Introduction
Undesirable interfacial adhesion causes numerous technical issues that
can impact various fields. A wide range of advanced anti-adhesion
materials capable of repelling both water and oils have been developed
to address these challenges, and they are described as
anti-adhesion,1 non-stick,2self-cleaning,3 antifouling,4anti-smudge,5 anti-graffiti,6superwettability,7 superoleophobic,8superamphiphobic,9 or slippery liquid-infused porous
surfaces (SLIPS).10 The common purpose of these
materials is to minimize the interfacial wetting behavior and
intermolecular forces between liquids and solid surfaces, which is
achieved via the construction of micro/nanomorphologies or the
manipulation of low-surface-energy molecules.
Micro/nanoscale roughened textures and re-entrant curvatures, which are
generally regarded as lotus bioinspired structures, can enhance the
liquid repellency of amphiphobic materials and render them
superamphiphobic due to the presence of air pockets, exhibiting contact
angles (CAs) greater than 150° and sliding angles (SAs) below
10°.11,12 Despite decades of intense research in this
area, the applicability of these intricate micro/nanoscale surfaces has
often been limited by their poor wear resistance, opacity, and the need
for complex manufacturing processes.13,14
Flat surfaces comprised of molecules with weak intermolecular forces,
including hydrogen bonds, electrostatic interactions, and van der Waals
interactions, can also exhibit anti-adhesion performance, such as the
repellency against water and cooking oil that is exhibited by
polytetrafluoroethylene (PTFE, Teflon). It is noteworthy that the
dynamics or rotation mobility of liquid molecules would greatly enhance
the anti-adhesion performance. For example, the anti-adhesion function
of solid Teflon would fail during contact with objects that exhibit
strong multivalent hydrogen bonding such as crude oil, blood, and
2-amino-4-hydroxy-6-methylpyrimidine (UPy) modified
hydrogels.1,15 In contrast, anti-adhesion behavior
against these objects could be achieved by using a perfluorinated
polyether (PFPE) lubricating film (with CAs of less than 120° and SAs
below 10°).10 Unfortunately, it is a challenge to
convert lubricating molecules into materials or incorporate them onto
surfaces. The use of chemically modified
monolayers,16,17 slippery liquid-infused porous
surfaces (SLIPS),4,18 heating or UV-triggered polymer
matrices,19,20 have been reported to achieve this so
far, but these strategies plagued with the requirement of complex
processes and extra equipment that restrict their on-site application
onto structures with large surface areas.
Herein, we report a novel large-area and flat anti-adhesion coating with
a lubricating surface that can be formed spontaneously at room
temperature, thus it could be readily applied on-site via
industrially-viable spray-, dip-, or paint-coating techniques onto
various objects. The silicon-based and solvent-free precursor system
also offers various attractive features, such as low cost, environmental
friendliness, and biocompatibility, thus further enhancing the
applicability of these anti-adhesion coatings.