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Preparation of periodic surface structures on doped poly(methyl metacrylate) films by irradiation with KrF excimer laser.

Kalachyova Y, Lyutakov O, Slepicka P, Elashnikov R, Svorcik V - Nanoscale Res Lett (2014)

Bottom Line: The mechanism of surface ordered structure formation is attributed to polymer ablation, which is more pronounced in the place of higher light intensity.The smoothness of the underlying substrate plays a key role in the quality of surface ordered structure.Most regular grating structures were obtained on polymer films deposited on atomically 'flat' Si substrates.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Solid State Engineering, Institute of Chemical Technology, Prague 166 28, Czech Republic.

ABSTRACT
In this work, we describe laser modification of poly(methyl methacrylate) films doped with Fast Red ITR, followed by dopant exclusion from the bulk polymer. By this procedure, the polymer can be modified under extremely mild conditions. Creation of surface ordered structure was observed already after application of 15 pulses and 12 mJ cm(-2) fluence. Formation of grating begins in the hottest places and tends to form concentric semi-circles around them. The mechanism of surface ordered structure formation is attributed to polymer ablation, which is more pronounced in the place of higher light intensity. The smoothness of the underlying substrate plays a key role in the quality of surface ordered structure. Most regular grating structures were obtained on polymer films deposited on atomically 'flat' Si substrates. After laser patterning, the dopant was removed from the polymer by soaking the film in methanol.

No MeSH data available.


Related in: MedlinePlus

Absorption spectra of the PMMA-FR films. Non-irradiated, after irradiation, and after different times (1 to 130 min) of FR extraction in methanol.
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Figure 10: Absorption spectra of the PMMA-FR films. Non-irradiated, after irradiation, and after different times (1 to 130 min) of FR extraction in methanol.

Mentions: Ablation of weakly absorbing polymers can be initiated either by application of high laser energy or by addition of dopant as in our case. However, the presence of dopant can significantly change the properties of a polymer. Doped polymers often exhibit worse thermal and mechanical properties. The tendency of dopants to aggregate and out-diffuse from polymer matrix causes significant decrease of material long-term stability and eliminate practical application of doped polymers [46,47]. For that reason, the FR dopant was removed from the polymer by soaking the polymer in methanol after laser modification. FR is well soluble but PMMA is completely insoluble in methanol. The presence of FR was estimated from UV-vis absorption measurement. Figure 10 gives the optical spectra of the PMMA-FR thin films measured after deposition, laser patterning, and at different times of FR soaking in methanol. Typical FR peaks at 230 to 300 nm indicates its residual amount after extraction. As can be expected, FR diffuses through the polymer matrix, and after 300 min of film soaking, ‘FR-free’ polymer film was obtained.Figure 11 gives the optical images of pristine, laser-modified, and FR-free PMMA films. The diffraction pattern is well visible after laser modification. After methanol soaking, light diffraction becomes less noticeable. However, polymer films remain optically active. Finally, Figure 12 represents the AFM images of the surface pattern of the previous case. The best light diffraction noticeable in the case of patterned PMMA-FR film is clearly visible and the surface structure is close to the ideal one. After soaking in methanol, the regularity of the prepared gratings decreases. The surface pattern is not as good as that in the previous case. On the other hand, the grating structure remains well visible in both optical and surface morphology measurements.


Preparation of periodic surface structures on doped poly(methyl metacrylate) films by irradiation with KrF excimer laser.

Kalachyova Y, Lyutakov O, Slepicka P, Elashnikov R, Svorcik V - Nanoscale Res Lett (2014)

Absorption spectra of the PMMA-FR films. Non-irradiated, after irradiation, and after different times (1 to 130 min) of FR extraction in methanol.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4215891&req=5

Figure 10: Absorption spectra of the PMMA-FR films. Non-irradiated, after irradiation, and after different times (1 to 130 min) of FR extraction in methanol.
Mentions: Ablation of weakly absorbing polymers can be initiated either by application of high laser energy or by addition of dopant as in our case. However, the presence of dopant can significantly change the properties of a polymer. Doped polymers often exhibit worse thermal and mechanical properties. The tendency of dopants to aggregate and out-diffuse from polymer matrix causes significant decrease of material long-term stability and eliminate practical application of doped polymers [46,47]. For that reason, the FR dopant was removed from the polymer by soaking the polymer in methanol after laser modification. FR is well soluble but PMMA is completely insoluble in methanol. The presence of FR was estimated from UV-vis absorption measurement. Figure 10 gives the optical spectra of the PMMA-FR thin films measured after deposition, laser patterning, and at different times of FR soaking in methanol. Typical FR peaks at 230 to 300 nm indicates its residual amount after extraction. As can be expected, FR diffuses through the polymer matrix, and after 300 min of film soaking, ‘FR-free’ polymer film was obtained.Figure 11 gives the optical images of pristine, laser-modified, and FR-free PMMA films. The diffraction pattern is well visible after laser modification. After methanol soaking, light diffraction becomes less noticeable. However, polymer films remain optically active. Finally, Figure 12 represents the AFM images of the surface pattern of the previous case. The best light diffraction noticeable in the case of patterned PMMA-FR film is clearly visible and the surface structure is close to the ideal one. After soaking in methanol, the regularity of the prepared gratings decreases. The surface pattern is not as good as that in the previous case. On the other hand, the grating structure remains well visible in both optical and surface morphology measurements.

Bottom Line: The mechanism of surface ordered structure formation is attributed to polymer ablation, which is more pronounced in the place of higher light intensity.The smoothness of the underlying substrate plays a key role in the quality of surface ordered structure.Most regular grating structures were obtained on polymer films deposited on atomically 'flat' Si substrates.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Solid State Engineering, Institute of Chemical Technology, Prague 166 28, Czech Republic.

ABSTRACT
In this work, we describe laser modification of poly(methyl methacrylate) films doped with Fast Red ITR, followed by dopant exclusion from the bulk polymer. By this procedure, the polymer can be modified under extremely mild conditions. Creation of surface ordered structure was observed already after application of 15 pulses and 12 mJ cm(-2) fluence. Formation of grating begins in the hottest places and tends to form concentric semi-circles around them. The mechanism of surface ordered structure formation is attributed to polymer ablation, which is more pronounced in the place of higher light intensity. The smoothness of the underlying substrate plays a key role in the quality of surface ordered structure. Most regular grating structures were obtained on polymer films deposited on atomically 'flat' Si substrates. After laser patterning, the dopant was removed from the polymer by soaking the film in methanol.

No MeSH data available.


Related in: MedlinePlus