Abstract The calibration of the CR39®and Makrofol®Nuclear Track Detectors of the MoEDAL experiment at the CERN-LHC was performed by exposing stacks of detector foils to heavy ion beams with energies ranging from 340 MeV/nucleon to 150 GeV/nucleon. After chemical etching, the base areas and lengths of etch-pit cones were measured using automatic and manual optical microscopes. The response of the detectors as measured by the ratio of the track-etching rate over the bulk-etching rate, was determined over a range extending from their threshold at Z/β∼ 7 and ∼ 50 for CR39 and Makrofol, respectively, up to Z/β∼ 92.
more »
« less
Tough polycyclooctene nanoporous membranes from etchable block copolymers
Polycyclooctene-polylactide triblock copolymer synthesis and subsequent processingviasolvent casting, polylactide etching, and plasma etching to yield tunable and tough nanoporous membranes with high surface porosities and hydrophilic properties.
more »
« less
- Award ID(s):
- 2003454
- PAR ID:
- 10542029
- Publisher / Repository:
- Royal Society of Chemistry
- Date Published:
- Journal Name:
- Soft Matter
- Volume:
- 20
- Issue:
- 2
- ISSN:
- 1744-683X
- Page Range / eLocation ID:
- 437–448
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
This paper reports the fabrication of silicon PN diode by using DNA nanostructure as the etching template for SiO2and also as then-dopant of Si. DNA nanotubes were deposited ontop-type silicon wafer that has a thermal SiO2layer. The DNA nanotubes catalyze the etching of SiO2by HF vapor to expose the underlying Si. The phosphate groups in the DNA nanotube were used as the doping source to locallyn-dope the Si wafer to form vertical P-N junctions. Prototype PN diodes were fabricated and exhibited expected blockage behavior with a knee voltage ofca.0.7 V. Our work highlights the potential of DNA nanotechnology in future fabrication of nanoelectronics.more » « less
-
Mesoporous polyetherimides are important high-performance polymers. Conventional strategies to prepare porous polyetherimides, and polyimide in general, are based on covalent organic framework or thermolysis of sacrificial polymers. The former produces micropores due to intrinsically crosslinked microstructures, and the latter results in macropores because of a blowing effect by the sacrificial polymers. The preparation of mesopores remains a challenge. Here we have prepared mesoporous polyetherimide films by hydrolyzing polylactide- b -polyetherimide- b -polylactide (AIA). Controlled by molecular weight and volume fraction of polylactide in AIA, the porous films exhibit an average pore width of 24 nm. The mesoporous polyetherimide films exhibit a storage modulus of ∼1 GPa at ambient temperatures. This work advances the chemistry of high-performance polymers and provides an alternative strategy to prepare mesoporous polymers, enabling potential use as high-performance membranes for separation, purification, and electrochemistry.more » « less
-
We report a two-step etching process involving inductively coupled plasma (ICP) etching followed by wet chemical etching to achieve smooth and vertical sidewalls, being beneficial for AlGaN-based electronic and optoelectronic devices. The influence of ICP power on the roughness of etched sidewalls is investigated. It is observed that ICP etching alone does not produce smooth sidewalls, necessitating subsequent wet chemical etching using tetramethyl ammonium hydroxide (TMAH) to enhance sidewall smoothness and reduce tilt angle. The morphological evolution of the etched sidewalls with wet etch time for the device structures is also thoroughly investigated. Consistent etch results are achieved for AlxGa1-xN alloys with Al compositions up to 70%, indicating the effectiveness of our etching process.more » « less
An official website of the United States government

