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A study of structure and properties of molecularly thin methanol film using the modified surface forces apparatus
Author(s) -
Zhao Gutian,
Cai Di,
Wu Gensheng,
Tan Qiyan,
Xiang Li,
Zhang Yin,
Xiang Nan
Publication year - 2014
Publication title -
microscopy research and technique
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 118
eISSN - 1097-0029
pISSN - 1059-910X
DOI - 10.1002/jemt.22425
Subject(s) - mica , adsorption , methanol , molecule , evaporation , layer (electronics) , chemical engineering , thin film , substrate (aquarium) , materials science , surface forces apparatus , chemistry , chemical physics , nanotechnology , analytical chemistry (journal) , composite material , chromatography , thermodynamics , organic chemistry , physics , oceanography , geology , engineering
A novel approach for studying the adsorption and evaporation processes of molecularly thin methanol film by the modified surface forces apparatus (M‐SFA) is reported. This method can be used precisely to measure the thickness, morphology, and mechanical properties of the film confined between two mica surfaces in a real‐time manner at gas atmosphere. By observing the adsorption and evaporation processes of the methanol molecule, it is found that the first adsorbed layer of the methanol film on the mica surface behaves as a solid‐like structure. The thickness of this layer is measured to be about 3.2 Å, approximately equal to the diameter of a methanol molecule. Besides, this first adsorbed layer can carry normalized loads of more than 5.6 atm due to the carrying capacity conserved by the bond of mica‐OH. The outer layers of the methanol film are further adsorbed with the increase of the exposure time, which are liquid‐like and can be easily eliminated out from the substrate. The present study suggests that the interacting mode between hydroxy and mica is of great potential in material science and biomedical systems. Microsc. Res. Tech. 77:851–856, 2014 . © 2014 Wiley Periodicals, Inc.