Deposition of Plasma‐Polymerized Polyacrylic Acid Coatings by a Non‐Equilibrium Atmospheric Pressure Nanopulsed Plasma Jet

Abstract

Successful plasma-polymerization of acrylic acid (AA), aimed at depositing plasmapolymerized polyacrylic acid (pPAA) coatings stable upon water contact with a high amount of carboxyl groups, using a non-equilibrium atmospheric pressure nanopulsed plasma jet is reported. Special attention is devoted to the surface chemical characterization of the pPAA coatings deposited on pristine and plasma pretreated polymeric substrates. The investigation of the pPAA chemical structure is performed by means of attenuated total reflectance-Fourier transform infrared and X-ray photoelectron spectroscopies. Insights on the morphological characteristics of the coatings are also provided by optical microscopy.

Co‐Deposition of Plasma‐Polymerized Polyacrylic Acid and Silver Nanoparticles for the Production of Nanocomposite Coatings Using a Non‐Equilibrium Atmospheric Pressure Plasma Jet

“…[41,51] Despite some works have indicated that ATR-FTIR might provide information about the molecular environment of the organic molecules on the surface of AgNPs [52,53] and thus lead to an indirect detection of the Ag in the coating through a slight shift of characteristic peaks of the spectrum, [40] we could not observe any significant difference between AgNPs/pPAA and a typical pPPA coating, probably because the amount of Ag in our coating is below the sensitivity threshold of the technique. The XPS survey spectrum of the AgNPs/pPAA coating, reported in Figure 6, highlighted the presence of Ag, C, O, and N through their corresponding XPS peaks (C 1s , O 1s , N 1s , Ag 3d , and Ag (A)).…”

“…[41] This result can be probably attributed to the low value of duty cycle employed for the co-deposition process: in fact, as highlighted by Boscher et al [55] in their work on the deposition of plasma-polymerized poly(glycidyl methacrylate) by means of DBD driven by ultra-short square pulses, the increase of the duty cycle leads to functional groups destruction and to the formation of a larger distribution of chemical bonds; conversely, films deposited using lower duty cycle conditions were found to be identical in terms of chemical composition to the ones obtained for conventionally polymerized poly(glycidyl methacrylate). [55] High-resolution XPS spectra of the Ag 3d are reported in Figure 8 and indicate that the binding energies of the corresponding spin orbit splitting of Ag 3d5/2 and Ag 3d3/2 due to AgNPs are centered at 368.2 eV and 374.2 eV, respectively.…”

“…[ 41] Simultaneously, a second flow of 2.5 slpm of Ar was introduced in a nebulizer system containing the dispersion of AgNPs in EtOH and the so formed aerosol was injected into the plasma source through the secondary gas channel. The mass flow rate of AA injected through the primary channel and of the AgNPs nebulized dispersion injected through the secondary channel, determined by the monomer and colloid consumption inside the flasks as reported in previous works, [47,48] were of 0.05 ml/min and 2.3 ml/min, respectively.…”

“…The produced plasma is ejected from the source through an orifice with a diameter of 4 mm, as described elsewhere. [41] The plasma source was driven by a micropulsed generator producing high-voltage sinusoidal pulses having peak voltage (PV) of up to 40 kV, frequency (f) of 20-50 kHz, variable pulse duration, and fixed pulsed repetition frequency (PRF) of 100 Hz. During the plasma co-deposition process, PV, f and duty cycle were kept constant at 23.4 kV, 20 kHz, and 40%, respectively.…”

Deposition of polyacrylic acid films on PDMS substrate in dielectric barrier corona discharge at atmospheric pressure

“…Hence, the new technology of atmospheric pressure plasmas to deposit organic coatings has gained much attention due to their high growth rates, low cost, safe operation, and ease of integration for inline processing. Relatively few reports on plasma polymerization of acrylic acid at atmospheric pressure can be found in literature compared with those performed in vacuum . Further work is, therefore, needed to explore the new techniques and investigate the effect of plasma processing parameters on the characteristics of the deposited film.…”