Electrically Tunable Soft-Solid Block Copolymer Structural Color.
One-dimensional photonic crystals based on the periodic stacking of two different dielectric layers have been widely studied, but the fabrication of mechanically flexible polymer structural color (SC) films, with electro-active color switching, remains challenging. Here, we demonstrate free-standing electric field tunable ionic liquid (IL) swollen block copolymer (BCP) films. Placement of a polymer/ionic liquid film-reservoir adjacent to a self-assembled poly(styrene-block-quaternized 2-vinylpyridine) (PS-b-QP2VP) copolymer SC film allowed the development of red (R), green (G), and blue (B) full-color SC block copolymer films by swelling of the QP2VP domains by the ionic liquid associated with water molecules. The IL-polymer/BCP SC film is mechanically flexible with excellent color stability over several days at ambient conditions. The selective swelling of the QP2VP domains could be controlled by both the ratio of the IL to a polymer in the gel-like IL reservoir layer and by an applied voltage in the range of -3 to +6 V using a metal/IL reservoir/SC film/IL reservoir/metal capacitor type device.
Department of Materials Science and Engineering, Yonsei University , 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
Tae Joon
TJ
Park
Department of Materials Science and Engineering, Yonsei University , 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
Sun Kak
SK
Hwang
Department of Chemical and Biomolecular Engineering, Yonsei University , 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
Sungmin
S
Park
Department of Materials Science and Engineering, Yonsei University , 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
Sung Hwan
SH
Cho
Department of Materials Science and Engineering, Yonsei University , 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
Tae Hyun
TH
Park
Department of Materials Science and Engineering, Yonsei University , 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
Beomjin
B
Jeong
Department of Materials Science and Engineering, Yonsei University , 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
Han Sol
HS
Kang
Department of Chemical and Biomolecular Engineering, Yonsei University , 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
Du Yeol
du Y
Ryu
Department of Chemical and Biological Engineering, Korea University , Anam-dong, Seongbuk-gu, Seoul 136-713, Republic of Korea.
June
J
Huh
Department of Materials Science and Nano Engineering, Rice University , Houston, Texas 77005, United States.
Edwin L
EL
Thomas
Department of Materials Science and Engineering, Yonsei University , 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749, Republic of Korea.
Cheolmin
C
Park
block copolymers; electrically switchable structural color; flexible photonic crystals; low operation voltage; soft-solid structural colored film