Polydimethylsiloxane (PDMS) has excellent physical–chemical
properties and good biocompatibility. Thus, PDMS has been widely applied
in biomedical applications. However, the low surface free energy and
surface hydrophobicity of PDMS can easily lead to adverse symptoms,
such as tissue damage and ulceration, during medical treatment. Therefore,
the construction of a hydrophilic low-friction surface on the PDMS
surface could be helpful for alleviating patient discomfort and would
be of great significance for broadening the application of PDMS in
the field of interventional medical catheters. Existing surface modification
methods such as hydrogel coatings and chemical grafting suffer from
several deficiencies including uncontrollable thickness, surface fragility,
and low surface strength. In this study, a hydrophilic surface with
ultra-low friction properties was prepared on the surface of PDMS
by an ultraviolet light (UV) curing method. The monomer acrylamide
(AM) was induced by a photoinitiator to form a coating on the surface
of the silicone rubber by in situ polymerization. The surface roughness
of the as-prepared coatings was regulated by adding different concentrations
of 2-acrylamido-2-methylpropanesulfonic acid (AMPS) to the monomer
solution, and the coating properties were systematically characterized.
The results indicated that the roughness and thickness of the as-prepared
coatings decreased with increasing AMPS concentration and the as-prepared
coatings had good hydrophilicity and low-friction properties. The
Coefficient of Friction (CoF) was as low as 0.0075
in the deionized water solution, which was 99.7% lower than that of
the unmodified PDMS surface. Moreover, the coating with a lower surface
roughness exhibited better low-friction properties. The results reported
herein provide new insight into the preparation of hydrophilic, low-friction
coatings on polymer surfaces.