Brushes of polyethylene glycol (PEG) were directly anchored onto bare gold substrates in solution. The nucleation kinetics of PEG binding were investigated successively in solution and dry air using atomic force microscopy (AFM) imaging. In addition, force spectroscopy mapping was used to measure the local mechanical response of selected PEG brushes. From these measurements, the morphology and elastic deformation of PEG of various molecular weights were determined by applying mechanical models to characterize the tensile and compressive responses of the PEG brushes. A constitutive description of the mechanical properties of PEG brushes was achieved through a combinatorial analysis of the statistical response of the PEG in tension and compression. Such a statistical characterization provides a straightforward procedure to distinctly identify the nanoscale assembly and mechanical response of PEG brushes of different molecular weights.
Citation: Journal of Physical Chemistry B
Pub Type: Journals
polyethylene glycol, nanoscale mechanics, atomic force microscopy