue number13
DOIs
Publication statusPublished - Jun 22 2004

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Colloid and Surface Chemistry

Fingerprint

Dive into the research topics of 'Aggregation states and surface wettability in films of poly(styrene-block- 2-perfluorooctyl ethyl acrylate) diblock copolymers synthesized by atom transfer radical polymerization'. Together they form a unique fingerprint.

Cite this