Exploiting Reactor Geometry to Manipulate the Properties of Plasma Polymerized Acrylic Acid Films

Abstract

A number of different reactor geometries can be used to deposit plasma polymer films containing specific functional groups and result in films with differing properties. Plasma polymerization was carried out in a low-pressure custom-built stainless steel T-shaped reactor using a radio frequency generator. The internal aluminium disk electrode was positioned in two different geometries: parallel and perpendicular to the samples at varying distances to demonstrate the effect of varying the electrode position and distance from the electrode on the properties of plasma polymerized acrylic acid (ppAAc) films. The surface chemistry and film thickness before and after aqueous immersion were analysed via X-ray photoelectron spectroscopy and spectroscopic ellipsometry, respectively. For a perpendicular electrode, the ppAAc film thicknesses and aqueous stability decreased while the COOH/R group concentrations increased as the distance from the electrode increased due to decreased fragmentation. For films deposited at similar distances from the electrode, those deposited with the parallel electrode were thicker, had lower COOH/R group concentrations and greater aqueous stability. These results demonstrate the necessity of having a well characterized plasma reactor to enable the deposition of films with specific properties and how reactor geometry can be exploited to tailor film properties.

Porous Carbon Substrate Improving the Sensing Performance of Copper Nanoparticles Toward Glucose

“…For the C1s spectrum of the two samples in Fig. 3d, three signals located at 289 eV, 286 eV and 284.8 eV correspond to the C=O, C-O, C-C/C-H, respectively, indicating the existence of oxygen-containing functional groups such as carboxyl group [42,43] and in consistent with the results from FTIR.…”

Design and characterization of a plasma chamber for improved radial and axial film uniformity

“…Higher electron flux likely results in greater monomer fragmentation, which produces higher deposition rates and greater film cross linking. [42] As the 0° samples deposited at 20 W and 80 mm from the electrode still showed a decrease in film thickness after water immersion, it can be suggested that an electron flux of ≥ 80 A/m 2 is required to produce stable ppAAc films. Such behavior indicates that O/C ratios lower than 0.4 are required for film stability not to be significantly compromised.…”

“…For distances from the electrode of 30 -80 mm and shorter probe travel distances, the electron flux decreases indicates reduced electron collisions further from the electrode, which has previously been reported in our research. [24,42] The decrease in the electron flux as the probe travels closer to the electrode at 15 mm is due to the probe travelling through the plasma sheath region, which is deficient of energetic electrons. [22] This article is protected by copyright.…”

Structure of plasma‐deposited copolymer films prepared from acrylic acid and styrene: Part III sulfonation and electrochemical properties

“…[19] The effects of plasma deposition on membrane surfaces can be controlled by variation of parameters such as treatment time, duty cycle, power of the plasma source (wattage), type of gas, flow rate, and others. [20][21][22][23][24][25][26] It is well known that plasma polymerization is an environmentally friendly process and is considered one of the most promising technologies for preparing thin films with functional groups and desirable properties. [27,28] These films are rigid.…”