Laser-induced nanometer expansion and contraction dynamics of polystyrene films depending on its molecular weight

Mito, Takashi; Masuhara, Hiroshi

doi:10.1016/s0169-4332(02)00417-8

Cited by 11 publications

(11 citation statements)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, there are several studies in literature addressing the impact of the molecular weight on polymer behavior when pulsed laser heated (Mito and Masuhara 2002 ; Rebollar et al 2006 ; Rebollar et al 2008 ). While a general correlation is reported, the underlying mechanism for a prediction of the behavior is not discussed.…”

Section: Introductionmentioning

confidence: 99%

A study of photothermal laser ablation of various polymers on microsecond time scales

Kappes

Schönfeld

et al. 2014

SpringerPlus

View full text Add to dashboard Cite

To analyze the photothermal ablation of polymers, we designed a temperature measurement setup based on spectral pyrometry. The setup allows to acquire 2D temperature distributions with 1 μm size and 1 μs time resolution and therefore the determination of the center temperature of a laser heating process. Finite element simulations were used to verify and understand the heat conversion and heat flow in the process. With this setup, the photothermal ablation of polystyrene, poly(α-methylstyrene), a polyimide and a triazene polymer was investigated. The thermal stability, the glass transition temperature Tg and the viscosity above Tg were governing the ablation process. Thermal decomposition for the applied laser pulse of about 10 μs started at temperatures similar to the start of decomposition in thermogravimetry. Furthermore, for polystyrene and poly(α-methylstyrene), both with a Tg in the range between room and decomposition temperature, ablation already occurred at temperatures well below the decomposition temperature, only at 30–40 K above Tg. The mechanism was photomechanical, i.e. a stress due to the thermal expansion of the polymer was responsible for ablation. Low molecular weight polymers showed differences in photomechanical ablation, corresponding to their lower Tg and lower viscosity above the glass transition. However, the difference in ablated volume was only significant at higher temperatures in the temperature regime for thermal decomposition at quasi-equilibrium time scales.

show abstract

Section: Introductionmentioning

confidence: 99%

A study of photothermal laser ablation of various polymers on microsecond time scales

Kappes

Schönfeld

et al. 2014

SpringerPlus

View full text Add to dashboard Cite

show abstract

“…We studied molecular weight dependent surface morphological changes of polystyrene film after 248 nm excimer laser irradiation. 36 In the case of low molecular weights (3.0 © 10 3 and 5.0 © 10 3 ), the surface contracts exponentially. In the case of high molecular weight (1.0 © 10 6 ), however, two different contraction processes were observed, that is, a major contraction and a minor tail.…”

Section: +mentioning

confidence: 99%

“…Laser ablation is one of representative nonlinear photochemical phenomena and has a threshold with respect with laser fluence. Initially most of laser ablation studies were carried out for metals, semiconductors, ceramics, and glasses, 2 while organic materials, 36 cells, tissues, and organs have recently been receiving more and more attentions. 7 In general ablation mechanism of organic and bio materials was discussed from photochemical and photothermal viewpoints.…”

mentioning

confidence: 99%

Time-Resolved Spectroscopic and Imaging Studies on Laser Ablation of Molecular Systems: From Mechanistic Study to Bio/Nano Applications

