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Oberreit D.,University of Minnesota | Oberreit D.,Fluid Measurement Technologies Inc. | Rawat V.K.,University of Minnesota | Larriba-Andaluz C.,University of Minnesota | And 3 more authors.
Journal of Chemical Physics | Year: 2015

The sorption of vapor molecules onto pre-existing nanometer sized clusters is of importance in understanding particle formation and growth in gas phase environments and devising gas phase separation schemes. Here, we apply a differential mobility analyzer-mass spectrometer based approach to observe directly the sorption of vapor molecules onto iodide cluster ions of the form (MI)xM+ (x = 1-13, M = Na, K, Rb, or Cs) in air at 300 K and with water saturation ratios in the 0.01-0.64 range. The extent of vapor sorption is quantified in measurements by the shift in collision cross section (CCS) for each ion. We find that CCS measurements are sensitive enough to detect the transient binding of several vapor molecules to clusters, which shift CCSs by only several percent. At the same time, for the highest saturation ratios examined, we observed CCS shifts of up to 45%. For x < 4, cesium, rubidium, and potassium iodide cluster ions are found to uptake water to a similar extent, while sodium iodide clusters uptake less water. For x ≥ 4, sodium iodide cluster ions uptake proportionally more water vapor than rubidium and potassium iodide cluster ions, while cesium iodide ions exhibit less uptake. Measured CCS shifts are compared to predictions based upon a Kelvin-Thomson-Raoult (KTR) model as well as a Langmuir adsorption model. We find that the Langmuir adsorption model can be fit well to measurements. Meanwhile, KTR predictions deviate from measurements, which suggests that the earliest stages of vapor uptake by nanometer scale species are not well described by the KTR model. © 2015 AIP Publishing LLC.

Blackford D.,Fluid Measurement Technologies Inc. | Ackermann A.,Microfier Inc. | Mildermuth G.,Microfier Inc. | Schoen S.,Balazs NanoAnalysis
Ultrapure Water | Year: 2010

A new ultrapure water (UPW) metrology device, called the nano-Particle Collection Device (nPCD), has been developed for collection and elemental identification of sub-50-nm particles in (UPW). The new device uses an agglomeration technique to create particles that are large for elemental analysis with a X-ray diffraction technique. The device significantly reduces the particles collection time, as they are agglomerated to larger size, enabling the established EDS technique to be used to identify the agglomeration process. The new device is an analytical adaptation of patented Microfiber Technology that has been developed and tested in the laboratory earlier. It captures, concentrates, and presents nanoparticle agglomerates for analysis using a traditional technique.

Libman S.,Air Liquide | Neuber A.,Applied Materials | Latimer B.,Hach Company | Schoen S.,Air Liquide | And 2 more authors.
Ultrapure Water | Year: 2011

The ITRS UTW benchmarking study results, using the nPCD, indicated the presence of nano-partieles in UPW. The data indicates that a significant concentration of particles downstream of the UF system possible. It is also ponsible that all (or a majority) of the detected particles are ultrafine particles (smaller than the rated pore size of the UF). However, the ability of UFs to efficiently control particles smaller than those that can be detected by OPC is not proven. Although the absolute size of the particles could not be confirmed by the method applied, there is a significant risk to semiconductor manufacturing from these particles, confirming the urgency of improvements in metrology and treatment technology for UPW. The ITRS is concerned that as the semiconductor industry moves forward with new devices, using evershrinking line widths, the inability to detect small particles will no longer be masked. Particularly troubling arc the following factors: The integrity of the final filters cannot be guaranted for 100% of the time. New filters may shed undetectable nm sized particles and require excessive rinsing and qnaliticafion before use to offer an acceptable level of nm particle removal. Particles may be generated downstream of the final filters. Improved system design and materials of construction should help to reduce the number of particles challenging the final fitters. Metal particles, even of very small size, present a high risk to the semiconductor manufacturing. Therefore, stainless steel components should be eliminated in the polish loop of UPW systems. Known colloids (including silica [SiO2], aluminum oxide {Al2O2 cerium oxide CeO2. alum, and calcium fluoride [CaF2], metal particles f including Fe, nickel [Ni] chromium [Cr], or titanium [Ti]), and organic particles will require continuous monitoring in the future, but as yet remain undetectable at sizes below 40 to 50 nm. Ultrafiltration appears to be efficient down to 10 nm. Improved cartridge filters are available now with 20-nm rating (2), but efficiency of particle removal is still not well know: and there is always a risk of potential integrity damage. Despite marginal improvements, no particle measurement metrology is available that fully meets the road-map reqerments in terms of speed, sensitivity, and statistical viability. In order to enable effective semiconductor manufacturing, particle counters that meet ITRS specifications are urgently required. With new particles metrology filtration efficiency needs to be validated and maintained.

Fluid Measurement Technologies Inc. | Date: 2015-03-23

A method and system of measuring the size distribution of particles within dilute colloids, for example, through variation of the minimum detected size of aerosolized colloid particles. The method of determining the size distribution of particles in a fluid, involves forming a stream of aerosol droplets of the fluid, the droplets containing particles and dissolved material, evaporating the droplets to generate particles, and measuring the concentration of particles by varying a detection threshold. A system or apparatus for determining the size distribution of particles in a fluid, includes a droplet former for forming a stream of aerosol droplets of the fluid, the droplets containing particles and dissolved material, and a condensation particle detector for evaporating the droplets to generate particles and for measuring the concentration of particles, the condensation particle detector having a variable detection threshold.

Agency: Department of Health and Human Services | Branch: | Program: SBIR | Phase: Phase I | Award Amount: 129.48K | Year: 2004

DESCRIPTION (provided by applicant): Chemical characterization of pharmaceutical products, from the drug discovery phase to the final product stage, is an important requirement of new drug development. The instruments and methods used should be sensitive

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