Periodic nanostructure induced on PEN surface by KrF laser irradiation

Abstract

There are several kinds of periodic surface structures, ranging from dots to ripples. The most common pattern is a ripple-like structure, where the direction of the ripples is parallel with the main polarisation of the laser beam. The distance between individual ripples (their period) depends on several factors, namely: the chemical structure of the polymer, wavelength of the laser irradiation and the angle of laser beam incidence. Oriented polyethylene naphthalate (PEN) foils with a thickness of 50 µm were used. The samples were irradiated with a KrF laser under laser beam incidence 0-45° to the laser beam. Selected polymer samples were also exposed by irradiation through a contact mask. Surface roughness and the dimensions of the ripple-like structures were measured by atomic force microscopy in tapping mode. The concentration of the elements on the surface was obtained from Angle Resolved X-ray Photoelectron Spectroscopy (ARXPS) spectra measured by X-ray Photoelectron Spectroscopy (XPS) spectrometer. The surface morphology and dimensions of prepared structures were evaluated and compared with those prepared on pristine samples without mask. The transition between the irradiated surface under the slits and the shielded surface in between the slits was evaluated. The optimal input parameters for nanopattern with high periodicity were determined. The shape and the surface roughness of the ripple pattern depend strongly on the angle of incidence of the laser beam. The surface roughness and ripple width increase with the angle of P. Slepička et al. laser beam incidence. Irradiation with laser leads to changes in chemical composition of the PEN surface layer. Even at initial phase of pattern formation a significant increase of carbonyl and carboxyl groups was detected.

Laterally-resolved mechanical and tribological properties of laser-structured polymer nanocomposites

“…A further approach to provide functionality to polymer materials consists in the surface patterning at the micro-and nanoscales [12,13]. As an alternative to lithographic methods, which need several step procedures and the use of clean-room facilities, high vacuum or complex mask fabrication, laser surface patterning techniques such as the formation of Laser Induced Periodic Surface Structures (LIPSS) have demonstrated to provide versatility and reliability, and constitute a potential method to obtain large processed surface areas in polymers [14][15][16][17][18][19]. During LIPSS formation, the polymer surface is heated and the temperature may overcome either the glass transition temperature ( ! )…”

Laser induced periodic surface structures formation by nanosecond laser irradiation of poly (ethylene terephthalate) reinforced with Expanded Graphite

“…Although lithographic methods are commonly used for generating polymer structures at the nanoscale [26][27][28] and aim at reproducibility and low cost, they require multiple-step procedures involving clean-room facilities, high vacuum or complex mask fabrication. As an alternative, laser surface patterning techniques such as the formation of Laser Induced Periodic Surface Structures (LIPSS) have demonstrated to provide versatility and reliability and constitute potential methods to obtain large processed surface areas in many types of materials [29][30][31][32], including polymers [33][34][35]. The formation of LIPSS in polymer surfaces has been observed by using lasers with pulse duration from nanosecond (ns) to femtosecond (fs), at wavelengths from the ultraviolet to the infrared [33,34,[36][37][38].…”

KrF Laser and Plasma Exposure of PDMS–Carbon Composite and Its Antibacterial Properties

“…One of the methods of modifying prepared carbon-polymeric substrates and creating a surface with new physical or chemical properties is laser modification. Laser techniques working with a specific frequency and wavelength can modify a wide spectrum of substrates [28,29]. By laser modification, various surface structures with different shapes or new forms of elements can be prepared, such as linear, globular, and web structures [30,31].…”