Molecular-structure-induced under-liquid dual superlyophobic surfaces

Zhihong Zhao, Yuzhen Ning, Xu Jin, Shuang Ben, Jinlong Zha, Bin Su, Dongliang Tian, Kesong Liu, Lei Jiang

Research output: Contribution to journalArticleResearchpeer-review

33 Citations (Scopus)

Abstract

Surfaces with under-water superoleophobicity or under-oil superhydrophobicity have attractive features due to their widespread applications. However, it is difficult to achieve under-liquid dual superlyophobic surfaces, that is, under-oil superhydrophobicity and under-water superoleophobicity coexistence, due to the thermodynamic contradiction. Herein, we report an approach to obtain the under-liquid dual superlyophobic surface through conformational transitions of surface self-assembled molecules. Preferential exposure of either hydrophobic or hydrophilic moieties of the hydroxythiol (HS(CH2)nOH, where n is the number of methylene groups) self-assembled monolayers to the surrounding solvent (water or oil) can be used to manipulate macroscopic wettability. In water, the surfaces modified with different hydroxythiols exhibit under-water superoleophobicity because of the exposure of hydroxyl groups. In contrast, surface wettability to water is affected by molecular orientation in oil, and the surface transits from under-oil superhydrophilicity to superhydrophobicity when n ≥ 4. This surface design can amplify the molecular-level conformational transition to the change of macroscopic surface wettability. Furthermore, on-demand oil/water separation relying on the under-liquid dual superlyophobicity is successfully demonstrated. This work may be useful in developing the materials with opposite superwettability.

Original languageEnglish
Pages (from-to)14869-14877
Number of pages9
JournalACS Nano
Volume14
Issue number11
DOIs
Publication statusPublished - 9 Nov 2020
Externally publishedYes

Keywords

  • Chain length
  • On-demand water/oil separation
  • Reconfigurable molecular conformation
  • Switchable wettability
  • Under-liquid dual superlyophobicity

Cite this