U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Dave Holbrook (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 22 of 22

On the Nature of Macroradicals Formed upon Radiolysis of Aqueous Poly(N--?vinylpyrrolidone)Solutions

April 2, 2020
Author(s)
Richard D. Holbrook, Clelia Dispenza, Maria Antonietta Sabatino, Natascia Grimaldi, Bjorn Dahlgren, Mohamad Al-Sheikhly, James F. Wishart, Zois Tsinas, Mats Jonsson
In this work we have explored the nature of macroradicals formed upon radiolysis of aqueous poly(N-­‐vinylpyrrolidone) (PVP) solutions using pulse radiolysis, density functional theory (DFT) and literature data. On the basis of literature data on site-­

Multiple method analysis of TiO2 nanoparticles uptake, accumulation and effects in rice (Oryza sativa L.) plants

August 4, 2017
Author(s)
Yinqging Deng, Elijah Petersen, Katie Challis, Savelas A. Rabb, Richard D. Holbrook, James Ranville, Bryant C. Nelson, Baoshan Xing
Understanding the translocation of nanoparticles (NPs) into plants is challenging because quantitative and qualitative methods are still being developed and the comparability of results among different methods is unclear. In this study, the uptake of NPs

Separation, Sizing, and Quantitation of Engineered Nanoparticles in an Organism Model Using Inductively Coupled Plasma Mass Spectrometry and Image Analysis

December 16, 2016
Author(s)
Monique E. Johnson, Shannon Hanna, Antonio R. Montoro Bustos, Christopher M. Sims, Lindsay C. Elliott, Babak Nikoobakht, John T. Elliott, Richard D. Holbrook, Keana C. Scott, Karen E. Murphy, Elijah J. Petersen, Lee L. Yu, Bryant C. Nelson, Akshay Lingayat, Adrian C. Johnston
For environmental studies assessing uptake of orally ingested engineered nanoparticles (ENPs), a key step in ensuring accurate quantification of ingested ENPs is efficient separation of the organism from ENPs that are either nonspecifically adsorbed to the

Preparation of silver nanoparticle loaded cotton threads to facilitate measurement development for textile applications

January 26, 2015
Author(s)
Justin M. Gorham, Karen E. Murphy, Jingyu Liu, Dimitri Tselenchuk, Gheorghe NMN Stan, Thao M. Nguyen, Richard D. Holbrook, Michael R. Winchester, Robert F. Cook, Robert MacCuspie, Vincent A. Hackley
FOREWORD This NIST special publication (SP) is one in a series of NIST SPs that address research needs articulated in the National Nanotechnology Initiative (NNI) Environmental, Health, and Safety Research Strategy published in 2011 [1]. This Strategy

Visualizing Nanoparticle Dissolution by Imaging Mass Spectrometry

March 10, 2014
Author(s)
Christopher W. Szakal, Melissa S. Ugelow, Justin M. Gorham, Andrew R. Konicek, Richard D. Holbrook
We demonstrate the ability to visualize nanoparticle dissolution while simultaneously providing chemical signatures that differentiate between citrate-capped silver nanoparticles (AgNPs), AgNPs forced into dissolution via exposure to UV radiation, silver

Surface Chemical Transformations of UV irradiated Silica-Epoxy Nanocomposites

May 15, 2013
Author(s)
Justin M. Gorham, Tinh Nguyen, Deborah S. Jacobs, Coralie Bernard, Richard D. Holbrook
Silica nanoparticles (SiNPs) incorporated into a polymeric matrix, or silica nanocomposites (SiNCs), are used in a wide variety of commercially available products in numerous natural and artificial environments. Environmental factors, such as light, may

UV-induced photochemical transformations of citrate capped silver nanoparticle suspensions

September 14, 2012
Author(s)
Justin M. Gorham, Robert I. MacCuspie, Kate L. Klein, D H. Fairbrother, Richard D. Holbrook
Due to the increasing use of silver nanoparticles (AgNPs) in consumer products, it is essential to understand how variables, such as light exposure, may change the physical and chemical characteristics of AgNP suspensions. To this end, the effect of 300 nm

