Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Surface Wettability Modification of Cyclic Olefin Polymer by Direct Femtosecond Laser Irradiation.

ABSTRACT: The effect of laser irradiation on surface wettability of cyclic olefin polymer (COP) was investigated. Under different laser parameters, a superhydrophilic or a superhydrophobic COP surface with a water contact angle (WCA) of almost 0° or 163°, respectively, could be achieved by direct femtosecond laser irradiation. The laser power deposition rate (PDR) was found to be a key factor on the wettability of the laser-treated COP surface. The surface roughness and surface chemistry of the laser-irradiated samples were characterized by surface profilometer and X-ray photoelectron spectroscopy, respectively; they were found to be responsible for the changes of the laser-induced surface wettability. The mechanisms involved in the laser surface wettability modification process were discussed.

SUBMITTER: Wang B

PROVIDER: S-EPMC5304633 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Surface Wettability Modification of Cyclic Olefin Polymer by Direct Femtosecond Laser Irradiation.

Wang Bing B Wang Xincai X Zheng Hongyu H Lam Yee Cheong YC

Nanomaterials (Basel, Switzerland) 20150828 3

The effect of laser irradiation on surface wettability of cyclic olefin polymer (COP) was investigated. Under different laser parameters, a superhydrophilic or a superhydrophobic COP surface with a water contact angle (WCA) of almost 0° or 163°, respectively, could be achieved by direct femtosecond laser irradiation. The laser power deposition rate (PDR) was found to be a key factor on the wettability of the laser-treated COP surface. The surface roughness and surface chemistry of the laser-irra ...[more]

PMID: 28347074

Similar Datasets

Biomimetic surface structures in steel fabricated with femtosecond laser pulses: influence of laser rescanning on morphology and wettability.

Project description:The replication of complex structures found in nature represents an enormous challenge even for advanced fabrication techniques, such as laser processing. For certain applications, not only the surface topography needs to be mimicked, but often also a specific function of the structure. An alternative approach to laser direct writing of complex structures is the generation of laser-induced periodic surface structures (LIPSS), which is based on directed self-organization of the material and allows fabrication of specific micro- and nanostructures over extended areas. In this work, we exploit this approach to fabricate complex biomimetic structures on the surface of steel 1.7131 formed upon irradiation with high repetition rate femtosecond laser pulses. In particular, the fabricated structures show similarities to the skin of certain reptiles and integument of insects. Different irradiation parameters are investigated to produce the desired structures, including laser repetition rate and laser fluence, paying special attention to the influence of the number of times the same area is rescanned with the laser. The latter parameter is identified to be crucial for controlling the morphology and size of specific structures. As an example for the functionality of the structures, we have chosen the surface wettability and studied its dependence on the laser processing parameters. Contact angle measurements of water drops placed on the surface reveal that a wide range of angles can be accessed by selecting the appropriate irradiation parameters, highlighting also here the prominent role of the number of scans.

| S-EPMC6244216 | biostudies-literature

Fast targeted gene transfection and optogenetic modification of single neurons using femtosecond laser irradiation.

Project description:A prevailing problem in neuroscience is the fast and targeted delivery of DNA into selected neurons. The development of an appropriate methodology would enable the transfection of multiple genes into the same cell or different genes into different neighboring cells as well as rapid cell selective functionalization of neurons. Here, we show that optimized femtosecond optical transfection fulfills these requirements. We also demonstrate successful optical transfection of channelrhodopsin-2 in single selected neurons. We extend the functionality of this technique for wider uptake by neuroscientists by using fast three-dimensional laser beam steering enabling an image-guided "point-and-transfect" user-friendly transfection of selected cells. A sub-second transfection timescale per cell makes this method more rapid by at least two orders of magnitude when compared to alternative single-cell transfection techniques. This novel technology provides the ability to carry out large-scale cell selective genetic studies on neuronal ensembles and perform rapid genetic programming of neural circuits.

| S-EPMC3836031 | biostudies-literature

Modification of Graphene Oxide/V2O5·nH2O Nanocomposite Films via Direct Laser Irradiation.

