University System of Maryland

Government of the United States of America, As Represented by the Secretary of Commerce

USA As Represented by Secretary of the Navy

Michael R Zachariah

Soo Hyoung Kim

Anand Prakash

Philip R DeShong

Jay Howard Hendricks

Richard E Cavicchi

Douglas P DuFaux

Douglas Stephen English

R Jason Jouet

Raymond J Phaneuf

George W Mulholland

Peter DeMuth

Charles Luckett

Mingdong Li

Prahalad Parthangal

De-Hao Tsai

Timothy D Corrigan

Daniel Kaplowitz

A method for extracting shape information for particles with similar shape and corresponding system of a tandem differential mobility analyzer (DMA) and pulse field differential mobility analyzer (PFDMA) system, that executes at least generating a steady state aerosol concentration; passing aerosol flow from the aerosol concentration thru a bipolar charger to produce a known charge distribution; passing aerosol thru a DMA with set sheath and aerosol flows and a set voltage to generate a mono-mobility aerosol; passing mono-mobility aerosol thru a PFDMA system; and measuring mobility as a function of electric field by varying the duty cycle of the pulse in the PFDMA system. Alternatively, the method and system relate to separating particles with different shapes by adjusting the duty cycle of the pulse to reach a higher or lower electric field than in the DMA in which the mono-mobility aerosol was generated; and separating particles based on shape.

Pulsed-field differential mobility analyzer system and method for separating particles and measuring shape parameters for non-spherical particles

Low temperature gas-phase methods for the preparation of faceted aluminum crystals are disclosed.

Aeosol synthesis of faceted aluminum nanocrystals

A method for synthesizing a mesoporous silica nanoparticle, a mesoporous silica nanoparticle, and applications thereof are provided. The method includes fractionating a mesoporous silica nanoparticle suspension to produce size-fractionated mesoporous silica nanoparticle. The method further includes etching the size-fractionated mesoporous silica nanoparticle to produce synthesized mesoporous silica nanoparticle having a hollow, porous morphology configured to receive one of a therapeutic agent and an imaging material. The etching includes differential etching of silica from areas of low polymeric density within the mesoporous silica nanoparticle and re-depositing of the silica in areas of higher polymeric density existing near the surface of the mesoporous silica nanoparticle. A target material is loaded into the synthesized mesoporous silica nanoparticle and a controlled released of the target material is provided by decreasing the physiological pH of the surface of the mesoporous silica nanoparticle.

Method for forming mesoporous silica nanoparticles, mesoporous silica nanoparticles, and applications thereof

Carbon nanotube structures are formed by providing metal composite particles including a catalyst metal and a non-catalyst metal, where the catalyst metal catalyzes the decomposition of a hydrocarbon compound and the formation of carbon nanotube structures on surfaces of the particles. The metal composite particles are combined with the hydrocarbon compound in a heated environment so as to form carbon nanotube structures on the surfaces of the metal composite particles. The metal composite particles can be include iron and aluminum at varying amounts. The carbon nanotubes formed on the metal particles can remain on the metal particles or, alternatively, be removed from the metal particles for use in different applications.

Carbon nanotube structures formed on large free floating substrates

An in situ approach toward connecting and electrically contacting vertically aligned nanowire arrays using conductive nanoparticles is provided. The utility of the approach is demonstrated by development of a gas sensing device employing the nanowire assembly. Well-aligned, single-crystalline zinc oxide nanowires were grown through a direct thermal evaporation process at 550&#xb0; C. on gold catalyst layers. Electrical contact to the top of the nanowire array was established by creating a contiguous nanoparticle film through electrostatic attachment of conductive gold nanoparticles exclusively onto the tips of nanowires. A gas sensing device was constructed using such an arrangement and the nanowire assembly was found to be sensitive to both reducing (methanol) and oxidizing (nitrous oxides) gases. This assembly approach is amenable to any nanowire array for which a top contact electrode is needed.

Approach to contacting nanowire arrays using nanoparticles

In a method and system for controllable electrostatic-directed deposition of nanoparticles from the gas phase on a substrate patterned to have p-n junction(s), a bias electrical field is reversely applied to the p-n junction, so that uni-polarly charged nanoparticles are laterally confined on the substrate by a balance of electrostatic, van der Waals and image forces and are deposited on a respective p-doped or n-doped regions of the p-n junction when the applied electric field reaches a predetermined strength. The novel controllable deposition of nanoparticles employs commonly used substrate architectures for the patterning of an electric field attracting or repelling nanoparticles to the substrates and offers the opportunity to create a variety of sophisticated electric field patterns which may be used to direct particles with greater precision.

Method and system for controllable deposition of nanoparticles on a substrate

A new low temperature method for nanostructured metal and ceramic thin film growth by chemical vapor deposition (CVD) involves the use of a low pressure co-flow diffusion flame reactor to react alkali metal vapor and metal halide vapor to deposit metal, alloy and ceramic films. The reaction chemistry is described by the following general equation:

Method of forming metallic and ceramic thin film structures using metal

A method of destroying halogenated compounds by a vapor phase chemical reaction using an alkali metal vapor, alkaline earth metal vapor, or a combination of the two, in a heated reactor to produce mineralized or solid products. The production of solid products, such as halide salts and particulate carbon, yields numerous advantages in the collection and disposal of the resulting products. The invention is especially useful for the destruction of chlorofluorocarbons.

Growing community of inventors

Potomac, MD, United States of America

Michael R Zachariah