Photo-induced Surface Transformation of Silica Nanocomposites

June 22, 2012
Author(s)
Justin M. Gorham, Tinh Nguyen, Coralie Bernard, Deborah S. Jacobs, Richard D. Holbrook
The physicochemical, UV-induced surface modifications to silica nanoparticle (SiNP) - epoxy composites have been investigated. The silica nanocomposites (SiNCs) were prepared using a two-part epoxy system with 10 % mass fraction of SiNPs and exposed to

Preparation and Measurement Methods for Studying Nanoparticle Aggregate Surface Chemistry

June 8, 2012
Author(s)
Christopher W. Szakal, James McCarthy, Andrew R. Konicek, Kacie Louis, Benjamin Yezer, Andrew A. Herzing, Robert Hamers, Richard D. Holbrook
Despite best efforts at controlling nanoparticle (NP) surface chemistries, the environment surrounding nanomaterials is always changing and can impart a permanent chemical memory. We present a set of preparation and measurement methods to be used as the

Copper oxide nanoparticle mediated DNA damage in terrestrial plant models

December 22, 2011
Author(s)
Bryant C. Nelson, Donald H. Atha, Elijah J. Petersen, Huanhua Wang, Danielle Cleveland, Richard D. Holbrook, Pawel Jaruga, M Miral Dizdar, Baoshan Xing
Engineered nanoparticles, due to their unique electrical, mechanical and catalytic properties, are presently found in many commercial products and will be intentionally or inadvertently released at increasing concentrations into the natural environment

Potential release pathways, environmental fate, and ecological risks of carbon nanotubes

October 11, 2011
Author(s)
Elijah J. Petersen, Andrew Whelton, Liwen Zhang, Qingguo Huang, Nasir M. Uddin, Nikolai Mattison, Denis O'Carroll, Theodore Henry, Tinh Nguyen, Richard D. Holbrook, Kai Chen
Carbon nanotubes are currently being used in a number of consumer products, and exponentially higher production masses and a broader range of applications are expected in future years. However, the data on the environmental release pathways, environmental

Association of Quantum dot nanoparticles with Pseudomonas aeruginosa biofilm

November 1, 2010
Author(s)
Jayne B. Morrow, Catalina Arango, Richard D. Holbrook
Quantum dots (QDs) of two different surface chemistries (carboxyl (COOH) and poly ethylene glycol (PEG) modified) were utilized to determine the impact of surface functionality on QD mobility and distribution in Pseudomonas aeruginosa PAO1 biofilms

Trophic Transfer of Nanoparticles in a Simplified Food Web

May 30, 2008
Author(s)
Richard D. Holbrook, Karen E. Murphy, Jayne B. Morrow, Kenneth D. Cole
Nanotechnological innovations depend largely on the unique chemical and physical properties of engineered nanomaterials. However, the same properties that make engineered nanomaterials attractive for numerous applications also contribute to their

Widefield Light Microscopy Method for High Resolution and Quantum Dot Spectral Studies

January 1, 2007
Author(s)
Cynthia J. Zeissler, Keana C. Scott, Richard D. Holbrook, Peter E. Barker, Yan Xiao
We are exploring methods to achieve 3D 200 nm resolution multispectral imaging with an ordinary inexpensive widefield microscope using incoherent white light sources and an electronically tunable filter. In this work, the capabilities were applied to

Quantum Dot Dissemination and Behavior in Bacterial Biofilms

May 7, 2006
Author(s)
Jayne B. Morrow, Richard D. Holbrook, Cynthia J. Zeissler
Quantum dots (QDs) are colloidal semiconductor nanocrystals that photoluminescence emission is proportional to the dot size and have been utilized in fluorescent imaging in biological systems. Biofilms are communities of microorganisms attached to surfaces

Direct Preparation of Particles From Liquid Suspension for ESEM or SEM Analysis

October 1, 2005
Author(s)
Scott A. Wight, Richard D. Holbrook
A simplified method for the preparation of particles from liquid suspensions has been developed. Particles are deposited directly on carbon planchets for rapid analysis by environmental scanning electron microscopy or by conventional scanning electron