Swollen polymer brushes are found in various applications including biomedical coatings where the brush provides stability against harsh environmental conditions and mediates interactions with the surroundings. The surface height fluctuations of planar polystyrene brushes (0.04–0.61 chains/nm2) highly swollen in toluene vapor are so strongly slowed by the tethering of the chains that they are unobservable in the current experimental window of length and time. This is the case despite the fact that the segmental dynamics of the brush chains should be very fast due to the substantial plasticization by the solvent. With respect to thermally stimulated fluctuations, the surfaces of these swollen brushes are solidlike on time scales and length scales pertinent to many practical applications.

The scaling of the thickness, hs, of a densely grafted polymer brush of chain length N and grafting density σ swollen in vapor agrees quantitatively with the scaling reported by Kuhl et al. for densely grafted brushes swollen in liquid. Deep in the brush, next to the substrate, the shape of the segment concentration profile is the same whether the brush is swollen by liquid or by vapor. Differences in the segment concentration profile are manifested primarily in the swollen brush interface with the surrounding fluid. The interface of the polymer brush swollen in vapor is much more abrupt than that of the same brush swollen in liquid. This has implications for the compressibility of the swollen brush surface and for fluctuations at that surface.

•Mesoscale adhesion maps correlate to macroscopic performance in latex films.•Three fluorosurfactant chain lengths were investigated.•Interplay among latex, fluorosurfactant, and cross-linker determines performance.The performances of three fluorosurfactants of different perfluoroalkyl chain lengths in styrene-butadiene (SB) and styrene-acrylic (SA) latex formulations having different virtual cross-linkers were investigated with atomic force microscopy (AFM). Topographic mapping provided no conclusive relationship with macroscopic observations of floor polish performance (with “performance” being judged by absence of haze and uniformity of flow and leveling.) Adhesion mapping of the film surfaces revealed mesoscale lateral phase separation for the zinc cross-linked SB latex formulations with specific fluorosurfactants, but not for the SA latex formulations with either calcium or zinc cross-linking. FT-IR spectroscopy analysis supports the contention that lateral phase separation occurred due to the formation of a complex between the fluorosurfactant and the zinc cross-linking agent when used in the SB formulations. All three fluorosurfactants successfully flowed and leveled the SA formulation, using either calcium or zinc cross-linking, without the formation of a complex. These experiments present high resolution adhesion maps of latex films that link mesoscopic properties to macroscopic performance of the dried floor polish films.

A hydrodynamic continuum theory (HCT) of thermally stimulated capillary waves describing surface fluctuations of linear polystyrene melts is found to describe surface fluctuations of sufficiently thick films of unentangled cyclic polystyrene. However, for cyclic polystyrene (CPS) films thinner than 10Rg, the surface fluctuations are slower than expected from the HCT universal scaling, revealing a confinement effect active over length scales much larger than Rg. Surface fluctuations of CPS films can be slower than those of films of linear polystyrene analogues, due to differences between the glass transition temperatures, Tg, of the linear and cyclic chains. The temperature dependences of the surface fluctuations match those of bulk viscosities, suggesting that whole chain dynamics dictate the surface height fluctuation dynamics at temperatures 25–60 °C above Tg. When normalized surface relaxation rates of thicker films are plotted as a function of T/Tg, a universal temperature behavior is observed for linear and cyclic chains.

•Mesoscale adhesion maps correlate to macroscopic performance in latex films.•Three fluorosurfactant chain lengths were investigated.•Interplay among latex, fluorosurfactant, and cross-linker determines performance.The performances of three fluorosurfactants of different perfluoroalkyl chain lengths in styrene-butadiene (SB) and styrene-acrylic (SA) latex formulations having different virtual cross-linkers were investigated with atomic force microscopy (AFM). Topographic mapping provided no conclusive relationship with macroscopic observations of floor polish performance (with “performance” being judged by absence of haze and uniformity of flow and leveling.) Adhesion mapping of the film surfaces revealed mesoscale lateral phase separation for the zinc cross-linked SB latex formulations with specific fluorosurfactants, but not for the SA latex formulations with either calcium or zinc cross-linking. FT-IR spectroscopy analysis supports the contention that lateral phase separation occurred due to the formation of a complex between the fluorosurfactant and the zinc cross-linking agent when used in the SB formulations. All three fluorosurfactants successfully flowed and leveled the SA formulation, using either calcium or zinc cross-linking, without the formation of a complex. These experiments present high resolution adhesion maps of latex films that link mesoscopic properties to macroscopic performance of the dried floor polish films.