Masuhara

2013

Bulletin of the Chemical Society of Japan

Self Cite

View full text Add to dashboard Cite

Studies on laser ablation of polymer films, molecular crystals in solution, protein solution, and culture media containing living cells are summarized and considered. Dynamics and mechanism of laser ablation were systematically studied by utilizing time-resolved spectroscopy and imaging; femtosecondnanosecond transient absorption and emission spectroscopy, nanosecond shadowgraphy, nanosecondnanometer interferometry, femtosecond surface light scattering imaging. It was confirmed by integrating both data that primary processes of laser ablation can be well understood in the framework of Jablonski diagram. For nanosecond laser ablation of doped polymers, it was demonstrated that cyclic multiphoton absorption is an efficient photothermal conversion process leading to photothermal ablation. For femtosecond laser ablation of dye films, transient pressure mechanism was proposed indicating photomechanical ablation. As applications of laser ablation, nanoparticle preparation, protein crystallization, and manipulation of living cells are presented. Laser ablation of molecular crystals in poor solvent gives small fragments whose size are in a few tens nm. The fabricated nanocolloids are stable without adding detergents and their size was the smallest as nanoparticles produced by the top-down-method. Multiphoton laser ablation of water generates local impulsive force due to bubble formation, shockwave propagation, and local convection flow. The force triggers molecular and protein crystallization in their supersaturated solutions, whose mechanisms are described and considered. The impulsive force is also very useful for manipulating living cells and its high potential was confirmed by examining cell functions such as division, differentiation, death, and migration. Finally summary and future plan are presented.Studies on molecular spectroscopy and photochemistry introduced lasers very early in 1960's and used them as light sources for spectroscopic measurements as well as for inducing photochemical reactions. When chemists started to use pulsed lasers, they soon became aware that laser irradiation induced vaporization, decomposition, and fragmentation of materials and found that the irradiated surface was etched. The left patterns on the colored papers were practically used to confirm optical alignment in experimental setups before infrared (IR) viewer became popular. Later this laser-induced phenomenon was called laser ablation by Srinivasan, 1 and its systematic application was quickly developed to fabricate microstructures of various materials by electronics engineers and to microsurgery by medical doctors. Laser ablation is made possible by applying pulsed lasers and never brought out by weak continuous wave (CW) laser even when its irradiation continues for 1 year. Laser ablation is one of representative nonlinear photochemical phenomena and has a threshold with respect with laser fluence. Initially most of laser ablation studies were carried out for metals, semiconductors, ceramics, and glasses, 2 while organic materi...

show abstract

“…However, only several studies reported about M w influence on polymer properties [13][14][15][16][17][18][19], even though the knowledge of M w values and their effect on polymeric ablation is crucial for laser processing applications. A study focusing on morphological changes of polymethylmethacrylate (PMMA) and (polystyrene) PS of different M w brings Masuhara et al [15]. There, the behavior of systems with various M w values after laser irradiation, which showed different rates of expansion and contraction of the polymer films, is investigated.…”

Section: Introductionmentioning

confidence: 99%

Nanostructured Polystyrene Doped with Acetylsalicylic Acid and Its Antibacterial Properties

et al. 2020

View full text Add to dashboard Cite

Homogeneous polystyrene foils doped with different concentrations of acetylsalicylic acid were prepared by the solvent casting method. The surface morphology and surface chemistry of as-prepared foils were characterized in detail. Excimer laser (krypton fluoride, a wavelength of 248 nm) was used for surface nanopatterning of doped polystyrene foils. Certain combinations of laser fluence and number of laser pulses led to formation of laser-induced periodic surface structures (LIPSS) on the exposed surface. Formation of the pattern was affected by the presence of a dopant in the polystyrene structure. Significant differences in surface chemistry and morphology of laser-treated foils compared to both pristine and doped polystyrene were detected. The pattern width and height were both affected by selection of input excimer exposure conditions, and the amount of 6000 pulses was determined as optimal. The possibility of nanostructuring of a honeycomb-like pattern doped with acetylsalicylic acid was also demonstrated. Selected nanostructured surfaces were used for study the antibacterial properties for a model bacteria strain of S. aureus. The combination of altered surface chemistry and morphology of polystyrene was confirmed to have an excellent antibacterial properties.

show abstract

Laser-induced nanometer expansion and contraction dynamics of polystyrene films depending on its molecular weight

Cited by 11 publications

References 9 publications

A study of photothermal laser ablation of various polymers on microsecond time scales

A study of photothermal laser ablation of various polymers on microsecond time scales

Time-Resolved Spectroscopic and Imaging Studies on Laser Ablation of Molecular Systems: From Mechanistic Study to Bio/Nano Applications

Nanostructured Polystyrene Doped with Acetylsalicylic Acid and Its Antibacterial Properties

Contact Info

Product

Resources

About