New Plasma Techniques for Polymer Surface Modification with Monotype Functional Groups

Abstract

The production of chemically‐defined plasma polymers and the introduction of monotype functional groups onto polymer surfaces are described. One method is to lower the energetic level of low‐pressure plasmas. Pressure‐ and plasma‐pulsed plasmas were successfully tested for the production of chemically‐defined plasma polymers by increasing the monomer supply during the plasma‐off period. Well‐defined ultra‐thin polymer films with regular structure were deposited from atmospheric plasmas by electrospray techniques. Post‐plasma wet‐chemical processing was also applied, as were gas/liquid‐based aerosols and underwater plasmas.magnified image

Structure of Plasma Poly(Acrylic Acid): Influence of Pressure and Dielectric Properties

“…At high pressure, the reigniting of plasma is more complicated and needs a much higher power input leading to additional thermal effects and therefore, to additional monomer fragmentation. Nevertheless, these plasma pulses generally introduce irregularities into the polymer layer and produce byproducts in the case of the simple pulsed mode, as well as in the case of the pressure [27]. On another hand, the interaction of the surface of substrates or even the polymer layer which deposited at the beginning and the growing layers play an important role for the deposition rate and it could be summarized as the following: as the pressure increases, ion flux and ion energy generally decrease which would lead to lower generation of surface radicals and therefore, less deposition.…”

Haloform plasma modification of polyolefin surfaces

“…The fraction of electrons with the maximal level of electron energy ("high-energy tail" of the electron energy distribution function, ca. N10 eV [4]), exceeds strongly the dissociation energies of C-C and C-H bonds (≈ 3 eV) in polymers [1].…”

“…This lowpressure process is the only known way for introduction of monosort functional groups onto polyolefin surfaces and was found 20 years ago [3,4]. Later on the bromination process was investigated in more detail [5].…”

Selective Surface Modification of Polypropylene using Underwater Plasma Technique or Underwater Capillary Discharge

“…Novel approaches to generate more homogenous and mono-functional surfaces are attracting general attention. Various interesting approaches to generate mono-functional polymer surface or to modify polymer surfaces by direct functionalization, cross-linked layer formation, and to graft or deposit mono-functional layer on the required substrate were recently studied by Friedrich et al [1][2][3] Underwater plasma is one of the techniques, which carries attention and novelty due to its ability to generate very selective hydroxyl functionalized polymer surface. Especially, liquid-plasma process with a high selectivity and high plasma-solution activity can be Among new types of plasma processes, the underwater plasma is one of the most attractive methods for functionalization of polymer surfaces.…”