Tailoring the wetting properties of polymers from highly hydrophilic to superhydrophobic using UV laser pulses

Abstract

This paper demonstrates the application of ultrashort-pulsed lasers as a unique tool for controllable modification of the surface wettability of polymers from high hydrophilicity to superhydrophobicity. This is achieved by exploiting the effect of laser pulse duration and photon energy on the surface chemistry and morphology and subsequent wetting properties of polymeric surfaces treated with UV laser pulses. In three different pulse duration regimes, ranging from femtosecond to nanosecond and two different photon wavelengths, we have systematically altered the wettability of polyethersulfone surfaces from highly hydrophilic to superhydrophobic. Our results indicate that, despite the remarkable changes in the surface morphology attained, the surface wettability variations are dominantly caused by laser-induced chemical modifications, which are highly dependent on the pulse energy and duration. The ability of tuning the wetting properties and thus the surface energy of laser-treated polymer surfaces within a broad range makes them excellent candidates for liquid flow control in microfluidics and biological adhesion applications.

Nanosecond laser micro- and nanotexturing for the design of a superhydrophobic coating robust against long-term contact with water, cavitation, and abrasion

“…Most studies in the literature have been conducted using femtosecond single-pulse duration laser treatment. At the same time, there has been increasing interest in nanosecond laser systems as a tool for surface processing in recent years [21][22][23]. In this study, we have used an Argent-M laser system (Russia) with an IR ytterbium fiber laser (wavelength 1.064 μm), which provides a wide choice of laser parameters, and an MS10 2-axis laser beam deflection unit, RAYLASE (Germany).…”

Laser surface modification of polyethersulfone films: effect of laser wavelength on biocompatibility

“…CA minima indicated is associated with a change of thermochemical composition of the surface following KrF laser irradiation, particularly to the release of sulfonic and disulfonic acids of the type R SO 3 H (R = H, phenols) as well as carboxylic acids R CO 2 H (R = phenols, methyl, H): all are well known as surfactants and formed by the exposure of polyarylsulfones to UV light [23]. The presence of disulfonic acid is indicated by the ATR FTIR spectra of the respective samples [18]. Above the ablation the surface chemistry changes especially carbonization with ns laser pulses which are observed in Raman spectra of the irradiated and non-irradiated surface leads to decreasing the hydrophilicity [17,18].…”

“…The presence of disulfonic acid is indicated by the ATR FTIR spectra of the respective samples [18]. Above the ablation the surface chemistry changes especially carbonization with ns laser pulses which are observed in Raman spectra of the irradiated and non-irradiated surface leads to decreasing the hydrophilicity [17,18]. The functional groups induced on the surface by ArF laser irradiation were examined with ATR-FTIR spectroscopy [20].…”

Superhydrophobic laser ablated PTFE substrates

“…The ablation threshold can also be reduced. The morphology, and the scale of the roughness are influenced by a variety of parameters originating from the material properties, laser irradiation environment, and most importantly laser parameters such as laser pulse energy, scan speed and number of pulses [39].…”