Background: To produce alternative hydrophilic patterns on the surface of a nanocomposite,
many different approaches have been used. The ionic liquid (IL) microemulsions expanding the
potential uses of ILs that can provide hydrophilic or hydrophobic nanodomains as a nanoreactor to the
synthesis of a novel type of nanocomposites with special properties.
Objective: This study aims to investigate photo-induced hydrophilicity of modified poly(methyl methacrylate)
(PMMA) containing TiO2 nanoparticles, synthesized by using ionic liquid-in-oil microemulsion
Materials and Methods: A series of visible light-responsive PMMA/TiO2 nanocomposite films were
prepared in an ionic liquid (IL) based microemulsion containing methyl methacrylate monomer, 1-
buthyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]), Triton X-100 and 1-buthanol. The ternary
phase diagram of the microemulsion system has been constructed and concluded that it is thermodynamically
stable at polymerization temperature of 60°C. The oil phase of the system was polymerized
to obtain the PMMA nanocomposite films with different concentration of TiO2 nanoparticles.
Techniques such as XRD, AFM and TEM were carried out to characterize the fabricated transparent
nanocomposite films. The visible light photo-induced hydrophilicity of the prepared
PMMA/IL/TiO2 films was evaluated by measuring the contact angle of water on a thin film of the
nanocomposite during the visible light illumination.
Results: The results showed that the surface hydrophilicity of the nanocomposites will be changed
significantly with light illumination and the PMMA/IL with 0.01 wt.% loading of TiO2 showed the
best hydrophilicity. The contact angle of the nanocomposite was decreased with increasing of irradiation
time and from that, the surface energy and work of adhesion increased.
Conclusion: It is concluded that modification of TiO2 nanoparticles with ionic liquid is a new approach
for making visible light photo-induced polymer nanocomposites with improved hydrophilicity