Deposition of polytetrafluoroethylene films by laser ablation

Blanchet, Graciela B.; Shah, S. Ismat

doi:10.1063/1.108514

Cited by 106 publications

(38 citation statements)

References 20 publications

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“…We concluded that the heterogephotoablation. 2 In other cases, photodegradation is a serious drawback that has often limited wideneous nature of PTFE (i.e., coexistence of crystalline and amorphous phases), is a determining facspread use of this polymer.…”

Section: Introductionmentioning

confidence: 99%

Interaction between UV radiation and filled polytetrafluoroethylene (PTFE). I. Degradation processes

Ferry

Vigier

Alexander‐Katz

et al. 1998

J. Polym. Sci. B Polym. Phys.

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Section: Introductionmentioning

confidence: 99%

Interaction between UV radiation and filled polytetrafluoroethylene (PTFE). I. Degradation processes

Ferry

Vigier

Alexander‐Katz

et al. 1998

J. Polym. Sci. B Polym. Phys.

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“…For instance, previous reports have described the successful use of the absorbed radiation to photothermally depolymerize the target material, with subsequent repolymerization at the substrate. 11,12,31 However, when the degree of re-polymerization was incomplete, as when a photochemical reaction caused the loss of a pendant functional group, the polymer was subjected to substantial structural modification in comparison with the bulk native material.…”

Section: Ultraviolet (Uv) Pld and Maplementioning

confidence: 99%

“…[32][33][34] Although the deposition of almost intact polymers is possible near the ablation threshold fluence, the process is complicated by molecular structures that cannot be subjected to the same bond-breaking and repolymerization scheme used for addition polymers. 11,12,31 Previous reports have described the use of a KrF excimer laser (248 nm) to deposit amorphous copper phthalocyanine (CuPc), aluminum tris-8-hydroxyquinline (Alq 3 ) and 4-dialkylamino-4 -nitrostilbensen (DANS), 32,33 and of a Nd:YAG laser (355 nm) for poly(p-phenylene vinylene) (PPV) films. 34 Although these films were electroluminescent, their efficiencies were not comparable to those of spin-coated or sublimated control materials as a result of losing molecular structure fidelity in the ablative transfer from target to substrate.…”

Section: Ultraviolet (Uv) Pld and Maplementioning

confidence: 99%

Mechanisms of Resonant Infrared Matrix-Assisted Pulsed Laser Evaporation

Torres

Johnson

Haglund

et al. 2011

Critical Reviews in Solid State and Materials Sciences

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For the last decade, a variant of pulsed laser ablation, Resonant-Infrared Matrix-Assisted Pulsed Laser Evaporation (RIR-MAPLE), has been studied as a deposition technique for organic and polymeric materials. RIR-MAPLE minimizes photochemical damage from direct interaction with the intense laser beam by encapsulating the polymer in a high infrared-absorption solvent matrix. This review critically examines the thermally-induced ablation mechanisms resulting from irradiation of cryogenic solvent matrices by a tunable free electron laser (FEL). A semi-empirical model is used to calculate temperatures as a function of time in the focal volume and determine heating rates for different resonant modes in two model solvents, based on the thermodynamics and kinetics of the phase transitions induced in the solvent matrices.Three principal ablation mechanisms are discussed, namely normal vaporization at the surface, normal boiling, and phase explosion. Normal vaporization is a highly inefficient polymer deposition mechanism as it relies on collective collisions with evaporating solvent molecules. Diffusion length calculations for heterogeneously nucleated vapor bubbles show that normal boiling is kinetically limited. During high-power pulsed-FEL irradiation, phase explosion is shown to be the most significant contribution to polymer deposition in RIR-MAPLE. Phase explosion occurs when the target is rapidly heated (10 8 to 10 10 K/s) and the solvent matrix approaches its critical temperature. Spontaneous density stratification (spinodal decay) within the condensed metastable phase leads to rapid homogeneous nucleation of vapor bubbles. As these vapor bubbles interconnect, large pressures build up within the condensed phase, leading to target explosions and recoil-induced ejections of polymer to a near substrate. Phase explosion is a temperature (fluence) threshold-limited process, while surface evaporation can occur even at very low fluences.

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“…7 It is also a very promising tool for polymer-film synthesis. [8][9][10][11][12][13] Although many groups have reported on the synthesis of materials by photo-reaction induced by infrared lasers, [14][15][16][17][18] those induced by excimer lasers are relatively few. [19][20][21][22][23][24][25] In the present paper, we report on synthesis of silicon-based polymer films by excimer laser-induced photoreaction of phenylsilane and methylphenylsilane.…”

Section: Introductionmentioning

confidence: 99%