Blisters

About: Blisters is a research topic. Over the lifetime, 980 publications have been published within this topic receiving 16229 citations.

Surface modification and deuterium retention of tungsten and tungsten-rhenium alloys exposed to deuterium plasma

Abstract: Surface modification and deuterium (D) retention in pure tungsten (W) and tungsten-rhenium (W-Re) alloys with Re concentration of 1, 3, 5 and 10 wt.% were investigated after exposure to D plasma with an incident energy of 38 eV/D at about 400 K and various fluences ranging from 7.2 × 1023 to 2.6 × 1025 D/m2. It is found that blistering depends strongly on the exposure fluence for both W and W-Re alloy samples. When the D fluence is higher than 2.8 × 1024 D/m2, the surface of W is covered by two types of blisters. One type is small blisters ( 8 μm) and extents over several grains. In the cases of W-Re alloys, only small blisters can be observed on their surface. The blisters on the surface of W-Re alloys preferentially appeared on grains with surface orientation close to (1 1 1). Cross-section views of blisters show that the blisters on W-Re alloys always originate from intra-granular cavities. The small and large blisters on W originate from intra- and inter-granular cavities, respectively. The surface blistering fluence threshold for W-Re alloys is lower than for W. For both types of materials, rupture of blisters occurs if the underlying crack reaches the surface at the edge of a blister. The number of ruptured blisters increases with increasing D fluence. TDS results show that there is an additional high-temperature peak at ∼ 800 K in W-Re alloys. The amount of D released from W and W-Re alloys increases with increasing D fluence. In addition, the accumulation of D in W-Re alloys is not noticeably influenced by the amount of Re doping at the exposure temperature of ∼ 400 K.

Femtosecond-laser-induced nanoscale blisters in polyimide thin films through nonlinear absorption

Abstract: Nonlinear absorption of femtosecond laser pulses provides a unique opportunity to confine energy deposition in any medium to a region that is below the focal diameter of a pulse. Illumination of a polymer film through a transparent high bandgap material such as glass, followed by nonlinear absorption of 800 nm light in polymers, allows us to further restrict absorption to a very thin layer along the propagation direction. We demonstrate this confinement by simulating femtosecond-laser-induced polymer modification by linear, two-photon and three-photon absorption, and discuss the control over energy absorption in polymers that multiphoton processes offer. Energy deposited behind a thin polymer film induces a protruding blister. We present experimental results of blister diameter and height scaling with pulse energy. Using 0.95 NA focussing, we obtained laser-induced blisters with diameters as small as 700 nm suggesting blister-based Laser-Induced Forward Transfer is possible on and below the single-micron scale. Sub-micrometer blister formation using femtosecond lasers also offers a novel method of direct, precise laser-writing of microstructures on films with single laser pulses. This method is a possible alternative to lithography, laser milling, and laser-based additive machining which leaves the surface composition unchanged.

PP043 Superglue Thermal Burn: Hot Sticky Mess

Abstract: Introduction: Cyanoacrylate adhesives (CNAs) are commercially known as superglue. Medical grade derivatives of this compound, such as 2-octyl-cyanoacrylate, being less toxic and irritable to skin, have been developed for use as surgical skin adhesives. Reported cases of CNA thermal burns were far and few, all being commercial grade glue and not medical grade glue. Case report: A 10-year-old boy presented to the ED with 2nd degree burn over fingers of both hands after spilling “3-Seconds Superglue” while attempting to fix a badge onto the fabric of his school cadet beret. His attempt to wash away the superglue with cold tap water was futile. Local examination showed multiple blisters on all fingers. Some of the blisters were intact while others had ruptured and deroofed. All were partial thickness burn. The solidified superglue compound was superimposed on the blisters and edges of exposed wound. The exposed raw tissues at the base of the deroofed blisters were tender. Lignocaine gel was applied to the raw area for local analgesic effect. Liquid paraffin was used successfully in the effort to remove the adhesive remnants without further traumatizing the sensitive skin. Discussion: Cyanoacrylate is a liquid monomer that polymerizes rapidly when in contact with water. The hydroxylation process is exothermic, releasing heat energy which can cause burn to the skin. Cotton, usually in fabric, acts as a highly potent catalyst which speeds up the polymerization reaction. In addition to thermal injury, repetitive contact between cyanoacrylate and the skin can cause epidermal spongiosis and eczema. Considering skin sensitivity and presence of raw wounds, liquid paraffin was used to remove the glue remnants as it is less irritable compared to acetone. Conclusion: Cyanoacrylate adhesives can cause thermal injuries when activated by moisture. Method of glue remnants removal warrants careful consideration of skin and wound conditions.