Project description:Herein, photothermal modification of nanocomposite films consisting of hydrated vanadium pentoxide (V2O5·nH2O) nanoribbons wrapped with graphene oxide (GO) flakes was performed via 405 nm direct laser irradiation. The combination of X-ray diffraction, X-ray photoelectron spectroscopy, Raman scattering, transmission electron microscopy, and scanning electron microscopy allowed comprehensive characterization of physical and chemical changes of GO/V2O5·nH2O nanocomposite films upon photothermal modification. The modified nanocomposite films exhibited porous surface morphology (17.27 m2 g-1) consisting of randomly distributed pillarlike protrusions. The photothermal modification process of GO/V2O5·nH2O enhanced the electrical conductivity of nanocomposite from 1.6 to 6.8 S/m. It was also determined that the direct laser irradiation of GO/V2O5·nH2O resulted in considerable decrease of C-O bounds as well as O-H functional groups with an increase of the laser power density.

| S-EPMC7467550 | biostudies-literature

Femtosecond-laser-irradiation-induced structural organization and crystallinity of Bi2WO6.

Project description:Controlling the structural organization and crystallinity of functional oxides is key to enhancing their performance in technological applications. In this work, we report a strong enhancement of the structural organization and crystallinity of Bi2WO6 samples synthetized by a microwave-assisted hydrothermal method after exposing them to femtosecond laser irradiation. X-ray diffraction, UV-vis and Raman spectroscopies, photoluminescence emissions, energy dispersive spectroscopy, field emission scanning electron microscopy, and transmission electron microscopy were employed to characterize the as-synthetized samples. To complement and rationalize the experimental results, first-principles calculations were employed to study the effects of femtosecond laser irradiation. Structural and electronic effects induced by femtosecond laser irradiation enhance the long-range crystallinity while decreasing the free carrier density, as it takes place in the amorphous and liquid states. These effects can be considered a clear cut case of surface-enhanced Raman scattering.

| S-EPMC7067817 | biostudies-literature

Controllable Plasmonic Nanostructures induced by Dual-wavelength Femtosecond Laser Irradiation.

Project description:We demonstrated an abnormal double-peak (annular shaped) energy deposition through dual-wavelength synthesis of the fundamental frequency (?) and the second-harmonic frequency (2?) of a femtosecond (fs) Ti:sapphire laser. The annular shaped distribution of the dual-wavelength fs laser was confirmed through real beam shape detection. This uniquely simple and flexible technique enables the formation of functional plasmonic nanostructures. We applied this double-peak fs-laser-induced dewetting effect to the controlled fabrication and precise deposition of Au nanostructures, by using a simple, lithography-free, and single-step process. In this process, the double-peak energy-shaped fs laser pulse induces surface patterning of a thin film followed by nanoscale hydrodynamic instability, which is highly controllable under specific irradiation conditions. Nanostructure morphology (shape, size, and distribution) modulation can be achieved by adjusting the laser irradiation parameters, and the subsequent ion-beam polishing enables further dimensional reduction and removal of the surrounding film. The unique optical properties of the resulting nanostructure are highly sensitive to the shape and size of the nanostructure. In contrast to a nanoparticle, the resonance-scattering spectrum of an Au nanobump exhibites two resonance peaks. These suggest that the dual-wavelength fs laser-based dewetting of thin films can be an effective means for the scalable manufacturing of patterned-functional nanostructures.

| S-EPMC5725531 | biostudies-literature

Direct Femtosecond Laser Surface Structuring with Optical Vortex Beams Generated by a q-plate.

Project description:Creation of patterns and structures on surfaces at the micro- and nano-scale is a field of growing interest. Direct femtosecond laser surface structuring with a Gaussian-like beam intensity profile has already distinguished itself as a versatile method to fabricate surface structures on metals and semiconductors. Here we present an approach for direct femtosecond laser surface structuring based on optical vortex beams with different spatial distributions of the state of polarization, which are easily generated by means of a q-plate. The different states of an optical vortex beam carrying an orbital angular momentum ℓ = ±1 are used to demonstrate the fabrication of various regular surface patterns on silicon. The spatial features of the regular rippled and grooved surface structures are correlated with the state of polarization of the optical vortex beam. Moreover, scattered surface wave theory approach is used to rationalize the dependence of the surface structures on the local state of the laser beam characteristics (polarization and fluence). The present approach can be further extended to fabricate even more complex and unconventional surface structures by exploiting the possibilities offered by femtosecond optical vector fields.

| S-EPMC4674747 | biostudies-other

The fragmentation mechanism of gold nanoparticles in water under femtosecond laser irradiation.

