Liao J, Wang W, Xu X, Jian H, Yang S. Interfacial Behavior of Giant Amphiphiles Composed of Azobenzene and Polyhedral Oligomeric Silsesquioxane.
LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2022;
38:1611-1620. [PMID:
35068145 DOI:
10.1021/acs.langmuir.1c03111]
[Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Giant amphiphiles containing azobenzene and polyhedral oligomeric silsesquioxane (POSS) units are synthesized by linking 4,4'-azodianiline (ADA) and POSS derivatives by stepwise amidation and further modification. The synthesized giant amphiphiles are photoresponsive and show trans-cis isomerization under ultraviolet (UV) irradiation. These giant amphiphiles are spread on the air-water interface and compressed by the barrier without and under UV irradiation. By compression, the giant amphiphiles undergo a phase transition from gas (G), liquid expanded (LE), liquid condensed (LC), and solid (S) to a final collapse on the water surface. The giant amphiphiles are cis-isomer-rich under UV irradiation and are trans-isomer-rich without UV irradiation. The trans-isomers are straight-shaped, while the cis-isomers are bent, and hence, their phase transition behaviors on the water surface exhibit a distinct difference.
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