US EPA

1610180 

Journal Article 

Selective Adsorption of Isopropyl Alcohol Aqueous Solution on Polypropylene Surfaces: A Molecular Dynamics Simulation 

Dai, ZWei; Wan, LShu; Huang, XJun; Ling, Jun; Xu, ZhiK 

2011 

Yes 

Journal of Physical Chemistry C
ISSN: 1932-7447
EISSN: 1932-7455 

115 

45 

22415-22421 

10.1021/jp206733b 

WOS:000296685800040 

Surface modification for hydrophilization is a versatile
approach to significantly improve the separation performance of membranes prepared from
hydrophobic polymers such as polypropylene (PP). This improvement is closely related to changes
in the chemical characteristics of membrane surface and alterations in the adsorption behaviors
of feed components. We simulated the interaction of isopropyl alcohol aqueous solution with
nascent and hydrophilized PP surfaces by molecular dynamics to understand the molecular mechanism
of these variations. The results were used to evaluate the selective adsorption of isopropyl
alcohol on the model surfaces. The isopropyl alcohol molecule shows surfactant-like behaviors due
to one hydroxyl group as the polar end and two methyl groups as the apolar end. For nascent PP
surface, dispersive force plays a key role in the interaction of isopropyl alcohol molecules with
model surface. Isopropanol is therefore selectively adsorbed from the aqueous solution, and water
is repelled out of the interfacial layer. For the hydrophilized surfaces, however, the
electrostatic interaction between water molecules and surface polar groups exceeds the effect of
dispersive force. As a result, water molecules are attracted onto the modified surface and
hydration layers are observed.