  We consider a functional surface comprising thermoresponsive polymer chains,
the material that has found numerous technological and biomedical applications.
However, to achieve the required time and length scales for computer modelling
of such applications, one is compelled to use coarse-grained mesoscopic
modelling approaches. The model used here is based on the previous work
[Soto-Figueroa et al., Soft Matter, 8, 1871 (2012)], and it mimics the
principal feature of the poly(N-iso-propylacrylamide) (PNIPAM), namely, the
rapid change of its hydrophilicity at the lower critical solution temperature
(LCST). For the case of an isolated chain, we discuss scaling properties of the
radius of gyration, end-to-end distance, various distribution functions, and
the density profile of monomers below and above the LCST. For the case of the
model thermoresposive brush, we search for the optimum grafting density at
which the change in the brush height, upon crossing the LCST, reaches its
maximum value. The interpretation of the thermoresponse, in terms of the
Alexander-de Gennes blobs and the level of solvation of polymer chains in a
brush, is provided.
