title: An X-ray and neutron reflectometry study of 'PEG-like' plasma polymer films.
abstract: Plasma-enhanced chemical vapour-deposited films of di(ethylene glycol) dimethyl ether were analysed by a combination of X-ray photoelectron spectroscopy, atomic force microscopy, quartz crystal microbalance with dissipation monitoring (QCM-D), X-ray and neutron reflectometry (NR). The combination of these techniques enabled a systematic study of the impact of plasma deposition conditions upon resulting film chemistry (empirical formula), mass densities, structure and water solvation, which has been correlated with the films' efficacy against protein fouling. All films were shown to contain substantially less hydrogen than the original monomer and absorb a vast amount of water, which correlated with their mass density profiles. A proportion of the plasma polymer hydrogen atoms were shown to be exchangeable, while QCM-D measurements were inaccurate in detecting associated water in lower power films that contained loosely bound material. The higher protein resistance of the films deposited at a low load power was attributed to its greater chemical and structural similarity to that of poly(ethylene glycol) graft surfaces. These studies demonstrate the utility of using X-ray and NR analysis techniques in furthering the understanding of the chemistry of these films and their interaction with water and proteins.
authors.affiliation: CSIRO Materials Science and Engineering, Clayton South, Victoria 3169,  Australia.
authors.forename: Donna J
authors.initials: DJ
authors.lastname: Menzies
authors.forename: Andrew
authors.initials: A
authors.lastname: Nelson
authors.forename: Hsin-Hui
authors.initials: HH
authors.lastname: Shen
authors.forename: Keith M
authors.initials: KM
authors.lastname: McLean
authors.forename: John S
authors.initials: JS
authors.lastname: Forsythe
authors.forename: Thomas
authors.initials: T
authors.lastname: Gengenbach
authors.forename: Celesta
authors.initials: C
authors.lastname: Fong
authors.forename: Benjamin W
authors.initials: BW
authors.lastname: Muir
mesh_terms: D005026:Ethylene Glycols / Q000737:chemistry*; D008422:Materials Testing / Q000379:methods*; D008567:Membranes, Artificial; D008738:Methyl Ethers / Q000737:chemistry*; D056951:Photoelectron Spectroscopy / Q000379:methods*; D011506:Proteins / Q000737:chemistry; D058525:Quartz Crystal Microbalance Techniques; D014867:Water
chemical_list: D005026:Ethylene Glycols; D008567:Membranes, Artificial; D008738:Methyl Ethers; D011506:Proteins; D014867:Water; C007391:diglyme