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This study presents a source for studying thin‐film deposition utilizing vacuum UV (VUV) radiation from a remote argon or helium atmospheric plasma to initiate photochemistry in the precursor gas. We aim to assess how this radiation affects the deposition process and film structure while avoiding deposition inside the plasma source or particle formation. Deposition occurs where radiation interacts with the precursor and the growing film, as well as further downstream. The measured film properties clearly show that photon interaction with the film has a significant effect. Using hexamethyldisiloxane (HMDSO) as a precursor, we achieved nearly carbon‐free silicon dioxide (SiO2 ) film growth due to photodesorption of hydrocarbons from the growing film, as confirmed by infrared spectra and positive ion mass spectrometry. [ABSTRACT FROM AUTHOR]

Thermoplastic starch (TPS) films underwent casting and plasma coating with Hexamethyldisiloxane (HMDSO) gas at various self‐bias voltages. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) imaging revealed slight swelling and grain structures in untreated TPS films due to starch dissolution. However, the HMDSO plasma treatment had minimal impact, with swollen grains still present beneath a layer of small granules. Contact angle measurements demonstrated that untreated films had an initial water contact angle of 32°, gradually decreasing over time. Conversely, HMDSO‐coated films exhibited stable hydrophobic behavior, with contact angles exceeding 100°. Statistical analysis confirmed TPS films' lower average roughness, while modified films showed no significant difference in height parameters. Higher self‐bias voltages correlated with larger grain sizes. Notably, experimental treatments decreased long‐range spatial correlations, as indicated by Hurst's exponent. [ABSTRACT FROM AUTHOR]

In a high‐rise building, due to the risk of flame spread and strict regulations associated, wood use is limited for interior finishes. This study aimed to evaluate the effect of a thin organosilicon layer (∼500 nm) prepared by atmospheric pressure plasma on the fire behavior of a wood substrate. The coating was deposited from hexamethyldisiloxane in argon on both untreated wood and wood with a preparatory coating of primer. The primer reduces the presence of cracks in the plasma layer and ensures more homogenous coverage of the substrates. Finally, the flame retardancy analysis highlights an improvement in fire behavior only when the primer is used. Our study suggests that plasma thin deposition has a synergic effect with primer to fireproof wood. [ABSTRACT FROM AUTHOR]

One interesting category of nano‐ and micro‐engineered surfaces is surface gradients, which allow the controlled optimization of biointerfaces at a small scale in an extended area length. Plasma coatings offer a large diversity of functionalities at the nanoscale, accompanied by high chemical stability and adhesion on a variety of substrates at ambient temperature. Atmospheric‐pressure plasma‐assisted deposition could be employed for the generation of surface gradients on thermosensitive materials. In this study, a corona plasma jet is used to deposit polydimethylsiloxane/SiO2‐like surface gradients on polyethylene foil by varying the O2 concentration in the discharge during the movement of the plasma source. We obtained, in a single‐step approach, gradient coatings along a length of ∼10 cm, with a gradual variation of both chemistry and surface energy. [ABSTRACT FROM AUTHOR]

A plasma probe and measuring method were developed to simultaneously determine both the electron density, ne, and floating potential in plasma‐enhanced chemical vapor deposition (PECVD) coating processes within low‐pressure plasmas. The functionality of the probe with a high deposition rate is demonstrated on the basis of examples using hexamethyldisiloxane as a precursor gas. The results show that the developed probe can determine both the ne (∼1015 m−3) and the time‐varying floating potential. The results also indicate that the probe is effective for monitoring the changes in the plasma condition caused by the pressure and the gas flow rate during the coating process. This method can contribute to confirm the process and chamber conditions in PECVD processes. [ABSTRACT FROM AUTHOR]

The short residence time of Ar–HMDSO (Ar–hexamethyldisiloxane) gas mixtures rapidly flowing across atmospheric‐pressure, glow‐type, single‐filament dielectric barrier discharges is utilized to accomplish thin‐film deposition via a purely ionic route. A comparison of thin‐film volumes obtained from profilometry, on the one hand, and from the transferred charge, on the other hand, enables to evaluate the mass of the ions contributing to the film growth. For HMDSO fractions at the lower end of the studied range of molar fractions, 50 ppm, pentamethyldisiloxanyl cations (Me3SiOSiMe2+, PMDS+), generated from the monomer via Penning ionization by Ar(1s) species, are mainly responsible for film formation. For HMDSO fractions growing beyond 1,000 ppm, ionic oligomerization processes by reactions of PMDS+ with HMDSO molecules result in a 2.5‐fold increase of the average deposited ion mass. [ABSTRACT FROM AUTHOR]

Bilayer plasma polymer (PP) films were examined using a combination of X-ray and neutron reflectometery and X-ray photoelectron spectroscopy to gain an understanding of the interfacial structures that form between the films. Three different PP films were produced from the monomers hexamethyldisiloxane (HMDSO), di(ethylene glycol) dimethyl ether (DG), and allylamine (AA) at different load powers. These films were used as 'substrates' for the subsequent deposition of a deuterated DG (dDG) PP top film. The width of the interfacial region was found to be strongly dependent on the chemical and physical properties of the substrate film. These findings have relevance to the general use and application of plasma polymer films. [ABSTRACT FROM AUTHOR]

In the present work two thin films, fabricated by plasma-polymerization of hexamethyldisiloxane (HMDSO) monomer, were studied by a combination of electron (ESID) and photon (PSID) stimulated ion desorption techniques. The organic character of the polymer film is evidenced by the high contribution of C2H n+ species and the absence of high mass fragments in its ESID spectrum. On the other hand, the inorganic character is elucidated by the presence of high mass silicon ionic fragments. NEXAFS and PSID spectra also show clear differences between organic and inorganic films. The marked reduction of CH3+ species for PSID spectra of the organic-polymeric film is in accordance with ESID analysis and may be interpreted by a screening effect of its cross-linked organic structure. [ABSTRACT FROM AUTHOR]