How self-assembled organophosphonic acid monolayers on Ti0.5Al0.5N hard coatings affect the adsorption of polycarbonate melt

New details of assembling bioactive films from dispersions of amphiphilic molecules on titania surfaces

“…7 Zhang et al reported that ODPA immobilization on titania nanotubes not only avoids bacterial adherence but can also modulate the release of Sr and Zn when these are dopants of the nanotubes. 7 ODPA is irreversibly adsorbed on Ti 0.5 Al 0.5 N surfaces forming a non-release system, as reported by Theile-Rasche et al 21 In addition to characterization, useful tools for revealing the arrangement of DMOAP and ODPA layers on surfaces are contact angle measurements, atomic force microscopy, and Xray photoelectron spectroscopy. DMOAP and ODPA modify the wettability of the surface due to their long alkyl chains.…”

“…However, indications for adventitious carbon species like C*-O (at 286.6 eV) and carboxylates (at 288.7 eV) were still observed as well as a contribution of organic nitrogen at 285.9 eV. 21,55 The O1s signal presented two contributions with the peaks centred at 529.9 eV and 531.6 eV (Fig. 5c and d).…”

“…44 The O1s signal presented two contributions attributed to oxidic oxygen from the titanium dioxide centred at 529.9 eV and organic oxygen/hydroxyl groups at 531.6 eV. 21,55 The C1s signal presented four contributions, aliphatic carbon at 285.0 eV, and further contributions at 286.6 eV and 288.7 eV that are also attributed to adventitious carbon in a sorption layer. Finally, in view of the nitrogen species accompanied by an N1s signal with a binding energy of 400.1 eV, a minor contribution of moieties containing organic nitrogen at 285.9 eV (ref.…”

“…Films assembled on these substrates from clear ODPA formulations were used as reference for a well-ordered monolayer with their structure widely studied over the years on polar oxide surfaces like alumina, silica, or titanium aluminium alloys. 21,43,56 Theile-Rasche et al recently reported photoelectron spectroscopic peculiarities in C1s spectra of ODPA SAMs on Ti 0.5 Al 0.5 N hard coatings. Therefore, a more detailed approach for the XPS signal tting was pursued.…”

“…Besides the binding situation and area density of the functional groups of those molecules, quaternary ammonium for DMOAP and phosphonate for ODPA can be detected by XPS. 18,[20][21][22] For tailoring the physicochemical properties in aqueous environment, such as zeta potential and wettability of the layer systems formed by immobilized DMOAP and ODPA, details about the adsorption process are important to understand. To elucidate the effects of process parameters in forming bioactive layers, combining microscopic and spectroscopic studies with nanoscale sensitivity and a layer build-up on at and chemically well-dened substrates is innovative, as was shown for designing highly active antifouling layers 23 and antimicrobial lms, promoting protein adsorption, 24 and verifying the inuence of electrolytes on contact angle.…”