Evaluation of Processing Effects on Polystyrene/Clay Nanocomposites Using an Excimer Laser

2007 ◽  
Author(s):  
I-Ta Chang ◽  
Erol Sancaktar
Keyword(s):  
Laser Ablation ◽  
Mass Loss ◽  
Excimer Laser ◽  
Clay Nanocomposites ◽  
Evaluation Tool ◽  
Clay Particles ◽  
Reinforced Polymer ◽  
Excimer Laser Irradiation ◽  
Injection Molded ◽  
Krf Excimer Laser

Polystyrene (PS)-Organically modified montmorillonite (OMMT) nanocomposites processed by injection molding were investigated for the effects of different OMMT concentration and melt-blending conditions using a KrF excimer laser operating at 248 nm wavelength. Results indicate that PS-OMMT nanocomposites show improved resistance to excimer laser irradiation, as revealed by reduced mass loss due to laser ablation at their surfaces, when the OMMT concentration is below 2 wt%. Further increases in OMMT wt%, above the 2 wt% value, resulted in increased mass loss due to laser ablation, when compared with ablation of the neat PS material. Our experimental results also revealed that the dispersion (exfoliation) state of OMMT plays an important role in excimer laser ablation behavior of PS-OMMT nanocomposites. This result indicates the possibility for using the excimer laser as an evaluation tool in assessing the degree of exfoliation in clay reinforced polymer nanocomposites, including the assessment of spatial distribution of clay particles in injection molded nanocomposite articles, as illustrated in this work.

Surface Modification of Polymer-Clay Nanocomposites by Excimer Laser Ablation

2011 ◽  
Author(s):  
I-Ta Chang ◽  
Erol Sancaktar
Keyword(s):  
Structure Formation ◽  
Excimer Laser ◽  
Surface Structures ◽  
Clay Nanocomposites ◽  
Nano Structure ◽  
Clay Nanoparticles ◽  
Dispersion State ◽  
Molded Parts ◽  
Injection Molded ◽  
Krf Excimer Laser

This paper investigates the effects of nanoclay (Organically Modified Montmorillonite -OMMT) dispersion state and morphology of nanocomposites on laser induced surface micro/nano structure formation and modification of Polystyrene-Clay Nanocomposites at various OMMT concentrations. Injection molded sample surfaces were irradiated by a 248 nm KrF excimer laser in air. Scanning electron microscopy, atomic force microscopy and Fourier Transform Infrared (FTIR) spectroscopy with attenuated total reflectance accessory were utilized to analyze the ablated surface. Results show that, in general, better dispersion of OMMT leads to less continuous surface structures and more pronounced carbonyl regions on FTIR spectra. Clay nanoparticles are exposed on ablated surfaces and affect surface structure formation after irradiation by laser. A mechanism for the formation of excimer laser induced surface structures on injection molded parts is thus proposed.

Surface Composition Changes and Ablation Dynamics in Excimer Laser Irradiated CdTe

1990 ◽  
Vol 191 ◽  
Author(s):  
P. D. Brewer ◽  
J. J. Zinck ◽  
G. L. Olson
Keyword(s):  
Laser Ablation ◽  
Excimer Laser ◽  
Surface Composition ◽  
Laser Ablation Process ◽  
Flight Mass Spectrometry ◽  
Rich Condition ◽  
Thermal Mechanism ◽  
Krf Excimer Laser ◽  
Composition Changes ◽  
Cdte Surface

ABSTRACTWe have investigated the dynamics of KrF excimer laser ablation of CdTe and the fluence dependent changes in surface stoichiometry that accompany the laser ablation process. The composition of the CdTe surface was reversibly controlled between stoichiometric and a Te-rich condition by varying the laser fluence over the range from 15–65 mJ/cm2. The primary species ejected from the irradiated surface were Cd atoms and Te2 molecules. Their velocity distributions as measured by time-of-flight mass spectrometry were found to be Maxwellian. From the analysis of the velocity distributions, the preferential desorption of surface atoms, and the reversible nature of the process, we conclude that the desorption is due to a photo-thermal mechanism which mediates the competition between Te2 formation and desorption and the desorption of Cd atoms.

scholarly journals Formation of Varistor Layer at the Surface of SrTiO3-Based Ceramics by KrF Excimer Laser Irradiation.

1999 ◽  
Vol 107 (1252) ◽  
pp. 1229-1231 ◽  
Author(s):  
Jong-Won YOON ◽  
Katsuki HIGAKI ◽  
Masaru MIYAYAMA ◽  
Tetsuichi KUDO
Keyword(s):  
Laser Irradiation ◽  
Excimer Laser ◽  
Excimer Laser Irradiation ◽  
Krf Excimer Laser

Improvement of resistance to corrosion of stainless steel 304 in acid solutions by simultaneous deposition with doping of Si using KrF excimer laser

1990 ◽  
Vol 5 (12) ◽  
pp. 2835-2840 ◽  
Author(s):  
Koji Sugioka ◽  
Hideo Tashiro ◽  
Koichi Toyoda ◽  
Hideyuki Murakami ◽  
Hiroshi Takai
Keyword(s):  
Stainless Steel ◽  
Laser Irradiation ◽  
Excimer Laser ◽  
Polarization Resistance ◽  
Cathodic Polarization ◽  
Acid Solutions ◽  
Stainless Steel 304 ◽  
Quantitative Verification ◽  
Excimer Laser Irradiation ◽  
Krf Excimer Laser

The chemical stability of the surface of stainless steel (SUS) 304 in acid immersion tests is greatly improved by the laser implant-deposition (LID) process, i.e., the simultaneous deposition and incorporation of silicon by KrF excimer laser irradiation. The etching depths of the treated samples in 1.32 N HCl solution are substantially zero at the laser irradiation conditions of more than 40 pulses and of more than 400 mJ/cm2 at the surface. By the quantitative verification of cathodic polarization in 1 N H2SO4, the highest polarization resistance is estimated to be 26.7 times that of the nontreated sample.

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