Project description:Plasmonic nanoparticles in aqueous solution have long been known to fragment under irradiation with intense ultrafast laser pulses, creating progeny particles with diameters of a few nanometers. However, the mechanism of this process is still intensely debated, despite numerous experimental and theoretical studies. Here, we use in situ electron microscopy to directly observe the femtosecond laser-induced fragmentation of gold nanoparticles in water, revealing that the process occurs through ejection of individual progeny particles. Our observations suggest that the fragmentation mechanism involves Coulomb fission, which occurs as the femtosecond laser pulses ionize and melt the gold nanoparticle, causing it to eject a highly charged progeny droplet. Subsequent Coulomb fission events, accompanied by solution-mediated etching and growth processes, create complex fragmentation patterns that rapidly fluctuate under prolonged irradiation. Our study highlights the complexity of the interaction of plasmonic nanoparticles with ultrafast laser pulses and underlines the need for in situ observations to unravel the mechanisms of related phenomena.

| S-EPMC8439145 | biostudies-literature

Biomimetic surface structuring using cylindrical vector femtosecond laser beams.

Project description:We report on a new, single-step and scalable method to fabricate highly ordered, multi-directional and complex surface structures that mimic the unique morphological features of certain species found in nature. Biomimetic surface structuring was realized by exploiting the unique and versatile angular profile and the electric field symmetry of cylindrical vector (CV) femtosecond (fs) laser beams. It is shown that, highly controllable, periodic structures exhibiting sizes at nano-, micro- and dual- micro/nano scales can be directly written on Ni upon line and large area scanning with radial and azimuthal polarization beams. Depending on the irradiation conditions, new complex multi-directional nanostructures, inspired by the Shark's skin morphology, as well as superhydrophobic dual-scale structures mimicking the Lotus' leaf water repellent properties can be attained. It is concluded that the versatility and features variations of structures formed is by far superior to those obtained via laser processing with linearly polarized beams. More important, by exploiting the capabilities offered by fs CV fields, the present technique can be further extended to fabricate even more complex and unconventional structures. We believe that our approach provides a new concept in laser materials processing, which can be further exploited for expanding the breadth and novelty of applications.

| S-EPMC5361190 | biostudies-literature

Crystallization of Ge2Sb2Te5 thin films by nano- and femtosecond single laser pulse irradiation.

Project description:The amorphous to crystalline phase transformation of Ge2Sb2Te5 (GST) films by UV nanosecond (ns) and femtosecond (fs) single laser pulse irradiation at the same wavelength is compared. Detailed structural information about the phase transformation is collected by x-ray diffraction and high resolution transmission electron microscopy (TEM). The threshold fluences to induce crystallization are determined for both pulse lengths. A large difference between ns and fs pulse irradiation was found regarding the grain size distribution and morphology of the crystallized films. For fs single pulse irradiated GST thin films, columnar grains with a diameter of 20 to 60?nm were obtained as evidenced by cross-sectional TEM analysis. The local atomic arrangement was investigated by high-resolution Cs-corrected scanning TEM. Neither tetrahedral nor off-octahedral positions of Ge-atoms could be observed in the largely defect-free grains. A high optical reflectivity contrast (~25%) between amorphous and completely crystallized GST films was achieved by fs laser irradiation induced at fluences between 13 and 16?mJ/cm(2) and by ns laser irradiation induced at fluences between 67 and 130?mJ/cm(2). Finally, the fluence dependent increase of the reflectivity is discussed in terms of each photon involved into the crystallization process for ns and fs pulses, respectively.

| S-EPMC4904278 | biostudies-literature

Structural relaxation phenomena in silicate glasses modified by irradiation with femtosecond laser pulses.

Project description:Structural relaxation phenomena in binary and multicomponent lithium silicate glasses were studied upon irradiation with femtosecond (fs) laser pulses (800 nm central wavelength, 130 fs pulse duration) and subsequent thermal annealing experiments. Depending on the annealing temperature, micro-Raman spectroscopy analyses evidenced different relaxation behaviours, associated to bridging and non-bridging oxygen structures present in the glass network. The results indicate that the mobility of lithium ions is an important factor during the glass modification with fs-laser pulses. Quantitative phase contrast imaging (spatial light interference microscopy) revealed that these fs-laser induced structural modifications are closely related to local changes in the refractive index of the material. The results establish a promising strategy for tailoring fs-laser sensitivity of glasses through structural mobility.

| S-EPMC5339791 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data